Ring for beverage brewing pod and beverage brewing pod including said ring

Abstract

Provided are: a ring which is for a beverage extraction pod, enables home composting, and has favorable heat sealability to a filter; and a beverage extraction pod in which a filter is attached to said ring. This ring for a beverage extraction pod, including a filter having a volume for storing a material to be extracted, a cylindrical side wall attached to a flange surface of the pod and adapted to constitute the beverage extraction pod, and the flange surface protruding outward from the cylindrical side wall, is characterized by comprising a thermoplastic resin composition (a) that mainly contains a thermoplastic resin A and is different from a thermoplastic resin composition (b) mainly containing a thermoplastic resin B constituting the filter, wherein the thermoplastic resin A is polyalkylene dicarboxylate, and the melting point of the thermoplastic resin composition (a) is lower than the melting point of the thermoplastic resin composition (b).

Description

[Technical Field]

[0001] The present invention relates to a ring for a beverage brewing pod and to a beverage brewing pod including said ring. [Background technology]

[0002] Generally, an extraction pod for obtaining a beverage is constructed by heat-sealing a reinforcing ring and a filter for containing the material to be extracted. Biodegradable rings are known, and for example, Patent Document 1 below discloses rings made of polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS), or a starch blend. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-522150 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to obtain a beverage extraction pod that is home compostable, both the ring and the filter, which are its components, must be made of a home compostable thermoplastic resin. Filters containing polybutylene adipate terephthalate (PBAT) are known as home compostable filters. However, Patent Document 1 does not disclose a beverage extraction pod that includes a filter and a ring, that is home compostable, and that has good heat sealing properties between the ring and the filter.

[0005] In view of this state of the art, the problem that the present invention aims to solve is to provide a ring for a beverage extraction pod that is home compostable and has good heat sealing properties with a filter, and a beverage extraction pod in which a filter is adhered to the ring for the beverage extraction pod. [Means for solving the problem]

[0006] The present inventors conducted extensive research and experimentation to solve the above-mentioned problems. As a result, they discovered that if the same thermoplastic resin composition with the same melting point is used for the filter and the ring (for example, if PBS is used as the thermoplastic resin composition for the filter and PBS with the same melting point is used as the thermoplastic resin composition for the ring), sufficient adhesion cannot be obtained when heat-sealing the ring and filter to produce a beverage extraction pod. The present inventors unexpectedly discovered that the above-mentioned problems can be solved by using a specific combination of thermoplastic resin compositions for the filter and the ring and by providing a specific melting point difference. Furthermore, they demonstrated that by making the ring home-compostable, the entire beverage pod including the ring and the filter can be home-composted, thereby completing the present invention. Specifically, the present invention is as follows.

[0007] [1] A ring for a beverage extraction pod, comprising a filter having a volume for accommodating the material to be extracted, a cylindrical side wall adapted to be bonded at its flange surface to form a beverage extraction pod, and a flange surface protruding outward from the cylindrical side wall, wherein the ring is made of a thermoplastic resin composition (a) mainly containing a thermoplastic resin A, which is different from the thermoplastic resin composition (b) mainly containing a thermoplastic resin B constituting the filter, wherein the thermoplastic resin A is a polyalkylene dicarboxylate, and the melting point of the thermoplastic resin composition (a) is lower than the melting point of the thermoplastic resin composition (b). [2] A ring for a beverage extraction pod as described in claim 1, wherein the difference in melting point between the thermoplastic resin composition (a) and the thermoplastic resin composition (b) is 10°C or more. [3] A ring for a beverage extraction pod as described in [1] or [2], wherein the thermoplastic resin A is a polyalkylene dicarboxylate containing two or more types of at least one of an aliphatic dicarboxylic acid and a linear glycol subjected to polycondensation. [4] The ring for a beverage extraction pod according to any one of [1] to [3], wherein the thermoplastic resin A is polybutylene succinate adipate (PBSA). [5] A beverage extraction pod comprising a ring for a beverage extraction pod described in any one of [1] to [4] above and a filter bonded to the flange surface of the ring and having a capacity for storing the material to be extracted. [6] The beverage extraction pod according to [5], wherein the ring has an absolute biodegradability of 70% or more within 12 months in a biodegradation test in a compost environment at 28°C in accordance with ISO 14855-1. [7] A beverage extraction pod according to [5] or [6], wherein the thermoplastic resin B is polybutylene adipate terephthalate (PBAT). [8] The beverage extraction pod according to any one of [5] to [7], wherein the filter is made of nonwoven fabric. [9] The air permeability of the filter is 10 cm 3 / (cm 2 The beverage extraction pod according to any one of [5] to [8], wherein the length is equal to or greater than 1 / 3 of the length of the beverage extraction pod.

