Press-through package lid material film and press-through package

Abstract

To provide a press-through package lid material film which is made of resin and has a good push-through property when breaking a lid material by pushing a tablet or the like with the finger.SOLUTION: A press-through package lid material film comprises a base material layer containing a polypropylene resin and a petroleum resin, and a heat-resistant layer on one surface side of the base material layer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a press-through package lid material film and a press-through package. [Background technology]

[0002] In the packaging field of pharmaceuticals, food, etc., PTP (press-through package) is used to package solid medicines such as capsules and tablets.

[0003] PTP is a type of packaging in which a pocket for storing solid medication such as capsules is formed, for example, by applying pressure forming, vacuum forming, plug forming, etc. to a transparent sheet, and after the capsules are placed in the pocket, a foil or film made of a material that can be easily torn or opened by hand, such as aluminum foil, is laminated as a lid to form an integrated package.By using PTP, the solid medication or food stored in the transparent sheet pocket can be directly confirmed with the naked eye before opening, and when opening it, the contents can be easily removed by pressing the solid medication in the pocket with a finger to break the lid.

[0004] Aluminum foil is widely used as the lid material for PTPs because it is easy to open. However, when recycling PTP sheets after use, the plastic and aluminum foil must be separated and collected. Because it is difficult to separate the plastic and aluminum foil of integrally molded PTPs at low cost, PTP recycling is not actively pursued at present.

[0005] In recent years, mono-material PTPs have been under consideration. For example, Patent Document 1 discloses a pharmaceutical package in which a resin lid material is bonded to a concavely shaped sheet. Patent Document 1 discloses that the lid material is a sheet formed by laminating (b) a sealing layer onto (a) a film in which a petroleum resin is added to an amorphous polyolefin resin as a base material, or a film in which a petroleum resin or an inorganic material is added to an amorphous polyolefin resin, or a film in which a petroleum resin or an organic resin is added to an amorphous polyolefin resin. Patent Document 2 also discloses a lid material for a press-through pack, which is formed by providing a heat-sealable resin layer on one side of a biaxially or uniaxially stretched film made of polypropylene or a copolymer thereof, or polypropylene or a copolymer thereof to which a photodecomposition accelerator has been added, and then irradiating it with electron beams or ultraviolet rays. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-313870 [Patent Document 2] Japanese Patent Application Publication No. 6-122180 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, the use of resin lid materials for PTPs has been considered, but in conventional technology, the push-through properties (easy-opening properties) when pushing tablets or the like with a finger to break the lid material were insufficient, and improvements were needed.

[0008] Therefore, in order to solve these problems of the conventional technology, the inventors have conducted research with the aim of providing a resin press-through package lid material film that has good push-through properties when tablets or the like are pressed with a finger to break the lid material. [Means for solving the problem]

[0009] Examples of specific embodiments of the present invention are given below.

[0010] [1] A press-through package lid material film having a base layer containing polypropylene resin and petroleum resin, and a heat-resistant layer on one side of the base layer. [2] The press-through package lid material film according to [1], wherein the base layer contains a nucleating agent. [3] The press-through package lid material film according to [1] or [2], wherein the base layer is composed mainly of homopolypropylene. [4] The press-through package lid material film according to any one of [1] to [3], wherein the heat-resistant layer contains a nucleating agent. [5] The press-through package lid material film according to any one of [1] to [4], wherein the heat-resistant layer is composed mainly of homopolypropylene. [6] The press-through package lid material film according to any one of [1] to [5], which comprises a seal layer on the other side of the base material layer. [7] The press-through package lid material film according to any one of [1] to [6], which has a puncture breaking elongation of 5.8 mm or less at a thickness of 40 μm under a condition of 23° C. [8] The press-through package lid material film according to any one of [1] to [7], which has a puncture breaking strength of 4.2 N or less at a thickness of 40 μm under a condition of 23° C. [9] The press-through package lid material film according to any one of [1] to [8], which has a puncture point displacement of 6.9 mm or less at a thickness of 40 μm under a condition of 23° C.

[10] The press-through package lid material film according to any one of [1] to [9], which has a puncture point energy of 0.030 J or less at a thickness of 40 μm under a condition of 23° C.

[11] The press-through package lid material film according to any one of [1] to

[10] , which has a thickness of 400 μm or less.

[12] A press-through package comprising the press-through package lid material film according to any one of [1] to

[11] and a base material having a recess for accommodating contents.

[13] The press-through package according to

[12] , which is for pharmaceutical packaging. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin press-through package lid material film that has good push-through properties when tablets or the like are pushed with a finger to break the lid material. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. The following description may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, when "X to Y" (X and Y are arbitrary numbers) is used, it means "X or more and Y or less" unless otherwise specified, and also includes "preferably greater than X" or "preferably less than Y." Furthermore, when "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it also includes the meaning "preferably greater than X" or "preferably less than Y." In the following description, the terms "film" and "sheet" are not clearly distinguished from each other, and the term "film" includes the term "sheet," and the term "sheet" includes the term "film."

[0013] (Press-through packaging lid film) The present embodiment relates to a press-through package lid material film (hereinafter also referred to as "this lid material film") that has a base layer containing a polypropylene resin and a petroleum resin and is provided with a heat-resistant layer on one side of the base layer.

[0014] The covering material film may be composed of two layers, a base layer and a heat-resistant layer, or may be a multi-layer film having a plurality of base layers and / or heat-resistant layers. The covering material film may also have layers other than the base layer and the heat-resistant layer. Examples of such layers include a sealing layer, an easy-adhesion layer, a protective layer, and a printing layer. For example, the covering material film may have a heat-resistant layer on one side of the base layer and a sealing layer on the other side of the base layer.

[0015] The present lid material film is a resin lid material film. The present lid material film has good push-through properties (easy-open properties) when a tablet or the like is pushed with a finger to break the lid material. In the present lid material film, the petroleum resin contained in the base layer penetrates into the amorphous part of the polypropylene resin and reduces the mobility of the amorphous part, which is thought to result in embrittlement of the base layer and thereby enhance the push-through properties.

[0016] The puncture breaking elongation of the present covering material film at a thickness of 40 μm under the condition of 23° C. is preferably 5.8 mm or less, more preferably 5.5 mm or less, even more preferably 5.0 mm or less, still more preferably 4.5 mm or less, even more preferably 4.0 mm or less, and particularly preferably 3.5 mm or less. The lower limit of the puncture breaking elongation at a thickness of 40 μm is not particularly limited, but is preferably 1.0 mm or more, for example.

