PTP lid material and method for manufacturing the same

Abstract

To provide a lid material for a PTP package which is excellent in print readability, recyclability and projection property, and a method for manufacturing the same.SOLUTION: A lid material for a PTP contains a polyolefin-based resin, and has an ignition residue of less than 5 mass%, gloss values at measurement angles of 20°, 45°, 60°, 75°and 85° of 70% or less, and piercing breaking elongation of less than 3.2 mm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a lid material for PTP (press-through pack) and a method for manufacturing the same. [Background technology]

[0002] One known packaging form for pharmaceuticals, food products, and other items is the PTP packaging, which consists of a bottom material and a lid material. PTP packaging is manufactured by vacuum forming or pressure forming a bottom material with pocket-shaped recesses from a plastic sheet made of polyvinyl chloride resin or polypropylene resin, filling these recesses with contents, and then heat-sealing the lid material to the flange portion, which is the part other than the recesses. The contents can be removed by applying force from the outside of the bottom material toward the lid material, thereby piercing the lid material.

[0003] Traditionally, aluminum foil and glassine paper have been used as lid materials due to their excellent properties of easily tearing by pushing out the contents (extrusion properties). However, the glossy surface of aluminum lid materials has made it difficult to read printed areas such as barcodes. Furthermore, in recent years, with the trend towards reducing single-use plastic products, implementing recycling, and shifting to renewable resources, there has been growing interest in environmentally friendly PTP packaging that uses plastic sheets not only for the bottom material but also for the lid, eliminating the need for sorting when disposing of it as waste and allowing for recycling.

[0004] For example, Patent Document 1 discloses a lid material having a press-through function, which uses a polypropylene resin film and a reinforcing resin layer laminated on the polypropylene resin film as a base material, and in which the polypropylene resin film is degraded by irradiation with radiation. Furthermore, Patent Document 2 discloses a lid material for PTP containing a styrene resin and a coloring agent. Patent Document 3 discloses a lid material for blister packaging, which is mainly composed of high-density polyethylene (HDPE) and includes additives for reducing elongation at break. Patent Document 4 discloses a lid material for PTP (Press-Through Packaging) that uses a sheet made of a resin composition containing a polypropylene resin and an inorganic substance (such as talc) to improve extrusion properties as a base material. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-256842 [Patent Document 2] Japanese Patent Publication No. 2014-201345 [Patent Document 3] International Publication No. 2021 / 074082 [Patent Document 4] Japanese Patent Application Publication No. 10-101133 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the lid materials described in Patent Documents 1 to 3 have problems such as high gloss, which makes it difficult to read printed parts such as barcodes, or there is room for further improvement in terms of protrusion. In addition, the lid material described in Patent Document 4 in particular contains a large amount of inorganic material, which can cause problems in the sorting process and lead to a decrease in the quality of recycled material, making it unsuitable for recycling.

[0007] Therefore, the present invention aims to provide a lid material for PTP packaging and a method for manufacturing the same that is excellent in print readability, recyclability, and ejection. [Means for solving the problem]

[0008] In other words, the present invention is as follows. [1] A lid material for PTP, characterized by containing a polyolefin resin, having a ignition residue of less than 5% by mass, a gross value of 70% or less at measurement angles of 20°, 45°, 60°, 75°, and 85°, and a puncture break elongation of less than 3.2 mm. [2] The lid material for PTP according to [1], wherein a maximum reflection intensity is 20 to 150 in goniophotometer measurement using light with an incident angle of 15°. [3] The lid material for PTP according to [1] or [2], wherein a half-value width of a reflection intensity distribution is 10° or more in goniophotometer measurement using light with an incident angle of 15°. [4] The lid material for PTP according to any one of [1] to [3], wherein an a* value in a (L*,a*,b*) color space is -12 to 10, and a b* value is -10 to 15. [5] The lid material for PTP according to any one of [1] to [4], wherein haze is 50% or more. [6] The lid material for PTP according to any one of [1] to [5], wherein the lid material for PTP has a printed surface, and an arithmetic average roughness Ra of the printed surface is 0.2 µm or more. [7] The lid material for PTP according to any one of [1] to [6], wherein a molecular weight distribution of a resin contained in the lid material for PTP is 4.0 to 7.0. [8] Having a weight average molecular weight of 2.0×10 5 ~3.5×10 5 The lid material for PTP according to any one of [1] to [7], comprising a polypropylene resin that is [9] The lid material for PTP according to [8], wherein a heat of crystal fusion measured by differential scanning calorimetry (DSC) is 70 J / g or more.

[10] Having a weight average molecular weight of 3.5×10 4 ~5.2×10 4 The lid material for PTP according to any one of [1] to [7], comprising a polyethylene resin that is

[11] The lid material for PTP according to

[10] , wherein a heat of crystal fusion measured by differential scanning calorimetry (DSC) is 140 J / g or more. [Advantageous Effects of Invention]

[0009] According to the present invention, it is possible to provide a lid material for PTP packaging and a method for manufacturing the same that is excellent in print readability, recyclability, and ejection. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view showing one embodiment of a PTP packaging body equipped with a lid material for PTP according to the present invention. [Figure 2] Figure 2 is a graph showing an example of a load-displacement curve obtained when a puncture test is performed on the PTP lid material according to the present invention. [Modes for carrying out the invention]

[0011] The following describes in detail an embodiment for carrying out the present invention (hereinafter referred to as "this embodiment"), but the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0012] [PTP lid material] The PTP lid material of this embodiment (hereinafter also simply referred to as "lid material") contains a polyolefin resin, has a ignition residue of less than 5% by mass, has a gross value of 70% or less at measurement angles of 20°, 45°, 60°, 75°, and 85°, and has a puncture break elongation of less than 3.2 mm. The PTP lid material of this embodiment may have a printing surface on which printed portions such as barcodes and QR codes are printed.

[0013] <Polyolefin resins> The lid material for PTP in this embodiment contains a polyolefin resin, and from the viewpoint of recyclability, it is preferable that it is made of a polyolefin resin. Polyolefin resins refer to polymers that contain monomer units derived from olefins, and examples include polyethylene resins and polypropylene resins.

[0014] The content of the polyolefin resin is preferably 60 to 100% by mass, more preferably 70 to 95% by mass, and still more preferably 75 to 90% by mass, based on 100% by mass of the PTP lid material. When the content of the polyolefin resin falls within the above range, good push-out property tends to be easily exhibited. Further, particularly when the content of the polyolefin resin is 100% by mass, the lid material has excellent recyclability.

[0015] <<Polyethylene-based resin>> The polyethylene-based resin is not particularly limited, and may be either an ethylene homopolymer or a copolymer of ethylene and another monomer. Examples thereof include ethylene homopolymers; ethylene-α-olefin copolymers such as ethylene-propylene copolymers, ethylene-butene copolymers, and ethylene-octene copolymers; ethylene-(meth)acrylic acid ester copolymers such as ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, and ethylene-ethyl acrylate-methyl methacrylate copolymers; and ethylene-vinyl acetate copolymers. Among these, ethylene homopolymers are preferable, since the puncture breaking elongation tends to decrease as the density increases. Further, from the viewpoint of environmental friendliness, the polyethylene-based resin may be bio-based polyethylene. Furthermore, the polyethylene-based resin may be used alone, or two or more types may be used in combination.

[0016] The weight average molecular weight (Mw) of the polyethylene-based resin is 3.5×10 4 to 5.2×10 4 , preferably 3.8×10 4 to 4.7×10 4 , more preferably 4.0×10 4 to 4.5×10 4Polyethylene resins with a weight-average molecular weight within the above range are not normally used for films due to their fragility. However, in the PTP lid material of this embodiment, this fragility is utilized, resulting in a tendency for excellent extrusion properties. Furthermore, by using polyethylene resins with a weight-average molecular weight within the above range, it is not necessary to degrade the resin by irradiation with radiation as in Patent Document 1. This avoids the generation of unpleasant odors due to resin decomposition during radiation irradiation, as well as the reduction in recyclability and sealing performance due to crosslinking of reinforcing resin layers, etc. The weight-average molecular weight can be measured using gel permeation chromatography (hereinafter also referred to as "GPC"), and specifically, it can be measured by the method described in the examples below.

