PTP packaging sheet

Abstract

The purpose of this invention is to provide a PTP packaging sheet using polypropylene resin containing biomass-derived polypropylene as a material. The present invention relates to a PTP packaging sheet comprising at least one polypropylene resin layer containing biomass-derived polypropylene, wherein the content of the biomass-derived polypropylene in the polypropylene resin layer is 10% by mass or more.

Description

PTP packaging sheet

[0001] The present invention relates to a PTP packaging sheet.

[0002] Medicines, foods, etc. in the form of tablets, capsules, etc. are usually distributed as PTP packages by forming a pocket (deep-drawn portion) of a predetermined depth in a press-through pack packaging sheet (hereinafter referred to as a "PTP packaging sheet"), which is a transparent plastic sheet, placing the medicine, food, etc. in the pocket, and sealing the opening with a sealing material (lid material) such as aluminum foil.The medicine, food, etc. placed in the pocket can be taken out from the sealing material side by, for example, pressing the pocket with a finger, and then taken.

[0003] A PTP package typically has a storage section with one pocket containing a content such as medicine or food. The PTP packaging sheet is required to be transparent so that the state of the content can be confirmed. Furthermore, to prevent contamination of the content by leakage from the PTP packaging sheet and damage or deformation of the content due to external impact or influence, the PTP packaging sheet is required to have storage stability, impact resistance, UV resistance, and other properties for the content. Specifically, regarding the storage stability of the content, according to the Ministry of Health, Labor and Welfare Notification No. 370 test, the sheet's n-heptane elution amount at 100°C is 150 μg / mL or less. Furthermore, the PTP packaging sheet is required to have water vapor barrier properties to ensure the quality of the content and thermoformability to mold it to the shape of the content.

[0004] Polypropylene-based resins are used as materials for PTP packaging sheets. Polypropylene homopolymers are used for PTP packaging sheets, and petroleum resins are generally added to improve water vapor barrier properties. However, because petroleum resins are extracted by n-heptane extraction, adding large amounts of petroleum resins results in failure to comply with Ministry of Health, Labor and Welfare Notification No. 370 testing, limiting the amount that can be added to improve water vapor barrier properties. While randomizing the polypropylene used in the material is considered to improve the thermoformability of PTP packaging sheets, using random polypropylene reduces water vapor barrier properties. Therefore, PTP packaging sheets using polypropylene-based resins are required to have a good balance of storage stability of the contents, water vapor barrier properties, and thermoformability. For example, Patent Document 1 discloses a PTP packaging sheet using a polypropylene-based resin that balances hygiene and water vapor barrier properties, which are related to the storage stability of the contents, as well as water vapor barrier properties and thermoformability.

[0005] In recent years, environmentally friendly resin materials using biomass-derived materials have also been studied. Regarding polypropylene-based resins, polypropylene-based resins containing biomass-derived polypropylene have been developed. From the perspective of reducing environmental impact, films and molded articles using polypropylene-based resins containing biomass-derived polypropylene have also been developed, instead of films and molded articles that were previously generally formed from petroleum-derived polypropylene-based resins. For example, Patent Document 2 describes monolayers and laminates containing biomass-derived propylene, which can significantly reduce the amount of fossil fuel used compared to conventional methods, reduce environmental impact, and have good mechanical properties and transparency, as well as molded articles comprising these. Furthermore, Patent Document 3 describes a non-oriented film that contains a plant-derived resin, thereby reducing environmental impact, and has excellent transparency, mechanical strength, and heat resistance.

[0006] JP 2009-083111 A JP 2022-152666 A JP 2022-61847 A

[0007] However, in PTP packaging sheets containing a polypropylene resin as a main component, replacing a portion of the polypropylene resin with biomass-derived polypropylene in order to reduce the environmental impact has not been considered, and there has been a demand for the development of PTP packaging sheets using a polypropylene resin containing biomass-derived polypropylene as a material. Also, there is room for further study on the storage stability of contents, water vapor barrier properties, and thermoformability of PTP packaging sheets using a polypropylene resin containing biomass-derived polypropylene as a material.

[0008] The present invention has been made in view of the above, and an object of the present invention is to provide a PTP packaging sheet using, as a material, a polypropylene resin containing biomass-derived polypropylene.

[0009] As a result of intensive research into solving the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by the following configuration examples, and have thus completed the present invention.

