Paper blister pack

Abstract

To provide a paper blister pack with excellent opening properties. [Solution] It has a base part and a container part formed from a paper blank, The fused pieces of the base portion and the container portion are both provided with a heat seal layer, and are fused together via the heat seal layer. The aforementioned paper blanks have a basis weight of 150 g / m². 2 More than 300g / m 2 The following base paper is provided, with crease lines and perforations formed on it: A paper blister pack in which at least a portion of the perforations is formed on the fused side of the side panel.

Description

[Technical Field]

[0001] This invention relates to a paper blister pack. [Background technology]

[0002] Blister packs, which use plastic sheets with recesses for containing items, are widely used for packaging various items such as stationery, cosmetics, and toys because they are transparent, allowing for inspection of the contents, and offer excellent protection for the items. In recent years, efforts have begun to prevent environmental damage caused by plastic waste, and there is a demand to replace disposable plastic products with materials that have a smaller environmental impact. Paper-based blister packs, which do not use plastic, have also been proposed (see Patent Documents 1-3, etc.). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-172465 [Patent Document 2] Japanese Patent Application Publication No. 11-321922 [Patent Document 3] Japanese Patent Publication No. 2001-253470 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Paper blister packs generally use strong cardboard to prevent damage to the contents even if they are subjected to impact during display. However, because cardboard is thick and has a high basis weight, considerable force is required to tear and open them, which can be difficult for the elderly, children, and people with disabilities to open. This invention was developed based on the above background, and aims to provide a paper blister pack with excellent openability. [Means for solving the problem]

[0005] The means for solving the problems of the present invention are as follows. 1. It has a base part and a container part formed from a paper blank, The fused pieces of the base portion and the container portion are both provided with a heat seal layer, and are fused together via the heat seal layer. The aforementioned paper blanks have a basis weight of 150 g / m². 2 More than 300g / m 2 The following base paper is provided, with crease lines and perforations formed on it: A paper blister pack characterized in that at least a portion of the perforations is formed in the region of the side panel on the fused side. 2. The paper blister pack according to claim 1, characterized in that at least a portion of the perforations is formed at the boundary between the side panel and the fused piece. 3. The paper blister pack according to 1. or 2., characterized in that the heat seal layer is a coating layer containing a biodegradable thermoplastic resin. 4. The paper blister pack according to 3, characterized in that the coating layer contains 1 to 250 parts by mass of EVA per 100 parts by mass of PHBH. 5. A paper blister pack according to any one of claims 1 to 4, characterized in that at least one of the paper substrates constituting the cardboard portion or the container portion has a pigment coating layer on the surface that faces outward from the container. [Effects of the Invention]

[0006] The paper blister pack of the present invention has excellent opening properties because the thick, rigid portion created by fusing the cardboard portion and the container portion (fused piece) provides support, and force can be easily applied to the perforations located near this support. The paper blister pack of the present invention, which has a coating layer containing a thermoplastic resin with a heat-sealing layer being biodegradable, will be rapidly decomposed even if it flows out into the environment as garbage. In the paper blister pack of the present invention where the coating layer contains 1 to 250 parts by mass of EVA with respect to 100 parts by mass of PHBH, the mount part and the container part are firmly heat-sealed and are unlikely to peel off. Further, since this coating layer is unlikely to peel off even when rubbed in a state where moisture is attached, for example, even when a wet article is stored in an opened paper blister pack, it is possible to prevent soiling by the coating layer.

Brief Description of the Drawings

[0007] [Figure 1] Perspective view seen from the container part side of the paper blister pack which is one embodiment. [Figure 2] Perspective view seen from the mount part side of the paper blister pack which is one embodiment. [Figure 3] Exploded view of the paper blister pack which is one embodiment. [Figure 4] Plan view of the carton blanks constituting the container part in the paper blister pack which is one embodiment. [Figure 5] Plan view of the mount part in the paper blister pack which is one embodiment. [Figure 6] View showing how to open the paper blister pack which is one embodiment.

