Transparent hygroscopic blister sheet

Abstract

To provide a transparent hygroscopic blister sheet which is excellent in manufacturing suitability, is excellent in hygroscopic property while having a simple layer constitution, is excellent in visibility of a content because of being excellent in transparency before and after moisture absorption, shields moisture from outside, absorbs moisture in a packaged content storage part space, and can prevent the content from being degraded by moisture during transportation and storage for a long period, and a transparent hygroscopic PTP bottom material and a transparent hygroscopic PTP package, which are manufactured using the transparent hygroscopic blister sheet.MEANS FOR SOLVING THE PROBLEM: A transparent hygroscopic blister sheet has a moisture absorbing layer containing at least a specific moisture absorbent and a specific binder resin, and is excellent in high hygroscopic property, high total light transmittance and a low haze.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a transparent, moisture-absorbing blister sheet having excellent transparency and high moisture absorption properties for suppressing moisture absorption by packaged contents, and a transparent, moisture-absorbing push-through package (PTP) base material and a transparent, moisture-absorbing PTP packaging body made using the transparent, moisture-absorbing blister sheet. The transparent moisture-absorbing blister sheet of the present invention can be applied to products in various fields that dislike moisture. For example, it can be suitably used as a packaging material for preventing rust on metal products such as automotive screws, shafts, and metal plates, as well as electrical components, and as a packaging material for suppressing deterioration due to moisture in foods, medicines, and the like. [Background technology]

[0002] PTP packaging, strip package (SP) packaging, blister packaging, etc. are widely used for packaging medicines and foods that are sensitive to moisture, but many of the conventional products have insufficient moisture resistance. To compensate for this, aluminum foil pillow bags are used as outer bags and desiccants are also included. However, the moisture-proofing properties are insufficient after the outer bag is opened, and there have been many accidents where the desiccant has been accidentally ingested. Therefore, packaging bags have been developed for the purpose of transporting or long-term storage of medicines and food. Furthermore, there is a demand for packaging materials that have more stable moisture-proof, waterproof and barrier properties and that have a simple layer structure and can be produced through a manufacturing process with a small number of steps so as to maintain the quality of the medicines and food contents. Patent Documents 1 to 3 propose packaging laminates in which a highly vaporizable rust inhibitor that volatilizes at room temperature and exerts a rust-preventing effect is contained in a resin for the purpose of preventing rust on metal product contents. However, there are concerns that the rust-preventive agent may have effects other than the rust-preventive effect, such as the need for a sealed exterior, deterioration of the contents or functional impairment if the vaporized rust-preventive agent comes into contact with the contents, and removal is also troublesome, limiting its uses. Therefore, there is a demand for rust-preventive laminates that do not use volatile rust-preventive agents. In order to improve the moisture resistance of PTP or blister packaging materials, Patent Document 4 proposes incorporating a desiccant or a barrier layer into the packaging material. However, the transparency of the packaging material is insufficient, and the visibility for checking the deterioration state of the contents is poor. In addition, it has been proposed in Reference 5 to incorporate a moisture absorbent of approximately 100 nm in size into a packaging material to increase transparency. However, the moisture absorbent causes secondary aggregation, making it difficult to obtain high transparency. In addition, in order to increase transparency, the content of the moisture absorbent must be reduced, making it difficult to obtain sufficient moisture absorption capacity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-254350 A [Patent Document 2] JP 2007-308726 A [Patent Document 3] JP 2010-052751 A [Patent Document 4] Patent No. 5429948 [Patent Document 5] JP 2021-147086 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention solves the above problems, and provides a film that is excellent in manufacturability, has a simple layer structure, is excellent in hygroscopicity, and has excellent transparency both before and after absorbing moisture, which allows the contents to be easily seen, blocks moisture from the outside, and absorbs moisture in the space of the packaged contents storage section, thereby preventing the contents from being easily exposed to moisture during transportation and storage. The present invention aims to provide a transparent moisture-absorbing blister sheet capable of suppressing deterioration of contents due to moisture during long-term storage, and a transparent moisture-absorbing PTP base material and a transparent moisture-absorbing PTP package produced using the transparent moisture-absorbing blister sheet. [Means for solving the problem]