[0010] [1] A PTP packaging sheet comprising at least one polypropylene resin layer containing biomass-derived polypropylene, wherein the content of biomass-derived polypropylene in the polypropylene resin layer is 10% by mass or more. [2] The PTP packaging sheet according to [1] above, wherein the amount of n-heptane elution from the surface of the PTP packaging sheet is 150 μg / mL or less. [3] The PTP packaging sheet according to [1] or [2] above, wherein the polypropylene resin layer further contains a petroleum resin. [4] The PTP packaging sheet according to [3] above, wherein the content of petroleum resin in the polypropylene resin layer is 1% by mass or more and 13% by mass or less. [5] The PTP packaging sheet according to any one of [1] to [4] above, wherein the polypropylene resin layer further contains petroleum-derived polypropylene that is a homopolymer and / or a random copolymer. [6] The PTP packaging sheet according to [5] above, wherein the content of petroleum-derived polypropylene in the polypropylene resin layer is 15% by mass or more and 90% by mass or less. [7] The PTP packaging sheet according to any one of [1] to [3] above, or the PTP packaging sheet according to [6] above, which has a multilayer structure and in which the content of petroleum resin in the surface resin layer constituting the outermost surface is 13% by mass or less. [8] The PTP packaging sheet according to [7] above, in which the surface resin layer contains biomass-derived polypropylene and the content of biomass-derived polypropylene in the surface resin layer is 40% by mass or less.

[0011] According to the present invention, it is possible to provide a PTP packaging sheet using, as a material, a polypropylene resin containing biomass-derived polypropylene.

[0012] 1 is a schematic diagram of a PTP packaging sheet according to the present invention having a multi-layer structure.

[0013] <Pressure Packaging Sheet> The pressure-packaging sheet according to the present invention (hereinafter also referred to as "the sheet") includes at least one polypropylene resin layer containing biomass-derived polypropylene, and the content of biomass-derived polypropylene in the polypropylene resin layer is 10% by mass or more.

[0014] The present sheet may include at least one polypropylene resin layer containing biomass-derived polypropylene. The present sheet may be a single-layer sheet consisting of only the biomass-derived polypropylene-containing polypropylene resin layer (hereinafter also referred to as "Layer A"), or a multilayer sheet including Layer A. In the case of such a multilayer sheet, it may include two or more Layers A, or may include two or more layers other than Layer A (hereinafter also referred to as "Layer B"). When the present sheet includes two or more Layers A, the two or more Layers A may be the same or different. When the present sheet includes two or more Layers B, the two or more Layers B may be the same or different. Examples of Layer B include a layer containing a resin in which the content of biomass-derived polypropylene is less than 10% by mass relative to 100% by mass of the resin constituting Layer B, and the layer may not contain biomass-derived polypropylene.

[0015] Suitable examples of the present sheet include a single-layer sheet consisting of only Layer A, a two-layer sheet in which Layer A and Layer B are laminated, a layer-B-surfaced multilayer sheet in which Layer A is disposed in the middle and Layer B is disposed on the surface side, and a layer-A-surfaced multilayer sheet in which Layer A or Layer B is disposed in the middle and Layer A is disposed on the surface side. For example, layer-B-surfaced multilayer sheets include a multilayer sheet in which Layer B, Layer A, and Layer B are laminated in this order, a multilayer sheet in which Layer B, Layer B, Layer A, Layer B, and Layer B are laminated in this order, and a multilayer sheet in which Layer B, Layer A, Layer B, Layer A, and Layer B are laminated in this order. Examples of layer-A-surface multilayer sheets include a multilayer sheet in which Layer A is disposed in the center and Layer A is disposed on the surface side (i.e., Layer A, Layer A, Layer A are laminated in this order), a multilayer sheet in which Layer A, Layer B, and Layer A are laminated in this order, a multilayer sheet in which Layer A, Layer A, Layer B, Layer A, and Layer A are laminated in this order, and a multilayer sheet in which Layer A, Layer B, Layer A, Layer B, and Layer A are laminated in this order. Among these, preferred are a single-layer sheet consisting of Layer A only, a two-layer sheet in which Layer A and Layer B are laminated, a layer-A-surface multilayer sheet in which Layer A is disposed in the center and Layer A is disposed on the surface side (i.e., Layer A, Layer A, Layer A are laminated in this order), and a layer-B-surface multilayer sheet in which Layer B, Layer A, and Layer B are laminated in this order. Adjacent layers may be laminated together, or may be laminated together in a structure of two or more layers. Furthermore, the present sheet may be a multilayer sheet in which a layer such as a gas barrier layer such as an oxygen barrier layer, a gas absorbing layer, a moisture-proof layer, a light-shielding layer, or a bleed-out prevention layer is laminated on one or both sides of the above-mentioned single-layer sheet or multilayer sheet, as required.