[0017] The puncture breaking strength of the present covering material film at a thickness of 40 μm under the condition of 23° C. is preferably 4.2 N or less, more preferably 4.0 N or less, even more preferably 3.8 N or less, and particularly preferably 3.6 N or less. The lower limit of the puncture breaking strength at a thickness of 40 μm is not particularly limited, but is preferably 1.0 N or more, for example.

[0018] The puncture breaking elongation and puncture breaking strength of this lid material film at a thickness of 40 μm at 23°C can be measured as follows. First, the lid material film is stretched and fixed on a 30 mm diameter frame of a precision universal testing machine. A puncture test is performed by attaching a needle with a diameter of 1.0 mm and a tip radius of 0.5 mm to the testing machine and pressing it into the fixed PTP lid material film. The measurement is performed in an environment of 23°C and 50% relative humidity, with the needle moving at a speed of 200 mm / min. The depth of the needle tip position at the time of tearing (the displacement from when the needle contacts the fixed PTP lid material film to the position at which tearing occurs) is defined as the puncture breaking elongation (mm), and the maximum load divided by the thickness of the test piece is defined as the puncture breaking strength.

[0019] The puncture point displacement of the present covering material film at a thickness of 40 μm under the condition of 23° C. is preferably 6.9 mm or less, more preferably 6.5 mm or less, and even more preferably 6.0 mm or less. The lower limit of the puncture point displacement at a thickness of 40 μm is not particularly limited, but is preferably, for example, 1.0 mm or more.

[0020] The puncture point energy of the present covering material film at a thickness of 40 μm under conditions of 23° C. is preferably 0.030 J or less, more preferably 0.025 J or less, even more preferably 0.020 J or less, and particularly preferably 0.015 J or less. The lower limit of the puncture point energy at a thickness of 40 μm is not particularly limited, but is preferably 0.001 J or more, for example.

[0021] The puncture point displacement and puncture point energy of this covering material film at a thickness of 40 μm under the condition of 23° C. can be measured using a puncture type film impact tester in accordance with JIS K-7211-2:2006.

[0022] In this embodiment, if the puncture breaking elongation and puncture breaking strength at a thickness of 40 μm are not more than the above upper limit values, it can be determined that the push-through property is good. The puncture breaking elongation and puncture breaking strength being not more than the above upper limit values ​​means that the film breaks without elongating when a puncture force is applied to the lid material film, which indicates that the lid material has good openability (tearability) when, for example, a tablet or the like is pressed with a finger to break the lid material.

[0023] The total thickness of the present covering material film is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The total thickness of the present covering material film is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less. By making the total thickness of the present covering material film equal to or greater than the above-mentioned lower limit, the strength and barrier properties of the covering material film can be ensured. By making the total thickness of the present covering material film equal to or less than the above-mentioned upper limit, the push-through property can be more effectively improved.

[0024] The present embodiment may also relate to a roll-shaped body obtained by winding up the present covering material film into a roll. The present covering material film has appropriate strength and flexibility, so that it can be stored or distributed as a roll-shaped body.

[0025] <Base material layer> The base layer constituting the present covering material film contains a polypropylene resin and a petroleum resin. The base layer preferably further contains a nucleating agent.

[0026] The thickness of the substrate layer is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more. The thickness of the substrate layer is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less. By making the thickness of the substrate layer equal to or greater than the above-mentioned lower limit, the strength and barrier properties of the covering material film can be ensured. By making the thickness of the substrate layer equal to or less than the above-mentioned upper limit, the push-through property can be more effectively improved.

[0027] The melting point of the substrate layer is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher. The melting point of the substrate layer is preferably 210°C or lower, more preferably 200°C or lower, and even more preferably 190°C or lower. By setting the melting point of the substrate layer to the above lower limit or higher, it is possible to prevent the covering material film from melting during heat sealing. By setting the melting point of the substrate layer to the above upper limit or lower, it is possible to form the covering material film at a low temperature, which is advantageous for production.

[0028] <<Polypropylene resin>> The polypropylene resin may be a propylene homopolymer (homopolypropylene (hPP)) or a copolymer of propylene with other components such as α-olefins. In the case of a copolymer, it may be either random polypropylene (rPP) or block polypropylene (bPP). Furthermore, a mixture of these may also be used as the polypropylene resin.

[0029] Examples of the copolymerization component include ethylene and 1-butene, and among these, ethylene is preferred.

[0030] Furthermore, when the above copolymer is used, the content of the copolymer component in the copolymer is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more, based on the total mass of the copolymer. Furthermore, the content of the copolymer component is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, based on the total mass of the copolymer. If the content of the copolymer component in the copolymer is within the above range, it is possible to impart suitable barrier properties to the film while maintaining good film-forming properties.

[0031] As the polypropylene resin, homopolypropylene or propylene-ethylene random copolymer consisting of a single component is more preferred, with homopolypropylene being particularly preferred. In this embodiment, the base layer preferably contains homopolypropylene as the main component. In this specification, the term "main component" refers to the resin with the highest mass proportion among the resins constituting the base layer, and refers to a case where the main component accounts for, for example, 50 mass% or more, 60 mass% or more, 70 mass% or more, 80 mass% or more, 90 mass% or more, or 100 mass% of the resins constituting the base layer. When the base layer contains homopolypropylene as the main component, the elongation of the base layer is more easily suppressed, and the push-through property can be more effectively improved. Furthermore, when the base layer contains homopolypropylene as the main component, the heat resistance of the covering material film can be effectively improved.

[0032] In this embodiment, the base layer may be made of a combination of two or more homopolypropylenes. For example, it is preferable to use a combination of two or more homopolypropylenes with different viscosities or molecular weights. By using a homopolypropylene with a relatively high viscosity in combination with a homopolypropylene with a relatively low viscosity, the film-forming properties of the base layer can be improved. Furthermore, by using a homopolypropylene with a relatively low viscosity (a homopolypropylene with a low molecular weight) in combination, it becomes easier to suppress the elongation of the base layer, and the push-through properties can be more effectively improved.

[0033] The polymerization method for the polypropylene resin is not particularly limited, and can be carried out by a conventionally known method. The catalyst used in the polymerization is also not particularly limited, and a conventionally known catalyst can be used.