[10] A beverage extraction pod as described in any of [5] to [9], wherein the ratio of the difference in thickness between the ring and the filter calculated by [{(thickness of the flange surface of the ring for the beverage extraction pod) - (thickness of the filter)} / (thickness of the flange surface of the ring for the beverage extraction pod)] x 100 is 70% or more. [Effects of the Invention]

[0008] The ring for a beverage extraction pod of the present disclosure and the beverage extraction pod with a filter attached thereto are entirely home compostable, and the adhesive strength between the flange surface of the ring and the filter is also high. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a schematic diagram of a ring for a beverage brewing pod according to an embodiment of the present invention; [Figure 2] 1 is a schematic diagram of a beverage brewing pod according to an embodiment of the present invention, including a ring; DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will now be described with reference to specific embodiments illustrated in the accompanying drawings. However, the invention is not limited to the specific embodiments shown in the following detailed description and drawings.

[0011] One embodiment of the present invention is a ring for a beverage extraction pod, comprising a filter having a volume for accommodating the material to be extracted, a cylindrical side wall adapted to be bonded at its flange surface to form a beverage extraction pod, and a flange surface protruding outward from the cylindrical side wall, wherein the ring is made of a thermoplastic resin composition (a) mainly containing a thermoplastic resin A, which is different from the thermoplastic resin composition (b) mainly containing a thermoplastic resin B that constitutes the filter, wherein the thermoplastic resin A is a polyalkylene dicarboxylate, and the melting point of the thermoplastic resin composition (a) is lower than the melting point of the thermoplastic resin composition (b). In the present specification, the "flange surface" of the "ring for a beverage extraction pod" will also be referred to as the "flange portion."

[0012] FIG. 1 is a schematic perspective view of a ring for a beverage brewing pod according to one embodiment of the present invention. The ring 1 of this embodiment includes a side wall 11 and a flange portion 12 protruding from the side wall 11. The flange portion 12 shown in Figure 1 has a uniform thickness, i.e., the thickness is constant over its entire length.

[0013] The following shows some dimensions of the ring of this embodiment as an example. The shape of the ring can be designed as appropriate depending on the application, in addition to the shapes described below.

[0014] 1 and 2, the flange portion 12 protrudes from one end of the side wall 11 toward the outside of the ring 1. The angle formed between the side wall 11 and the flange portion 12 is 90° or more.

[0015] The side wall 11 and flange portion 12 may be manufactured as a single piece, for example by hot and / or injection molding, compression processing, or thermoforming processes.

[0016] 1 and 2, the side wall 11 has a tapered shape in which the circumferential diameter gradually increases in the direction in which the flange portion 12 protrudes.

[0017] The inner diameter of the narrowest part of the side wall 11 is, for example, 41.0 mm or more and 43.0 mm or less.

[0018] The inner diameter of the widest part of the side wall 11 is, for example, 44.0 mm or more and 45.0 mm or less.

[0019] The thickness of the side wall 11 can be 0.1 mm or more and 1.6 mm or less, and is preferably 0.3 to 1.1 mm.

[0020] The inner diameter of the flange portion 12 is, for example, 44.0 mm or more and 45.0 mm or less, and the outer diameter of the flange portion 12 is, for example, 50.0 mm or more and 52.0 mm or less.

[0021] The thickness of the flange portion 12 of the ring can be 0.5 mm or more and 10.0 mm or less, preferably 0.5 mm or more and 8.0 mm or less, and more preferably 1.0 mm or more and 5.0 mm or less from the viewpoint of home compostability of the ring. If it is 0.5 mm or more, sufficient adhesive strength can be obtained when the filter and the ring are heat-sealed. From the viewpoint of shape retention of the ring, a larger thickness of the flange portion 12 is preferable, but from the viewpoint of shortening the cooling time after heat-sealing the flange portion 12 of the ring and the filter, a thickness of 10.0 mm or less is preferable.

[0022] The dimensions of the ring can be modified as needed. Furthermore, the shape, arrangement, number, and dimensions of the thinned areas and grooves can be added or modified as needed. For example, the thinned areas may have a circular, square, rectangular, or a combination thereof, or an equivalent contour. Furthermore, the horizontal cross section of the side wall portion is not limited to a circular or cylindrical shape, but can also be a polygon, such as a triangle, square, rectangle, pentagon, hexagon, octagon, or dodecagon. The flange portion 12 may be any component used to connect the end of the brewing pod to the end of the beverage brewing device during beverage extraction. While the flange portion 12 preferably has the same shape as the contour of the ring, any shape can be used as long as it fulfills the function of this connection. For example, to reduce the amount of thermoplastic resin used for the flange portion 12, a portion of the contour of 12 in FIG. 1 may be missing. Furthermore, the flange portion 12 may have a shape other than a circular or cylindrical shape.