[0017] The polyethylene resin content is preferably 60 to 100% by mass, more preferably 70 to 95% by mass, and even more preferably 75 to 90% by mass, with the polyolefin resin content being 100% by mass. When the polyethylene resin content is within the above range, it tends to exhibit good ejection properties. In particular, when the polyethylene resin content is 100% by mass, it results in a lid material with excellent recyclability.

[0018] The method for producing polyethylene resins is not particularly limited, and polymerization can be carried out using known catalysts such as single-site catalysts and multi-site catalysts.

[0019] <<Polypropylene resin>> Examples of polypropylene resins include propylene homopolymers, copolymers of propylene and other monomers, and modified products thereof. Among these, propylene homopolymers are preferred from the viewpoint of heat resistance, water vapor barrier properties, and puncture break elongation. Furthermore, from an environmental perspective, bio-polypropylene may be used. In addition, polypropylene resins may be used individually or in combination of two or more types.

[0020] Examples of monomers copolymerizable with propylene include ethylene, 1-butene, isobutylene, 1-pentene, 1-hexene, and other α-olefins. The polymerization form is not particularly limited and may be random copolymer, block copolymer, etc.

[0021] The method for producing polypropylene resins is not particularly limited, and known methods such as polymerizing propylene or other monomers in the presence of a catalyst can be used. Specifically, for example, a method can be used in which propylene or other monomers are polymerized in the presence of a catalyst and an alkylaluminum compound at a polymerization temperature of 0 to 100°C and a polymerization pressure of 3 to 100 atmospheres. Examples of the catalysts mentioned above include titanium trichloride catalysts and titanium halide catalysts supported on a support such as magnesium chloride. A chain transfer agent such as hydrogen may be added to adjust the molecular weight of the polymer.

[0022] In the production of polypropylene resins, in addition to the catalyst mentioned above, an electron-donating compound can be used as an internal or external donor component as a third component to enhance the isotacticity and polymerization activity of polypropylene. The electron-donating compound is not particularly limited and any known compound can be used, such as ester compounds such as ε-caprolactone, methyl methacrylate, ethyl benzoate, and methyl toluate; phosphite esters such as triphenyl phosphite and tributyl phosphite; phosphoric acid derivatives such as hexamethylphosphoric triamide; alkoxyester compounds; aromatic monocarboxylic acid esters; aromatic alkylalkoxysilanes; aliphatic hydrocarbon alkoxysilanes; various ether compounds; various alcohols; and various phenols.

[0023] The polymerization method in the above method may be either batch or continuous. Examples of polymerization methods include solution polymerization under solvents such as butane, pentane, hexane, heptane, and octane; slurry polymerization; bulk polymerization in monomers under solvent-free conditions; and gas-phase polymerization in gaseous monomers.

[0024] Polypropylene resins may be obtained by modifying an unmodified polypropylene resin with a modifying agent such as an α,β-unsaturated carboxylic acid or its derivatives (including acid anhydrides and esters). Examples of modified polypropylene resins include those obtained by grafting or adding an α,β-unsaturated carboxylic acid or its derivative to an unmodified polypropylene resin. Specific examples include those in which an α,β-unsaturated carboxylic acid or its derivative is grafted or added to the polypropylene resin in a proportion of approximately 0.01 to 10% by mass of the total polypropylene resin. Modified polypropylene resins are obtained, for example, by reacting an unmodified polypropylene resin with a modifying agent in a molten state, a solution state, or a slurry state, with or without a radical generating agent, at a temperature in the range of 30 to 350°C.

[0025] When the polypropylene resin is a mixture of unmodified polypropylene and modified polypropylene, the mixing ratio of unmodified polypropylene to modified polypropylene is not particularly limited and may be any ratio.

[0026] The weight-average molecular weight (Mw) of polypropylene resin is 2.0 × 10⁻⁶. 5 ~3.5×10 5 Preferably, it is 2.2 × 10 5 ~3.2×10 5 More preferably 2.3 × 10 5 ~3.0×10 5 Polypropylene resins with a weight-average molecular weight within the above range are not normally used in films due to their fragility, but in the PTP lid material of this embodiment, this fragility is utilized to achieve excellent extrusion properties. Furthermore, by using a polypropylene resin with a weight-average molecular weight within the above range, it is not necessary to degrade the propylene resin by irradiation with radiation as in Patent Document 1, thus avoiding the generation of unpleasant odors due to resin decomposition during radiation irradiation, as well as the reduction in recyclability and sealing performance due to crosslinking of reinforcing resin layers, etc. The weight-average molecular weight can be measured using GPC, specifically by the method described in the examples below.

[0027] The content of the above polypropylene resin is calculated with polyolefin resin as 100% by mass. The polypropylene resin content is preferably 60-100% by mass, more preferably 70-95% by mass, and even more preferably 75-90% by mass. When the polypropylene resin content is within the above range, it tends to exhibit good ejection properties. In particular, when the polypropylene resin content is 100% by mass, it results in a lid material with excellent recyclability.

[0028] The PTP lid material of this embodiment may be a laminate having a layer containing the polyolefin resin described above (hereinafter also referred to as the "polyolefin resin layer"). Other layers laminated on the polyolefin resin layer include, for example, a sealing layer to improve sealing performance with the bottom material for PTP, an adjustment layer to adjust the physical properties of the lid material such as strength and protrusion, a reinforcing layer to prevent film tearing during packaging, and a barrier layer to improve gas barrier properties. The number of layers is not particularly limited, but from the viewpoint of balancing strength, extrusion resistance, water vapor barrier properties, sealing properties, and recyclability, it is preferably 2 to 5 layers, and more preferably 2 to 3 layers.

[0029] The thickness of the polyolefin resin layer is preferably 60-95%, more preferably 70-95%, and even more preferably 75-90%, with the total thickness of the PTP lid material being 100%. When the thickness of the polyolefin resin layer is within the above range, it tends to exhibit good extrusion properties and water vapor barrier properties.

[0030] In one embodiment, the PTP lid material of this embodiment may include a polyolefin resin layer containing the polyethylene resin or polypropylene resin described above, and at least one surface layer containing polyethylene resin, polypropylene resin, or polyolefin elastomer. The surface layer may be either the surface layer on the bottom material side that is bonded to the bottom material, or the outer surface layer (outermost layer), or both. For example, the outer surface layer may serve as a reinforcing layer to prevent film tearing during packaging. Furthermore, by including polyethylene resin, polypropylene resin, or polyolefin elastomer, the surface layer exhibits excellent heat-sealing properties, and since these resins are co-extrudeable, the application of emulsion-type heat sealants becomes unnecessary, and unpleasant odors are not generated even in high-temperature environments, making it suitable as the surface layer on the bottom material side that is bonded to the bottom material. In particular, a layer containing polyolefin elastomer is preferred because it exhibits excellent low-temperature sealing properties, and from the viewpoint of recyclability, it is preferable that the layer contains polyethylene resin or polypropylene resin so that the entire PTP lid material is composed of polyethylene resin or polypropylene resin. The thickness of the surface layer is preferably 5 to 40%, more preferably 5 to 30%, and even more preferably 10 to 25%, with the total thickness of the PTP lid material being 100%. When the thickness of the surface layer is within the above range, good heat sealability can be provided without worsening the protrusion properties, and film tearing can be prevented.

