Thermoforming sheet and packaging container

Abstract

The present invention provides a thermoforming sheet that can support a broader molding temperature range and can enhance the moldability of thermoformed products that are produced by thermoforming. A thermoforming sheet according to the present invention comprises: a plurality of base material layers that contain a polyester resin; and an intermediate layer disposed between base material layers. The polyester resin contains polyethylene terephthalate that has been modified with neopentyl glycol or isophthalic acid.

Description

Thermoforming sheets and packaging containers

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

[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 produced into thermoformed products by thermoforming.

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

[0004] Japanese Patent Application Publication No. 2016-049704

[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 aims to provide a thermoforming sheet that can expand the molding temperature range and improve the moldability of thermoformed products produced by thermoforming.

[0007] In order to solve the above problems, the present invention has the following configuration. [1] A thermoformable sheet comprising a plurality of base layers containing a polyester-based resin and an intermediate layer disposed between the base layers, wherein the polyester-based resin contains polyethylene terephthalate modified with neopentyl glycol or isophthalic acid. [2] The thermoformable sheet according to [1], wherein the modification rate of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 3 to 25 mol%. [3] The thermoformable 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 thermoformable 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 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 less. [6] The thermoforming sheet according to any one of [1] to [5], wherein the thickness of the base 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 to 55 μm. [9] The thermoforming sheet according to any one of [1] to [8], wherein an adhesive resin layer is disposed between the base 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 packaging container comprising: a container having a recess capable of accommodating contents and a flange provided around the opening edge of the recess; and a lid material sealed to the flange portion of the container to close the opening of the container, wherein at least one of the container and the lid material comprises a molded product obtained by thermoforming the thermoforming sheet according to any one of [1] to

[11] .

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

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

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. To facilitate understanding of the description, the same components in each drawing are designated by the same reference numerals, and duplicate descriptions may be omitted. Furthermore, the scale of each component 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 one embodiment of the present invention will be described. In this specification, the "thermoforming sheet" refers to a sheet for producing synthetic resin products, such as packaging containers. In the following description, the "thermoforming sheet" may also be 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 substrate layer 11A, an intermediate layer 12, and a substrate layer 11B laminated in this order, with adhesive layers (adhesive resin layers) 14 between each of the substrate layers 11A, 11B and the intermediate layer 12, and the laminate is formed into a sheet (film). The thermoforming sheet 1 is thermoformed into a thermoformed product. The thermoformed product is used as a packaging container or 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] The thermoforming sheet 1 may have two or more of each of the substrate layer 11A, the intermediate layer 12, and the substrate layer 11B, or may have layers other than these layers.

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

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

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

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

[0019] The base material layers 11A, 11B preferably contain 80% by mass or more of polyester-based resin relative to the total amount constituting the base material layers 11A, 11B. The base material layers 11A, 11B more preferably contain 90% by mass or more of polyester-based resin relative to the total amount constituting the base material layers 11A, 11B. The upper limit of the content of polyester-based resin is not particularly limited, but it is preferable that the content of polyester-based resin be 99% by mass or less relative to the total amount constituting the base material layers 11A, 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 layers 11A and 11B, and moldability of the thermoforming 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 layers 11A, 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 modified with NPG or IPA. Because the intermediate layer 12 in the thermoforming sheet 1 is harder than the base layers 11A and 11B, the moldable temperature range of the thermoforming sheet 1 tends to depend heavily on the base layers 11A and 11B. Therefore, by including PET modified with NPG or IPA as the modified polyester resin in the base layers 11A and 11B, the moldable temperature range of the thermoforming sheet 1 can be broadened.

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

[0026] The "modification rate of PET" as used herein 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 exceeds 1.2 dl / g, the load during extrusion becomes excessive, which is undesirable.

[0028] The glass transition temperature Tg of the PET modified with NPG or IPA is preferably 70 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 to 78° C., the resin composition forming the base layers 11A, 11B can be prevented from sticking to nip rolls or the like when forming the base layers 11A, 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 layers 11A and 11B may have the same composition or different compositions.