[0023] The melting point (Tm) of the ring is lower than the melting point of the filter. The melting point of the ring is synonymous with the melting point of the thermoplastic resin composition (a) and can be designed based on the raw materials of the thermoplastic resin A mainly contained in the thermoplastic resin composition (a), the additives used depending on the application, and the amounts of these additives added. The melting point of the thermoplastic resin composition (a) may be 80°C or higher and 165°C or lower. In particular, from the viewpoint of the heat sealability between the filter and the ring and the cooling property after heat sealing, it is preferably 80°C or higher and 130°C or lower, more preferably 80°C or higher and 115°C or lower.

[0024] The thermoplastic resin A contained in the thermoplastic resin composition (a) of the ring of this embodiment is a polyalkylene dicarboxylate formed by polycondensation of an aliphatic dicarboxylic acid and a linear glycol. By including the thermoplastic resin A as the main component of the thermoplastic resin composition (a), home compostability can be imparted to the ring, thereby providing a home compostable beverage extraction pod. The thermoplastic resin A is preferably a polyalkylene dicarboxylate containing two or more types of at least one of the aliphatic dicarboxylic acid and the linear glycol. The content of the polyalkylene dicarboxylate as the thermoplastic resin A is 50% by mass or more and 100% by mass or less relative to the total mass of the thermoplastic resin composition (a). From the viewpoints of home compostability and heat sealability, it may be 70% by mass or more and 95% by mass or less. In this specification, the term "thermoplastic resin composition (a) mainly containing thermoplastic resin A" means that the thermoplastic resin composition (a) contains thermoplastic resin A in an amount of 50 mass % or more.

[0025] Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, and sebacic acid.

[0026] Examples of the straight-chain glycol include 1,4-butanediol and polyethylene glycol.

[0027] The polyalkylene dicarboxylate that is the thermoplastic resin A is preferably polybutylene succinate adipate (hereinafter also referred to as "PBSA") obtained by polycondensation of succinic acid and adipic acid as aliphatic dicarboxylic acids and 1,4-butanediol as a linear glycol.

[0028] The thermoplastic resin composition (a) constituting the ring of this embodiment can be blended with other biodegradable thermoplastic resins to obtain a desired melting point. For example, polybutylene succinate (hereinafter also referred to as "PBS") may be blended in addition to the thermoplastic resin A of this embodiment. From the viewpoints of improving heat sealability by reducing crystallinity and home compostability, the blend amount of PBS (% by mass of PBS relative to the total mass of the thermoplastic resin composition (a) containing PBSA and PBS) can be more than 0% and less than 50%. From the same viewpoint, the blend amount of PBS may be 5% or more and 30% or less. Furthermore, the thermoplastic resin composition (a) may contain one or more additives, such as softeners, plasticizers, pigments, antistatic agents, and biodegradable agents, depending on the purpose.

[0029] In the beverage extraction pod of this embodiment, in terms of the heat sealability between the ring and the filter, it is preferable that the thermoplastic resin composition (a) and the thermoplastic resin composition (b) are not the same type, but are thermoplastic resin compositions with different melting points. By designing the melting point of the thermoplastic resin composition (a) to be lower than the melting point of the thermoplastic resin composition (b), the molten thermoplastic resin composition (a) can easily penetrate the filter (nonwoven fabric) in the thickness direction during the heat sealing process, thereby achieving the desired heat seal strength. The difference in melting point between the thermoplastic resin composition (a) and the thermoplastic resin composition (b) is more preferably 1°C or more, even more preferably 3°C or more, even more preferably 10°C or more, and even more preferably 18°C ​​or more. A melting point difference of 1°C or more allows the thermoplastic resin composition (a) to melt while maintaining the structure of the filter (nonwoven fabric), which is useful from the perspective of improving shape retention.