Modes for Carrying Out the Invention

[0008] The present invention relates to a paper blister pack having a mount part and a container part. In the paper blister pack of the present invention, the container part is formed from paper blanks, and these paper blanks are base papers having a basis weight of 150 g / m 2 or more and 300 g / m 2 or less. In the present invention, the paper substrate for forming the base portion is not particularly limited, and either the same paper substrate as the paper blank for forming the container portion or a different paper substrate may be used. However, a paper substrate that satisfies the same conditions as the paper blank for forming the container portion described below is preferred. Note that a paper substrate that satisfies the same conditions as the paper blank means that the composition, basis weight, density, coating amount, etc., are the same, and as long as the conditions are satisfied, different compositions, basis weights, densities, coating amounts, etc., may be used.

[0009] The paper blanks that form the container section are equipped with a base paper. The base paper is a sheet made primarily of pulp, and is obtained by papermaking a pulp containing fillers, various auxiliary agents, etc. Examples of pulp include chemical pulps such as bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), unbleached softwood pulp (NUKP), and sulfite pulp; mechanical pulps such as stone-ground pulp and thermomechanical pulp; wood fibers such as deinked pulp and recycled paper pulp; and non-wood fibers obtained from kenaf, bamboo, hemp, etc. One or more of these can be used in appropriate blends. Among these, chemical pulps made from wood fibers and mechanical pulps made from wood fibers are preferred, and more preferably, chemical pulps made from wood fibers, because they are less likely to cause foreign matter contamination in the paper substrate, are less likely to discolor over time when recycled as recycled paper raw material, and have high whiteness, resulting in a good surface texture when printed. Furthermore, when using chemical pulps, it is preferable to use bleached pulp when whiteness is required, and unbleached pulp when a natural feel is required. The amount of chemical pulp containing wood fibers such as LBKP and NBKP relative to the total pulp is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and most preferably 100% by mass.

[0010] As fillers, known fillers such as talc, kaolin, calcined kaolin, clay, heavy calcium carbonate, light calcium carbonate, white carbon, zeolite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon dioxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, barium sulfate, calcium sulfate, and other inorganic fillers, as well as organic fillers such as urea-formaldehyde resin, polystyrene resin, phenolic resin, and fine hollow particles can be used. Note that fillers are not essential materials and may not be used.

[0011] Examples of various additives include sizing agents such as rosin, alkyl ketene dimer (AKD), and alkenyl succinic anhydride (ASA); dry strength enhancers such as polyacrylamide polymers, polyvinyl alcohol polymers, cationized starch, various modified starches, urea-formaldehyde resins, and melamine-formaldehyde resins; wet strength enhancers; yield enhancers; water drainage enhancers; coagulants; aluminum sulfate; bulk enhancers; dyes; fluorescent whitening agents; pH adjusters; defoamers; UV inhibitors; fade inhibitors; pitch control agents; and slime control agents. These can be selected and used as needed.

[0012] The base paper may have its surface treated with various chemicals. Examples of chemicals include oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, surface sizing agents, water-resistant agents, water-retaining agents, thickeners, and lubricants, which can be used individually or in combination of two or more. Furthermore, these various chemicals may be used in combination with pigments. Examples of pigments include inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicates, colloidal silica, and satin white, as well as organic pigments such as dense, hollow, or core-shell types, which can be used individually or in combination of two or more.

[0013] The method for manufacturing (papermaking) the base paper is not particularly limited, and known manufacturing (papermaking) methods and papermaking machines such as a fourdrinier papermaking machine, a cylinder papermaking machine, a twin-wire papermaking machine such as a shoe-former type, a hybrid former type (onto-former type), etc. can be selected. Also, the pH during papermaking may be in any of the acidic region (acid papermaking), pseudo-neutral region (pseudo-neutral papermaking), neutral region (neutral papermaking), and alkaline region (alkaline papermaking). After papermaking in the acidic region, an alkaline agent may be applied to the surface of the paper layer. When treating the surface of the base paper with a chemical, the surface treatment method is not particularly limited, and known coating devices such as a rod metering size press, a pond size press, a gate roll coater, a spray coater, a blade coater, a curtain coater, etc. can be used.

