Sheet for thermoforming and packaging container

Abstract

To provide a sheet for thermoforming which can expand a molding temperature range, and can enhance formability of a thermoformed article produced by thermoforming.SOLUTION: A sheet for thermoforming includes a plurality of base material layers containing a polyester-based resin, and an intermediate layer arranged between the base material layers, wherein the polyester-based resin contains polyethylene terephthalate modified with neopentyl glycol or isophthalic acid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermoforming sheet and a packaging container. [Background technology]

[0002] Thermoforming sheets are widely used in various fields as materials for forming thermoformed products such as packaging containers or molded parts used for packaging food, medicine, etc. Thermoforming sheets are constructed by laminating resin layers containing thermoplastic resins such as polystyrene-based resins, polypropylene-based resins, or polyester-based resins, and are manufactured into thermoformed products by thermoforming.

[0003] As a thermoforming sheet formed by laminating such resin layers, for example, a thermoforming sheet has been disclosed in which one base layer contains a polyester having structural units derived from cyclohexanedimethanol and having a glass transition temperature of 90°C or higher, and the other base layer contains polypropylene (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-049704 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 does not describe the formability of the thermoforming sheet when it is molded into a thermoformed product such as a packaging container. When packaging pharmaceuticals and the like, the packaging container is required to have higher formability than when packaging food and the like. Therefore, when the thermoforming sheet disclosed in Patent Document 1 is used as a packaging container for packaging pharmaceuticals and the like, the formability of the thermoformed product produced by thermoforming the thermoforming sheet may be insufficient.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a thermoforming sheet that can expand the molding temperature range and improve the moldability of thermoformed products produced by thermoforming. [Means for solving the problem]

[0007] In order to solve the above problems, one embodiment of the present invention has the following configuration. [1] A plurality of base layers including a polyester-based resin; an intermediate layer disposed between the base material layers; Equipped with The thermoforming sheet, wherein the polyester resin comprises polyethylene terephthalate modified with neopentyl glycol or isophthalic acid. [2] The thermoforming sheet according to [1], wherein the modification rate of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 3 mol % to 25 mol %. [3] The thermoforming sheet according to [1] or [2], wherein the viscosity of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 0.65 dl / g or more. [4] The thermoforming sheet according to any one of [1] to [3], wherein the glass transition temperature of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 70°C to 78°C. [5] The thermoforming sheet according to any one of [1] to [4], wherein the melting point of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 250°C or lower. [6] The thermoforming sheet according to any one of [1] to [5], wherein the thickness of the substrate layer is 200 μm or less. [7] The thermoforming sheet according to any one of [1] to [6], wherein the intermediate layer contains polychlorotrifluoroethylene. [8] The thermoforming sheet according to any one of [1] to [7], wherein the thickness of the intermediate layer is 10 μm to 55 μm. [9] The thermoforming sheet according to any one of [1] to [8], wherein an adhesive resin layer is disposed between the substrate layer and the intermediate layer.

[10] The thermoforming sheet according to [9], wherein the adhesive resin layer contains maleic anhydride-modified polyethylene.

[11] The thermoforming sheet according to any one of [1] to

[10] , wherein the thickness of the thermoforming sheet is 400 μm or less.

[12] A container having a recess capable of accommodating contents and a flange provided on the opening periphery of the recess; a lid material sealed to the flange portion of the container to close the opening of the container; and A packaging container, wherein at least one of the container and the lid comprises a molded product obtained by thermoforming the thermoforming sheet according to any one of [1] to

[11] . [Effects of the Invention]

[0008] The thermoforming sheet according to the present invention can widen the molding temperature range and improve the moldability of the thermoformed product produced by thermoforming. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of a thermoforming sheet according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing an example of the appearance of a packaging container using a thermoforming sheet according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view schematically illustrating an example of a packaging container using a thermoforming sheet according to an embodiment of the present invention. [Figure 4] 1A to 1C are schematic diagrams illustrating an example of a method for manufacturing a packaging container. [Figure 5] FIG. 1 is a schematic diagram illustrating an example of a method for thermoforming a thermoforming sheet. [Figure 6] FIG. 2 is a diagram showing measurement points for the thickness of a packaging container. [Figure 7] The graph shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 1 at 93°C. [Figure 8] The graph shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 2 at 110°C. [Figure 9] The graph shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 3 at 96°C. [Figure 10] The graph shows the thickness of the packaging containers thermoformed by heating the thermoforming sheet of Example 4 at 106°C. [Figure 11] The graph shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 5 at 95°C and 100°C. [Figure 12] 1 shows the results for the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 6 at 96°C. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail. To facilitate understanding of the description, the same components in each drawing will be assigned the same reference numerals, and duplicate explanations will be omitted. The scale of each member in the drawings may differ from the actual scale. In this specification, unless otherwise specified, "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0011] <Thermoforming sheet> A thermoforming sheet according to an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described. In this specification, a "thermoforming sheet" refers to a sheet for producing synthetic resin products, such as packaging containers. In the following description, a "thermoforming sheet" may also be simply referred to as a "sheet."