[0031] The polyethylene resin contained in the surface layer described above can be of the same type as the polyethylene resin described above. Among these, ethylene-α-olefin copolymer is preferred from the viewpoint of excellent low-temperature sealing performance. Furthermore, from the viewpoint of environmental considerations, biopolyethylene may also be used. The molecular weight of the polyethylene resin is not particularly limited, but it is preferably higher than that of the polyethylene resin contained in the polyolefin resin layer mentioned above. For example, a polyethylene resin with a melt flow rate (MFR, measured at 190°C and a load of 2.16 kgf in accordance with ASTM D-1238) of 1.5 to 6 g / 10 min is suitable. Polyethylene resins may be used individually or in combination of two or more types.

[0032] The polypropylene resin contained in the surface layer described above can be of the same type as the polypropylene resin described above. Among these, low-density propylene-α-olefin copolymer is preferred from the viewpoint of excellent low-temperature sealing performance. Furthermore, from the viewpoint of environmental considerations, bio-polypropylene may also be used. The molecular weight of the polypropylene resin is not particularly limited, but it is preferably higher than that of the polypropylene resin contained in the polyolefin resin layer mentioned above. For example, a polypropylene resin with a melt flow rate (MFR, measured at 230°C and a load of 2.16 kgf in accordance with ASTM D-1238) of 3 to 15 g / 10 min is suitable. Polypropylene resins may be used individually or in combination of two or more types.

[0033] Polyolefin elastomers are low-crystallinity or amorphous olefin polymers with a crystallinity of 50% or less. Examples of monomers (olefins) for polyolefin elastomers include α-olefins such as ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-butene, 2-methyl-1-butene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, as well as cyclic olefins such as cyclobutene, cyclopentene, and cyclohexene. In particular, polypropylene elastomers with a low melting point (55-90°C) are preferred due to their excellent low-temperature sealing properties. Furthermore, from an environmental perspective, bio-polyolefin elastomers may also be used. In addition, polyolefin elastomers may be used individually or in combination of two or more types.

[0034] The method for producing polyolefin elastomers is not particularly limited, and polymerization can be carried out using known catalysts such as single-site catalysts and multi-site catalysts.

[0035] The polyolefin elastomer content is preferably 5 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass, with the PTP lid material being 100% by mass. When the polyolefin elastomer content is within the above range, good heat sealability can be provided without deteriorating the extrusion properties, and film tearing can be prevented.

[0036] In another embodiment, the PTP lid material of this embodiment may include an adjustment layer between the polyolefin resin layer and the surface layer for adjusting the physical properties of the lid material, such as strength and protrusion. The thickness of the adjustment layer is preferably 10-40%, more preferably 15-35%, and even more preferably 20-30%, with the total thickness of the PTP lid material being 100%.

[0037] From the viewpoint of recyclability, it is preferable to use a polyolefin resin for the above-mentioned adjustment layer. Examples of polyolefin resins include those similar to the polyethylene resins or polypropylene resins mentioned above. The molecular weight of the polyolefin resin is not particularly limited, but it is preferably higher than that of the polyolefin resin contained in the polyolefin resin layer described above. For example, if the polyolefin resin is a polyethylene resin, a melt flow rate (measured at 190°C and a load of 2.16 kgf according to MFR, ASTM D-1238) of 1.5 to 6 g / 10 min is appropriate. If the polyolefin resin is a polypropylene resin, a melt flow rate (measured at 230°C and a load of 2.16 kgf according to MFR, ASTM D-1238) of 3 to 15 g / 10 min is appropriate. Polypropylene resins may be used individually or in combination of two or more types.

[0038] <Inorganic substances> The PTP lid material of this embodiment may contain inorganic materials in order to increase the fracture initiation point and improve the protrusion properties. The inorganic materials are not particularly limited and include, for example, amorphous alumina silicates, silica, alumina, talc, kaolin, mica, wollastonite, clay, calcium carbonate, glass fibers, aluminum sulfate, etc.

[0039] The inorganic content is preferably 0.1 to 3% by mass, more preferably 0.3 to 2% by mass, and even more preferably 0.5 to 1% by mass, based on 100% by mass of the PTP lid material. When the inorganic content is within the above range, the lid material exhibits good ejection properties, has few impurities, and is highly recyclable.

[0040] The PTP lid material of this embodiment may contain additives commonly used in the art, such as metal soaps that aid in the dispersion of the inorganic substances, colorants, plasticizers, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, antistatic agents, crystal nucleating agents, and the like. Furthermore, the PTP lid material of this embodiment may be subjected to treatments such as corona treatment, plasma treatment, ultraviolet treatment, and AC (anchor coat) treatment for the purpose of improving printing characteristics. In particular, white colorants and printing are preferred for the following reasons. In recent years, there has been a growing need for PTP packaging for pharmaceuticals to include barcodes containing various information such as product codes, expiration dates, manufacturing numbers, and quantities, in addition to the conventional product name logo and illustrations showing how to use the product, for the purpose of preventing medical errors and ensuring traceability. When using lid materials containing white colorants or white printing, the areas without lines (the parts of the lid material that are directly visible) are white, creating a contrast in color between these areas and the lines of the barcode (generally black), making the barcode easier to read. The additive content is preferably 3% by mass or less, with the PTP lid material being 100% by mass.

[0041] The resin contained in the PTP lid material of this embodiment preferably has a molecular weight distribution (Mw / Mn), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), of 4.0 to 7.0, more preferably 4.2 to 6.5, and even more preferably 4.5 to 6.0. When the molecular weight distribution of the resin contained in the PTP lid material is 4.0 or higher, the heat of fusion of crystals tends to be large (high degree of crystallinity), and when the molecular weight distribution is 7.0 or lower, the ejection properties tend to be good. Furthermore, the molecular weight distribution can be measured using GPC, and specifically, it can be measured by the method described in the examples below.

[0042] The thickness of the PTP lid material in this embodiment is preferably 10 to 100 μm, more preferably 30 to 80 μm, and even more preferably 40 to 60 μm. A thickness of 10 μm or more makes it easier to exhibit tensile strength and water vapor barrier properties that can withstand the processing steps, while a thickness of 100 μm or less makes it easier to exhibit good protrusion properties.

[0043] The lid material for PTP in this embodiment has an ignition residue of less than 5% by mass, preferably 3% by mass or less, and more preferably 1% by mass or less. When the ignition residue is within the above range, the amount of fillers and other substances contained in the PTP lid material is small, resulting in excellent recyclability. There are no particular restrictions regarding the lower limit of the ignition residue. The ignition residue can be measured by the method described in the examples below.

[0044] The lid material for PTP in this embodiment has a gloss value of 70% or less at measurement angles of 20°, 45°, 60°, 75°, and 85°, preferably 60% or less, more preferably 45% or less, and even more preferably 40% or less. When the gloss value at measurement angles of 20°, 45°, 60°, 75°, and 85° is within the above range, the gloss is low, and the readability of the printed portion (barcode, QR code, etc.) from all angles is improved. There are no particular restrictions on the lower limit of the gloss value, but it is preferably 5% or more. Methods for controlling the above-mentioned gross value include, for example, adjusting the type of resin and the cooling of the lid material during manufacturing for PTP. For example, the gross value can be reduced by selecting a resin with high crystallinity or by slowing down the cooling process when manufacturing the PTP lid material using the direct inflation method. The gloss value (glossiness) can be measured using a gloss meter in accordance with JIS Z8741-1997, and specifically, it can be done by the method described in the examples below.