[0014] The basis weight of the base paper is 150 g / m 2 or more and 300 g / m 2 or less. When the basis weight of the base paper is within this range, it has sufficient strength as a paper blister pack and also has excellent peelability. From the perspective of peelability, the basis weight of the base paper is more preferably 260 g / m 2 or less, even more preferably 220 g / m 2 or less, and still more preferably 180 g / m 2 or less. On the other hand, from the perspective of strength, the basis weight of the base paper is more preferably 180 g / m 2 or more, even more preferably 220 g / m 2 or more, and still more preferably 260 g / m 2 or more. The density of the base paper is preferably 0.5 g / cm 3 or more and 1.0 g / cm 3 or less. From the perspective of peelability, the density of the base paper is more preferably 0.9 g / cm 3 or less, even more preferably 0.8 g / cm 3 or less. On the other hand, from the perspective of strength, the density of the base paper is more preferably 0.6 g / cm 3 or more, even more preferably 0.7 g / cm 3 or more. In the present invention, the base paper may be either a paper consisting of only a single layer or a multilayer paper having two or more layers. If the base paper is a multilayer paper, the pulp, basis weight, etc. of each layer may be the same or different.

[0015] In the present invention, the base paper is preferably free from curling, from the viewpoint of satisfying transportability and processability. Furthermore, in particular, for base paper used in the container portion, it is required that no creases occur when processing it into the container shape. The occurrence of curling and creases can be prevented by adjusting the paper thickness, density, stiffness of the base paper, etc.

[0016] • Heat seal layer The paper blanks that form the container and the backing paper substrate are provided with a heat seal layer in at least the areas to be fused. The paper blanks and the backing paper substrate may have a heat seal layer over the entire surface of the surface to be fused (the inner surface of the container), or they may also have a heat seal layer on the non-fused surface (the outer surface of the container). However, if high printability is required, it is preferable to have a pigment coating layer on the outermost surface of the container. In addition, other layers such as an anchor layer, a water vapor barrier layer, a gas barrier layer, and an ink receiving layer may also be present.

[0017] The heat-seal layer may be either a laminate layer or a coating layer, but a coating layer is preferred from the viewpoint of ease of opening. The thermoplastic resin contained in the heat-sealable coating layer (hereinafter also referred to as the coating layer) is not particularly limited as long as it can form a heat-sealable coating film by coating, but it is preferable that it contains a biodegradable resin. Examples of biodegradable resins include PHBH, polylactic acid, polycaprolactone, polybutylene succinate adipate, polybutylene succinate, polybutylene adipate terephthalate, polybutylene azelate terephthalate, polyvinyl alcohol, polyvinyl acetate, EVA, etc., and among these, it is preferable to use PHBH and EVA in combination. The coating layers of the paper blanks and the backing paper substrates may contain different thermoplastic resins as long as they can be fused together. Biodegradable resins are defined as resins that are broken down by microorganisms into at least water and carbon dioxide, and whose aerobic biodegradation rate, measured according to ISO-14855-2 (2018), is 50% or more in 6 months.

[0018] If the coating layer contains thermoplastic resins other than PHBH and EVA, it is preferable that the other thermoplastic resins are biodegradable resins. Furthermore, the total ratio of PHBH and EVA to the total thermoplastic resins contained in the coating layer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, even more preferably 99% by mass or more, and most preferably 100% by mass.

[0019] <phbh> PHBH is a copolymer of 3-hydroxybutyrate (hereinafter also referred to as 3HB) and 3-hydroxyhexanoate (hereinafter also referred to as 3HH), and is a biodegradable resin known to be produced by microorganisms. In the present invention, PHBH may be derived from microorganisms or from petroleum resources, but it is preferable to use PHBH derived from microorganisms from the viewpoint of reducing environmental impact.

[0020] The composition ratio (mol%) of PHBH is preferably 3HB:3HH = 97:3 to 75:25, and more preferably 95:5 to 85:15. The composition ratio of PHBH can be measured by NMR analysis of the powder obtained by centrifuging an aqueous dispersion and then drying it. Here, in this specification, "A to B" (where A and B are numerical values ​​or ratios) refers to a numerical range including A and B. Microbially produced PHBH is a random copolymer. Methods to adjust the molar ratio of the copolymer include selecting the microbial cells, selecting the carbon source as the raw material, blending with PHBH of different molar ratios, and blending with 3HB homopolymer.

[0021] The weight-average molecular weight of PHBH is preferably between 50,000 and 1,500,000. When the weight-average molecular weight of PHBH is within this range, film formation at low temperatures is possible when coating with PHBH, and heat sealing at low temperatures is also possible. A weight-average molecular weight of 100,000 to 500,000 is more preferable, and 150,000 to 450,000 is even more preferable. The weight-average molecular weight of PHBH can be determined by gel permeation chromatography (GPC, such as Showa Denko's "Shodex GPC-101") using a polystyrene gel column (such as Showa Denko's "Shodex K-804") with chloroform as the mobile phase, and the molecular weight converted to polystyrene equivalent. For measurement, a powder obtained by centrifuging an aqueous dispersion containing PHBH and then drying it is used.