[0012] Fig. 1 is a cross-sectional view showing an example of the configuration of a thermoforming sheet according to this embodiment. As shown in Fig. 1, the thermoforming sheet 1 according to this embodiment is a laminate comprising a base layer 11A, an intermediate layer 12, and a base layer 11B laminated in this order, with adhesive layers (adhesive resin layers) 14 between the base layer 11A, the intermediate layer 12, and the base layer 11B, and is formed into a sheet (film). The thermoforming sheet 1 becomes a thermoformed product by thermoforming. The thermoformed product is used as a packaging container or a molded part for packaging food, medicine, etc.

[0013] In FIG. 1, the lower side of the thermoforming sheet 1 is the inner side of the thermoforming sheet 1, and the upper side of the thermoforming sheet 1 is the outer side of the thermoforming sheet 1.

[0014] Furthermore, the thermoforming sheet 1 may have two or more of each of the base layer 11A, the intermediate layer 12, and the base layer 11B, or may have layers other than these layers.

[0015] Furthermore, the thermoforming sheet 1 may have another base material layer between any of the base material layer 11A, the intermediate layer 12, and the base material layer 11B, with an adhesive resin layer 14 interposed therebetween.

[0016] (base material layer) Base material layers 11A and 11B are layers located on the outside of thermoforming sheet 1, and base material layer 11A may be located on the inside of thermoforming sheet 1, and base material layer 11B may be located on the outside of thermoforming sheet 1. Alternatively, base material layer 11A may be located on the outside of thermoforming sheet 1, and base material layer 11B may be located on the inside of thermoforming sheet 1.

[0017] The base material layer 11A and the base material layer 11B mainly contain a polyester-based resin. The base material layer 11A and the base material layer 11B may contain general additives such as a stabilizer, an antistatic agent, or a colorant as optional components other than the polyester-based resin.

[0018] The phrase "mainly containing polyester-based resin" means that the content of polyester-based resin is 50% by mass or more relative to the total amount constituting base layer 11A and base layer 11B.

[0019] Base material layer 11A and base material layer 11B preferably contain 80% by mass or more of polyester-based resin relative to the total amount constituting base material layer 11A and base material layer 11B. Base material layer 11A and base material layer 11B more preferably contain 90% by mass or more of polyester-based resin relative to the total amount constituting base material layer 11A and base material layer 11B. There is no particular upper limit for the amount of polyester-based resin, but it is preferable that the amount of polyester-based resin be 99% by mass or less relative to the total amount constituting base material layer 11A and base material layer 11B.

[0020] The polyester resin includes a polyester resin or a modified polyester resin, and may also include a copolyester resin.

[0021] Examples of polyester-based resins include aromatic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene succinate adipate (PBSA), and polybutylene adipate terephthalate (PBAT), aliphatic polyesters such as polybutylene succinate (PBS), polyhydroxyalkanoic acid (PHA), polylactic acid (PLA), and polyarylate (PAR). Among these, PET is preferred in terms of production cost, ease of supply, transparency of the base layer 11A and the base layer 11B, and moldability of the thermoformable sheet 1. Therefore, when the polyester-based resin is PET, PET or modified PET is used as the polyester-based resin.

[0022] The polyester resin may be a crystalline polyester or an amorphous polyester depending on its type.

[0023] The glass transition temperature (Tg) of the polyester resin contained in the base layer 11A and the base layer 11B varies depending on the type of polyester resin, but is preferably 70° C. or higher, more preferably 75° C. or higher, and even more preferably 77° C. or higher. The upper limit of the Tg of the polyester resin is not particularly limited, but may be 90° C. or lower.

[0024] The modified polyester resin includes PET modified with neopentyl glycol (NPG) or isophthalic acid (IPA), and may include a polyester resin other than PET that has been modified with NPG or IPA. In thermoforming sheet 1, intermediate layer 12 is harder than substrate layers 11A and 11B, so the moldable temperature range of thermoforming sheet 1 tends to depend heavily on substrate layers 11A and 11B. Therefore, by including PET modified with NPG or IPA as the modified polyester resin in substrate layers 11A and 11B, the moldable temperature range of thermoforming sheet 1 can be broadened.