[0034] The melt flow rate (hereinafter also referred to as "MFR") of the polypropylene resin measured in accordance with JIS K7210:2014 at 230°C under a load of 2.16 kg is preferably 0.3 g / 10 min or more, more preferably 0.5 g / 10 min or more, and even more preferably 0.8 g / 10 min or more. Furthermore, the melt flow rate at 230°C under a load of 2.16 kg is preferably 20 g / 10 min or less, more preferably 10 g / 10 min or less, and even more preferably 8 g / 10 min or less. When the MFR of the polypropylene resin is within the above range, stable film-forming properties are obtained, and a press-through package lid material film with good push-through properties is easily obtained.

[0035] The density of polypropylene resin measured in accordance with JIS K7112:1999D is 0.850 to 0.950 g / cm 3 It is preferable that the density is 0.870 to 0.930 g / cm 3 More preferably, it is 0.890 to 0.910 g / cm 3 By setting the density of the polypropylene resin within the above range, the push-through properties of the press-through package lid material film can be more effectively improved.

[0036] The number average molecular weight (Mn) of the polypropylene resin is preferably 30,000 or more, more preferably 50,000 or more. There is no particular upper limit to the number average molecular weight (Mn) of the polypropylene resin, but from the viewpoint of extrusion moldability, it is preferably 200,000 or less, particularly 150,000 or less. By keeping the number average molecular weight (Mn) of the polypropylene resin within the above range, stable film formability can be achieved, making it easier to obtain a press-through package lid material film with good push-through properties.

[0037] The weight-average molecular weight (Mw) of the polypropylene resin is preferably 200,000 or more, more preferably 250,000 or more, and even more preferably 300,000 or more. The weight-average molecular weight (Mw) of the polypropylene resin is preferably 1,500,000 or less, and more preferably 1,000,000 or less. By keeping the weight-average molecular weight (Mw) of the polypropylene resin within the above range, stable film-forming properties are achieved, making it easier to obtain a press-through package lid material film with good push-through properties.

[0038] The molecular weight distribution (Mw / Mn) calculated from the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polypropylene resin is preferably 3.5 or more, more preferably 4.0 or more, and even more preferably 4.5 or more. Furthermore, the molecular weight distribution (Mw / Mn) is preferably 20 or less, more preferably 15 or less. By setting the molecular weight distribution (Mw / Mn) to the above-mentioned lower limit or more, the molding processability of the film is improved, and a press-through package lid material film with good push-through properties is easily obtained. Furthermore, by setting the molecular weight distribution (Mw / Mn) to the above-mentioned upper limit or less, the inclusion of extremely low molecular weight components can be suppressed, and bleeding of extremely low molecular weight components and formation of extremely high molecular weight components as unmelted materials during molding can be suppressed. Here, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) can be calculated using a Malvern Instruments high temperature GPC system (Viscotek triple detector HT-GPC model SG system) using orthodichlorobenzene as the solvent, a measurement temperature of 140°C, detector RI (reference flow method), and polystyrene equivalent molecular weight.

[0039] The polypropylene resin content is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on the total mass of the base layer. The polypropylene resin content is preferably 99% by mass or less, more preferably 98% by mass or less, based on the total mass of the base layer. By setting the polypropylene resin content within the above range, the adhesion between the press-through package lid material film and the press-through package sheet (base material) can be improved. By setting the polypropylene resin content within the above range, a press-through package lid material film with good push-through properties can be easily obtained.

[0040] <<Petroleum resin>> The base layer further contains a petroleum resin in addition to the polypropylene resin. The petroleum resin is compatible with the above-mentioned polypropylene resin, penetrates into the amorphous portion of the polypropylene resin, and reduces the mobility of the amorphous portion. As a result, it is believed that the base layer becomes embrittled and the push-through property is improved. In this embodiment, the petroleum resin controls the mobility of the polypropylene resin, so it can also be called an amorphous portion mobility-reducing resin.

[0041] Examples of petroleum resins include C5 petroleum resins, C9 petroleum resins, C5-C9 copolymer petroleum resins, and alicyclic hydrocarbon petroleum resins such as dicyclopentadiene petroleum resins, as well as hydrogenated derivatives thereof. Other examples of petroleum resins that can be used include rosin resins such as rosin diol resins and rosin ester resins, terpene resins, phenolic resins, xylene resins, coumarone resins, chroman-indene resins, ketone resins, and modified resins (hydrogenated derivatives) thereof, and acrylic oligomers. Among these, the petroleum resin is preferably at least one selected from the group consisting of C5 petroleum resins, C9 petroleum resins, C5-C9 copolymer petroleum resins, alicyclic hydrocarbon petroleum resins, terpene resins, chroman-indene resins, rosin resins, and hydrogenated derivatives thereof. More preferably, the petroleum resin is at least one selected from the group consisting of alicyclic hydrocarbon petroleum resins, terpene resins, rosin resins, and hydrogenated derivatives thereof. Alicyclic hydrocarbon petroleum resins are particularly preferred.

[0042] The weight average molecular weight of the petroleum resin is not particularly limited, but is preferably 1,000 to 30,000, and more preferably 3,000 to 15,000.

[0043] Examples of the terpene resin include terpene resins such as α-pinene polymers, β-pinene polymers, and dipentene polymers, as well as modified terpene resins such as terpene phenol resins, styrene-modified terpene resins, and hydrogenated terpene resins.

[0044] Examples of the coumarone-indene resin include a thermoplastic synthetic resin obtained by purifying a 160 to 180°C fraction of tar and polymerizing coumarone having 8 carbon atoms and indene having 9 carbon atoms as main monomers.

[0045] Examples of the rosin-based resin include unmodified rosins such as tall rosin, gum rosin, and wood rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleic acid-modified rosin, and fumaric acid-modified rosin, as well as esterified rosin resins obtained by modifying any of these with glycerin, pentaerythritol, ethylene glycol, or the like.

[0046] As the petroleum resin, it is preferable to use a hydrogenated derivative from the viewpoint of exhibiting good compatibility when mixed with polypropylene resin and further improving color tone, thermal stability, barrier properties, etc. In particular, it is preferable to use a petroleum resin or terpene resin that has a hydrogenation rate (hydrogenation rate) of 95% or more and that does not substantially contain polar groups such as hydroxyl groups, carboxy groups, and halogens, or unsaturated bonds such as double bonds, and it is more preferable to use a petroleum resin.

[0047] The softening point of the petroleum resin is preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher. The softening point of the petroleum resin is preferably 150°C or lower. When the softening point of the petroleum resin is within the above range, the compatibility of the petroleum resin is enhanced, making it easier to obtain a film with excellent push-through properties. When the softening point of the petroleum resin is within the above range, blocking of the raw material pellets during film formation can be prevented, which tends to improve productivity.