[0022] The average particle size of PHBH is preferably 0.1 to 50 μm. PHBH with an average particle size of less than 0.1 μm is difficult to produce by microorganisms, and even when obtained by chemical synthesis, a process of micronization is required. If the average particle size exceeds 50 μm, uneven coating may occur on the surface when a coating solution containing PHBH is applied. The average particle size of PHBH is more preferably 0.5 to 10 μm. The average particle size of PHBH refers to the particle size corresponding to the 50% accumulation of all particles measured by adjusting an aqueous suspension of PHBH to a predetermined concentration using a general-purpose particle size analyzer such as a Microtrac particle size analyzer (Nikkiso, FRA).

[0023] <eva> EVA (ethylene vinyl acetate copolymer) is a copolymer in which ethylene and vinyl acetate are monomers, and other monomers may also be used as monomers. However, it is preferable that the EVA of the present invention is not saponified and does not have vinyl alcohol units produced by the saponification of vinyl acetate units. When the EVA has other monomers as monomers, it is preferable that the content of constituent units derived from other monomers relative to the total EVA is 30% by mass or less. This content is not particularly limited as long as it does not impair the effects of the present invention, and can be, for example, 20% by mass or less, 10% by mass or less, 5% by mass or less, 3% by mass or less, 1% by mass or less, etc.

[0024] The glass transition temperature of EVA is preferably -50 to 30°C from the viewpoint of heat seal strength. More preferably -40°C or higher, even more preferably -35°C or higher, even more preferably 20°C or lower, and even more preferably 10°C or lower. In this specification, the glass transition temperature refers to the intermediate glass transition temperature measured in accordance with JIS K 7121-1987. In EVA, the molar ratio of ethylene to vinyl acetate (component units derived from ethylene:component units derived from vinyl acetate, also expressed as ethylene:vinyl acetate, with a total of 100) is preferably 1:99 to 60:40 from the viewpoint of heat seal strength. This molar ratio is more preferably 3:97 to 50:50, and even more preferably 5:95 to 45:55.

[0025] The coating layer preferably contains 1 to 250 parts by mass of EVA per 100 parts by mass of PHBH. By including PHBH and EVA in this ratio, a coating layer with excellent wet-rub properties can be obtained. The ratio of EVA to 100 parts by mass of PHBH is more preferably 6 parts by mass or more, even more preferably 11 parts by mass or more, and even more preferably 16 parts by mass or more. There is no particular upper limit to this ratio of EVA, but for example, it can be 230 parts by mass or less, 210 parts by mass or less, 190 parts by mass or less, etc.

[0026] <Inorganic pigments> The coating layer may also contain inorganic pigments. Inorganic pigments used in paper coatings can be used without particular limitations, including, for example, kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, bentonite, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicates, colloidal silica, and satin white. One or more of these can be used. Among these, one or more of kaolin, heavy calcium carbonate, light calcium carbonate, mica, talc, and bentonite are preferred.

[0027] From the viewpoint of adhesion to the coating layer, it is preferable that the inorganic pigment has a 50% volume average particle diameter (D50, hereinafter also referred to as "average particle diameter") of 6.0 μm or less, as measured by laser diffraction / scattering. Examples of laser diffraction / scattering measurement devices include Horiba's particle size distribution analyzer "Partica" and Malvern's particle size distribution analyzer "MASTER SIZER S". From the viewpoint of adhesion to the coating layer, the average particle diameter of the inorganic pigment is more preferably 5.0 μm or less, even more preferably 4.0 μm or less, even more preferably 3.0 μm or less, and even more preferably 2.0 μm or less. There is no particular lower limit to the average particle diameter of the inorganic pigment, but from the viewpoint of dispersibility, for example, it is preferably 0.1 μm or more, and more preferably 0.2 μm or more. When two or more inorganic pigments are included, it is preferable that the average particle size of at least one of them is within the numerical range described above, and it is preferable that the proportion of inorganic pigments satisfying this average particle size to the total inorganic pigments is 50% by mass or more, and more preferably 70% by mass or more.