[0025] The modification rate of PET modified with NPG or IPA is preferably 3 mol% to 25 mol%. The modification rate is more preferably 3 mol% or more, and even more preferably 5 mol% or more. The modification rate is more preferably 18 mol% or less, and even more preferably 16 mol% or less. When the modification rate is within the above-mentioned preferred range, the flexibility of base layers 11A and 11B is enhanced. When the modification rate is 3 mol% or more, the physical properties of the polyester resin, such as PET, contained in base layers 11A and 11B are prevented from becoming dominant, thereby preventing a decrease in the formability of base layers 11A and 11B. When the modification rate is 25 mol% or less, base layers 11A and 11B do not become too soft, which prevents an effect on the formability or film-forming properties of thermoforming sheet 1, and therefore prevents thermoforming sheet 1 from sticking to a roll or mold during molding or film-forming.

[0026] The term "modification rate of PET" used in this specification refers to the proportion of PET modified with NPG or IPA to the terephthalic acid that constitutes PET.

[0027] The viscosity of the PET modified with NPG or IPA is preferably 0.65 dl / g or more, more preferably 0.80 dl / g or more, and even more preferably 0.90 dl / g or more. If the viscosity of the PET modified with NPG or IPA is 0.65 dl / g or more, the strength of packaging containers such as PTP packages formed using the thermoforming sheet 1 can be increased. Furthermore, the viscosity of the PET modified with NPG or IPA is preferably 1.2 dl / g or less, more preferably 1.1 dl / g or less, and even more preferably 1.0 dl / g or less. If the viscosity of the PET modified with NPG or IPA is high, the load during extrusion will be excessive, which is undesirable.

[0028] The glass transition temperature Tg of the PET modified with NPG or IPA is preferably 70°C to 78°C. The glass transition temperature Tg is more preferably 75°C or higher. Furthermore, the glass transition temperature Tg is more preferably 77°C or lower. If the glass transition temperature Tg of the PET modified with NPG or IPA is 70°C to 78°C, the resin compositions forming the base layer 11A and the base layer 11B can be prevented from sticking to nip rolls or the like when forming the base layer 11A and the base layer 11B.

[0029] When the PET modified with NPG or IPA is a crystalline polyester, the melting point of the PET is preferably 250°C or lower, and may be 240°C or lower.

[0030] The base material layer 11A and the base material layer 11B may have the same composition or different compositions.

[0031] The thicknesses of base material layers 11A and 11B may be adjusted as desired. However, in order to use thermoforming sheet 1 as a mono-material packaging container for packaging containers made of as single a material as possible, it is preferable that base material layers 11A and 11B be as thick as possible. The thicknesses of base material layers 11A and 11B are preferably, for example, 60% or more, more preferably 70% or more, of the overall thickness of thermoforming sheet 1. The thicknesses of base material layers 11A and 11B may be 90% or less of the overall thickness of thermoforming sheet 1. Because the polyester resin contained in base material layers 11A and 11B includes easily recyclable PET, if the thicknesses of base material layers 11A and 11B are 60% or more of the overall thickness of thermoforming sheet 1, the thermoforming sheet 1 can be largely formed from a mono-material consisting of a single material, PET, making it easier to form the thermoforming sheet 1 into a mono-material packaging container.

[0032] In this specification, the thickness of base layer 11A and base layer 11B refers to the length in the direction perpendicular to the main surface of base layer 11A and base layer 11B. The thickness of base layer 11A and base layer 11B may be, for example, the thickness measured at an arbitrary location on the cross section of base layer 11A and base layer 11B, or may be the average value of measurements measured at several arbitrary locations. Hereinafter, the definition of thickness is similar for other members.

[0033] The thickness of the base layer 11A may be adjusted to any appropriate thickness depending on the thickness of the thermoforming sheet 1, and may be, for example, 200 μm or less, or may be 60 μm to 200 μm. The thickness of the base layer 11A may be 65 μm or more, 120 μm or more, or 140 μm or more.

[0034] The thickness of base layer 11B may be adjusted to any appropriate thickness depending on the thickness of thermoforming sheet 1, and may be, for example, 60 μm to 200 μm, similar to base layer 11A. The thickness of base layer 11A may be 65 μm or more, 120 μm or more, or 140 μm or more.

[0035] The thicknesses of the base material layer 11A and the base material layer 11B may be the same or different, and the ratio between the thicknesses of the base material layer 11A and the base material layer 11B can be adjusted to any appropriate value.

[0036] The base layer 11A and the base layer 11B may contain an anti-blocking agent. In this specification, the term "anti-blocking agent" refers to an agent that reduces the coefficient of friction of the thermoforming sheet 1, making it easier to remove a packaging container formed from the thermoforming sheet 1 from a mold or the like. The anti-blocking agent is poorly compatible with polyester, and is therefore exposed on the surface 11a of the base layer 11A (the back surface of the thermoforming sheet 1) and the surface 11b of the base layer 11B (the surface of the thermoforming sheet 1).

[0037] When a packaging container formed from a sheet is removed from a mold, the packaging container may be difficult to remove from the mold. Therefore, when removing the formed packaging container from the mold, the packaging container may rub against the mold, causing scratches and the like on the packaging container. By adding an antiblocking agent, the formed packaging container can be easily removed from the mold, and the occurrence of scratches and the like on the packaging container can be suppressed.