[0031] The thickness of the base layers 11A, 11B may be adjusted as desired, but from the viewpoint of using the thermoforming sheet 1 as a mono-material packaging container for packaging containers made of as single a material as possible, it is preferable that the base layers 11A, 11B be as thick as possible. The thickness of the base layers 11A, 11B is preferably 60% or more, and more preferably 70% or more, of the total thickness of the thermoforming sheet 1. The thickness of the base layers 11A, 11B may be 90% or less of the total thickness of the thermoforming sheet 1. Because the polyester resin contained in the base layers 11A, 11B includes PET, which is easily recyclable, if the thickness of the base layers 11A, 11B is 60% or more of the total thickness of the thermoforming sheet 1, the thermoforming sheet 1 can be formed largely 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 the base material layers 11A and 11B refers to the length in the direction perpendicular to the main surface of the base material layers 11A and 11B. The thickness of the base material layers 11A and 11B may be, for example, the thickness measured at an arbitrary location on the cross section of the base material layers 11A and 11B, or may be the average value of measurements measured at several arbitrary locations. Hereinafter, the definition of thickness is similarly defined for other members.

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

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

[0036] The base layers 11A and 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] (Intermediate Layer) The intermediate layer 12 is provided between the base material layer 11A and the base material 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 is 50 mass % or more with respect to the total amount constituting the intermediate layer 12.

[0041] The intermediate layer 12 preferably contains 85% by mass or more of the fluororesin relative to the total amount constituting the intermediate layer 12. The intermediate layer 12 more preferably contains 90% by mass or more of the fluororesin relative to the total amount constituting the intermediate layer 12. The upper limit of the content is not particularly limited, 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 can prevent moisture from penetrating 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 0.60 g / (m ２ ·day) or less, and even more preferably 0.50 g / (m ２ The lower limit of the water vapor transmission rate 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 in water vapor barrier properties, mechanical strength, gas barrier properties, and ease of molding among fluororesins.

[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 total thickness of the thermoforming sheet 1. The thickness of the intermediate layer 12 is more preferably 5% or more of the total thickness of the thermoforming sheet 1. The thickness of the intermediate layer 12 is more preferably 20% or less of the total 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 to 55 μm. If the thickness of the intermediate layer 12 is within the above range, the intermediate layer 12 can exhibit a water vapor barrier function while being in close contact with the base layers 11A and 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] The adhesive resin contained in the adhesive resin layers 14A, 14B may be a known adhesive resin. The adhesive resin layers 14A, 14B preferably contain primarily an acid-modified polyolefin. Here, "primarily containing an acid-modified polyolefin" means that the content of the acid-modified polyolefin is 50 mass% or more of the total amount constituting the adhesive resin layers 14A, 14B.

[0050] The adhesive resin layers 14A, 14B preferably contain 50% by mass or more of acid-modified polyolefin relative to the total amount of the adhesive resin layers 14A, 14B. The adhesive resin layers 14A, 14B more preferably contain 70% by mass or more of acid-modified polyolefin relative to the total amount of the adhesive resin layers 14A, 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, 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] Examples of the acid-modified polyolefin contained in the adhesive resin layers 14A, 14B include acid-modified polyethylene and acid-modified polypropylene. The acid-modified polyolefin contained in the adhesive resin layers 14A, 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 desired. The thickness of the adhesive resin layer 14A is preferably 1 to 10% of the total thickness of the thermoforming sheet 1. The thickness of the adhesive resin layer 14A is more preferably 3% or more of the total thickness of the thermoforming sheet 1. The thickness of the adhesive resin layer 14A is more preferably 8% or less of the total 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 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 total 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 to 400 μm, or may be, for example, 300 μm or less.