[0016] [Biomass-derived polypropylene] One example of a method for producing biomass-derived polypropylene is to produce biopropane using vegetable oil (including waste oil, residual oil, etc.) as a raw material, and then dehydrogenate it to convert it into propylene to produce biopolypropylene. The biomass-derived polypropylene may contain propylene other than biomass-derived propylene. The biomass-derived polypropylene used in the sheet may or may not contain a nucleating agent, and commercially available products can be used. Commercially available biomass-derived polypropylene products include, but are not limited to, Lyondellbasell's "C14 HP640J," "C14 HP456J," "C14 EP448T," and "C14 EP348U."

[0017] The biomass-derived polypropylene contained in the biomass-derived polypropylene-containing polypropylene resin layer (Layer A) of the present sheet is not particularly limited, but refers to a propylene homopolymer, a copolymer of propylene and ethylene, a copolymer of propylene and an α-olefin having 4 to 8 carbon atoms, or a copolymer of propylene, ethylene, and an α-olefin having 4 to 8 carbon atoms, with random copolymers being preferred. Specific examples of α-olefins having 4 to 8 carbon atoms include, but are not limited to, 1-butene, 4-methyl-1-pentene, 1-pentene, 1-hexene, and 1-octene. The monomer components other than propylene constituting the biomass-derived polypropylene described above may be used alone or in combination of two or more types. The biomass-derived polypropylenes described above may be used alone or in combination of two or more types.

[0018] The content of biomass-derived polypropylene in the polypropylene resin layer (Layer A) containing biomass-derived polypropylene of this sheet is 10% by mass or more relative to 100% by mass of the polypropylene resin constituting the polypropylene resin layer (Layer A). The content of biomass-derived polypropylene is a value measured by radiocarbon (C14) measurement of the biomass-derived carbon content. It is known that atmospheric carbon dioxide contains a certain proportion of C14 (107 pMC), and therefore the C14 content in the oils of plants that grow by absorbing atmospheric carbon dioxide is also approximately 107 pMC. It is also known that fossil fuels contain very little C14. Therefore, by measuring the proportion of C14 contained in the polypropylene resin layer (Layer A) containing biomass-derived polypropylene of this sheet, the proportion of biomass-derived carbon can be calculated, and the content (mass%) of biomass-derived polypropylene in Layer A can be calculated. When the C14 content in the polypropylene resin layer (Layer A) of this sheet is Pc14, the content (mass%) of biomass-derived polypropylene can be calculated using the following formula: (Content of biomass-derived polypropylene in layer A) (mass%) = 100 × (Pc14 of layer A) / 107

[0019] The content of biomass-derived polypropylene in the polypropylene resin layer (Layer A) of the present sheet containing biomass-derived polypropylene can theoretically be 100% by mass, relative to 100% by mass of the polypropylene resin constituting the polypropylene resin layer (Layer A), and may be, for example, 80% by mass or less. The content of biomass-derived polypropylene in the polypropylene resin layer (Layer A) is preferably 60% by mass or less, and more preferably 40% by mass or less.

[0020] The amount of n-heptane elution from the surface of the sheet is preferably 150 μg / mL or less. This is because the storage stability of the contents of the sheet is ensured when the amount of n-heptane elution from the surface is within this range. The amount of n-heptane elution is a value measured by the n-heptane elution test specified in Ministry of Health, Labor and Welfare Notification No. 370. The surface of the sheet refers to the surface of Layer A when the sheet is a single-layer sheet containing Layer A. When the sheet is a multi-layer sheet containing Layer A, the surface of the sheet refers to the outermost layer. When the sheet is a multi-layer sheet, the outermost layer may be Layer A or Layer B. Regardless of the layer, the n-heptane elution from either layer is sufficient as long as it is within the standard value of 150 μg / mL or less as specified in Ministry of Health, Labor and Welfare Notification No. 370. Furthermore, as long as the amount of n-heptane elution from the surface of the sheet is within the range of 150 μg / mL or less, the layer disposed on the surface of the sheet (Layer A when the sheet is a single-layer sheet) may contain various additives as needed.