[0028] When the coating layer contains an inorganic pigment, the solid content mass ratio of the total thermoplastic resin to the inorganic pigment (thermoplastic resin:inorganic pigment, total 100) is preferably 90:10 to 0.01:99.99. By further incorporating an inorganic pigment into a coating solution containing a thermoplastic resin and EVA, the adhesion of the resulting coating layer is improved. Although the mechanism is unknown, the inventors speculate that because inorganic pigments have better thermal conductivity than thermoplastic resins, the inorganic pigment heats up quickly when the coating solution dries, and this heat is transferred from the inorganic pigment to the thermoplastic resin, causing the thermoplastic resin to heat up and soften sufficiently, making it easier to adhere to the base paper. The solid content mass ratio (PHBH:inorganic pigment, total 100) of the thermoplastic resin to the inorganic pigment is more preferably 70:30 to 1:99, even more preferably 60:40 to 2:98, and even more preferably 50:50 to 3:97, from the viewpoint of adhesion of the coating layer.

[0029] In addition to thermoplastic resins and inorganic pigments, the coating layer may contain other water-soluble resins and water-dispersible resins. Furthermore, it may optionally contain various additives used in coating solutions in the papermaking field, such as dispersants, viscosity modifiers, defoamers, water-resistant agents, pH adjusters, cationic resins, anionic resins, UV absorbers, metal salts, lubricants, coloring dyes, and pigments.

[0030] (Manufacturing method) The coating layer can be manufactured by conventionally known coating methods. For example, coating equipment includes blade coaters, bar coaters, roll coaters, air knife coaters, reverse roll coaters, curtain coaters, spray coaters, size press coaters, and gate roll coaters. As for the coating system, there are water-based coatings using solvents such as water, and solvent-based coatings using solvents such as organic solvents. However, water-based coatings are preferred from a safety and environmental standpoint, and water-dispersion coatings are even more preferred from the standpoint of ease of opening.

[0031] The coating amount is 1 g / m² by dry mass. 2 More than 50g / m 2 The following is preferable: Coating amount of 1 g / m 2 If the amount is less than 50 g / m², it may be difficult to form a uniform coating. 2 A higher amount increases the drying load during coating. The coating amount for the coating layer is 3g / m². 2 The above is more preferable: 5 g / m 2 The above is even more preferable, 40 g / m 2 The following is more preferable: 30g / m 2 The following are even more preferable.

[0032] "Paper blister pack" The paper blister pack of the present invention will be described below with reference to the figures. Figures 1 and 2 show perspective views of a paper blister pack 100, one embodiment of the product, from the container portion 1 side and the backing card portion 2 side, respectively. Figure 3 shows an exploded view of the paper blister pack 100, one embodiment of the product. Figure 4 shows a plan view of the paper blanks 10 that form the container portion 1. Figure 5 shows a plan view of the backing card portion 2. Figure 6 shows how to open the paper blister pack 100, one embodiment of the product. Hereinafter, in this specification, up, down, left, and right refer to the top, bottom, left, and right directions when the paper blister pack is suspended and viewed from the container side.

[0033] • Backing board The cardboard base 2 is roughly rectangular in shape, and a hanging hole 221 is formed at the top. • Paper blanks The paper blank 10 has a rectangular top panel 11, to which side panels, consisting of a top panel 12, a bottom panel 13, a left side panel 14, and a right side panel 15, are connected via fold lines 22, 23, 24, and 25. Furthermore, fused pieces 32, 33, 34, and 35 are connected to the side panels 12, 13, 14, and 15 via perforations 42, 43, 44, and 45. A suspension hole 321 is formed in the fused piece 32 connected to the top panel 12. In addition, an upper flap panel and a lower flap panel can also be connected to the side panels 12, 13, 14, and 15 via fold lines (not shown). The paper blank 10 is folded along the crease lines 22, 23, 24, and 25 and the perforations 42, 43, 44, and 45 to form the container section 1.

[0034] In one embodiment of the paper blister pack 100, the perforations 42, 43, 44, and 45 are formed on the boundary between the side panels 12, 13, 14, and 15 and the fused pieces 32, 33, 34, and 35. The pattern shape of the perforations is not particularly limited, and known patterns such as straight, micro, V-shape, S-shape, and Y-shape can be used. Furthermore, two straight perforations can be provided close together and parallel to each other.