[0030] Furthermore, in the beverage extraction pod of this embodiment, the thickness of the filter (nonwoven fabric) is preferably smaller than the thickness of the flange surface of the ring, and it is more preferable that the ratio of the difference in thickness between the flange surface of the ring and the filter (nonwoven fabric) is set to a specific range. Here, the ratio of the difference in thickness between the flange surface of the ring and the filter (nonwoven fabric) is defined by the following formula: {(thickness of flange surface of ring for beverage extraction pod)-(thickness of filter)} / (thickness of flange surface of ring for beverage extraction pod)×100 This is the value calculated as follows. By setting the ratio of the difference in thickness between the flange surface of the ring and the filter (nonwoven fabric) within a specific range, a beverage extraction pod with good heat-sealing properties and suitable for high productivity can be obtained. From the viewpoints of ease of temperature transmission during heat sealing and the adhesive strength between thermoplastic resin A and thermoplastic resin B, the ratio of the difference in thickness between the flange surface of the ring and the filter is preferably 10% or more. If the filter is thick, heat generated from the filter side is less likely to be transmitted to the flange surface of the ring. From the viewpoint of improving productivity during heat sealing of the flange surface of the ring and the filter, the ratio of the difference in thickness between the flange surface of the ring and the filter is preferably 99% or less. Furthermore, if the flange surface of the ring itself is thin, the ring may deform during heat sealing. If the flange surface of the ring is thick, the amount of thermoplastic resin composition (a) required for adhesion to the filter increases, which increases the amount of resin required for adhesion to the filter, thereby requiring longer cooling times after heat sealing the ring and the filter, which may result in lower productivity of the beverage extraction pod. In view of the above, in this embodiment, the ratio of the difference in thickness between the flange surface of the ring and the nonwoven fabric is more preferably 40% or more, and even more preferably 70% or more, of the thickness of the flange surface of the ring.

[0031] The crystallinity of the thermoplastic resin composition (a) constituting the ring of this embodiment is preferably 10% to 70%, more preferably 15% to 60%, even more preferably 20% to 45%, and even more preferably 20% to 35%. The lower the crystallinity, the better the heat-sealing properties. By setting the crystallinity to 70% or less, a home-compostable ring with excellent heat-sealing properties to the filter can be obtained.

[0032] 2 is a schematic diagram showing a beverage brewing pod 2 according to one embodiment of the present invention, which includes a ring 1 and a filter 22 having a volume 21 for containing an ingredient to be brewed in obtaining a desired beverage, such as ground coffee, powdered coffee, tea leaves, chocolate, powdered milk, etc.

[0033] From the viewpoint of shape retention, the melting point of the filter 22 (the melting point of the thermoplastic resin composition (b) when the filter is a nonwoven fabric) should be higher than the melting point of the thermoplastic resin composition (a) of the ring at a temperature of 80°C or higher and 165°C or lower, and should have the above-mentioned melting point difference.

[0034] The filter 22 is preferably a thermoforming material that is liquid-permeable and has a filtering function. Among these, nonwoven fabric is preferred from the viewpoint of heat-sealability. The thermoplastic resin B contained in the thermoplastic resin composition (b) constituting the nonwoven fabric can be selected from the following thermoplastic resins from the viewpoint of home composting: polyhydroxybutyrate valerate (PHBV), polyhydroxybutyrate (PHB), nylon 4 (PA4), polyglycolic acid (PGA), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene terephthalate succinate (PBTS), polybutylene succinate carbonate (PBSC), polybutylene adipate terephthalate (PBAT), polyethylene succinate (PES), polyethylene terephthalate succinate (PETS), and polyvinyl alcohol (PVA). The thermoplastic resin composition (b) can be composed of a single or multiple thermoplastic resins B. (However, thermoplastic resin composition (b) does not include thermoplastic resin composition (a).) From the viewpoints of home compostability, moldability of the nonwoven fabric, heat resistance, and adhesion to the ring, it is preferable to select PBSA, PBAT, PBS, or a combination of these as the main component of thermoplastic resin B, and from the viewpoint of home compostability, PBAT is more preferable. Furthermore, thermoplastic resin composition (b) may contain one or more additives such as softeners, plasticizers, pigments, antistatic agents, and biodegradable agents, depending on the purpose. In this specification, the term "thermoplastic resin composition (b) mainly containing thermoplastic resin B" means that the thermoplastic resin composition (b) contains thermoplastic resin B in an amount of 50 mass % or more.

[0035] The method for producing the nonwoven fabric contained in the filter of this embodiment is not limited, and known methods such as spunbonding, meltblowing, airlaid, carding, and papermaking can be used. Bonding methods that can be used include embossing, thermal bonding, columnar flow entanglement, mechanical entanglement, and needle punching. The melt spinning method is preferred as a method for producing long-fiber nonwoven fabrics, as it allows for efficient production and can suppress fuzzing after molding, and production by the spunbonding method is more preferred.