[0038] As the anti-blocking agent, for example, anti-blocking agents commonly used in the production of thermoforming sheets, such as glass and polydimethylsiloxane resin, may be used.

[0039] (middle class) The intermediate layer 12 is provided between the base layer 11A and the base layer 11B and has a water vapor barrier function.

[0040] The intermediate layer 12 mainly contains a fluororesin. Here, "mainly contains a fluororesin" means that the content of the fluororesin relative to the total amount constituting the intermediate layer 12 is at least 50 mass % or more.

[0041] The intermediate layer 12 preferably contains 85% by mass or more of fluororesin relative to the total amount constituting the intermediate layer 12. The intermediate layer 12 more preferably contains 90% by mass or more of fluororesin relative to the total amount constituting the intermediate layer 12. There is no particular upper limit to the content, but it is preferable that the fluororesin content be 100% by mass or less relative to the total amount constituting the intermediate layer 12.

[0042] The inclusion of a fluororesin in the intermediate layer 12 makes it possible to prevent moisture from entering from the outside into the thermoforming sheet 1. The moisture may include water vapor.

[0043] The water vapor permeability of the intermediate layer 12 is preferably 0.80 g / (m 2 ·day) or less, and more preferably 0.60g / (m 2 ·day) or less, and even more preferably 0.50 g / (m 2 The lower limit of the water vapor permeability is not particularly limited, but is, for example, 0.001 g / (m 2 The water vapor transmission rate of the intermediate layer 12 is measured in accordance with JIS K7129-2 "Plastics - Films and sheets - Determination of water vapor transmission rate - Part 2: Infrared sensor method."

[0044] The fluororesin contained in the intermediate layer 12 is preferably polychlorotrifluoroethylene (PCTFE), which is excellent among fluororesins in terms of water vapor barrier properties, mechanical strength, gas barrier properties, and ease of molding.

[0045] The intermediate layer 12 may contain general additives such as a stabilizer, an antistatic agent, and a colorant as optional components other than the fluororesin.

[0046] The thickness of the intermediate layer 12 can be adjusted as desired. The thickness of the intermediate layer 12 is preferably 3% to 25% of the overall thickness of the thermoforming sheet 1. The thickness of the intermediate layer 12 is more preferably 5% or more of the overall thickness of the thermoforming sheet 1. The thickness of the intermediate layer 12 is more preferably 20% or less of the overall thickness of the thermoforming sheet 1, and even more preferably 10% or less.

[0047] The thickness of the intermediate layer 12 may be, for example, 1 μm to 55 μm. If the thickness of the intermediate layer 12 is within the above range, the intermediate layer 12 can exert a water vapor barrier function while being in close contact with the base layer 11A and the base layer 11B.

[0048] (Adhesive resin layer) The adhesive resin layer 14 has an adhesive resin layer 14A arranged between the base material layer 11A and the intermediate layer 12, and an adhesive resin layer 14B arranged between the base material layer 11B and the intermediate layer 12. The adhesive resin layer 14A bonds the base material layer 11A and the intermediate layer 12, and the adhesive resin layer 14B bonds the base material layer 11B and the intermediate layer 12. The adhesive resin layers 14A and 14B may be formed of the same type of material or different types of materials.

[0049] Known adhesive resins can be used as the adhesive resins contained in the adhesive resin layers 14A and 14B. The adhesive resin layers 14A and 14B preferably contain mainly an acid-modified polyolefin. Here, "mainly containing an acid-modified polyolefin" means that the content of the acid-modified polyolefin is at least 50 mass% or more of the total amount constituting the adhesive resin layers 14A and 14B.

[0050] The adhesive resin layers 14A and 14B preferably contain 50% by mass or more of acid-modified polyolefin relative to the total amount of the adhesive resin layers 14A and 14B. The adhesive resin layers 14A and 14B more preferably contain 70% by mass or more of acid-modified polyolefin relative to the total amount of the adhesive resin layers 14A and 14B. The upper limit of the acid-modified polyolefin content is not particularly limited, but is preferably 100% by mass or less relative to the total amount of the adhesive resin layers 14A and 14B.

[0051] The adhesive resin layers 14A and 14B may contain, as optional components other than the acid-modified polyolefin, commonly used additives such as a stabilizer, an antistatic agent, and a colorant.

[0052] The acid-modified polyolefin contained in the adhesive resin layers 14A and 14B may be, for example, acid-modified polyethylene or acid-modified polypropylene. The acid-modified polyolefin contained in the adhesive resin layers 14A and 14B is preferably acid-modified polyethylene. The acid group of the acid-modified polyolefin is preferably maleic anhydride. That is, the acid-modified polyethylene is preferably maleic anhydride-modified polyethylene.