[0005] As a result of various investigations, the present inventors have found that the above object can be achieved by a transparent moisture absorbing blister sheet including a moisture absorbing layer containing at least a specific moisture absorbent and a specific binder resin. That is, the present invention is characterized in the following points. 1. A transparent moisture-absorbing blister sheet for use as a base material for a blister container, the sheet having at least a moisture-absorbing layer, The moisture absorbing layer contains at least a moisture absorbent and a binder resin, The moisture absorbent contains hydrotalcite, the binder resin contains a polyvinyl chloride resin and / or a polyolefin resin, When subjected to moisture absorption treatment at 25℃ 50% for 11 days, the moisture absorption amount was 3g / m 2 or more, the total light transmittance before and after the moisture absorption treatment is 60% or more and 99% or less, and the haze before and after the moisture absorption treatment is 10% or more and 70% or less. A transparent moisture-absorbing blister sheet. 2. The transparent moisture-absorbing blister sheet according to the above item 1, wherein the content of hydrotalcite in the moisture-absorbing layer is 10% by mass or more and 40% by mass or less. 3. A transparent moisture-absorbing blister sheet further comprising a base layer on one or both sides of the moisture-absorbing layer, The substrate layer contains a polyvinyl chloride resin and / or a polyolefin resin, The transparent moisture-absorbing blister sheet has a thickness of 200 μm or more. 3. The transparent moisture-absorbing blister sheet according to 1 or 2 above. 4. A transparent, moisture-absorbing blister sheet according to any one of 1 to 3 above, which contains a phosphorus-based antioxidant and / or a thioether-based antioxidant. 5. A transparent, moisture-absorbing push-through package (PTP) base material comprising the transparent, moisture-absorbing blister sheet according to any one of 1 to 4 above. 6. A transparent, moisture-absorbing press-through package (PTP) packaging body having a lid material and a transparent, moisture-absorbing push-through package (PTP) base material as described above in 5. Effect of the Invention

[0006] According to the present invention, it is possible to obtain a transparent moisture-absorbing blister sheet which has excellent manufacturability, has a simple layer structure yet has excellent moisture absorption properties, and has excellent transparency both before and after moisture absorption, thereby allowing excellent visibility of the contents, blocks moisture from the outside, absorbs moisture in the packaged contents storage space, and can suppress deterioration of the contents due to moisture during transportation and long-term storage, as well as a transparent moisture-absorbing PTP base material and a transparent moisture-absorbing PTP packaging body made using the transparent moisture-absorbing blister sheet. By using the transparent moisture-absorbing packaging bag of the present invention in PTP packaging, SP packaging, and blister packaging for medicines, deterioration and discoloration of the medicine can be suppressed. In addition, there is no need to include a moisture-absorbing sachet containing silica gel or the like, and the risk of accidentally ingesting the moisture-absorbing sachet can be avoided. Furthermore, the risk of losing tablets, dropping them, or identifying broken tablets can be reduced. Furthermore, when the contents are metal products such as metal equipment, rusting of the metal products can be prevented, eliminating the need to protect the metal products with oiled paper or the like that has been used conventionally. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of a transparent moisture-absorbing blister sheet of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing one example of another embodiment of the layer structure of the transparent moisture-absorbing blister sheet of the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the transparent moisture-absorbing blister sheet of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the transparent moisture-absorbing blister sheet of the present invention. [Diagram 5] FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of a transparent moisture-absorbing PTP packaging body of the present invention.

[0008] In each drawing, the size and ratio of the components may be changed or exaggerated for ease of understanding. Also, for ease of understanding, parts that are unnecessary for the explanation or repeated reference numerals may be omitted. Although not shown in the drawings, an adhesive layer may be provided between each layer. Furthermore, if necessary, in order to strengthen the adhesive strength (adhesion strength) between each layer, the laminated surfaces of each layer may be previously subjected to a physical surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, sandblasting treatment, etc., or a chemical surface treatment such as oxidation treatment using chemicals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The transparent moisture-absorbing blister sheet, the transparent moisture-absorbing PTP base material, and the transparent moisture-absorbing PTP package of the present invention will be described in more detail below. Specific examples will be given, but the present invention is not limited thereto. In the present invention, the terms film and sheet are used synonymously, and water absorption or moisture absorption refers to the absorption of gaseous and / or liquid water.

[0010] I. Transparent moisture absorbing blister sheet The transparent moisture-absorbing blister sheet of the present invention may be composed of only one absorbent layer containing a moisture absorbent and a binder resin, or may further have a substrate layer on one or both sides of the moisture-absorbing layer. Furthermore, each of the absorbent layer and the base layer may be multi-layered. In addition, the transparent, moisture-absorbing blister sheet of the present invention can maintain transparency even after absorbing moisture, for example, after being left to stand for 11 days in an environment at a temperature of 25°C and a humidity of 50% RH, or at a temperature of 40°C and a humidity of 90% RH.