[0035] In the present invention, at least a portion of the perforations is formed in the region on the fused piece side of the side panel. Here, in this specification, "region on the fused piece side of the side panel" means the region where the shortest distance to an adjacent fused piece is less than or equal to the shortest distance to the top panel. That is, at least a portion of the perforations 42, 43, 44, and 45 are formed in the side panels 12, 13, 14, and 15 at a position between 0 and 50 on the straight line connecting adjacent fused pieces 32, 33, 34, and 35 and the top panel 11, where the boundary with the fused pieces 32, 33, 34, and 35 is expressed as 0 and the boundary with the top panel 11 is expressed as 100. In the paper blister pack of the present invention, the position of at least a portion of the perforations is preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, even more preferably 10 or less, even more preferably 5 or less, and most preferably 0, i.e., located on the boundary between the side panel and the fused piece (a form of one embodiment).

[0036] The length of the perforations 42, 43, 44, and 45 formed in the region of the side panels 12, 13, 14, and 15 on the fused pieces 32, 33, 34, and 35 sides is preferably 5 mm or more, more preferably 7 mm or more, even more preferably 9 mm or more, even more preferably 11 mm or more, even more preferably 13 mm or more, and even more preferably 15 mm or more. There is no particular upper limit on the length of the perforations formed in this region.

[0037] • Paper blister pack Both the cardboard base 2 and the paper blank 1 have a heat-seal layer (not shown) on one side. By fusing the cardboard base 2 and the fusion pieces 32, 33, 34, and 35 of the container 1 via this heat-seal layer, a paper blister pack 100 is formed.

[0038] In this invention, the backing paper substrate and the paper blanks are measured in accordance with JIS Z1707:2019 7.4 "Heat seal strength test", with a pressurized temperature of 160°C and a pressurized pressure of 0.2 MPa (20.0 N / cm²). 2 ) When a heat-sealed product that has been heat-sealed for a pressurizing time of 1.0 second is peeled off in a T-shape, the heat seal strength is preferably 4.0 N / 15 mm or more, more preferably 5.0 N / 15 mm or more, even more preferably 6.0 N / 15 mm or more, and even more preferably 6.5 N / 15 mm or more. Furthermore, the heat seal strength of the backing paper substrate and the paper blanks, measured in the same manner except that the pressurizing temperature was 180°C, is preferably 4.0 N / 15 mm or more, more preferably 5.0 N / 15 mm or more, even more preferably 6.0 N / 15 mm or more, and even more preferably 6.5 N / 15 mm or more.

[0039] In the paper blister pack of the present invention, the ratio of biodegradable material to the total non-ash content of the paper blister pack is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. The total non-ash content of the paper blister pack refers to the non-ash content of the paper blister pack as measured in accordance with JIS P8251:2003; for example, if the ash content is 1%, it means the remaining 99%. Biodegradable material refers to a material that is decomposed by microorganisms into at least water and carbon dioxide, and means a resin whose aerobic biodegradation rate, measured in accordance with ISO-14855-2 (2018), is 50% or more in 6 months. Examples of biodegradable material in the paper blister pack of the present invention include pulp and biodegradable resin contained in the heat seal layer.

[0040] • How to open a paper blister pack In one embodiment of the paper blister pack 100, the area where the cardboard portion 2 and the fused pieces 32, 33, 34, and 35 are fused together is thicker and more rigid. Perforations 42, 43, 44, and 45 are formed near this thick, rigid portion of the paper blister pack 100. Because it is easy to apply force to the perforations 42, 43, 44, and 45 using this rigid portion as support, the perforations 42, 43, 44, and 45 are easy to break, resulting in excellent initial opening performance. Furthermore, once at least a portion of the perforations 42, 43, 44, and 45 is broken, it is easy to break the continuous perforations 42, 43, 44, and 45 starting from the broken portion, thus the paper blister pack 100 has excellent opening performance. In this case, since the backing paper portion 2 and the fused pieces 32, 33, 34, and 35 are firmly fused together, even if force is applied to break the perforations 42, 43, 44, and 45 by pulling them apart from both sides, the fused pieces 32, 33, 34, and 35 remain fused to the backing paper portion 2.