[0053] The adhesive resin layers 14A and 14B may have the same composition or different compositions.

[0054] The thickness of each of the adhesive resin layers 14A and 14B may be adjusted as appropriate. The thickness of the adhesive resin layer 14A is preferably 1% to 10% of the overall thickness of the thermoforming sheet 1. The thickness of the adhesive resin layer 14A is more preferably 3% or more of the overall thickness of the thermoforming sheet 1. The thickness of the adhesive resin layer 14A is more preferably 8% or less of the overall thickness of the thermoforming sheet 1.

[0055] The thickness of the adhesive resin layer 14A is not particularly limited, but may be, for example, 5 μm to 30 μm. The thickness of the adhesive resin layer 14A may be 10 μm or more, or 15 μm or more. The thickness of the adhesive resin layer 14A may be 27 μm or less, or 25 μm or less.

[0056] The preferred range of the thickness of the adhesive resin layer 14B relative to the overall thickness of the thermoforming sheet 1 may be the same as that of the adhesive resin layer 14A. The preferred range of the thickness of the adhesive resin layer 14B may also be the same as that of the adhesive resin layer 14A.

[0057] The thicknesses of the adhesive resin layers 14A and 14B may be the same or different.

[0058] The thickness of the thermoforming sheet 1 can be adjusted as appropriate and may be, for example, 250 μm to 400 μm, or may be, for example, 300 μm or less.

[0059] The thermoforming sheet 1 may include base layers 11A and 11B, an intermediate layer 12, and adhesive resin layers 14A and 14B, but may also include other layers between base layer 11A and base layer 11B as needed. In this case, adhesive resin layer 14 may be introduced between the other layers and base layer 11A, base layer 11B, or intermediate layer 12.

[0060] The method for manufacturing the thermoforming sheet 1 is not particularly limited, and general sheet lamination methods such as thermal lamination, extrusion lamination, and dry lamination can be used. The method for manufacturing the thermoforming sheet 1 involves sequentially laminating resins that serve as raw materials for the base layer 11A, adhesive resin layer 14A, intermediate layer 12, adhesive resin layer 14B, and base layer 11B using general lamination methods such as extrusion lamination and dry lamination to form each layer that constitutes the thermoforming sheet 1, thereby forming the thermoforming sheet 1.

[0061] Although the thermoforming sheet 1 has five layers, namely, substrate layer 11A, adhesive resin layer 14A, intermediate layer 12, adhesive resin layer 14B, and substrate layer 11B, as described above, it may have a plurality of any of these layers. For example, the thermoforming sheet 1 may have seven layers, laminated in this order: substrate layer 11A, adhesive resin layer 14A, intermediate layer 12, adhesive resin layer, another substrate layer, adhesive resin layer 14B, and substrate layer 11B.

[0062] As described above, thermoforming sheet 1 comprises substrate layer 11A, intermediate layer 12, and substrate layer 11B laminated in this order, with substrate layer 11A and substrate layer 11B containing PET modified with NPG or IPA. PET modified with NPG or IPA can broaden the moldable temperature range when heated during molding, thereby enhancing flexibility and formability. This reduces sticking of thermoforming sheet 1 to the heating plate during transport and facilitates processing. Because intermediate layer 12 is an essential layer in thermoforming sheet 1, the moldable temperature range of thermoforming sheet 1 can be said to be largely determined by substrate layers 11A and 11B. Therefore, by including substrate layers 11A and 11B modified with NPG or IPA in thermoforming sheet 1, the molding temperature range can be broadened, thereby improving the formability of thermoformed products produced by thermoforming sheet 1.

[0063] Therefore, when the thermoforming sheet 1 is heated and molded, it can be processed into a thermoformed product with high moldability.

[0064] Furthermore, the thermoforming sheet 1 is formed such that the base layers 11A and 11B, which are the main base material of the thermoforming sheet 1, contain PET. PET is a recyclable resin, so by recovering it after discarding the thermoforming sheet 1, the PET can be separated, recovered, and recycled. Furthermore, the base layers 11A and 11B can be formed using recycled PET. Therefore, the thermoforming sheet 1 can be manufactured and disposed of while reducing the burden on the environment. Furthermore, by manufacturing the thermoforming sheet 1 using recycled PET for the base layers 11A and 11B, the manufacturing cost can be reduced.

[0065] As described above, the thermoforming sheet 1 can produce thermoformed products with high formability and excellent film-forming properties, and therefore, when used as a packaging container for storing medicines, foods, nutrients, food and drink, cosmetics, industrial chemicals, pesticides, etc., it is possible to obtain a packaging container with excellent film-forming properties. For this reason, the thermoforming sheet 1 can be suitably used as a PTP (Press Through Package) packaging sheet for packaging containers, etc.