[0011] The moisture absorption amount of the transparent moisture-absorbing blister sheet of the present invention is, for example, 3 g / m2 when placed in an environment of 25°C and 50% for 11 days. 2If the moisture absorption amount is less than the above range, it is likely to be difficult to suppress deterioration of the contents, whereas if the moisture absorption amount is greater than the above range, it is substantially difficult to obtain a product.

[0012] The transparent moisture-absorbing blister sheet of the present invention may contain an antioxidant. However, phenol-based antioxidants are not preferred because they tend to cause yellowing of the transparent moisture-absorbing blister sheet, and it is preferable to contain an antioxidant other than the phenol-based antioxidant. Preferred antioxidants include phosphorus-based antioxidants and / or thioether-based antioxidants.

[0013] The transparent moisture absorbing blister sheet of the present invention has high transparency because the moisture absorbent is fine and the difference in refractive index between the moisture absorbent and the binder resin is small, thereby suppressing interfacial reflection and scattering. The total light transmittance of the transparent moisture-absorbing blister sheet of the present invention is preferably 60% or more, more preferably 80% or more, before moisture absorption and after moisture absorption at 25° C. and 50% for 11 days. If the total light transmittance is lower than the above range, the transparency is likely to decrease. The upper limit is most preferably 100%, but substantially, it is preferably 99% or less, and more preferably 95% or less. Here, the total light transmittance refers to the light transmittance measured using a color information measuring device or the like according to the method specified in JIS K7361 (Testing method for optical properties of plastics).

[0014] The haze of the transparent moisture-absorbing blister sheet of the present invention is preferably 70% or less, more preferably 30% or less, before moisture absorption and after moisture absorption at 25° C. and 50% for 11 days. If the haze is higher than the above range, the transparency is likely to decrease. The lower limit is most preferably 0%, but substantially, it is preferably 10% or more, and more preferably 14% or more.

[0015] If the transparent moisture-absorbing blister sheet lacks support (rigidity), it may further include a reinforcing layer.

[0016] Although there is no particular limitation on the thickness of the transparent moisture-absorbing blister sheet of the present invention, it is preferably 150 μm or more and 500 μm or less, and more preferably 200 μm or more and 400 μm or less. If it is thinner than the above range, it is difficult to fully exhibit the moisture absorption effect and the moisture absorption effect resulting therefrom, and if it is thicker than the above range, the moisture absorption effect is not improved so much, and the rigidity of the transparent moisture-absorbing blister sheet becomes too strong, which tends to make it difficult to use as a packaging material and tends to reduce transparency. The layers constituting the transparent moisture-absorbing blister sheet may be laminated via an adhesive layer or an anchor coat layer.

[0017] <Method of manufacturing transparent moisture-absorbing blister sheet> The method for producing the transparent moisture-absorbing blister sheet of the present invention will be described below. The method for producing the transparent moisture-absorbing blister sheet shown below is one example and is not intended to limit the present invention. The formation and lamination of each layer constituting the transparent moisture-absorbing blister sheet can be carried out by any method, such as wet lamination, dry lamination, solventless dry lamination, extrusion lamination, T-die coextrusion molding, coextrusion lamination, inflation molding, and the like. When the above lamination is performed, if necessary, the surface of each layer may be subjected to a pretreatment such as corona treatment, ozone treatment, etc. Also, anchor coating agents such as isocyanate (urethane), polyethyleneimine, polybutadiene, and organic titanium, or anchor coating agents such as polyurethane, polyacrylic, polyester, epoxy, polyvinyl acetate, cellulose, and other lamination adhesives may be used as desired.

[0018] For example, when preparing a transparent moisture-absorbing blister sheet having a layer structure of substrate layer 1 / moisture-absorbing layer / substrate layer 2, a resin composition for substrate layer 1, a resin composition for the moisture-absorbing layer, and a resin composition for substrate layer 2 can be formed into films and laminated by inflation film formation. The obtained transparent moisture-absorbing blister sheet can also be subjected to secondary processing for the purpose of imparting surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubrication functions, optical functions, thermal functions, and biocompatibility, within the scope that maintains transparency and moisture absorption properties.

[0019] Examples of secondary processing include embossing, painting, adhesive, printing, metallizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.) etc. The transparent moisture absorbing blister sheet can also be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-processing.

[0020] I-1. Moisture absorption layer The moisture absorbing layer is a layer containing a moisture absorbing agent and a binder resin, and the moisture absorbing agent is dispersed in the binder resin. The binder resin may have heat-sealing properties, and may contain other thermoplastic resins having heat-sealing properties within the range that does not impair transparency.