[0048] The petroleum resin may be commercially available, such as the "Alcon" series (trade name) from Arakawa Chemical Industries, Ltd., the "Hi-Let's" series and the "Petrogin" series (trade name) from Mitsui Chemicals, Inc., the "Clearon" series (trade name) from Yasuhara Chemical Co., Ltd., the "Imarve" series (trade name) from Idemitsu Petrochemical Co., Ltd., and the "Escoretz" series (trade name) from Tonex Corporation.

[0049] The content of the petroleum resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, relative to the total mass of the base layer. Furthermore, the content of the petroleum resin is preferably 50% by mass or less, more preferably 40% by mass or less, relative to the total mass of the base layer. In particular, the content of the alicyclic hydrocarbon petroleum resin is preferably within the above range. By keeping the content of the petroleum resin within the above range, good film-forming properties and push-through properties can be maintained.

[0050] <<Nucleating agent>> The base layer preferably contains a nucleating agent, which can control the crystallinity of the polypropylene resin, thereby effectively improving the push-through properties of the covering material film.

[0051] As the nucleating agent, fatty acid metal salts, phosphates, aromatic phosphonates, polyhydric alcohols, fatty acid amides, copolymers of olefin and maleic acid, etc. can be used.

[0052] Examples of fatty acid metal salts include lithium stearate, barium stearate, zinc stearate, sodium stearate, calcium stearate, magnesium stearate, aluminum stearate, calcium 12-hydroxystearate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, aluminum 12-hydroxystearate, barium 12-hydroxystearate, lithium 12-hydroxystearate, sodium 12-hydroxystearate, sodium montanate, calcium montanate, lithium montanate, zinc montanate, magnesium montanate, aluminum montanate, calcium laurate, barium laurate, zinc laurate, lithium laurate, sodium laurate, calcium ricinoleate, barium ricinoleate, zinc ricinoleate, potassium caprylate, sodium caprylate, calcium caprylate, magnesium caprylate, aluminum octoate, zinc myristate, zinc palmitate, and sodium dimethyl sulfoisophthalate. Among these fatty acid metal salts, from the viewpoint of compatibility with polypropylene resin, at least one selected from the group consisting of 12-hydroxystearic acid salt, stearic acid salt, and montanic acid salt is preferred, stearic acid salt is more preferred, and magnesium stearate is particularly preferred.

[0053] Examples of phosphates include sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, iron phosphate, and ammonium phosphate. Of these, sodium phosphate and calcium phosphate are preferred. Examples of aromatic phosphonates include zinc phenylphosphonate, a composition containing the Na salt of 2-hydroxy-2-oxo-4,6,10,12-tetra-tert-butyl-1,3,2-dibenzo[d,g]perhydrodioxaphosphalocin, and aluminum bis(4,4',6,6'-tetra-tert-butyl-2,2'-methylenediphenyl phosphate) hydroxide.

[0054] Examples of polyhydric alcohols include trimethylolpropane, inositol, and pentaerythritol. Of these, pentaerythritol is preferred.

[0055] Examples of fatty acid amides include N-stearyl oleic acid amide, N-stearyl erucic acid amide, N-oleyl stearic acid amide, lauric acid amide, N-stearyl stearic acid amide, palmitic acid amide, stearic acid amide, hydroxystearic acid amide, N-methylol stearic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bishydroxystearic acid amide, hexamethylene bisstearic acid amide, N,N'-distearyl adipic acid amide, methylene bisstearic acid amide, hexamethylene bisbehenic acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bislauric acid amide, ethylene biscapric acid amide, and erucic acid amide. Of these, N-oleylstearic acid amide, hydroxystearic acid amide, hexamethylene bishydroxystearic acid amide, ethylene bishydroxystearic acid amide, and erucic acid amide are preferred, and hexamethylene bishydroxystearic acid amide and ethylene bishydroxystearic acid amide are particularly preferred.

[0056] Examples of the copolymer of olefin and maleic acid include a copolymer of olefin and maleic anhydride, a copolymer of styrene and maleic anhydride, etc. The copolymer of olefin and maleic anhydride is preferred.

[0057] From a safety standpoint, nucleating agents are preferably compounds listed on the positive list for food utensils and containers under the Food Sanitation Act, compounds approved as food additives under the U.S. Food and Drug Administration's Food Additive Petition, or compounds certified under the European Regulation (EC) No. 1935 / 2004 on materials and products in contact with food. Preferred nucleating agents, due to their high safety, include fatty acid metal salts, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, aluminum phosphate, iron phosphate, ammonium phosphate, pentaerythritol, and hexamethylenebishydroxystearamide.

[0058] The substrate layer may contain only one type of the above-mentioned nucleating agent, or may contain two or more types.

[0059] As the nucleating agent, commercially available products can also be used, such as the nucleating agent masterbatch "Clear Master R200" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.

[0060] The content of the nucleating agent is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, relative to the total mass of the base layer. Furthermore, the content of the nucleating agent is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total mass of the base layer. In particular, the content of magnesium stearate is preferably within the above range. By setting the content of the nucleating agent within the above range, push-through properties can be more effectively improved.

[0061] <<Optional ingredients>> The substrate layer may contain various additives as needed. Examples of additives include heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, colorants, inorganic fillers, organic fillers, antiblocking agents, hydrolysis inhibitors, plasticizers, and flame retardants. These may be used alone or in combination of two or more.

[0062] The base layer may contain other resins in addition to the polypropylene resin, provided that the effects of the present invention are not impaired. Examples of such other resins include polyester resins such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, and polybutylene terephthalate; polyolefin resins such as polyethylene, cyclopolyolefin, and polymethylpentene; cellulose derivatives such as acetyl cellulose, nitrocellulose, acetylbutyl cellulose, ethyl cellulose, and methyl cellulose; vinyl resins such as vinyl acetate and its copolymers, vinyl chloride and its copolymers, and vinylidene chloride and its copolymers; acetal resins such as polyvinyl formal and polyvinyl butyral; acrylic resins such as polyacrylates and their copolymers, and methacrylic resins such as polymethacrylates and their copolymers; polystyrene resins; polyamide resins; and polycarbonate resins. These may be used alone or in combination of two or more.

[0063] When the base layer contains other resins, the content of the other resins is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the total mass of each layer.

[0064] <Heat-resistant layer> The present covering material film has a heat-resistant layer on one side of the base material layer. The heat-resistant layer may be provided on only one side of the base material layer, or on both sides. In this embodiment, the heat-resistant layer can prevent the resin of the base material layer from melting and bleeding out during heat sealing to form a press-through package. The presence of the heat-resistant layer in the present covering material film makes it possible to perform heat sealing at an appropriate temperature, thereby improving heat sealability and more effectively increasing adhesion to the base material sheet that constitutes the press-through package.