[0021] The polypropylene resin layer (Layer A) containing biomass-derived polypropylene in the present sheet preferably further contains a petroleum resin. This is because the inclusion of a petroleum resin in the polypropylene resin layer (Layer A) containing biomass-derived polypropylene improves the water vapor barrier properties and thermoformability of the present sheet. Examples of the petroleum resin include petroleum resins such as C5 petroleum resins, C9 petroleum resins, and C5-C9 copolymer petroleum resins, alicyclic hydrocarbon petroleum resins such as dicyclopentadiene petroleum resins, and hydrogenated derivatives thereof. The petroleum resin may also be contained in polypropylene containing petroleum-derived polypropylene.

[0022] In the present sheet, the petroleum resin content in the polypropylene resin layer (Layer A) containing biomass-derived polypropylene is preferably 1% by mass or more and 13% by mass or less. If the petroleum resin content in Layer A is less than 1% by mass relative to 100% by mass of the polypropylene-based resin constituting Layer A, the water vapor permeability of Layer A may not be sufficiently reduced, resulting in a decrease in water vapor barrier properties. Furthermore, in blister molding using the present sheet, blister moldability at low temperatures may be insufficient, potentially resulting in a decrease in thermoformability. On the other hand, if the petroleum resin content in Layer A exceeds 13% by mass relative to 100% by mass of the polypropylene-based resin constituting Layer A, the amount of n-heptane elution may increase, potentially resulting in a decrease in the storage stability of the contents of the present sheet. When the petroleum resin content in Layer A is within the above range, the present sheet is preferably a single-layer sheet of Layer A or a multilayer sheet with Layer A as the outermost surface.

[0023] The polypropylene resin layer (Layer A) of the present sheet containing biomass-derived polypropylene preferably further contains petroleum-derived polypropylene that is a homopolymer and / or random copolymer, because the thermoformability of the present sheet is improved by containing petroleum-derived polypropylene (hereinafter also referred to as petroleum-derived PP) in addition to biomass-derived polypropylene (hereinafter also referred to as biomass-derived PP) in Layer A of the present sheet.

[0024] In this sheet, the content of petroleum-derived polypropylene in the polypropylene resin layer (Layer A) is preferably 15% by mass or more and 90% by mass or less, relative to 100% by mass of the polypropylene-based resin constituting Layer A. If the content of petroleum-derived polypropylene in the polypropylene resin layer (Layer A) is less than 15% by mass, relative to 100% by mass of the polypropylene-based resin constituting Layer A, the effect of improving thermoformability may be insufficient, while if it exceeds 90% by mass, the content of biomass-derived PP in Layer A decreases, resulting in a decrease in the effect of reducing the environmental load. The content of petroleum-derived polypropylene in the polypropylene resin layer (Layer A) is more preferably 89% by mass or less, even more preferably 85% by mass or less, even more preferably 80% by mass or less, and particularly preferably 77% by mass or less, relative to 100% by mass of the polypropylene-based resin constituting Layer A.

[0025] The petroleum-derived polypropylene is not particularly limited, and examples thereof include propylene homopolymers and copolymers of propylene with at least one selected from ethylene and α-olefins having 4 or more carbon atoms. Examples of the α-olefins having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, and 4,4-dimethylpentene-1. The proportion of structural units derived from propylene in the petroleum-derived polypropylene is preferably 50% by mass or more, more preferably 76% by mass or more, even more preferably 80% by mass or more, and even more preferably 85% by mass or more.

[0026] When the present sheet has a multilayer structure, the content of petroleum resin in the surface resin layer constituting the outermost surface is preferably 13% by mass or less, relative to 100% by mass of the surface resin constituting the surface resin layer. If the content of petroleum resin in the outermost resin layer exceeds 13% by mass, there is a risk of an increase in the amount of n-heptane elution, which may result in a decrease in the storage stability of the contents of the present sheet. The surface resin layer may be Layer A or Layer B. Furthermore, when the present sheet is a multilayer sheet having a multilayer structure and Layer A is disposed as an intermediate layer, the content of petroleum resin contained in the intermediate Layer A is not particularly limited and may, for example, exceed 13% by mass.