[0066] <Packaging container> A packaging container using the thermoforming sheet 1 according to this embodiment will be described. Examples of the packaging container include PTP packaging. The use of the packaging container is not particularly limited, and the packaging container can be used, for example, as a packaging container for pharmaceuticals and the like.

[0067] Fig. 2 is a diagram showing an example of the appearance of a packaging container using the thermoforming sheet according to this embodiment, and Fig. 3 is a cross-sectional view showing a typical example of a packaging container using the thermoforming sheet according to this embodiment. As shown in Figs. 2 and 3, packaging container 20 has container 21 and lid 22 that covers the opening of container 21, and stores the contents in a sealed state in a space covered by container 21 and lid 22.

[0068] Examples of contents include medicines, foods, nutrients, food and drink, cosmetics, industrial chemicals, and agricultural chemicals.

[0069] The size of the packaging container 20 may be adjusted appropriately depending on the type and size of the contents.

[0070] The container 21 has a recess 211 capable of accommodating contents, and a flange 212 formed on the periphery of the opening of the recess 211.

[0071] The shape of container 21 is not particularly limited and may be any shape as long as the contents can be accommodated inside container 21. Note that, although container 21 has a substantially circular shape in plan view in Fig. 2, it may have other shapes such as a substantially rectangular or substantially elliptical shape in plan view.

[0072] The recess 211 has a cylindrical shape with a bottom, and the flange portion 212 extends outward in the horizontal direction from the opening of the recess 211.

[0073] Container 21 is a thermoformed container comprising a molded body obtained by thermoforming the above-mentioned thermoforming sheet 1, and may be composed of a molded body obtained by thermoforming the thermoforming sheet 1. In container 21, base layer 11A of thermoforming sheet 1 is disposed on the inner surface side of recess 211 of container 21. As a method for thermoforming container 21, plug-assisted molding can be used, in which thermoforming sheet 1 is pre-stretched with a plug into a cavity formed to the outer shape of container 21, and then pressure forming, vacuum forming, or the like is performed.

[0074] The container 21 is not limited to the above-mentioned configuration shown in FIGS. 2 and 3, but may be a tray-shaped container, a blow-molded container, or the like.

[0075] The lid material 22 has an outer diameter approximately equal to the outer diameter of the flange portion 212 of the container 21. The lid material 22 has water vapor barrier properties. Like the container 21, the lid material 22 may comprise a molded product obtained by thermoforming the above-mentioned thermoforming sheet 1, or may be a lid material formed from a material commonly used for packaging containers. The lid material 22 may also be formed from a molded product obtained by thermoforming the above-mentioned thermoforming sheet 1. Commonly used materials include, for example, resin films, metal foils, and metal-resin composite films in which a metal layer is laminated on a resin film. Examples of resin films include polyethylene films and PET films. The resin film may have a laminate structure with a sealant layer on one surface. The metal layer is not particularly limited, but is preferably a metal foil or a metal vapor-deposited layer, and more preferably aluminum foil from the standpoints of gas barrier properties and productivity.

[0076] As with the container 21, when the above-mentioned thermoforming sheet 1 has a thermoformed molded body, the base material layer 11A or base material layer 11B of the thermoforming sheet 1 is arranged on the side where the lid material 22 is sealed to the flange portion 212 of the container 21.

[0077] When contents are placed in container 21 and sealed, the contents are placed in container 21, and lid 22 is attached to container 21 by sealing flange 212 with adhesive, heat sealing, or the like so as to close the opening of container 21. As a result, packaging container 20 stores the contents in a sealed state in a space surrounded by container 21 and lid 22. The heat sealing temperature is not particularly limited and may be a general heat sealing temperature. When removing the contents from container 21, the lid 22 is torn by pressing the center or edge of lid 22 attached to container 21. This allows the contents to be removed from container 21. Alternatively, the contents from container 21 may be removed by manually pulling any position on the edge of lid 22, which tears the portion of flange 212 sealed to lid 22 and peeling it off together with lid 22.

[0078] (Manufacturing method of packaging containers) An example of a manufacturing method for a packaging container 20 will now be described. Fig. 4 is a schematic diagram illustrating an example of a manufacturing method for a packaging container. As shown in Fig. 4, the packaging container 20 is manufactured by heating and softening a thermoforming sheet 1 with a heating device 100, and then thermoforming the sheet using a mold device 200.

[0079] (heating device) The heating device 100 includes a pair of heating plates 110A and 110B. The heating plates 110A and 110B are arranged so that the thermoforming sheet 1 can pass between them. The heating plates 110A and 110B may each include a heater or the like inside, and heat the thermoforming sheet 1 with the heat of the heater. The heating device 100 may also be of a type that heats the thermoforming sheet 1 by heat pressing.