[0065] The heat-resistant layer constituting the present covering material film preferably contains a polypropylene resin. The heat-resistant layer preferably contains the same polypropylene resin as the main component of the base layer. By containing the same polypropylene resin as the main component of the base layer, the heat-resistant layer can effectively improve interlayer adhesion.

[0066] The thickness of the heat-resistant layer is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. The thickness of the heat-resistant layer is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. By making the thickness of the heat-resistant layer equal to or greater than the above-mentioned lower limit, the heat resistance of the covering material film can be more effectively improved. By making the thickness of the heat-resistant layer equal to or less than the above-mentioned upper limit, the push-through property can be more effectively improved.

[0067] The melting point of the heat-resistant layer is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. The melting point of the heat-resistant layer is preferably 220°C or lower, more preferably 210°C or lower, and even more preferably 200°C or lower. By setting the melting point of the heat-resistant layer to the above-mentioned lower limit or higher, the heat resistance of the covering material film can be more effectively improved. By setting the melting point of the heat-resistant layer to the above-mentioned upper limit or lower, the covering material film can be formed at a low temperature, which is advantageous for production. From the viewpoint of improving the heat resistance of the heat-resistant layer, the melting point of the heat-resistant layer is preferably higher than the melting point of the base layer.

[0068] <<Polypropylene resin>> The heat-resistant layer preferably contains a polypropylene resin. The polypropylene resin that the heat-resistant layer may contain is the same as the polypropylene resin that the base layer may contain. The polypropylene resin contained in the heat-resistant layer is more preferably a homopolypropylene or a propylene-ethylene random copolymer consisting of a single component, and homopolypropylene is particularly preferred. The heat-resistant layer is preferably a layer containing homopolypropylene as a main component. Furthermore, the homopolypropylene used in the heat-resistant layer preferably has high stereoregularity.

[0069] The content of homopolypropylene is preferably 60% by mass or more, more preferably 65% ​​by mass or more, even more preferably 70% by mass or more, even more preferably 75% by mass or more, and particularly preferably 80% by mass or more, based on the total mass of the heat-resistant layer. The content of homopolypropylene may be 100% by mass, based on the total mass of the heat-resistant layer. By setting the content of homopolypropylene within the above range, the heat-resistant layer can exhibit better heat resistance.

[0070] <<Nucleating agent>> In this embodiment, the heat-resistant layer preferably contains a nucleating agent. Examples of the nucleating agent include the same nucleating agents that can be contained in the base material layer, and the same applies to preferred nucleating agents. When the heat-resistant layer contains a nucleating agent, the push-through property of the present covering material film can be more effectively improved.

[0071] The content of the nucleating agent is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more, relative to the total mass of the heat-resistant layer. Furthermore, the content of the nucleating agent is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total mass of the heat-resistant layer. In particular, the content of magnesium stearate is preferably within the above range. By setting the content of the nucleating agent within the above range, push-through properties can be more effectively improved.

[0072] <<Optional ingredients>> The heat-resistant layer may contain various additives as needed. Examples of additives include heat stabilizers, antioxidants, UV absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, colorants, inorganic fillers, organic fillers, antiblocking agents, hydrolysis inhibitors, plasticizers, and flame retardants. These may be used alone or in combination of two or more. The heat-resistant layer may also contain other resins in addition to the polypropylene resin, as long as the effects of the present invention are not impaired. Examples of other resins include the resin types described above, and the upper limit of the content is also as described above.

[0073] In order to ensure heat resistance, the heat-resistant layer preferably does not substantially contain petroleum resin. In this specification, "substantially does not contain" means that the content of petroleum resin is 1% by mass or less, preferably 0.1% by mass or less, relative to the total mass of the heat-resistant layer.

[0074] <Sealing layer> The present covering material film preferably includes a heat-resistant layer on one side of the base material layer and a sealing layer on the other side of the base material layer. In this embodiment, the sealing layer serves to improve heat sealing properties when forming a press-through package. By including the sealing layer in the present covering material film, adhesion to the base material sheet constituting the press-through package can be more effectively improved.

[0075] The thickness of the sealing layer is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. The thickness of the sealing layer is preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. By making the thickness of the sealing layer equal to or greater than the above-mentioned lower limit, the heat sealability of the covering material film can be more effectively improved. By making the thickness of the sealing layer equal to or less than the above-mentioned upper limit, the push-through property can be more effectively improved.

[0076] The melting point of the sealing layer is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 60°C or higher. The melting point of the sealing layer is preferably 160°C or lower, more preferably 155°C or lower, and even more preferably 150°C or lower. By setting the melting point of the sealing layer to the above-mentioned lower limit or higher, the sealing layer softens at room temperature, preventing unintended adhesion. By setting the melting point of the sealing layer to the above-mentioned upper limit or lower, a difference in melting point is created between the sealing layer and the heat-resistant layer, preventing adhesion of the heat-resistant layer during sealing and preventing melting of layers other than the sealing layer. From the viewpoint of improving the heat-sealability of the sealing layer, the melting point of the sealing layer is preferably lower than the melting point of the base layer.

[0077] The difference in melting point between the heat-resistant layer and the sealing layer is preferably 20° C. or more, more preferably 25° C. or more, and even more preferably 30° C. or more. The difference in melting point between the heat-resistant layer and the sealing layer is preferably 110° C. or less, more preferably 100° C. or less, and even more preferably 90° C. or less. By keeping the difference in melting point between the heat-resistant layer and the sealing layer at the above-mentioned upper limit or less, it is possible to prevent the heat-resistant layer from sticking together during sealing and to prevent layers other than the sealing layer from melting.

[0078] <<Polypropylene resin>> The sealing layer preferably contains a polypropylene resin. The polypropylene resin may be a propylene homopolymer (homopolypropylene (hPP)) or a copolymer of propylene with other components such as α-olefins. In the case of a copolymer, it may be either random polypropylene (rPP) or block polypropylene (bPP). A mixture of these may also be used as the polypropylene resin.