[0027] When the sheet has a multilayer structure, the surface resin layer preferably contains biomass-derived polypropylene, and the content of biomass-derived polypropylene in the surface resin layer is preferably 40% by mass or less, relative to 100% by mass of the surface resin constituting the surface resin layer. That is, the surface resin layer may be Layer A or Layer B, and preferably contains 40% by mass or less of biomass-derived polypropylene. When the surface resin layer is Layer A, containing 10% by mass or more and 40% by mass or less of biomass-derived polypropylene further reduces the environmental load. When the surface resin layer is Layer B, the biomass-derived polypropylene is contained in an amount of less than 10% by mass, but in this case, Layer A is disposed as an intermediate layer, thereby reducing the environmental load of the sheet as a whole.

[0028] The polypropylene resin constituting the biomass-derived polypropylene-containing polypropylene resin layer (Layer A) of the present sheet preferably has an MFR, measured in accordance with JIS K 7210 (230°C, 2.16 kg load), of 0.1 to 10 g / 10 min, more preferably 0.3 to 7 g / 10 min. Use of a polypropylene resin having an MFR within the above range is preferred because it provides superior moldability when producing the present sheet.

[0029] The present sheet may optionally contain various additives in the polypropylene resin layer (Layer A) and / or Layer B containing biomass-derived polypropylene, to the extent that the effects of the present invention are not impaired. Examples of the various additives include dispersants, stabilizers such as heat stabilizers and light resistance stabilizers, neutralizing agents, UV absorbers, softeners, plasticizers, lubricants, processing aids, reinforcing agents, coloring pigments, UV scattering agents, antistatic agents, antioxidants, lubricants, nucleating agents, various fillers, etc. These other components may each be used alone or in combination of two or more.

[0030] For example, coloring pigments include pearl pigments such as condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and mica. Fillers include talc, calcium carbonate, silica, alumina, carbon black, zinc oxide, zeolite, hydrotalcite, glass fiber, paper powder, and wood powder. Heat stabilizers include hindered phenols, sulfur-based stabilizers, and phosphorus-based stabilizers. Neutralizing agents include metal stearates and hydrotalcite. UV absorbers include benzotriazoles, benzoates, benzophenones, and benzotriazines. Light stabilizers include hindered amines. Lubricants include hydrocarbon lubricants, fatty acids, fatty acid amides, metal soaps, esters, and fluorine-based stabilizers. Nucleating agents include sorbitol-based stabilizers.

[0031] <Method for Manufacturing the Present Sheet> The present sheet can be produced, for example, by adding the above-mentioned other components as needed to the polypropylene-based resin constituting the biomass-derived polypropylene-containing polypropylene resin layer (Layer A) and molding it into a sheet using a known method such as the single-layer T-die melt molding method, calendaring, or extrusion molding. When the present sheet has a multilayer structure, it can be produced using a method similar to that used for manufacturing conventional laminates. For example, when the present sheet is the Layer B surface-type multilayer sheet described above, it may be produced by overlapping sheets forming Layer B on both sides of Layer A and then heat-sealing them, or by bonding the sheets forming each layer via an adhesive layer or the like. Furthermore, to improve the interlayer adhesion of the resulting multilayer sheet, the surface of any of the layers forming the multilayer sheet may be pretreated in advance by a method such as corona treatment, low-temperature plasma treatment, ion bombardment treatment, chemical treatment, or solvent treatment.

[0032] Furthermore, when the present sheet has a multilayer structure, it can also be produced by a general multilayer sheet molding method, such as a co-extrusion method such as a multilayer T-die method or a multilayer inflation method, or a casting method such as a wet casting method or a dry casting method, using raw materials for each layer, or if necessary, a pre-blended mixture of the raw materials for each layer. The temperature during co-extrusion can be appropriately selected depending on the raw materials used, but is preferably 160 to 300°C, more preferably 180 to 250°C. For example, the temperature during extrusion of Layer A may be different from the temperature during extrusion of Layer B.

[0033] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to these examples.