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

[0060] The manufacturing method of 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 manufacturing method of the thermoforming sheet 1 involves sequentially laminating the 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 a general lamination method 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, the substrate layer 11A, the adhesive resin layer 14A, the intermediate layer 12, the adhesive resin layer 14B, and the 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: the substrate layer 11A, the adhesive resin layer 14A, the intermediate layer 12, the adhesive resin layer, another substrate layer, the adhesive resin layer 14B, and the substrate layer 11B.

[0062] As described above, the thermoforming sheet 1 comprises a substrate layer 11A, an intermediate layer 12, and a substrate layer 11B laminated in this order, with the substrate layers 11A and 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 adhesion of the thermoforming sheet 1 to the heating plate during transport, making it easier to process. Since the intermediate layer 12 is an essential layer in the thermoforming sheet 1, the moldable temperature range of the thermoforming sheet 1 can be said to be largely determined by the substrate layers 11A and 11B. Therefore, by configuring the thermoforming sheet 1 so that the substrate layers 11A and 11B contain PET modified with NPG or IPA, the molding temperature range can be broadened, thereby improving the formability of the thermoformed product produced by thermoforming the 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 base layers 11A and 11B of the thermoforming sheet 1 using recycled PET, manufacturing costs 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 used 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 a thermoforming sheet according to this embodiment, and Fig. 3 is a cross-sectional view showing a typical example of a packaging container using a 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, food, nutrients, food and drink, cosmetics, industrial chemicals, and pesticides.

[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 around the opening edge of the recess 211 .

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

[0072] The recess 211 has a cylindrical shape with a bottom, and the flange portion 212 extends horizontally outward 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 the same as 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 composed of 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 film and PET film. 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 deposition 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 layer 11A or base 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 the contents are placed in the container 21 and sealed, the contents are placed in the container 21, and the lid material 22 is attached to the container 21 by sealing the flange portion 212 with adhesive, heat sealing, or the like so as to close the opening of the container 21. Thus, the packaging container 20 stores the contents in a sealed state in a space covered by the container 21 and the lid material 22. The heat sealing temperature is not particularly limited, and may be a general heat sealing temperature. When removing the contents from the container 21, the lid material 22 is torn by pressing the center or edge of the lid material 22 attached to the container 21. This allows the contents to be removed from the container 21. Alternatively, the contents from the container 21 may be removed by manually pulling any position on the edge of the lid material 22, causing the portion of the flange portion 212 sealed to the lid material 22 to break and peeling it off together with the lid material 22.

[0078] (Method for manufacturing packaging container) An example of a method for manufacturing a packaging container 20 will be described. Fig. 4 is a schematic diagram illustrating an example of a method for manufacturing a packaging container. As shown in Fig. 4, the packaging container 20 is manufactured by heating and softening a thermoforming sheet 1 using 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 Apparatus) The molding apparatus 200 can be used for thermoforming by a plug method or the like. The molding 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 thermoforming sheet 1 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. 5B, 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 the thermoforming sheet 1 is then brought into close contact with the inner surface of the recess 210A. The formed portion of the thermoforming sheet 1 is then cooled or otherwise treated 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, modifications, etc. can be made without departing from the spirit of the invention. These 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.