[0021] It is preferable that the composition contains hydrotalcite as a moisture absorbent. The content of hydrotalcite in the moisture absorbing layer is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 40% by mass or less, even more preferably 25% by mass or more and 40% by mass or less, and particularly preferably 30% by mass or more and 40% by mass or less. If the content is less than the above range, the moisture absorbing effect is likely to be insufficient, and if the content is more than the above range, the film formability is likely to be poor.

[0022] Although there is no particular limitation on the thickness of the moisture absorbing layer, it is preferably 80 μm or more and 300 μm or less, and more preferably 100 μm or more and 250 μm or less. If it is thinner than the above range, it is difficult to fully exert the moisture absorbing effect, and if it is thicker than the above range, the moisture absorbing effect is not improved so much, and the rigidity of the transparent moisture absorbing blister sheet becomes too strong, which tends to make it difficult to use as a packaging material.

[0023] The moisture absorbent is preferably incorporated into the moisture absorbing layer via a master batch in which the moisture absorbent is melt-blended with a thermoplastic resin. Specifically, it is preferable to prepare a master batch by melt blending the moisture absorbent with a thermoplastic resin at a relatively high concentration, and then dry blending the master batch with a binder resin to obtain a desired concentration in the moisture absorbing layer. The thermoplastic resin to be melt-blended may be one type or two or more types, and may be the same as the binder resin.

[0024] The content of the moisture absorbent in the master batch is preferably 20% by mass or more and 90% by mass or less, and more preferably 30% by mass or more and 70% by mass or less. Within the above range, it is easy to include a necessary and sufficient amount of the moisture absorbent in the moisture absorbing layer in a dispersed state.

[0025] [Moisture absorbent] There is no particular limitation on the number average particle size of the moisture absorbent. However, in order to obtain stable film-forming properties, the number average particle size of the moisture absorbent is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 1 μm or less. If it is larger than the above range, the film-forming properties tend to decrease, and the transparency of the transparent moisture-absorbing blister sheet also tends to decrease. The number average particle size of the moisture absorbent is preferably 0.1 μm or more, as it is difficult to stably obtain a moisture absorbent smaller than the above range. There is no particular restriction on the refractive index of the moisture absorbent, but the smaller the difference in refractive index between the moisture absorbent and the binder resin, the greater the transparency of the transparent moisture-absorbing blister sheet. The difference in refractive index between the moisture absorbent and the binder resin is preferably 0.05 or less. The moisture absorbent preferably contains hydrotalcite.

[0026] (Hydrotalcite) The hydrotalcite used in the present invention includes calcined hydrotalcite and a magnesium oxide-aluminum oxide solid solution obtained by further decomposing the calcined hydrotalcite by heating. Calcined type hydrotalcite is a compound represented by the following formula, which may further contain bound water. Mg 1-x Al x (OH)2(CO3) x / 2 In the above formula, x is a number from 0.1 to 0.4. Magnesium oxide-aluminum oxide solid solution is a compound represented by the following formula, and has a higher hygroscopicity than calcined hydrotalcite. Mg 0.7 Al 0.3 O 1.15

[0027] [Binder resin] The binder resin is required to be a resin capable of dispersing the moisture absorbent, and may have heat sealability. The binder resin preferably contains a polyvinyl chloride resin and / or a polyolefin resin. By including these resins in the binder resin, it is possible to obtain an excellent balance of dispersibility of the moisture absorbent, gas barrier properties, moisture resistance, and moldability.

[0028] (Polyvinyl chloride resin) Specific examples of polyvinyl chloride resins include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), vinyl chloride copolymers which are copolymers of vinyl chloride monomers and various polymerizable monomers, and vinylidene chloride copolymers which are copolymers of vinylidene chloride monomers and various polymerizable monomers. Among the polyvinyl chloride resins, PVC and PVDC are more preferable.

[0029] (Polyolefin resin) Specific examples of polyolefin resins include polyethylene (PE) resins, polypropylene (PP) resins, polymethylpentene, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, and mixtures of these resins.

[0030] Specific examples of polyethylene-based resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), general-purpose polyethylene (general-purpose PE), and polyethylene-based copolymers (PE-based copolymers). Among the polyethylene resins, LDPE, LLDPE, general-purpose PE, PE copolymers, etc. are more preferable, and LLDPE is even more preferable. Among the polyolefin resins, polypropylene resins and ethylene-propylene copolymers are more preferred.