[0079] Among these, the polypropylene resin is preferably a copolymer from the viewpoint of heat-sealing properties. When the polypropylene is a copolymer, either random polypropylene (rPP) or block polypropylene (bPP) may be used, but rPP is particularly preferred from the viewpoint of heat-sealing properties. When the polypropylene is a copolymer of propylene and an α-olefin, the number of carbon atoms in the α-olefin is not particularly limited. However, from the viewpoint of versatility, it is preferably 2 to 20, more preferably 2 to 10, even more preferably 2 to 5, and even more preferably 2 to 4. Among these, the polypropylene is preferably a copolymer of propylene and ethylene, particularly a random copolymer, from the viewpoint of lamination processability and interlayer adhesion. The content of the α-olefin in the copolymer of propylene and an α-olefin is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, even more preferably 2 to 10% by mass, and particularly preferably 3 to 7% by mass, from the viewpoint of the balance between moldability and rigidity.

[0080] Furthermore, polypropylene resins produced using a single-site catalyst are preferred, and metallocene polypropylene (mPP) is more preferred. Metallocene polypropylene is polypropylene polymerized using a metallocene catalyst and is a copolymer of propylene and ethylene. Using polypropylene resin polymerized using a metallocene catalyst makes it easier to produce polypropylene resin with a narrow molecular weight distribution, which tends to improve film strength. Furthermore, using polypropylene resin polymerized using a metallocene catalyst makes it possible to control the melting point of the sealing layer low, and furthermore, it is possible to minimize the variation in melting point (melting point range).

[0081] In this embodiment, the sealing layer may be made of two or more metallocene polypropylenes. For example, it is preferable to use two or more metallocene polypropylenes having different viscosities or molecular weights. By using a metallocene polypropylene with a relatively high viscosity and a metallocene polypropylene with a relatively low viscosity in combination, the sealing properties of the sealing layer can be improved while suppressing the extrusion of the sealing layer from the edge.

[0082] <<Optional ingredients>> The sealing layer may contain various additives as needed. Examples of additives include heat stabilizers, antioxidants, UV absorbers, light stabilizers, antibacterial and antifungal agents, antistatic agents, lubricants, colorants, inorganic fillers, organic fillers, antiblocking agents, hydrolysis inhibitors, plasticizers, and flame retardants. These may be used alone or in combination of two or more. Furthermore, the sealing layer may contain other resins in addition to the polypropylene resin, as long as the effects of the present invention are not impaired. Examples of other resins include the resin types described above, and the upper limit of the content is also as described above.

[0083] <<Petroleum resin>> The sealing layer may further contain a petroleum resin in addition to the polypropylene resin. The petroleum resin is compatible with the above-mentioned polypropylene resin, penetrates into the amorphous portion of the polypropylene resin, and reduces the mobility of the amorphous portion. As a result, it is thought that the seal layer becomes embrittled and the push-through property is improved. In this embodiment, the petroleum resin controls the mobility of the polypropylene resin, so it can also be called an amorphous portion mobility-reducing resin.

[0084] Examples of petroleum resins used in the sealing layer include petroleum resins such as C5 petroleum resins, C9 petroleum resins, C5-C9 copolymer petroleum resins, alicyclic hydrocarbon petroleum resins such as dicyclopentadiene petroleum resins, and hydrogenated derivatives thereof. Other examples of petroleum resins that can be used include rosin resins such as rosin diol resins and rosin ester resins, terpene resins, phenol resins, xylene resins, coumarone resins, chroman-indene resins, ketone resins, and modified resins (hydrogenated derivatives) thereof, as well as acrylic oligomers. Among these, the petroleum resin is preferably at least one selected from the group consisting of C5 petroleum resins, C9 petroleum resins, C5-C9 copolymer petroleum resins, alicyclic hydrocarbon petroleum resins, terpene resins, chroman-indene resins, rosin resins, and hydrogenated derivatives thereof, more preferably at least one selected from the group consisting of alicyclic hydrocarbon petroleum resins, terpene resins, rosin resins, and hydrogenated derivatives thereof, and particularly preferably an alicyclic hydrocarbon petroleum resin.

[0085] The weight average molecular weight of the petroleum resin is not particularly limited, but is preferably 1,000 to 30,000, and more preferably 3,000 to 15,000.

[0086] Examples of the terpene resin include terpene resins such as α-pinene polymers, β-pinene polymers, and dipentene polymers, as well as modified terpene resins such as terpene phenol resins, styrene-modified terpene resins, and hydrogenated terpene resins.

[0087] Examples of the coumarone-indene resin include a thermoplastic synthetic resin obtained by purifying a 160 to 180°C fraction of tar and polymerizing coumarone having 8 carbon atoms and indene having 9 carbon atoms as main monomers.

[0088] Examples of the rosin-based resin include unmodified rosins such as tall rosin, gum rosin, and wood rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleic acid-modified rosin, and fumaric acid-modified rosin, as well as esterified rosin resins obtained by modifying any of these with glycerin, pentaerythritol, ethylene glycol, or the like.

[0089] As the petroleum resin, it is preferable to use a hydrogenated derivative from the viewpoint of exhibiting good compatibility when mixed with polypropylene resin and further improving color tone, thermal stability, barrier properties, etc. In particular, it is preferable to use a petroleum resin or terpene resin that has a hydrogenation rate (hydrogenation rate) of 95% or more and that does not substantially contain polar groups such as hydroxyl groups, carboxy groups, and halogens, or unsaturated bonds such as double bonds, and it is more preferable to use a petroleum resin.

[0090] The softening point of the petroleum resin contained in the seal layer is preferably 120°C or lower, more preferably 110°C or lower, and even more preferably 100°C or lower. The softening point of the petroleum resin is preferably 60°C or higher. When the softening point of the petroleum resin contained in the seal layer is within the above range, the melting point of the entire seal layer decreases, increasing the difference in melting point with the heat-resistant layer. Therefore, when used as a PTP lid material film, adhesion of the heat-resistant layer during sealing can be suppressed, and layers other than the seal layer can be suppressed from melting. Furthermore, blocking of raw material pellets can be prevented during film formation, which tends to improve productivity.

[0091] The petroleum resin may be commercially available, such as the "Alcon" series (trade name) from Arakawa Chemical Industries, Ltd., the "Hi-Let's" series and the "Petrogin" series (trade name) from Mitsui Chemicals, Inc., the "Clearon" series (trade name) from Yasuhara Chemical Co., Ltd., the "Imarve" series (trade name) from Idemitsu Petrochemical Co., Ltd., and the "Escoretz" series (trade name) from Tonex Corporation.

[0092] The content of the petroleum resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the total mass of the sealing layer. Furthermore, the content of the petroleum resin is preferably 50% by mass or less, more preferably 40% by mass or less, based on the total mass of the sealing layer. In particular, the content of the alicyclic hydrocarbon petroleum resin is preferably within the above range. By keeping the content of the petroleum resin within the above range, good film-forming properties and push-through properties can be maintained.