[0034] The components used in the examples and comparative examples are as follows: (Biomass PP containing biomass-derived polypropylene) - "Circulen Renew C14 HP640J" (manufactured by Lyondellbasell, renewable raw material made from bio-based waste oil and residual oil), MFR = 3.2 g / 10 min, biomass-derived PP content 36% - "Circulen Renew C14 HP456J" (manufactured by Lyondellbasell, renewable raw material made from bio-based waste oil and residual oil, raw material containing no nucleating agent), MFR = 3.4 g / 10 min, biomass-derived PP content 25.2% (Petroleum-derived polypropylene) - "Novatec FY6" homo PP (manufactured by Japan Polypropylene Corporation), MFR = 2.5 g / 10 min・"Novatec EG7F" random PP, ethylene-propylene random copolymer (Japan Polypropylene Corporation), MFR = 1.3 g / 10 min. ・Homo PP with petroleum resin. Petroleum resin content is 24%. ・Petroleum resin

[0035] Examples 1 to 4 and Comparative Examples 1 and 2 The PTP packaging sheets of Examples 1 to 4 and Comparative Examples 1 and 2 were produced as follows. The resin components shown in Table 1 were mixed in the formulations shown in Table 1, and the resulting mixture was melt-kneaded and extruded at a resin temperature of 200°C to produce a PTP packaging sheet with a thickness of 250 μm. The resulting PTP packaging sheets of each of the Examples and Comparative Examples were subjected to the following evaluation tests.

[0036] (1) n-heptane elution test Measurement was carried out by the n-heptane elution test in accordance with Ministry of Health, Labour and Welfare Notification No. 370.

[0037] (2) Water Vapor Permeability (MOCON Method) The water vapor permeability of the sheet was measured under the following conditions using the following measuring device: Measurement conditions: 40°C, 91% RH Measuring device: PERMATRAN-W 3 / 34 (manufactured by MOCON)

[0038] (3) Blister Formability (FBP-M2) The blister formability of the sheet was examined by molding under the following conditions, and the obtained molded product was visually inspected. Test equipment: PTP molding machine FBP-M2 (manufactured by CKD Corporation) Pocket size: φ11×4 mm Blow pressure: 5.0 kgf / cm ２Plug pressure: 3.0 kgf / cm ２ Molding temperature: 110°C to 145°C. The blister moldability was evaluated as "Good" when the blister molding temperature range, which was considered to be the acceptable range for blister molded products, was below 140°C, and as "Fair" when the blister molding temperature range was 140°C or higher. The results obtained from the above evaluation tests are shown in Table 1.

[0039]

[0040] As shown in Table 1, the sheets according to Examples 1 to 4 containing biomass-derived PP had water vapor permeability comparable to or lower than that of the sheets according to Comparative Examples 1 and 2, demonstrating excellent water vapor barrier properties. Furthermore, the sheet according to Example 1 had a higher blister molding temperature range, considered the acceptable range for blister-molded bodies, compared to the sheet according to Comparative Example 1, but thermoformability was confirmed in the temperature range of 140 to 142°C. Furthermore, the sheets according to Examples 2 and 4 containing biomass-derived PP and petroleum resin had a wider blister molding temperature range of 138 to 142°C (Example 2) or 136 to 140°C (Example 4) compared to the sheet according to Example 1, which did not contain petroleum resin, demonstrating excellent thermoformability. The biomass PP containing biomass-derived polypropylene used in the sheet according to Example 2 was a raw material containing a nucleating agent, while the biomass PP containing biomass-derived polypropylene used in the sheet according to Example 4 was a raw material not containing a nucleating agent. However, the sheet according to Example 2, formed from the biomass PP containing a nucleating agent, was superior in terms of water vapor permeability. Furthermore, the sheet of Example 3, which was made using 100% biomass PP containing biomass-derived polypropylene, had an excellent n-heptane elution test result of 0.33, and although the blister molding temperature range was high, thermoformability at 144°C was confirmed.

[0041] Examples 5 to 13 and Comparative Examples 3 to 7 Plates according to Examples 5 to 13 and Comparative Examples 3 to 7 were produced as follows. The resin components shown in Table 2 were mixed in the formulations shown in Table 2, and the resulting mixture was melt-kneaded at a resin temperature of 230°C and injection-molded to produce plates with a thickness of 1 mm and dimensions of 50 mm x 80 mm. The above-mentioned n-heptane elution test was carried out on the resulting plates according to each Example and Comparative Example. In addition, it was confirmed whether the content of biomass-derived polypropylene in each plate satisfied 10% by mass, and an environmental load reduction evaluation was carried out on the plates according to each Example and Comparative Example. The results obtained are shown in Table 2 below.

[0042]

[0043] The plate according to Example 5 was produced using a mixture of the same resin components as the sheet according to Example 1 in the same blend, and the plate according to Example 6 was produced using a mixture of the same resin components as the sheet according to Example 2 in the same blend. Comparisons between Example 5 and Example 1, and between Example 6 and Example 2, confirmed that the results of the n-heptane elution test showed almost the same values. Therefore, the results of the n-heptane elution test for the plates according to Examples 7 to 13 and Comparative Examples 3 to 7 can be treated as equivalent to the test results for PTP packaging sheets obtained using mixtures of the same resin components in the same blend.