[0041] The examples shown in Figures 1-6 represent only one embodiment, and the paper blister pack of the present invention is not limited thereto. For example, a panel that forms the base can be connected to a paper blank that constitutes the container, and the container and base can be constructed from a single paper blank. In addition, in the paper blank, a fold line can be superimposed on the perforations that separate the side panel and the fused piece to facilitate folding. Alternatively, in the paper blister pack of the present invention, it is sufficient that at least a portion of the perforations is located in the region on the fused piece side of the side panel, and perforations that are continuous with the perforations formed on the fused piece side of the side panel, or independent perforations, can also be formed in the region on the top side of the side panel or on the top panel. [Examples]

[0042] The present invention will be specifically described below with reference to examples, but the present invention is of course not limited to these examples. Unless otherwise specified, parts and % in the examples refer to parts by mass and mass%, respectively.

[0043] (Evaluation method) Wet Love The prepared paper substrate was placed on a horizontal surface and subjected to temperature and humidity control (conditions: 23°C, 50% humidity) for at least 24 hours. Then, a cross pattern was drawn on the coated surface using a new oil-based marker (ZEBRA Maki Extra Fine) that had been opened immediately before the test, and it was allowed to dry for 5 minutes. After that, the pattern was lightly traced back and forth 50 times with a wet finger, and the degree of pattern retention and peeling of the coating layer were evaluated according to the following criteria. A rating of 5 or 4 indicates that there are no practical problems. 5: No change 4: Less than 10% of white areas occurred. 3: White areas appearing in 10% to less than 50% of areas. 2: Whitening occurs in 20% to less than 50% of areas + leaching of the coating layer. 1: Whitening occurs in areas between 50% and 100% of the surface, and the coating layer is leached out. <Example of judgment> [Table 1]

[0044] Tape pick The prepared paper substrate was placed on a horizontal table and subjected to temperature and humidity control (conditions: 23°C, 50% humidity) for at least 24 hours. Then, a 12mm wide mending tape (3M Japan, Scotch® Mending Tape 810-1-12) was applied to the surface of the coating layer of the coated paper. A 130mm wide, 1.8kg rubber roller was then moved back and forth 20 times under its own weight over the mending tape to ensure close adhesion of the mending tape to the coating layer surface. Immediately afterward, the mending tape was quickly peeled off, and the ratio of the area where the coating layer adhered to the mending tape and peeled away from the substrate (interface failure area) to the area where the mending tape was applied, or the ratio of the area where part of the substrate adhered to the mending tape along with the coating layer and the substrate was damaged (internal substrate failure area), was calculated. The adhesion between the substrate and the coating layer was then evaluated according to the following criteria. An evaluation of 5 or 4 indicates no practical problems. 5: No peeling 4: Less than 0-10% peeling of the adhesive surface. 3: Less than 10-50% of the adhesive surface is peeled off. 2: Less than 50-90% of the adhesive surface is peeled off. 1: 90-100% of the adhesive surface has peeled off.

[0045] • Heat seal strength The test was conducted in accordance with JIS Z1707:2019 7.4 "Heat seal strength test". Two 100 mm square test pieces were cut from the obtained paper substrate, and the coated layers were brought into contact with each other. The test was performed at a pressurized temperature of 160°C or 180°C and a pressurized pressure of 0.2 MPa (20.0 N / cm²). 2 After heat-sealing with a pressurization time of 1.0 second, the specimen was left to stand for 24 hours in an environment of 23°C and 50% humidity. Then, a measurement sample was cut from the heat-sealed 100mm square test piece so that the long side was 100mm and the short side was 15mm. Subsequently, the peeled long edge was clamped in the upper and lower fixtures of a vertical tensile testing machine (Tensilon, manufactured by A&D Company, Ltd.), and the sample was peeled from the long edge side at a speed of 200 mm / min (T-type), while measuring the peel strength, i.e., the HS strength (N / 15 mm). Furthermore, the detached surface was visually inspected and evaluated according to the following criteria. Measurements are taken twice, and the average value of the peel strength is shown. If the evaluation results differ based on visual observation, both results are shown. ○: The entire surface of the heat-sealed area is damaged. △: Partial material damage on the heat-sealed surface ×: Delamination occurs between coating layers (no material breakage). -: Without heat sealing

[0046] (material) Base paper: Nippon Paper Industries, basis weight 260g / m² 2 NEW Ultra H PHBH: Kaneka Corporation, mass-average molecular weight 600,000 Inorganic pigment: Shiraishi Industries Co., Ltd., kaolin, KCS, average particle size 3.6 μm, aspect ratio 10-15