[0045] In this embodiment, the PTP lid material preferably has a maximum reflectance of 20 to 150, more preferably 25 to 100, and even more preferably 30 to 50, when measured with a variable-angle photometer using light at an incident angle of 15°. When the maximum reflectance is 20 or higher, the reflectance is sufficient at all angles, and when the maximum reflectance is 150 or lower, the occurrence of saturation is suppressed, and the readability of the printed portion (barcode, QR code, etc.) from all angles tends to improve. Furthermore, the PTP lid material of this embodiment preferably has a half-width of 10° or more in a variable-angle photometer measurement using light at an incident angle of 15°, and more preferably... The angle is 12-25°, more preferably 15-22°. When the maximum reflectance is within this range, scattered light spreads over a wide area, making the printed portion (barcode, QR code, etc.) easier to read from any direction. The full width at half maximum (FWHM) of the reflection intensity distribution was calculated as the difference between θ1 and θ2, where θ1 is the larger of the two reflection angles that result in half the maximum reflection intensity, and θ2 is the smaller of the two reflection angles. Angle-shifting photometer measurement using light with an incident angle of 15° can be performed specifically by the method described in the examples below.

[0046] In this embodiment, the lid material for PTP preferably has an a* value of -12 to 10, which is an indicator of redness, and a b* value of -10 to 15, which is an indicator of yellowness, in the (L*, a*, b*) color space. More preferably, the a* value is -8 to 6 and the b* value is -6 to 8, and even more preferably, the a* value is -5 to 3 and the b* value is -3 to 4. When the a* and b* values ​​are within the above ranges, the contrast is clearer, which tends to make printed areas (barcodes, QR codes, etc.) easier to read. The a* and b* values ​​in the (L*, a*, b*) color space can be measured using a colorimeter, specifically by the method described in the examples below.

[0047] The PTP lid material of this embodiment preferably has a haze of 50% or more, more preferably 60% or more, and even more preferably 70% or more. When the haze is within the above range, the printed surface of the PTP lid material is less affected by the opposite surface, and the printed portion (barcode, QR code, etc.) tends to become easier to read. There are no particular restrictions on the upper limit of the haze, but it is preferably 99% or less. The haze is a value measured in accordance with JIS-K-7136, and can be specifically measured by the method described in the examples below.

[0048] The lid material for PTP in this embodiment preferably has an arithmetic mean roughness Ra of 0.2 μm or more on the printed surface, more preferably 0.25 μm or more, and even more preferably 0.3 μm or more. When the arithmetic mean roughness Ra is within the above range, the surface of the printed surface tends to be rough and light tends to scatter easily. There are no particular restrictions on the upper limit of the arithmetic mean roughness Ra of the printed surface, but it is preferably 1.0 μm or less. Methods for controlling the arithmetic mean roughness Ra of the printed surface include, for example, selecting resins with different polymerization catalysts or polymerization methods, and changing the weight-average molecular weight. As an example, the arithmetic mean roughness Ra of the printed surface can be increased by increasing the weight-average molecular weight. The arithmetic mean roughness Ra can be calculated using the method described in the examples below.

[0049] The lid material for PTP in this embodiment is an olefin resin with a weight-average molecular weight of 3.5 × 10 4 ~5.2×10 4 When a polyethylene-based resin is included, the heat of fusion of the crystals, as measured by differential scanning calorimeter (DSC), is preferably 130 J / g or more, more preferably 145 to 290 J / g, and even more preferably 160 to 290 J / g. When the heat of fusion of the crystals is within the above range, the elongation at puncture fracture is favorable, and the material tends to exhibit good extrusion properties. Furthermore, the PTP lid material of this embodiment is an olefin resin with a weight-average molecular weight of 2.0 × 10 5 ~3.5×10 5 When a polypropylene-based resin is included, the heat of fusion of the crystals, as measured by differential scanning calorimeter (DSC), is preferably 70 J / g or more, more preferably 75 to 200 J / g, and even more preferably 80 to 200 J / g. When the heat of fusion of the crystals is within the above range, the elongation at puncture fracture is favorable, and the material tends to exhibit good thrust properties. Methods for controlling the heat of fusion of crystals in PTP lid materials include, for example, adjusting the cooling of the lid material during manufacturing, annealing after manufacturing, and the addition of a crystal nucleating agent. As an example, the heat of fusion can be increased by slowing down the cooling process when manufacturing PTP lid materials by the direct inflation method, annealing the lid material after manufacturing, and adding a crystal nucleating agent. Furthermore, the measurement of the heat of fusion of crystals using a differential scanning calorimeter (DSC) can be specifically performed by the method described in the examples below.

[0050] The MD orientation of the PTP lid material in this embodiment is preferably -0.035 to 0.035, more preferably -0.03 to 0.03, even more preferably -0.025 to 0.025, and even more preferably -0.02 to 0.02. When the MD orientation is within the above range, it tends to exhibit good protrusion properties. Methods for controlling the degree of MD orientation of PTP lid material include, for example, adjusting the cooling of the lid material during manufacturing, the TD stretching ratio (BUR), or the timing. As an example, when manufacturing PTP lid material by the direct inflation method, the degree of MD orientation can be reduced by slowing down the cooling of the lid material with an air ring, increasing the TD stretching ratio (BUR), or manufacturing by sequential secondary stretching. The degree of MD orientation can be measured using FT-IR, and specifically, it can be measured by the method described in the examples below. Furthermore, since the MD orientation degree indicates the orientation toward MD relative to TD, it can also be calculated from the results of measuring the orientation toward MD in the thickness direction and the orientation toward TD in the thickness direction of the PTP lid material, respectively. In this case, if the PTP lid material has a multilayer structure, the thickest layer has the greatest influence on the properties of the PTP lid material, so it is sufficient to measure the orientation degree of the thickest layer (or any of the thickest layers if there are multiple thickest layers). Furthermore, the degree of MD orientation can also be measured using a Raman microscope, similar to the method used with FT-IR.

[0051] In the load-displacement curve during a puncture test of PTP lid material, the maximum load reduction per 0.1 mm of displacement in the fracture region is preferably 3 to 20 N, more preferably 4 to 18 N, and even more preferably 5 to 15 N. PTP lid material with a maximum load reduction of more than 20 N per 0.1 mm of displacement indicates that it is less likely to tear when removing contents such as tablets from the PTP packaging, and tends to have poor puncture resistance. Furthermore, the maximum load reduction per 0.1 mm of displacement is one of the factors that most affects the ease of opening, and if the maximum load reduction per 0.1 mm of displacement is less than 3 N, it indicates that the PTP lid material is brittle, and there is almost no sound when removing contents such as tablets, and it tends to have poor ease of opening. Figure 2 shows an example of a load-displacement curve obtained when a puncture test is performed on the PTP lid material of this embodiment. In the case of the PTP lid material in Figure 2, the maximum load reduction per 0.1 mm of displacement is 8 N. As a method for controlling the maximum load reduction per 0.1 mm displacement of a PTP lid material, examples include a method of adjusting the weight average molecular weight of a polypropylene-based resin, the thickness of the PTP lid material, and the reinforcing layer. Increasing the weight average molecular weight of the polypropylene-based resin, increasing the thickness of the PTP lid material, or providing a reinforcing layer can increase the maximum load reduction per 0.1 mm displacement. Note that the maximum load reduction per 0.1 mm displacement in the breaking region of the load-displacement curve can be specifically measured by the method described in the examples below.

[0052] The puncture breaking elongation of the PTP lid material of the present embodiment is preferably less than 3.2 mm, more preferably from 1 to 2.9 mm, and still more preferably from 1.3 to 2.5 mm. When the puncture breaking elongation is 1 mm or more, the PTP lid material can be prevented from being broken by an external force during transportation of a PTP package or the like. In addition, puncture breaking elongation is one of the factors that most affect push-out properties similarly to tensile elongation, puncture strength, and the like, and when the puncture breaking elongation is less than 3.2 mm, a PTP lid material excellent in push-out properties can be obtained. As a method for controlling the puncture breaking elongation of a PTP lid material, examples include a method of adjusting the weight average molecular weight of a polyolefin-based resin, the layer ratio of the PTP lid material, the heat of crystal fusion (crystallinity), the degree of MD and TD orientation, and the like. When the weight average molecular weight of the polyolefin-based resin is decreased, the proportion of a low-molecular-weight polyolefin-based resin is increased, the heat of crystal fusion (crystallinity) is increased, or the degree of MD and TD orientation is decreased, the puncture breaking elongation tends to decrease. Note that the puncture breaking elongation can be specifically measured by the method described in the examples below.