[0044] As can be seen from Table 2, the plates according to Examples 5 to 13 all had a biomass-derived polypropylene content of 10% by mass or more, thereby reducing the environmental impact. On the other hand, the plates according to Comparative Examples 3 to 7 had a biomass-derived polypropylene content of less than 10% by mass, resulting in insufficient reduction in environmental impact. Furthermore, the plates according to Comparative Examples 3 to 7 all failed the n-heptane elution test. This is believed to be due to the low blending amount of biomass PP containing biomass-derived polypropylene and the increased blending amount of petroleum resin-containing polypropylene, resulting in an increased petroleum resin content in the plates. The results in Table 2 confirm that when the petroleum resin content in the plates, i.e., the PTP packaging sheet, is 13% by mass or less, the n-heptane elution amount is 150 μg / mL or less. Furthermore, the results of Example 13 confirm that even when the only resin component used in plate production was biomass PP containing biomass-derived polypropylene, the n-heptane elution amount was low, thereby sufficiently reducing the environmental impact.

[0045] Example 14 A PTP packaging sheet (three layers, outer layer / center layer / outer layer) according to Example 14 was prepared as follows. The resin components for the center layer shown in Table 3 were mixed in the formulation shown in Table 3, and the resulting mixture was melt-kneaded. The materials for forming the outer and center layers were co-extruded from a two-kind, three-layer multi-manifold nozzle at a die temperature of 210°C while adjusting the extrusion rate so that the outer layer had a thickness of 30 μm and the center layer had a thickness of 90 μm. The resulting sheet was cooled using a cast roll to prepare a PTP packaging sheet. The obtained PTP packaging sheet was subjected to the above-described evaluation tests [(1) n-heptane elution test, (2) water vapor permeability (MOCON method), and (3) blister moldability (FBP-M2)]. The results are shown in Table 3 below.

[0046]

[0047] As shown in Table 3, the PTP packaging sheet of Example 14, which had a three-layer structure including an outer layer formed using biomass-derived PP and a central layer formed from biomass-derived PP and a petroleum resin, had an extremely low water vapor permeability of 0.8 or less, and was particularly excellent in water vapor barrier properties. Furthermore, the sheet of Example 14 had a blister molding temperature range of 130 to 136°C, which is the acceptable range for blister-molded products, and was confirmed to be thermoformable over a wide temperature range below 140°C, confirming that it also had excellent thermoformability.

[0048] The PTP packaging sheet of the present invention uses polypropylene resin containing biomass-derived polypropylene as a material, thereby reducing the environmental impact. In addition, since it has an excellent balance of storage stability for the contents, water vapor barrier properties, and thermoformability, it can be suitably used as PTP packaging for medical and food products.

[0049] 1 PTP packaging sheet 2 Surface resin layer 3 Intermediate layer

Claims

1. A PTP packaging sheet comprising at least one polypropylene resin layer containing biomass-derived polypropylene, wherein the content of biomass-derived polypropylene in the polypropylene resin layer is 10% by mass or more.

2. The PTP packaging sheet according to claim 1, wherein the amount of n-heptane eluted from the surface of the PTP packaging sheet is 150 μg / mL or less.

3. The PTP packaging sheet according to claim 1 or 2, wherein the polypropylene resin layer further contains a petroleum resin.

4. The PTP packaging sheet according to claim 3, wherein the content of petroleum resin in the polypropylene resin layer is 1% by mass or more and 13% by mass or less.

5. The PTP packaging sheet according to claim 1 or 2, wherein the polypropylene resin layer further contains a petroleum-derived polypropylene which is a homopolymer and / or a random copolymer.

6. The PTP packaging sheet according to claim 5, wherein the content of petroleum-derived polypropylene in the polypropylene resin layer is 15% by mass or more and 90% by mass or less.

7. A PTP packaging sheet according to claim 1 or 2, which has a multi-layer structure and in which the petroleum resin content in the surface resin layer constituting the outermost surface is 13 mass % or less.

8. A PTP packaging sheet as described in claim 7, wherein the surface resin layer contains biomass-derived polypropylene, and the content of biomass-derived polypropylene in the surface resin layer is 40 mass% or less.

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