[0093] <Arbitrary layer> The covering material film may further have an optional layer on the heat-resistant layer or the sealing layer. The optional layer may be provided between the heat-resistant layer and the base layer, or between the base layer and the sealing layer. Examples of the optional layer include a barrier layer, an adhesive layer, and a printing layer.

[0094] For example, the barrier layer preferably contains a fluorine-based resin, such as polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether (EPA), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and chlorotrifluoroethylene-ethylene copolymer (ECTFE).

[0095] The barrier layer may contain various additives other than the fluorine-based resin, if necessary. Examples of additives include heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, nucleating agents, antibacterial and antifungal agents, antistatic agents, and lubricants. These may be used alone or in combination of two or more.

[0096] When the present covering material film has an adhesive layer, examples of the adhesive constituting the adhesive layer include polyester-based resins, polyester urethane-based resins, urethane-based resins, epoxy-based resins, etc. Among these, from the viewpoint of improving interlayer adhesion, the adhesive is preferably a polyester-based resin, a polyurethane-based resin, or both of these resins.

[0097] The printing layer is a layer on which a desired printing pattern, such as letters, figures, symbols, designs, etc., is printed to form the printing pattern. The printing layer can be formed by printing the ink composition on one side of the substrate layer or the heat-resistant layer using a printing method such as gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexographic printing, etc. The printing layer is provided, for example, between the substrate layer and the sealing layer or on the heat-resistant layer. The ink composition may contain, as necessary, a plasticizer, a stabilizer, an antioxidant, a light stabilizer, an ultraviolet absorber, a curing agent, a crosslinking agent, a lubricant, an antistatic agent, a filler, etc.

[0098] (Method of manufacturing press-through package lid material film) The method for producing the present lid material film preferably includes the steps of melt-mixing a resin composition for forming a base layer containing a polypropylene resin and a petroleum resin, and a resin composition for forming a heat-resistant layer, using a single-screw or twin-screw extruder, co-extruding the mixture through a T-die, and quenching and solidifying the mixture with a cast roll, thereby obtaining a press-through package lid material film having a base layer and a heat-resistant layer.

[0099] The press-through package covering material film may be an unstretched film or a stretched film stretched uniaxially or biaxially. However, from the viewpoint of formability, the press-through package covering material film is preferably an unstretched film. Here, in this specification, the term "unstretched film" means a film that is not actively stretched for the purpose of increasing the strength of the film, and includes, for example, a film that is stretched less than twice its original size by a stretching roll during extrusion molding.

[0100] By producing a press-through package lid material film using the above method, it is not necessary to provide an adhesive layer between the base layer and the heat-resistant layer, and it is possible to achieve excellent productivity and cost. From the viewpoint of adhesiveness, it is preferable that the base layer and the heat-resistant layer each contain a polypropylene resin.

[0101] (Press-through package manufacturing method) A press-through package (PTP) is "a packaging material consisting of a sheet-like base material with a recess (pocket) for placing tablets or capsules, and a press-through package lid material film that seals the recess, allowing tablets or the like to be removed by pressing and opening the recess." When manufacturing a press-through package, the PTP (press-through package) base material is formed into a molded body with a recess by, for example, vacuum forming, pressure forming, pressure vacuum forming, press forming, plug forming, or other thermoforming, and the recess is then sealed with the press-through package lid material film.

[0102] The contents of the PTP are not particularly limited as long as they can be stored in the pocket, such as tablets or capsules.

[0103] When sealing with a press-through package lid material film, the surface of the base material (flange portion) and the surface of the lid material film are overlapped and heat-sealed to seal. The heat-sealing temperature is, for example, 50 to 200°C, and preferably 80 to 150°C. The heat-sealing time is, for example, 0.05 to 3 seconds, and preferably 0.2 to 1 second. The heat-sealing pressure is, for example, 0.2 to 0.6 MPa, and preferably 0.3 to 0.5 MPa. By setting the heat-sealing conditions within the above ranges, it becomes difficult for the contents to leave burn marks, and sufficient seal strength can be easily obtained.

[0104] (Press-through package) This embodiment also relates to a press-through package having the above-mentioned press-through package lid material film and a base material having a recess for accommodating contents. The press-through package is a package obtained by placing contents such as capsules in pockets formed in a sheet-like base material, and then sealing and integrating the pockets with the press-through package lid material film.

[0105] The contents to be stored in the press-through package are not particularly limited as long as they can be stored in the pocket, such as tablets or capsules. Examples of the contents include medicines, foods, and supplements. Among these, the contents of the press-through package are preferably medicines, and the press-through package is preferably used for pharmaceutical packaging. The present covering material film has excellent push-through properties and is therefore suitable for pharmaceutical packaging. [Example]

[0106] The features of the present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0107] <Raw materials> The raw materials used in the examples and comparative examples will be explained below.

[0108] [Polypropylene resin] (PP-1): Homopolypropylene (density = 0.90 g / cm 3 , MFR=5.0g / 10min (measured at 2.16kgf, 230℃), Mn=90,000, Mw=530,000, Mw / Mn=5.9, melting point=160℃) (PP-2): Homopolypropylene (density = 0.90 g / cm 3 , MFR=2.3g / 10min (2.16kgf, measured at 230℃), Mn=110,000, Mw=620,000, Mw / Mn=27.5, melting point=160℃) (PP-3): Metallocene-based ethylene-propylene copolymer (density = 0.9 g / cm 3 , MFR=2.0g / 10min (2.16kgf, measured at 230℃), Mn=150,000, Mw=420,000, Mw / Mn=2.8, melting point=124℃) (PP-4): Metallocene-based ethylene-propylene copolymer (density = 0.9 g / cm 3 , MFR=7.0g / 10min (measured at 2.16kgf, 230℃), Mn=112,000, Mw=280,000, Mw / Mn=2.5, melting point=124℃)

[0109] [Petroleum resin] (Petroleum resin-1): A hydrogenated derivative of C9 petroleum resin (density = 0.999 g / cm 3 , softening point=125℃) (Petroleum resin-2): A hydrogenated derivative of C9 petroleum resin (density = 0.999 g / cm 3 , softening point=90℃)

[0110] [Polypropylene resin containing nucleating agent] (Nucleating agent-1): A masterbatch containing 95% by mass of random polypropylene (ethylene-propylene copolymer) and 5% by mass of nucleating agent.