[0053] <Method for Producing PTP Lid Material> The method for manufacturing PTP lid material is not particularly limited, but one example is the direct inflation method, in which the above-mentioned constituent material is extruded into a tube shape using a known melt extruder equipped with an annular die, then air is blown directly into it to stretch it, and then it is solidified by air cooling to obtain a film. If the PTP lid material is a laminate consisting of multiple layers, the co-extrusion direct inflation method is preferable.

[0054] In the air-cooled solidification process of the direct inflation method described above, it is preferable for the distance from the die lip surface of the annular die to the frost line (the distance of the cooling section) to be greater. When the distance from the die lip surface to the frost line is greater, the film extruded from the annular die cools more slowly, which is thought to increase the amount of heat required for crystal fusion (resulting in higher crystallinity) and larger crystal size. This makes light more easily scattered, Correspondingly, gloss is reduced, and print readability is improved. For example, when the die cap is 1 to 4 mm and the die lip outer diameter is 100 to 150 mm, the distance from the die lip surface of the annular die to the frost line (cooling section distance) is preferably 30 to 100 cm, more preferably 50 to 90 cm, and even more preferably 60 to 80 cm. In the examples described later, the extrusion rate was set to 18 kg / hr, the die gap to 3 mm, and the die lip outer diameter to 125 mm. Furthermore, the frost line refers to the white boundary line that forms when the constituent material extruded in a tubular shape from the annular die cools and solidifies, due to the density difference between it and the molten resin. This corresponds to the position where stretching in the MD and TD directions ends.

[0055] The following outlines the method for manufacturing laminated PTP lid material using the co-extrusion direct inflation method.

[0056] The resin or resin composition that is the constituent material of each layer is melted at a temperature equal to or higher than the melting temperature of the resin, and each layer is extruded simultaneously using a number of extruders corresponding to the number of layers. The extruded resin or resin composition of each layer is fed to an annular die through a feed pipe, and a tubular film in which each layer is laminated is produced through the annular die. Although there are no particular restrictions, as an example, as described above, the extrusion rate is 18 kg / hr, the die gap is 3 mm, and the outer diameter of the die lip is 125 mm. Subsequently, air (such as air or nitrogen) is blown into the film to form bubbles, and the film is stretched in the MD and TD directions and solidified by air cooling, thereby producing a lid material for PTP. In solidification by air cooling, the distance from the die lip surface of the annular die to the frost line is preferably 30 to 100 cm as described above. There are no particular restrictions on the stretching temperature of the film, and it may be adjusted appropriately so that the distance from the die lip surface to the frost line falls within the above-described preferred range.

[0057] The MD draw ratio (DDR) of the film is preferably 8 to 23 times, more preferably 10 to 20 times. When the MD draw ratio is 8 times or more, bubble pulsation is suppressed, and stretching tends to be stabilized. In addition, when the MD draw ratio is 23 times or less, the MD orientation degree is suitable, the balance between the MD and TD orientation degrees is excellent, and a lid material exhibiting excellent push-out property can be obtained. In addition, the TD draw ratio (BUR) of the film is preferably 1.3 to 4 times, more preferably 1.5 to 2.5 times. When the TD draw ratio is 1.3 times or more, the MD orientation degree is suitable, the balance between the MD and TD orientation degrees is excellent, and a lid material exhibiting excellent push-out property can be obtained. In addition, when the TD draw ratio is 4 times or less, bubble pulsation is suppressed, and stretching tends to be stabilized. Note that the MD draw ratio can be adjusted by the speed of the pinch rollers, and the TD draw ratio can be adjusted by the volume of air blown into the film.

[0058] <PTP package> The PTP packaging of this embodiment is characterized by including the PTP lid material of this embodiment described above and a bottom material having a recess for containing the contents. Figure 1 is a cross-sectional view showing an example of a PTP packaging body equipped with a PTP lid material according to this embodiment. The PTP packaging body 1 comprises a PTP lid material 2 and a bottom material 3. The bottom material 3 has a pocket-shaped recess 4 and a flange portion 5 that is bonded to the lid material 2, and the recess 4 is filled with contents 6.

[0059] <Bottom material> Examples of sheet materials that make up the bottom material of the PTP packaging in this embodiment include sheet materials containing well-known synthetic resins such as polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin (e.g., polyethylene resin, polypropylene resin, ethylene-vinyl alcohol copolymer resin, cyclic olefin resin, etc.), polychlorotrifluoroethylene, and polyester, and preferably sheet materials made of these synthetic resins. In particular, from the viewpoint of recyclability, it is preferable to include polyethylene resin, polypropylene resin, and cyclic olefin resin, and it is most preferable to use the same resin as the PTP lid material.

[0060] From the viewpoint of providing a wide range of molding conditions for vacuum or pressure forming the pocket-shaped recesses of the base material, the heat distortion temperature of the base material is preferably 50 to 160°C, and more preferably 80 to 120°C, in accordance with JIS K7191.

[0061] The shape of the base material is not particularly limited as long as it has a recess for accommodating contents, and the shape of the bottom portion of the recess and the opening portion may be rectangular (square, rectangle, triangle, etc.) or circular (circle, ellipse, etc.), and the corners of the rectangle may be rounded.

[0062] The size of the base material is not particularly limited, and may be appropriately determined according to the size, number and the like of the contents. For example, the depth of the recessed portion may be 1 to 15 mm, and preferably 2 to 10 mm. Further, particularly when the opening portion and the bottom surface portion of the recessed portion are circular in shape, the diameter of the opening portion may be, for example, 5 to 150 mm each, preferably 10 to 100 mm, and the diameter of the bottom surface portion may be 5 to 20% smaller than the diameter of the opening portion, respectively.

[0063] Further, the flange portion, which is a portion other than the recessed portion, is not particularly limited, and may be provided so as to extend in a direction orthogonal to the depth direction of the recessed portion. The average width of the flange portion may be, for example, 2 to 100 mm, and preferably 4 to 50 mm.

[0064] The thickness of the base material 1 is not particularly limited, and may be, for example, 100 to 500 µm, preferably 150 to 300 µm.

[0065] <Method for Producing PTP Package>[==============================================================================================================================================================================] The PTP package according to the present embodiment can be produced by stacking the surface (flange portion) of the base material and the surface of the lid material on each other and heat-sealing the stacked surfaces. For example, the heat sealing temperature is 80 to 160°C, and 90 to 150°C is preferable from the viewpoint that burn marks are less likely to be formed on the contents. Further, for example, the heat sealing time is 0.05 to 3 seconds, and 0.2 to 1 second is preferable from the viewpoints that burn marks are less likely to be formed on the contents and sufficient sealing strength can be obtained. Further, for example, the heat sealing pressure is 0.2 to 0.6 MPa, and 0.3 to 0.5 MPa is preferable from the viewpoints that burn marks are less likely to be formed on the contents and sufficient sealing strength can be obtained.

[0066] Examples of molding machines used to form the PTP packaging in this embodiment include a roll seal molding machine that heat-seals the lid material and bottom material by sandwiching them between a heat seal roll and a sealing lower roll, and a flat seal molding machine that has flat heating molds on the top and bottom and forms the lid material and bottom material by sandwiching them between the molds. Among these, it is preferable to use a flat seal molding machine that can easily obtain sufficient seal strength. [Examples]

[0067] The following describes this embodiment with reference to specific examples and comparative examples, but this embodiment is not limited to these.