[0031] (thermoplastic resin) The thermoplastic resin other than the binder resin contained in the moisture absorbing layer is preferably a resin that has excellent dispersibility of the moisture absorbent, does not significantly reduce the moisture absorption or transparency of the transparent moisture absorbing blister sheet, and can withstand use as a packaging material, and may also be a heat-sealable resin.

[0032] The thermoplastic resin preferably contains a polyolefin resin. Among the polyolefin resins, polyethylene resins and polymethylpentene are more preferable. Specific examples of polyethylene resins include LDPE, MDPE, HDPE, LLDPE, general-purpose PE, and PE copolymers. Among the polyethylene resins, LDPE, LLDPE, general-purpose PE, PE copolymers, etc. are more preferable, and LLDPE is even more preferable.

[0033] (Antioxidants) The transparent moisture-absorbing blister sheet of the present invention contains a phosphorus-based antioxidant and / or a thioether. The composition may contain an antioxidant. Specific examples of phosphorus-based antioxidant products include ADK STAB PEP-8 (ADEKA), ADK STAB PEP-36 (ADEKA), ADK STAB HP-10 (ADEKA), ADK STAB 2112 (ADEKA), ADK STAB 1178 (ADEKA), ADK STAB 1500 (ADEKA), and Irgafos 168 (BASF). Specific examples of thioether antioxidant products include ADK STAB AO-412S (ADEKA), ADK STAB AO-26 (ADEKA), KEMINOX PLS (Chemipro Chemicals), and RIANOX (Rianlin).

[0034] I-2. Base material layer The substrate layer preferably contains a polyvinyl chloride resin and / or a polyolefin resin. When the base layer contains these resins, the gas barrier property and moisture resistance of the transparent moisture absorbing blister sheet can be improved. In addition, it is preferable that these resins have the rigidity required for the base layer. When the base layer contains these resins having rigidity, the transparent moisture-absorbing blister sheet has excellent moldability, and can form the PTP base material and maintain its shape.

[0035] The substrate layer may be configured with multiple layers having the same or different compositions, and layers within the substrate layer may be laminated via an adhesive layer. The substrate layer may be laminated directly to the moisture absorbing layer or the reinforcing layer, or may be laminated via an adhesive layer, an anchor coat layer, or the like.

[0036] The total light transmittance of the base layer is preferably 60% or more and 99% or less, more preferably 65% ​​or more and 95% or less. If it is lower than the above range, the transparency of the transparent moisture-absorbing blister sheet as a whole tends to be poor, and it is easy to make it difficult to visually confirm the contents. It is difficult to increase it above the above range, and the production process and quality control become complicated, which tends to reduce productivity.

[0037] The haze of the substrate layer is preferably 0% or more and 70% or less, more preferably 0% or more and 30% or less, before and after moisture absorption. It is difficult to lower it below the above range, and the production process and quality control become complicated, which tends to reduce productivity. If it is higher than the above range, the transparency of the entire transparent moisture-absorbing blister sheet tends to be poor, and it is easy to make it difficult to visually check the contents.

[0038] (Polyvinyl chloride resin) Specific examples of polyvinyl chloride resins include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), vinyl chloride copolymers which are copolymers of vinyl chloride monomers and various polymerizable monomers, and vinylidene chloride copolymers which are copolymers of vinylidene chloride monomers and various polymerizable monomers. Among polyvinyl chloride resins, PVC and vinylidene chloride copolymers are more preferred.

[0039] (Polyolefin resin) Specific examples of polyolefin resins include polyethylene resins, polypropylene resins, polymethylpentene, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, and mixtures of these resins.

[0040] Specific examples of polyethylene resins include LDPE, MDPE, HDPE, LLDPE, general-purpose PE, and PE copolymers. Among polyethylene resins, LDPE, LLDPE, general-purpose PE, PE copolymers, etc. More preferred is LLDPE, even more preferred. Among the polyolefin resins, polypropylene resins and ethylene-propylene copolymers are more preferred.

[0041] I-3. Reinforcement layer The reinforcing layer is a layer that is included when the transparent moisture-absorbing blister sheet lacks support (rigidity), and is preferably a layer made of a reinforcing film.

[0042] In addition, the reinforcing layer has a total light transmittance and haze comparable to those of the base material layer and the moisture absorbing layer, and has excellent mechanical, physical, chemical and other properties, and is particularly strong and tough, and preferably has heat resistance. By making the reinforcing layer transparent, the entire transparent moisture-absorbing blister sheet can also become transparent.