[0080] (Molding equipment) The mold apparatus 200 can be used for thermoforming by a plug method or the like. The mold apparatus 200 includes a lower mold 210 and an upper mold 220 housed in a chamber (not shown). The lower mold 210 and the upper mold 220 can be moved up and down independently, and when they are separated, the thermoforming sheet 1 can pass between the lower mold 210 and the upper mold 220. The lower mold 210 has a plurality of recesses 210A for forming the container 21. The upper mold 220 has a plurality of plugs 221 protruding toward the lower mold 210. The plurality of plugs 221 are provided at positions corresponding to the plurality of recesses 210A of the lower mold 210. Each plug 221 is arranged in the upper mold 220 so as to be insertable into the corresponding recess 210A.

[0081] (Thermoforming) When thermoforming sheet 1 is thermoformed, first, thermoforming sheet 1 is softened by heating device 100 and transported to mold device 200. Then, as shown in Fig. 5(A), lower mold 210 is moved upward relative to thermoforming sheet 1 softened by heating device 100, so that the sheet is brought into close contact with lower mold 210. At this time, thermoforming sheet 1 may be slightly lifted to apply tension to thermoforming sheet 1.

[0082] Next, as shown in FIG. 5(B), the upper die 220 is moved downward to insert the plug 221 into the recess 210A.

[0083] 5(C), the upper mold 220 is moved upward to separate the plug 221 from the recess 210A, and then the thermoforming sheet 1 is brought into close contact with the inner surface of the recess 210A. Thereafter, the formed portion of the thermoforming sheet 1 is cooled or the like to fix the shape of the thermoforming sheet 1.

[0084] Next, as shown in Fig. 5(D), the lower mold 210 is moved downward and released to obtain a primary molded product. The primary molded product is cut to obtain the packaging container 20 shown in Figs. 2 and 3.

[0085] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, or modifications can be made without departing from the spirit of the invention. The above embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims. [Example]

[0086] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples. Examples 1 to 4 are working examples, and Examples 5 and 6 are comparative examples.

[0087] <Preparation of thermoforming sheets> [Example 1] Using the resins described below, a five-layer thermoforming sheet was produced by laminating a substrate layer (back surface layer), adhesive resin layer (AD), intermediate layer, adhesive resin layer (AD), and substrate layer (surface layer) in this order. The resins used as raw materials for each layer were laminated to the thicknesses shown in Table 1. The resins used as raw materials for each layer are as follows. "NPG-modified PET" refers to PET modified with NPG. In Table 1, the layer structure of the thermoforming sheet is such that the left side is the inside of the thermoforming sheet and the right side is the outside of the thermoforming sheet. (Materials for each layer) Base layer: NPG-modified PET1 (E03, manufactured by Bell Polyester Products, Tg: 75°C) Middle layer: Polychlorotrifluoroethylene resin (PCTFE) (DF0050-C1, manufactured by Daikin Industries, Ltd.) Adhesive resin layer: Maleic anhydride-modified polyethylene (Admer (registered trademark), manufactured by Mitsui Chemicals, Inc.)

[0088] [Examples 2 to 6] Thermoforming sheets were produced in the same manner as in Example 1, except that the resins forming each layer were changed to the raw materials shown in Table 1. Note that "IPA-modified PET" and "CHDM-modified PET" refer to PET modified with IPA and PET modified with cyclohexanedimethanol (CHDM), respectively. (raw material for base layer) IPA-modified PET1 (IFG8L, manufactured by Bell Polyester Products, modification rate: 12 mol%, viscosity: 0.80 dl / g, Tg: 76°C, Tm: 224°C) IPA-modified PET2 (PIFG5H, manufactured by Bell Polyester Products, modification rate: 5 mol%, viscosity: 0.97 dl / g, Tg: 77°C, Tm: 240°C) CHDM-modified PET (GN071, manufactured by Eastman Chemical, modification rate: 31 mol%, viscosity: 0.75 dl / g, Tg: 82°C) PET (EFG70, manufactured by Bell Polyester Products, viscosity: 0.75 dl / g, Tg: 80°C, Tm: 255°C)

[0089] <Production of packaging containers> The thermoforming sheets of each example were thermally processed using the thermal processing method for thermoforming sheets shown in Figure 4 to produce the packaging containers shown in Figures 2 and 3. The molding conditions during thermal processing were the molding plug stop position, molding stop angle, molding blow pressure, molding plug timing, and molding plug temperature, as shown in Table 1, and the thermoforming sheets were thermoformed at heating plate temperatures ranging from 86°C to 122°C to produce a plurality of packaging containers.