[0068] The raw materials used in the examples and comparative examples are as follows: <Polypropylene resin (PP)> • PP1: Polypropylene (manufactured by Sun Allomer Co., Ltd., PLB00A, weight-average molecular weight: 2.2 × 10⁻⁶) 5 ) • PP2: Polypropylene (manufactured by Sun Allomer Co., Ltd., PLA00A, weight-average molecular weight: 2.6 × 10⁻⁶) 5 ) • PP3: Polypropylene (manufactured by Sun Allomer Co., Ltd., VS700A, weight-average molecular weight: 3.8 × 10⁻⁶) 5 ) • PP4: Polypropylene (manufactured by Sun Allomer Co., Ltd., PL500A, weight-average molecular weight: 6.0 × 10) 5 )

[0069] <Polyethylene resin (PE)> • PE1: Polyethylene (manufactured by Asahi Kasei Corporation, Suntech HD J300, weight-average molecular weight: 4.0 × 10) 4 ) • PE2: Polyethylene (manufactured by Asahi Kasei Corporation, Suntech HD J311, weight-average molecular weight: 4.9 × 10⁻⁶) 4 ) • PE3: Polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., Yumerit 0520F, weight-average molecular weight: 6.0 × 10) 4 ) • PE4: Polyethylene (manufactured by Asahi Kasei Corporation, Suntech HD B161, weight-average molecular weight: 1.4 × 10⁻⁶) 5 )

[0070] <Crystallizing agent> • Masterbatch for crystallization nucleating agent for polyethylene (manufactured by Riken Vitamin Co., Ltd., Rikemaster CN-002)

[0071] <Polyolefin-based elastomer (TPO)> • TPO1: Propylene-α-olefin copolymer (manufactured by Mitsui Chemicals, Inc., Toughmer XM7070S) • TPO2: Ethylene-α-olefin copolymer (manufactured by Mitsui Chemicals, Inc., Tuffmer A4085S)

[0072] <Ethylene-vinyl acetate copolymer (EVA)> • Ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation, UltraCen 634)

[0073] <Polystyrene resin (PS)> • Styrene-methacrylate-methyl methacrylate copolymer (manufactured by PS Japan Co., Ltd., MM290)

[0074] <Inorganic substances> • Amorphous aluminosilicate (manufactured by Mizusawa Chemical Industries, Ltd., Silton JC-70) • Titanium dioxide (manufactured by Ishihara Sangyo Co., Ltd., rutile type, particle size 0.25 μm)

[0075] <others> • Aluminum foil (manufactured by Toyo Aluminum Co., Ltd.)

[0076] <Bottom material> ·PP: A single-layer sheet with a thickness of 300 μm was prepared by co-extrusion direct inflation using the polypropylene (Sun Allomer Co., Ltd., PL500A) 80 parts by mass and polypropylene (Sun Allomer Co., Ltd., PC540R) 20 parts by mass. Subsequently, it was molded into a base material with a depth of 4 mm, a circular opening with a diameter of 10 mm, a circular recess with a diameter of 8 mm at the bottom, and a flange portion with an average width of 10 mm extending in a direction perpendicular to the depth direction. The openings were arranged in mutually perpendicular vertical and horizontal rows, and the distance between the centers of the openings was 20 mm vertically and 20 mm horizontally. • PP / PE: A 300 μm thick multilayer sheet was fabricated by co-extrusion direct inflation using polypropylene (Sun Allomer Co., Ltd., PL500A), polypropylene (Sun Allomer Co., Ltd., PC540R), and polyethylene (Ube Maruzen Polyethylene Co., Ltd., Yumerit 0520F) in that order. Subsequently, the polyethylene side of the multilayer sheet was used as the heat-sealed surface and molded in the same manner as the polypropylene single-layer sheet described above. • PVC: A single-layer polyvinyl chloride sheet (Sumilight VSS-F110 (thickness 250 μm) manufactured by Sumitomo Bakelite Co., Ltd.) was used and molded in the same manner as the single-layer polypropylene sheet described above.

[0077] The measurement and evaluation methods used in the examples and comparative examples are described below.

[0078] [Weight-average molecular weight of polypropylene resins] The weight-average molecular weight (Mw) of the polypropylene resin used for the PTP lid material was measured using the following procedure. First, 1,2,4-trichlorobenzene was added to the sample to a concentration of 1 mg / mL, and after standing at 160°C for 30 minutes, it was dissolved by shaking at 160°C for 1 hour. The dissolved solution was filtered through a 0.5 μm PTFE filter, and the weight-average molecular weight in polystyrene equivalent was determined using GPC (Agilent, PL-GPC220). The column used for the measurement was TSK-gelGMH manufactured by Tosoh Corporation. HRTwo -H(20)HT (7.8mm × 30cm) columns were linked together, and the column temperature was set to 160°C.

[0079] [Weight-average molecular weight of polyethylene resins] The weight-average molecular weight (Mw) of the polyethylene resin used for the PTP lid material was measured using the following procedure. First, o-dichlorobenzene was added to the sample to a concentration of 1.3 mg / mL, and the mixture was stirred at 150°C for 1 hour to dissolve. The weight-average molecular weight was then measured using GPC (Waters 150-C ALC / GPC). Separately, the polyethylene-equivalent molecular weight was obtained by multiplying the Mw of commercially available standard polystyrene by a coefficient of 0.43, and a primary calibration curve was created from the plot of elution time and polyethylene-equivalent molecular weight. Based on the GPC measurement results and the above calibration curve, the weight-average molecular weight was determined. The column used for the measurement consisted of one AT-807S manufactured by Showa Denko K.K. and two TSK-gel GMH-H6 manufactured by Tosoh Corporation linked together, and the column temperature was 140°C.

[0080] [Molecular weight distribution] For PTP lid materials containing polypropylene resin, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured using the same procedure as described above for [weight-average molecular weight of polypropylene resin], and the molecular weight distribution (Mw / Mn) was determined. Furthermore, for PTP lid materials containing polyethylene resin, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured using the same procedure as described above for [weight-average molecular weight of polyethylene resin], and the molecular weight distribution (Mw / Mn) was determined. Furthermore, for the PTP lid material of Comparative Example 5, which contains both polypropylene resin and polyethylene resin, since polypropylene accounts for the highest proportion among the resins constituting the PTP lid material, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were measured using the same procedure as described above for [weight-average molecular weight of polypropylene resin], and the molecular weight distribution (Mw / Mn) was determined. Furthermore, if the sample did not contain either polypropylene or polyethylene resin, the measurement was performed using a solvent and column appropriate to the constituent resin. For the PTP lid material in Comparative Example 4, the following procedure was followed: First, tetrahydrofuran was added to the sample to a concentration of 1 mg / mL, and it was allowed to stand at room temperature for 1 day to dissolve. The solution was filtered through a 0.45 μm PTFE filter, and the weight-average molecular weight in polystyrene terms was determined using GPC (HLC-8120, manufactured by Tosoh Corporation). The column used for the measurement consisted of two TSK-gelGMHHR-H columns (7.8 mm I.D × 30 cm) connected together, manufactured by Tosoh Corporation, and the column temperature was 40°C.

[0081] [Ignition residue] For PTP lid material, the ignition residue (mass%) was measured using the following procedure. First, 1 g of PTP lid material was placed in a platinum crucible, and the crucible was heated together with the material in an electric furnace (Isuzu Manufacturing Co., Ltd., EPDS-16R) at 500°C for 3 hours. After cooling, the mass of the residue was measured, and the ignition residue was determined by calculating the ratio to 1 g of PTP lid material.