[0043] The total light transmittance of the reinforcing layer is preferably 60% or more and 99% or less, more preferably 65% ​​or more and 95% or less. If it is lower than the above range, the transparency of the transparent moisture-absorbing blister sheet as a whole tends to be poor, and it is easy to make it difficult to visually confirm the contents. It is difficult to increase it above the above range, and the production process and quality control become complicated, which tends to reduce productivity.

[0044] The haze of the reinforcing layer is preferably 0% or more and 70% or less, more preferably 0% or more and 30% or less, before and after moisture absorption. It is difficult to lower it below the above range, and the production process and quality control become complicated, which tends to reduce productivity. If it is higher than the above range, the transparency of the entire transparent moisture-absorbing blister sheet tends to be poor, and it is easy to make it difficult to visually check the contents. Examples of resins for the reinforcing layer to obtain sufficient support include tough thermoplastic resins such as polyester-based resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin-based resins such as polypropylene, polyamide-based resins such as nylon, polyaramid-based resins, polycarbonate-based resins, polyacetal-based resins, fluorine-based resins, and others. The reinforcing film may be either an unstretched film or a uniaxially or biaxially stretched film. Among the above, resin films containing polyester-based resins and / or polyamide-based resins are preferred, and biaxially oriented PET films and biaxially oriented nylon films are more preferably used.

[0045] I-4.Adhesive layer The adhesive used in the adhesive layer may be, for example, an adhesive for DL ​​(dry lamination), an adhesive for EC (extrusion coating), an adhesive for non-solvent lamination, or the like. The adhesive may be of any of the following types: heat-curable, ultraviolet-curable, and electron-beam-curable types; and may be in any form, such as aqueous, solution, emulsion, and dispersion types. The adhesive may be in any form, such as film / sheet, powder, and solid. The adhesive mechanism may be any of the following types: chemical reaction, solvent volatilization, thermal melting, and thermal pressure.

[0046] Examples of components that form such an adhesive layer include polyvinyl acetate resins such as polyvinyl acetate and vinyl acetate-ethylene copolymers, polyacrylic acid resins consisting of copolymers of polyacrylic acid and polystyrene, polyester, polyvinyl acetate, etc., cyanoacrylate resins, ethylene copolymer resins consisting of copolymers of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose resins, polyurethane resins, polyester resins, polyester polyurethane resins, polyamide resins, polyimide resins, polyolefin resins such as LDPE, and amide resins consisting of urea resins or melamine resins. Examples of the resin include elastomer resins such as polyolefin resins, phenolic resins, epoxy resins, reactive (meth)acrylic resins, chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, silicone resins, and inorganic resins such as alkali metal silicates and low-melting glass.

[0047] I-5. Anchor coat layer An anchor coat layer formed from an anchor coating agent may be provided on the adhesive surfaces between layers or on the laminated surfaces to enhance the adhesiveness at the interface. The anchor coat layer is preferably formed in advance on the surface to which the adhesive, liquid resin composition, or molten resin is to be applied or laminated. As the anchor coating agent, polyester polyurethane resins are preferred, and aliphatic polyester polyurethane resins are more preferred.

[0048] II.Transparent moisture-absorbing PTP bottom material The transparent, moisture-absorbing PTP base material of the present invention is a base material made from the transparent, moisture-absorbing blister sheet of the present invention. The transparent moisture-absorbing PTP base material has a shape having a recess for accommodating the contents.

[0049] III.Transparent moisture-absorbing PTP packaging The transparent moisture-absorbing PTP package of the present invention is a package comprising the transparent moisture-absorbing PTP base material of the present invention and a lid material. The transparent moisture absorbing PTP base material and the cover material are bonded together via, for example, an adhesive layer. The recessed space between the transparent moisture-absorbing PTP base material and the lid material can accommodate the contents and store the contents in a low moisture-absorbing state. The contents can be removed by pressing the recessed portion of the transparent, moisture-absorbing PTP base material from the outside, forcing the contents against the lid material and breaking the lid material. EXAMPLES

[0050] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. Details of the raw materials used in the examples are as follows.

[0051] [Moisture absorbent] Moisture absorbent 1: Metal oxide-based moisture absorbent, DHT-4C, manufactured by Kyowa Chemical Industry Co., Ltd. Calcined hydrotalcite (magnesium and aluminum), number average particle size 380 nm, refractive index 1.51. Moisture absorbent 2: Metal oxide-based moisture absorbent, LT015B, manufactured by Toda Kogyo Co., Ltd. Calcined hydrotalcite (magnesium and aluminum), number average particle size 200 nm, refractive index 1.51. Moisture absorbent 3: Metal oxide-based moisture absorbent, KW2000, manufactured by Kyowa Chemical Industry Co., Ltd. Hydrotalcite (magnesium and aluminum) solid solution, number average particle size 7 μm, refractive index 1.57.