[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 Sheet> [Example 1] Using the resins described below, a five-layer thermoforming sheet was produced by laminating a substrate layer (back surface layer), an adhesive resin layer (AD), an intermediate layer, an adhesive resin layer (AD), and a 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 neopentyl glycol (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 of each layer) Base layer: NPG-modified PET1 (E03, manufactured by Bell Polyester Products Co., Ltd., modification rate: 16 mol%, viscosity: 0.83 dl / g, Tg: 75°C) Intermediate 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 in Example 1 were changed to the raw materials shown in Table 1. Note that "IPA-modified PET" and "CHDM-modified PET" refer to PET modified with isophthalic acid (IPA) and PET modified with cyclohexanedimethanol (CHDM), respectively. (Raw materials for base layer) IPA-modified PET1 (IFG8L, manufactured by Bell Polyester Products Co., Ltd., modification rate: 12 mol%, viscosity: 0.80 dl / g, Tg: 76°C, Tm: 224°C) IPA-modified PET2 (PIFG5H, manufactured by Bell Polyester Products Co., Ltd., modification rate: 5 mol%, viscosity: 0.97 dl / g, Tg: 77°C, Tm: 240°C) CHDM-modified PET (GN071, manufactured by Eastman Chemical Co., Ltd., modification rate: 31 mol%, viscosity: 0.75 dl / g, Tg: 82°C) PET (EFG70, manufactured by Bell Polyester Products Co., Ltd., 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 shown in Table 1, and the thermoforming sheets were thermoformed at heating plate temperatures ranging from 86 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 Figure 6. Examples of thickness measurement results for the packaging containers of Examples 1 to 6 are shown in Figures 7 to 12. Note that Figure 7 shows the thickness of a packaging container thermoformed using the thermoforming sheet of Example 1 at a heating plate temperature of 93°C, and Figure 8 shows the thickness of a packaging container thermoformed using the thermoforming sheet of Example 2 at a heating plate temperature of 110°C. Figure 9 shows the thickness of a packaging container thermoformed using the thermoforming sheet of Example 3 at a heating plate temperature of 96°C, and Figure 10 shows the thickness of a packaging container thermoformed using 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] [Forming temperature range] When the thermoforming sheet was thermoformed at each of the heating temperatures described above, the forming temperature range of the thermoforming sheet was determined to satisfy the following conditions for use of the packaging container. (Conditions for use of packaging container) - No white color occurs in the formed part of the container. - Thickness variation in the formed part of the container is 1 / 4 or less of the total thickness of the thermoforming sheet.

[0092] [Film-forming suitability] Film-forming suitability was evaluated based on the following evaluation criteria depending on the film-forming conditions. (Evaluation criteria) A: The molten web was cooled, no roll sticking occurred, and film formation was possible without any problems. B: The molten web was not partially cooled, and roll sticking occurred, but film formation was possible. C: The molten web was not cooled, and roll sticking occurred, making long-term film formation impossible.

[0093] The layer structure and total thickness of the thermoforming sheets prepared 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]

[0095]

[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 reduces sticking to the heating plate when conveying the thermoforming sheet during thermoforming and makes it easier to process. Therefore, the thermoforming sheets of Examples 1 to 4 can be said to have a wider molding temperature range and improve the moldability of the thermoformed products produced by thermoforming. Therefore, it was confirmed that the packaging containers molded using the thermoforming sheets of Examples 1 to 4 are useful as plastic containers for storing pharmaceuticals and other products.

[0098] 1... thermoforming sheet, 11A, 11B... base material layer, 12... intermediate layer, 14... adhesive layer (adhesive resin layer), 20... packaging container, 21... container, 22... lid material

Claims

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

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. 　 The thermoforming sheet according to any one of claims 1 to 3, wherein the glass transition temperature of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 70 to 78°C. 　 The thermoforming sheet according to any one of claims 1 to 4, wherein the melting point of the polyethylene terephthalate modified with neopentyl glycol or isophthalic acid is 250°C or lower. 　 The thermoforming sheet according to any one of claims 1 to 5, wherein the thickness of the substrate layer is 200 µm or less. 　 The thermoforming sheet according to claim 1 , wherein the intermediate layer contains polychlorotrifluoroethylene. 　 The thermoforming sheet according to any one of claims 1 to 7, wherein the thickness of the intermediate layer is 10 to 55 µm. 　 The thermoforming sheet according to any one of claims 1 to 8, wherein an adhesive resin layer is disposed between the substrate layer and the intermediate layer. 　 The thermoforming sheet according to claim 9, wherein the adhesive resin layer comprises maleic anhydride-modified polyethylene. 　 The thermoforming sheet according to any one of claims 1 to 10, wherein the thickness of the thermoforming sheet is 400 µm or less. 　 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 molded article obtained by thermoforming the thermoforming sheet according to any one of claims 1 to 11.

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