[0082] [Heat of fusion of crystals] Samples (5-10 mg) were cut from PTP lid material and measured using a differential scanning calorimeter (DSC) (Hitachi High-Tech Science Co., Ltd., DSC7000X) under a nitrogen atmosphere, with indium used as the calorimetric standard. The heating program involved heating the sample from 0°C to 200°C at a rate of 10°C / min. The heat of fusion (J / g) was determined by extrapolating the endothermic peaks caused by melting in the resulting heat flow curve from the high-temperature side, using the resulting straight line as the baseline. If multiple endothermic peaks caused by melting were present, the sum of the heats of fusion of each peak was considered the heat of fusion of the PTP lid material.

[0083] [MD orientation degree (when polypropylene resin is included)] The degree of MD orientation of PTP lid materials was measured using a Fourier transform infrared spectrophotometer (JASCO Corporation, FT / IR4100). Measurements were taken for PTP lid materials with grid polarizers at 0° (MD) and 90° (TD), and the results for each polypropylene resin were measured at 973 cm². -1 The degree of MD orientation was determined using the absorbance of the following element and the following formula. Dichroic ratio (R) = absorbance (MD) / absorbance (TD) MD orientation degree=(R-1) / (R+2)×1.17 The measurement process involved 16 cumulative measurements and a resolution of 4 cm. -1 The average value of the measurements taken for the five test specimens was defined as the degree of MD orientation.

[0084] [MD orientation degree (when polyethylene resin is included)] The degree of MD orientation of PTP lid materials was measured using a Fourier transform infrared spectrophotometer (JASCO Corporation, FT / IR4100). Measurements were taken for PTP lid materials with grid polarizers at 0° (MD) and 90° (TD), and the 720 cm² values ​​were measured for each polyethylene resin. -1 The degree of MD orientation was determined using the absorbance of the following element and the following formula. Dichroic ratio (R) = absorbance (TD) / absorbance (MD) MD orientation degree=(R-1) / (R+2) The number of cumulative measurements during the measurement was 32, and the resolution was 2 cm. -1 The average value of the measurements taken for the five test specimens was defined as the degree of MD orientation.

[0085] [Puncture break elongation] The puncture fracture elongation of the PTP lid material was measured using the following procedure. The PTP lid material was fixed in place, stretched over a 10mm diameter frame. A 4mm diameter needle with a flat tip was attached to a precision universal testing machine (Shimadzu Corporation, Autograph) and pressed into the fixed PTP lid material to perform a puncture test. Measurements were taken at a temperature of 23°C and a humidity of 50%RH, with a needle movement speed of 50mm / min. The depth of the needle tip position at the time of tearing (the displacement from the needle's contact with the fixed PTP lid material to its position at the time of tearing) was defined as the puncture fracture elongation (mm). The values ​​measured for five test pieces were averaged to determine the puncture fracture elongation of the PTP lid material.

[0086] [Reduction in maximum load at fracture during puncture test] For PTP lid materials, the load reduction at the time of fracture in a puncture test was measured using the following procedure. A PTP lid was fixed in place, stretched over a 10mm diameter frame. A 4mm diameter needle with a flat tip was attached to a precision universal testing machine (Shimadzu Corporation, Autograph) and pressed into the fixed PTP lid to perform a puncture test. Measurements were taken at a temperature of 23°C and a humidity of 50%RH, with a needle movement speed of 50mm / min. In the fracture region of the obtained load-displacement curve (the load reduction associated with fracture), the value at which the load reduction per 0.1mm displacement was maximum was determined. The values ​​measured for five test pieces were averaged to determine the maximum load reduction per 0.1mm displacement of the PTP lid.

[0087] [Maximum reflectance and full width at half maximum of the reflectance distribution] For the PTP lid material, a three-dimensional variable-angle photometer (GP-200, manufactured by Murakami Color Technology Laboratory Co., Ltd.) was used to measure the maximum reflectance and the full width at half maximum of the reflectance distribution by irradiating the first layer with measurement light. During the measurement, the measurement mode was set to reflection, the incident angle to 15°, the receiving angle to -60 to 90°, the tilt angle to 0°, the diaphragm to 3, the receiving diaphragm to 4, the sensitivity adjustment value (S) to 999, and the sensitivity adjustment value (HV) to 450. The maximum reflected intensity was defined as the value where the reflection and scattering intensity of light was highest relative to the light reception angle. Of the two reflection angles that yield half the maximum reflected intensity, the larger reflection angle was defined as θ1 and the smaller reflection angle as θ2, and θ1-θ2 was defined as the full width at half maximum of the reflected intensity distribution. In each case, measurements were taken on three test specimens, and the average was taken as the maximum reflectance and the full width at half maximum (FWHM) of the reflectance distribution.

[0088] [a* value, b* value] For PTP lid materials, the a* and b* values ​​were measured using a colorimeter (ZE6000, manufactured by Nippon Denshoku Industries, Ltd.) in transmission mode at 23°C and 50%RH. The values ​​measured for three test pieces were averaged to determine the a* and b* values ​​for the PTP lid material.

[0089] [Gross value] For PTP lid material, gloss was measured in accordance with JIS Z8741-1997 at measurement angles of 0°, 45°, 60°, 75°, and 85° from the first layer side, with n=3 measurements. The average of the obtained gloss values ​​was used as the gloss value (%).

[0090] [Haze on PTP lid material] For the PTP lid material, the haze (%) was measured using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS-K-7136.

[0091] [Arithmetic mean roughness Ra of the printed surface] The arithmetic mean roughness Ra (μm) of the printed surface of PTP lid material was measured at three locations using a CNC surface roughness measuring instrument (Mitutoyo Corporation, SURFTEST EXTREME SV-3000 CNC), and the average of the measured values ​​was calculated. During measurement, the reference length was 2.5 mm, the number of intervals was 2, λc was 0.8 mm, λs was 0.008 mm, and the filter selection was Gaussian.

[0092] [Print (QR code) readability] For PTP lid materials, the printed QR code was read 10 times at a 90° angle to the printed surface using a QR code reader (Honeywell Xenon 1950), and the readability of the printed (QR code) was evaluated according to the following evaluation criteria. <Evaluation Criteria> ◎ (Excellent): The QR code reading success rate is 80% or higher. ○ (Good): The QR code reading success rate is between 60% and 80%. × (Failure): The QR code reading success rate is less than 60%.

[0093] [Recyclability] First, the cut PTP lid material was kneaded for 5 minutes at 200°C and 50 rpm using a kneading and extrusion molding evaluation test device (Laboplastmill, manufactured by Toyo Seiki Co., Ltd.). The kneaded material was sandwiched between polyimide film (Kapton, manufactured by Toray DuPont Co., Ltd.), then sandwiched between metal plates, and finally pressed for 90 seconds at 200°C and 20 MPa using a sheet hot press machine (manufactured by Toyo Seiki Co., Ltd.). After that, it was cooled for 1 minute to produce a sheet with a thickness of 90-110 μm. The haze of the press sheet was measured three times using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.), as described above, and the average value was used to evaluate its recyclability according to the evaluation criteria below. <Evaluation Criteria> ○ (Good): Haze is less than 60%. × (Poor): Haze level is 60% or higher.

[0094] [Protruding nature] The puncture break elongation of the PTP lid material and the presence or absence of delamination when the lid material of the PTP packaging is punctured were comprehensively evaluated according to the following evaluation criteria to assess the protrusion properties. <Evaluation Criteria> ◎(Excellent): The puncture break elongation is less than 2.6 mm, and when the lid material of the PTP packaging is punctured, no delamination or partial breakage occurs. ○ (Good): The elongation at puncture break is 2.6 mm or more and less than 3.2 mm, and no delamination or partial breakage occurs when the lid material of the PTP packaging is punctured. × (Defective): The elongation at puncture breakage is 3.2 mm or more, or delamination or partial breakage occurs when the lid material of the PTP packaging is punctured.