[0052] [Binder resin, resin for base layer] PVC resin 1: Polyvinyl chloride, TK-800, manufactured by Shin-Etsu Chemical Co., Ltd. K value 61 (JIS K7367-2:1999), average degree of polymerization 790 (JIS K6720-2:1999). PVDC resin 1: Saran Latex L580C, a coating agent manufactured by Asahi Kasei Chemicals Corporation. Contains vinylidene chloride copolymer. PVDC resin 2: Saran Latex L574A, a coating agent manufactured by Asahi Kasei Chemicals Corporation. Contains vinylidene chloride copolymer. PP resin 1: Polypropylene manufactured by Mitsubishi Chemical Corporation, Novatec PP, EG7FTB . MFR1.3, density 0.9g / cm 3 .

[0053] [others] AC agent 1: Aliphatic polyester polyurethane anchor coating agent. Mass ratio of Takelac A-616 / Takenate A-65 = 16 / 1 mixture.

[0054] [Example 1] The following parts by mass of PVC resin for binder resin 1 and moisture absorbent 1 were mixed in a ribbon blender, then melt-kneaded using a mill roll, and calendered to obtain a 250 μm-thick transparent moisture-absorbing blister sheet. Then, various evaluations were carried out. PVC resin 1 85.5 parts by mass Moisture absorbent 1 14.5 parts by weight

[0055] [Examples 2, 6, 7, 12, Comparative Examples 1, 2, 4] A transparent moisture-absorbing blister sheet was obtained in the same manner as in Example 1, except that the types and amounts of the binder resin and moisture absorbent were changed to those shown in Tables 1 to 3, and was evaluated in the same manner.

[0056] [Example 3] The following parts by mass of PVC resin 1 and moisture absorbent 1 were mixed in a ribbon blender to prepare a resin composition for a moisture absorbent layer. PVC resin 1 64 parts by mass Moisture absorbent 1 36 parts by weight Then, the resin composition for the moisture absorbing layer obtained above and PVC resin 1 for base layers 1 and 2 were used to obtain a transparent moisture absorbing blister sheet having the following three-layer structure by co-extrusion molding. Base layer 1 / moisture absorption layer / base layer 2 = PVC resin 1 (75μm thickness) / resin composition for moisture absorption layer (100μm thickness) / PVC resin 1 (75μm thickness)

[0057] [Examples 4, 5, 8, 11, 13, Comparative Example 5] A transparent moisture-absorbing blister sheet was obtained in the same manner as in Example 3, except that the composition and thickness of the moisture-absorbing layer and the type and thickness of the base layers 1 and 2 were changed to those shown in Tables 1 to 3, and was evaluated in the same manner.

[0058] [Example 9] The following parts by mass of PVC resin for binder resin 1 and moisture absorbent 1 were mixed in a ribbon blender, then melt-kneaded using a mill roll, and calender-molded to obtain a moisture absorbent layer sheet having a thickness of 200 μm. PVC resin 1 81.5 parts by mass Moisture absorbent 1 18.5 parts by weight Next, AC agent 1 was applied to one side of the obtained sheet for moisture absorbing layer and dried to form an anchor coat layer having a thickness of 2 μm (after drying). Then, PVDC resin 1 was applied onto the surface of the resulting anchor coat layer and dried to form a base layer 1 having a thickness of 7 μm (after drying). Furthermore, PVDC resin 2 was applied and dried on the surface of the obtained base layer 1, and this was repeated six times to form a PVDC layer 2 having a thickness of 42 μm after drying, thereby obtaining a transparent moisture-absorbing blister sheet having the following layer structure. Base layer [PVDC layer 2 / PVDC layer 1 / anchor coat layer] / moisture absorbing layer=[PVDC resin 2 (42 μm thick) / PVDC resin 1 (7 μm thick) / AC agent 1 (2 μm thick)] / resin composition for moisture absorbing layer (100 μm thick)

[0059] [Example 10, Comparative Example 3] A transparent moisture-absorbing blister sheet was obtained in the same manner as in Example 9, except that the composition and thickness of the moisture-absorbing layer were changed to those shown in Table 1, and was evaluated in the same manner.