[0090] [Thickness measurement] The thickness of each of the produced packaging containers was measured at multiple measurement points (13 points) along the conveying direction of the thermoforming sheet, as shown in FIG. 6. Examples of the measurement results for the thickness of the packaging containers of Examples 1 to 6 are shown in FIGS. 7 to 12. Note that FIG. 7 shows the thickness of a packaging container thermoformed by heating the thermoforming sheet of Example 1 at a heating plate temperature of 93°C, and FIG. 8 shows the thickness of a packaging container thermoformed by heating the thermoforming sheet of Example 2 at a heating plate temperature of 110°C. FIG. 9 shows the thickness of a packaging container thermoformed by heating the thermoforming sheet of Example 3 at a heating plate temperature of 96°C, and FIG. 10 shows the thickness of a packaging container thermoformed by heating the thermoforming sheet of Example 4 at a heating plate temperature of 106°C. FIG. 11 shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 5 at a heating plate temperature of 95°C or 100°C, and FIG. 12 shows the thickness of packaging containers thermoformed by heating the thermoforming sheet of Example 6 at a heating plate temperature of 96°C.

[0091] [Molding temperature range] When the thermoforming sheet was thermoformed at each of the above heating temperatures, the molding temperature range of the thermoforming sheet that satisfied the following conditions for use of the packaging container was determined. (Conditions for use of packaging containers) No white coloring occurs on the molded parts of the container. The thickness variation in the formed part of the container is less than 1 / 4 of the total thickness of the thermoforming sheet.

[0092] [Film production suitability] Depending on the film formation conditions, the film formation suitability was evaluated based on the following evaluation criteria. (Evaluation criteria) A: The molten web is cooled, no roll sticking occurs, and film formation is possible without any problems. B: The molten web cannot be cooled in part, and film formation is possible despite roll sticking. C: The molten web is not cooled, causing roll sticking, making long-term film production impossible.

[0093] The layer structure and total thickness of the thermoforming sheets produced in each example, as well as the molding conditions, are shown in Table 1, and the evaluation results of the molding temperature range and film-forming suitability of the thermoforming sheets are shown in Table 2. In Table 1, the numbers in parentheses indicate the thickness of each layer.

[0094] [Table 1]

[0095] [Table 2]

[0096] As can be seen from Table 2, in Examples 1 to 4, the thermoforming sheets had a wide molding temperature range and sufficient moldability to obtain thermoformed products, satisfying the conditions for use as packaging containers. Furthermore, Examples 1 and 4 had excellent film-forming suitability. On the other hand, in Examples 5 and 6, the thermoforming sheets had a narrow molding temperature range and did not satisfy the conditions for use as packaging containers.

[0097] Therefore, in the thermoforming sheets of Examples 1 to 4, the base layer contains NPG or IPA-modified PET, which prevents the thermoforming sheet from sticking to the heating plate when transported during thermoforming and makes it easier to process. Therefore, the thermoforming sheets of Examples 1 to 4 can be said to have a wider forming temperature range and improve the formability of the thermoformed products produced by thermoforming. It was therefore confirmed that the packaging containers formed using the thermoforming sheets of Examples 1 to 4 are useful as plastic containers for storing pharmaceuticals and the like. [Explanation of symbols]

[0098] 1. Thermoforming sheet 11A, 11B base material layer 12 Middle Class 14 Adhesive layer (adhesive resin layer) 20 Packaging containers 21 Container 22 Lid material

Claims

1. a plurality of base material layers containing a polyester-based resin; an intermediate layer disposed between the base material layers; Equipped with The thermoforming sheet, wherein the polyester resin comprises polyethylene terephthalate modified with neopentyl glycol or isophthalic acid.

2. 2. The thermoforming sheet according to claim 1, wherein the modification rate of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 3 mol % to 25 mol %.

3. 3. The thermoforming sheet according to claim 1, wherein the viscosity of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 0.65 dl / g or more.

4. 3. The thermoforming sheet according to claim 1, wherein the glass transition temperature of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 70°C to 78°C.

5. 3. The thermoforming sheet according to claim 1, wherein the melting point of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 250°C or lower.

6. The thermoforming sheet according to claim 1 or 2, wherein the thickness of the substrate layer is 200 μm or less.

7. The thermoforming sheet according to claim 1 or 2, wherein the intermediate layer comprises polychlorotrifluoroethylene.

8. The thermoforming sheet according to claim 1 or 2, wherein the thickness of the intermediate layer is 10 μm to 55 μm.

9. The thermoforming sheet according to claim 1 or 2, wherein an adhesive resin layer is disposed between the substrate layer and the intermediate layer.

10. The thermoforming sheet according to claim 9, wherein the adhesive resin layer comprises maleic anhydride-modified polyethylene.

11. 3. The thermoforming sheet according to claim 1, wherein the thickness of the thermoforming sheet is 400 μm or less.

12. a container having a recess capable of accommodating contents and a flange provided on the periphery of the opening of the recess; a lid material sealed to the flange portion of the container to close the opening of the container; and A packaging container, wherein at least one of the container and the lid comprises a formed article obtained by thermoforming the thermoforming sheet according to claim 1 or 2.

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