[0095] [Opening recognition] For PTP packaging, the sound of opening the lid and removing the contents was measured using a standard sound level meter (NA-29, manufactured by Rion Co., Ltd.), and the recognizability of opening was evaluated according to the following evaluation criteria. When measuring the opening sound, the distance between the microphone tip and the lid to be pierced was set to 30 mm, and the average value of 10 measurements was adopted. <Evaluation Criteria> ◎ (Excellent): 80dB or higher ○ (Good): 60dB or higher, less than 80dB × (Defective): Less than 60dB, or unable to penetrate the lid material.

[0096] [Film odor] The presence or absence of film odor in PTP lid material was measured using dynamic headspace GC / MS (Gestels DHS, Agilent GC-7890 MSD-5977B). Sample preparation involved placing 2 g of PTP lid material in a 20 mL glass vial and heating it at 50°C for 30 minutes. During this time, 1950 mL of nitrogen gas was used to adsorb odor components contained in the PTP lid material onto an activated carbon adsorbent (Agilent, Carbopack B / Carbopack X). After heating, the gas adsorbed on the activated carbon adsorbent was desorbed at 300°C in the TDU section using a thermal desorption device (Gestel, TDU2) installed at the GC / MS inlet. During this time, the gas was reconcentrated at -40°C in the CIS section and heated again to 300°C for GC / MS measurement. Unpleasant odor components in PTP lid materials include acetic acid, butanoic acid, and acetylacetone. Film odor was evaluated as follows, based on the detected amounts of butanoic acid and acetic acid. [Evaluation Criteria] ○ (Good): The amount of butanoic acid detected is less than 0.005 ppm, and the amount of acetic acid detected is less than 0.08 ppm. △ (Poor): Anything other than ○ (Good) above or × (Inferior) below. × (Inferior): The detected amount of butanoic acid is 0.01 ppm or higher, or the detected amount of acetic acid is 0.1 ppm or higher.

[0097] [Example 1] A two-layer PTP lid material was fabricated by laminating a polypropylene resin (PP) layer (first layer) and a polyolefin-based elastomer (TPO) layer (second layer) using the co-extrusion direct inflation method. Specifically, resin pellets, which are the raw materials for each layer, were melted at a temperature above the melting point of the resin, and each layer was simultaneously extruded using multiple extruders (extrusion rate: 18 kg / h). The extruded resin of each layer was fed through a feed pipe to an annular die (lip outer diameter: 125 mm, die gap: 3 mm), and a tubular laminated film was created by stacking each layer via the annular die. The thickness ratio was adjusted so that the PP layer:TPO layer = 80:20. Next, a 40 μm thick PTP lid material was obtained by blowing air into the laminated film and stretching it. The stretching ratios were 30 times for the MD and 2 times for the TD, and the stretching temperature was 61°C. The distance from the die lip surface of the annular die to the frost line was 35 cm. Tablets were filled into the recesses of the PP base material, and the PP base material and the lid material (TPO layer side) were bonded together by heat sealing using an Eishin Pack Sealer (manufactured by Eishin Pack Industries Co., Ltd., semi-automatic OS) to obtain a PTP package. The heat sealing conditions were set to a temperature of 140°C, a pressure of 0.4 MPa, and a time of 1 second. Table 1 shows the measurement and evaluation results for each physical property.

[0098] [Examples 2-7, Comparative Examples 1-4, 6] Examples 2-7 and Comparative Examples 1-4 and 6 were prepared in the same manner as in Example 1, except that the raw materials, formulation amounts, and the distance from the die lip surface of the annular die to the frost line were changed, as shown in Table 1, to obtain PTP packaging. In Example 4 and Comparative Example 6, the first layer was prepared by mixing amorphous aluminosilicate with polypropylene resin (PP2) before extrusion. In Example 5, the first layer was prepared by melt-kneading polypropylene resin (PP1) and polypropylene resin (PP2) before extrusion. In Comparative Example 4, the first layer was prepared by mixing titanium oxide with polystyrene resin (PS) before extrusion. Comparative Example 3 used aluminum foil as the PTP lid material. Detailed conditions and the measurement and evaluation results for each physical property are shown in Table 1.

[0099] [Comparative Example 5] Comparative Example 5 involved changing the raw materials and formulations as shown in Table 1, and then preparing a two-layer film by laminating the first and second layers in the same manner as in Example 1. Following the example in Patent Document 1, a lid material for PTP was prepared by irradiating the film with an electron beam at an acceleration voltage of 250 kV and an irradiation dose of 60 kGy. The PP / PE base material (PE layer side) and the lid material (PE layer side) were bonded together in the same manner as in Example 1 to obtain a PTP package. Detailed conditions and the measurement and evaluation results for each physical property are shown in Table 1.

[0100] [Comparative Example 7] Comparative Example 7 obtained a PTP package in the same manner as in Example 1, except that the preparation of the lid material for the PTP was modified as follows, and a PP / PE bottom material was used. Similar to Example 1, a three-layer laminated film was prepared using the co-extrusion direct inflation method by laminating a polyethylene resin (PE4) layer mixed with amorphous aluminosilicate (first layer), a polyethylene resin (PE4) layer mixed with a nucleating agent (second layer), and an ethylene-vinyl acetate copolymer (EVA) layer (third layer), and this was used as a lid material (a) for PTP. The total thickness was 80 μm (PE4 layer (first layer): 20 μm, PE4 layer (second layer): 50 μm, EVA layer (third layer): 10 μm). A PTP package was obtained by bonding the PP / PE base material (PE layer side) and the lid material (EVA layer side) in the same manner as in Example 1. Detailed conditions and the measurement and evaluation results for each physical property are shown in Table 1.

[0101] [Table 1] [Industrial applicability]

[0102] The lid material for PTP packaging of the present invention can be suitably used for packaging pharmaceuticals such as tablets and capsules, and food products such as candies and chocolates. [Explanation of Symbols]

[0103] 1 PTP package 2 Cover material for PTP 3 Base material 4 Recessed portion 5 Flange portion 6 Content

Claims

1. A lid material for PTP, comprising a polyolefin resin including a polyethylene resin and / or a polypropylene resin, characterized in that the ignition residue is less than 5% by mass, the gross values ​​at measurement angles of 20°, 45°, 60°, 75°, and 85° are all 70% or less, and the elongation at puncture break is less than 3.2 mm.

2. The PTP lid material according to claim 1, wherein the maximum reflectance is 20 to 150 in a variable-angle photometer measurement using light at an incident angle of 15°.

3. The PTP lid material according to claim 1 or 2, wherein, in a variable-angle photometer measurement using light with an incident angle of 15°, the half-width of the reflectance intensity distribution is 10° or more.

4. The PTP lid material according to claim 1 or 2, wherein the a* value in the (L*, a*, b*) color space is -12 to 10 and the b* value is -10 to 15.

5. The PTP lid material according to claim 1 or 2, wherein the haze is 50% or more.

6. The PTP lid material according to claim 1 or 2, wherein the PTP lid material has a printed surface, and the arithmetic mean roughness Ra of the printed surface is 0.2 μm or more.

7. The PTP lid material according to claim 1 or 2, wherein the molecular weight distribution of the resin contained in the PTP lid material is 4.0 to 7.

0.

8. Weight-average molecular weight is 2.0 × 10⁻⁶ ５ ~3.5 x 10 ５ A lid material for PTP according to claim 1 or 2, comprising a polypropylene resin.

9. The PTP lid material according to claim 8, wherein the heat of fusion of the crystals measured by differential scanning calorimeter (DSC) is 70 J / g or more.

10. Weight-average molecular weight is 3.5 × 10⁻⁶ ４ ~5.2 x 10 ４ A PTP lid material according to claim 1 or 2, comprising a polyethylene resin.

11. The PTP lid material according to claim 10, wherein the heat of fusion of the crystals measured by differential scanning calorimeter (DSC) is 140 J / g or more.

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