[0111] [Polypropylene resin containing coloring agent] (Colorant-1): A masterbatch containing 70% by mass of colorant and 30% by mass of random polypropylene (ethylene-propylene copolymer).

[0112] The physical properties of the raw materials were measured by the following methods. (density) JIS K7112:1999D method (MFR) JIS K7210:2014 method (Mn, Mw, Mw / Mn) The calculation was performed using a Malvern Instruments high-temperature GPC system (Viscotek triple detector HT-GPC model SG system), with the solvent used being orthodichlorobenzene, the measurement temperature being 140°C, the detector RI (reference flow method), and the molecular weight converted into polystyrene. (softening point) The softening point was measured using an automatic softening point measuring device (APS-MG2 type manufactured by Meitec Corporation) according to the JIS K2207:1996 method. (Melting Point) The melting point is the temperature indicated by the peak top of the crystal melting peak measured in accordance with JIS K7121 (2012).

[0113] <Examples 1 to 5 and Comparative Example 1> The raw materials listed in Table 1 for the resin composition for forming the base layer were fed into a T-die single-screw extruder and kneaded at 230°C. The raw materials listed in Table 1 for the resin composition for forming the heat-resistant layer were fed into a T-die single-screw extruder and kneaded at 230°C. The raw materials listed in Table 1 for the resin composition for forming the seal layer were fed into a T-die single-screw extruder and kneaded at 230°C. The mixture was extruded through the T-die so that the thickness of each layer was as shown in Table 1, and then quenched with a casting roll at about 45°C to produce a 40 μm-thick press-through package lid material film (PTP lid material film).

[0114] (Measurement and evaluation methods) [Puncture elongation and strength] The puncture elongation and puncture strength of PTP lid material films were measured using the following procedure. The PTP lid material film was fixed in a stretched state on a 30 mm diameter frame of a precision universal testing machine (Shimadzu Corporation, Autograph). A needle with a diameter of 1.0 mm and a tip radius of 0.5 mm was attached to the testing machine and pressed into the fixed PTP lid material film to perform the puncture test. The measurement was performed at a temperature of 23°C and a relative humidity of 50%, with the needle moving at a speed of 200 mm / min. The depth of the needle tip at the time of tearing (the displacement from when the needle contacted the fixed PTP lid material film to the position at which tearing occurred) was defined as the puncture elongation (mm), and the maximum load divided by the thickness of the test piece was defined as the puncture strength. The values ​​measured for five test pieces were averaged, and this value was used as the puncture elongation and strength of the PTP lid material film.

[0115] [Puncture point displacement, energy] The puncture point displacement and puncture point energy (J) were measured using a puncture type film impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with JIS K-7211-2:2006.

[0116] [Push-through] The puncture breaking elongation, puncture breaking strength, puncture point displacement, and puncture point energy of the PTP lid material film were taken into consideration and the ejectability was evaluated according to the following evaluation criteria. Evaluation Criteria A (good): The puncture breaking elongation at a thickness of 40 μm is less than 4.1 mm, and the puncture breaking strength is less than 4.2 N. B (fairly good): The puncture breaking elongation at a thickness of 40 μm is 4.1 mm or more and less than 5.8 mm, and the puncture breaking strength is less than 4.2 N, or the puncture breaking elongation at a thickness of 40 μm is less than 4.1 mm, and the puncture breaking strength is 4.2 N or more. C (slightly poor): The puncture breaking elongation at a thickness of 40 μm is 4.1 mm or more and less than 5.8 mm, and the puncture breaking strength is 4.2 N or more, or the puncture breaking elongation at a thickness of 40 μm is 5.8 mm or more, and the puncture breaking strength is less than 4.2 N. D (poor): The puncture breaking elongation at a thickness of 40 μm is 5.8 mm or more, and the puncture breaking strength is 4.2 N or more.

[0117] [Table 1]

[0118] The PTP lid material films obtained in Examples 1 to 5 had better push-through properties than Comparative Example 1. The difference in melting point between the heat-resistant layer and the sealing layer (melting point of the heat-resistant layer - melting point of the sealing layer) was 36°C (160°C - 124°C), which was sufficient, in all of Examples 1 to 4 and Comparative Example 1. Therefore, when any of these films is used as a PTP covering film, it is possible to prevent the heat-resistant layer from sticking during sealing and to prevent layers other than the sealing layer from melting. On the other hand, in Example 5, in which a petroleum resin was added to the seal layer, the melting point of the seal layer was 120°C, and the difference in melting point between the heat-resistant layer and the seal layer was 40°C (160°C - 120°C). Since Example 5 has a larger melting point difference than Example 4, when used as a PTP lid material film, there are fewer restrictions on the molding temperature, making it possible to perform molding processing. Furthermore, Example 5 has a lower puncture breaking strength than Example 4, and therefore has better push-through properties. Therefore, by comparing Example 4 and Example 5, it is clear that the inclusion of petroleum resin in the sealing layer provides an improvement in push-through performance and sealing performance.

Claims

1. A press-through package lid material film having a base layer containing a polypropylene resin and a petroleum resin, and a heat-resistant layer on one side of the base layer.

2. The press-through package lidstock film of claim 1 , wherein the substrate layer comprises a nucleating agent.

3. 2. The press-through package lid material film according to claim 1, wherein the base layer is composed mainly of homopolypropylene.

4. The press-through package lidstock film of claim 1 , wherein the heat-resistant layer comprises a nucleating agent.

5. 2. The press-through package lid material film according to claim 1, wherein the heat-resistant layer is composed mainly of homopolypropylene.

6. The press-through package lid material film according to claim 1 , further comprising a seal layer on the other surface side of the base material layer.

7. 2. The press-through package lid material film according to claim 1, which has a puncture breaking elongation of 5.8 mm or less at a temperature of 23°C when the film is 40 μm thick.

8. 2. The press-through package lid material film according to claim 1, which has a puncture breaking strength of 4.2 N or less at a temperature of 23°C when the film is 40 μm thick.

9. 2. The press-through package lid material film according to claim 1, wherein the puncture point displacement at a thickness of 40 μm under a condition of 23° C. is 6.9 mm or less.

10. 2. The press-through package lid material film according to claim 1, which has a puncture point energy of 0.030 J or less at a temperature of 23°C and a thickness of 40 μm.

11. 2. The press-through package lid material film according to claim 1, having a thickness of 400 μm or less.

12. A press-through package comprising the press-through package lid material film according to any one of claims 1 to 11 and a base material having a recess for accommodating contents.

13. The press-through package of claim 12 for pharmaceutical packaging.

Images