[0060] <Evaluation method>

[0061] [Film forming property] The appearance of the transparent moisture-absorbing blister sheet was observed with the naked eye, and the presence or absence of defects was evaluated according to the following evaluation criteria. Passed: The transparent moisture-absorbing blister sheet had no wrinkles, bumps, or peeling. Rejected: The transparent moisture-absorbing blister sheet had wrinkles, bumps, or peeling.

[0062] [Moisture absorption amount] The transparent moisture-absorbing blister sheet was cut into a size of 100 mm length x 100 mm width, and left to stand for 11 days in an environment of 25°C temperature and 50% RH. The weight change of the transparent moisture-absorbing blister sheet was then calculated based on the weight of the blister sheet. 2 The amount of moisture absorbed per unit was determined.

[0063] [Total light transmittance and haze] The transparent moisture-absorbing blister sheet was cut to dimensions of 50 mm in length x 50 mm in width, and the total light transmittance and haze of the transparent moisture-absorbing blister sheet were measured using a color information measuring device, a haze meter (HM-150, manufactured by Murakami Color Research Laboratory Co., Ltd.), in accordance with JIS K7361 (Testing method for optical properties of plastics).

[0064] [Packaging manufacturability] The PTP was formed using a blister pack molding machine (CKD Corporation), the bottom of the PTP package was made from a transparent moisture-absorbing blister sheet, and an aluminum PTP lid material was heat-sealed to produce the PTP package. When the aluminum PTP lid material was heat sealed to a layer containing a polyolefin resin, ALT-PP (manufactured by Kanae Co., Ltd.) was used as the aluminum PTP lid material, and when the aluminum PTP lid material was heat sealed to a layer containing a polyvinyl chloride resin, ALT-VC (manufactured by Kanae Co., Ltd.) was used as the aluminum PTP lid material. The pass / fail criteria are as follows: Passed: No wrinkles occurred during PTP molding and molding was successful. Rejected: Numerous wrinkles occurred during PTP molding, and good molding was not possible.

[0065] [Table 1]

[0066] [Table 2]

[0067] [Table 3]

[0068] <Summary of Results> The transparent moisture-absorbing blister sheets of all the examples of the present invention exhibited a good balance of film-forming property, high moisture absorption property, high total light transmittance before and after moisture absorption, and low haze. On the other hand, the sheets of Comparative Examples 1 to 4, which contained too little moisture absorbent, exhibited poor moisture absorption and high haze, while the sheet of Comparative Example 5, which contained too much moisture absorbent, exhibited poor film-forming properties and PTP packaging fabrication properties. [Explanation of symbols]

[0069] 1 Transparent moisture absorbing blister sheet 2. Moisture absorption layer 3 Base material layer 1 3a Base material layer 1a 3b Base material layer 1b 4 Base material layer 2 5 Anchor coat layer 7 PTP packaging 8 PTP packaging base 9 Next layer 10 PTP packaging cover

Claims

1. A transparent moisture-absorbing blister sheet for a blister base material, comprising at least a moisture-absorbing layer, The moisture absorbing layer contains at least a moisture absorbent and a binder resin, The moisture absorbent contains hydrotalcite, the binder resin contains a polyvinyl chloride resin and / or a polyolefin resin, When subjected to moisture absorption treatment at 25°C and 50% humidity for 11 days, the moisture absorption amount was 3 g / m 2 or more, the total light transmittance before and after the moisture absorption treatment is 60% or more and 99% or less, and the haze before and after the moisture absorption treatment is 10% or more and 70% or less. A transparent moisture-absorbing blister sheet.

2. 2. The transparent moisture-absorbing blister sheet according to claim 1, wherein the content of hydrotalcite in the moisture-absorbing layer is 10% by mass or more and 40% by mass or less.

3. A transparent moisture-absorbing blister sheet further comprising a base layer on one or both sides of the moisture-absorbing layer, The substrate layer contains a polyvinyl chloride resin and / or a polyolefin resin, The transparent moisture-absorbing blister sheet has a thickness of 200 μm or more.

2. The transparent moisture-absorbing blister sheet according to claim 1 .

4. 2. The transparent moisture-absorbing blister sheet according to claim 1, which contains a phosphorus-based antioxidant and / or a thioether-based antioxidant.

5. A transparent, moisture-absorbing push-through package (PTP) base material comprising the transparent, moisture-absorbing blister sheet according to any one of claims 1 to 4.

6. A transparent, moisture-absorbing press-through package (PTP) package having a lid material and a transparent, moisture-absorbing push-through package (PTP) base material according to claim 5.

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