[0047] PVA1: Kuraray Co., Ltd., 28-98, fully saponified PVA PVA2: Kuraray Co., Ltd., HR3010, high water resistance Partially saponified EVA: Kuraray Co., Ltd., RS-1713 EVA1: Sumika Chemtex Co., Ltd., S-400HQ, Tg 0℃, Ethylene:Vinyl Acetate = 20:80 EVA2: Sumika Chemtex Co., Ltd., S-305HQ, Tg 7℃, Ethylene:Vinyl Acetate = 10:90 EVA3: Sumika Chemtex Co., Ltd., S-410HQ, Tg -18℃, Ethylene:Vinyl Acetate = 30:70 EVA4: Sumika Chemtex Co., Ltd., S-408HQE, Tg -30℃, Ethylene:Vinyl Acetate = 40:60

[0048] "Manufacturing of paper substrates" PHBH, EVA or PVA, and an inorganic pigment were mixed and stirred in the parts by mass shown in Table 2 to obtain a coating solution with a solid content concentration of 40% by mass. A coating solution was applied to one surface of the base paper using the bar-blade method to achieve the dry mass shown in Table 2. After drying at 105°C for 1 minute, a heat treatment was performed at 140°C for 1 minute to form a paper substrate with a coating layer on the outermost surface of one side of the base paper.

[0049] [Table 2]

[0050] The paper substrates obtained in manufacturing examples 1-15 could all be firmly heat-sealed at 180°C. The paper substrates obtained in manufacturing examples 5-15, which used PHBH and EVA in combination, also showed excellent wet-rub evaluation scores of "5".

[0051] "Example 1" From the paper substrate obtained in Manufacturing Example 7, a base portion and a paper blank, which are one embodiment shown in Figures 1-6, were created, and a container portion was formed from the paper blank. A paper blister pack was manufactured by fusing the cardboard backing and the container part together under the following conditions, with one oil-based marker (Zebra Corporation, Hi-Macky) inserted inside. • Fusion conditions After heating the container portion from the container side at 185°C for 3.0 seconds, the adhesive surfaces were aligned with the backing paper portion, and heat sealing was performed at 205°C for 2.0 seconds under the conditions of 2kN. "Comparative Example 1" A paper blister pack was manufactured in the same manner as in Example 1, except that a crease line was provided at the boundary between the side panel and the fused piece of the paper blank, and perforations were formed at the boundary between the side panel and the top panel.

[0052] The paper blister pack manufactured in Example 1 was easy to open; simply pressing near the perforations on the side panel with a finger would tear the perforations. In contrast, the paper blister pack manufactured in Comparative Example 1 was difficult to open, as even when pressing with a finger near the perforations on the side panel or the top panel with the same force as when opening in Example 1, only the container deformed, and the perforations did not tear. [Explanation of symbols]

[0053] Paper blister pack, 100 Container part 1 Paper blanks 10 Top panel 11 Top panel 12 Bottom panel 13 Left side panel 14 Right side panel 15 Folded lines 22, 23, 24, 25 Fusion piece 32, 33, 34, 35 Perforations 42, 43, 44, 45 321 hanging holes Cardboard backing 2 Hanging hole 221< / eva> < / phbh>

Claims

1. It has a base part and a container part formed from a paper blank, The fused pieces of the base portion and the container portion are both provided with a heat seal layer, and are fused together via the heat seal layer. The aforementioned paper blanks have a basis weight of 150 g / m². ２ More than 300g / m ２ The following base paper is provided, with crease lines and perforations formed on it: A paper blister pack characterized in that at least a portion of the perforations is formed in the region of the side panel on the fused side.

2. The paper blister pack according to claim 1, characterized in that at least a portion of the perforations is formed at the boundary between the side panel and the fused piece.

3. The paper blister pack according to claim 1 or 2, characterized in that the heat-seal layer is a coating layer containing a biodegradable thermoplastic resin.

4. The paper blister pack according to claim 3, characterized in that the coating layer contains 1 to 250 parts by mass of EVA per 100 parts by mass of PHBH.

5. The paper blister pack according to claim 1 or 2, characterized in that at least one of the paper substrates constituting the cardboard portion or the container portion has a pigment coating layer on the surface that faces outward from the container.

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