[0036] The nonwoven fabric included in the filter of this embodiment may have a laminated structure, such as SS, SSS, SSSS, SMS, SMMS, or SMSM. Here, S means a spunbonded long-fiber nonwoven fabric, and M means a meltblown ultrafine nonwoven fabric. Alternatively, a short-fiber nonwoven fabric layer may be laminated on the nonwoven fabric substrate, or a hydroentangled nonwoven fabric with a cellulose fiber layer may be used.

[0037] The shape of the fibers constituting the nonwoven fabric included in the filter of this embodiment is not particularly limited, and may be round, flat, or have an irregular cross section such as C-shape, Y-shape, or V-shape, or may have a hollow structure, a sea-island structure, a sheath-core structure, or a split fiber structure.

[0038] The basis weight of the filter can be selected appropriately depending on the material to be extracted, but from the viewpoint of thickness and breathability, it is recommended to use a weight of 10 g / m 2 More than 250g / m 2 It is preferable that:

[0039] The thickness of the filter is preferably 0.1 mm or more and 1.0 mm or less. From the viewpoint of adhesiveness to the ring, the thickness of the filter is preferably 0.1 mm or more, and from the viewpoint of ease of heat transmission during heat sealing, the thickness of the filter is preferably 1.0 mm or less.

[0040] The air permeability of the filter (nonwoven fabric) can be selected appropriately depending on the material to be extracted. From the viewpoint of heat sealing, the structure of the nonwoven fabric should have many voids. Therefore, the air permeability of the filter should be 10 cm 3 / (cm 2 s) or more is preferable, 20cm 3 / (cm 2 The upper limit of the air permeability can be set appropriately depending on the application. When the material to be extracted is coffee powder, it is preferable to set it above 100 cm from the viewpoint of preventing powder leakage. 3 / (cm 2 ·s) or less is preferred.

[0041] The air permeability of the filter can be adjusted by the fiber diameter of the nonwoven fabric, which can be between 6 μm and 35 μm. The filter 22 can be disposed on the inner surface of the side wall 11 of the ring 1 .

[0042] Another embodiment of the present invention is a beverage brewing pod including a ring for the beverage brewing pod and a filter bonded to a flange surface of the ring and having a volume for receiving a material to be brewed.

[0043] The ring, the filter, and the beverage extraction pod preferably have an absolute biodegradability of 70% or more, more preferably 90% or more, and even more preferably 95% or more within 12 months in a biodegradation test in a compost environment at 28°C in accordance with ISO 14855-1. In this case, by combining them with the ring, the entire beverage extraction pod can be home composted.

[0044] For example, when the filter is made of a nonwoven fabric, the beverage extraction pod of this embodiment can be manufactured by the following steps: bringing the flange portion of the ring into surface contact with the thermoformable nonwoven fabric; a step of applying heat from the nonwoven fabric side to heat-seal the nonwoven fabric and the flange portion; and shaping the nonwoven fabric so that the nonwoven fabric passes through the ring to form a volume for containing the material to be extracted; It can be produced by a method comprising:

[0045] The method for manufacturing the beverage extraction pod of this embodiment further includes the following steps: Filling the filter with the material to be extracted; and heat sealing the lid to enclose the material to be extracted; may include: [Example]

[0046] The present invention will be specifically described below with reference to Examples and Comparative Examples. The nonwoven fabrics described in the Examples can be appropriately interpreted as filters, and the resins can be appropriately interpreted as thermoplastic resins or thermoplastic resin compositions.

[0047] (1) Melting point Tm (℃) and crystallinity (%) of ring and filter The samples used were a thermoplastic resin composition (a) for the ring and a thermoplastic resin composition (b) for the filter. Using a PerkinElmer DSC6000 differential scanning calorimeter, 3 to 6 mg of the sample was heated from 20°C to 300°C at a heating rate of 10°C / min. The apex of the peak corresponding to the melting peak in the obtained chart was taken as the melting point Tm (°C). The heat amounts of the cold crystallization portion and the melting portion were calculated using the following formula: Crystallinity (%)=(△Hm-ΔHc) / ΔHf×100 (Formula 1) {In the formula, ΔHm and ΔHc represent the enthalpy of the endotherm in the DSC measurement and the enthalpy of the exotherm due to crystallization, respectively, and ΔHf is a value given in the literature.} The crystallinity (%) was calculated by the following method.

[0048] (2) Heat sealability (2)-1. Evaluation method based on peel strength The heat sealability was evaluated by the peel strength between the flange of the ring and the nonwoven fabric. However, since it was difficult to directly measure the peel strength between the flange of the ring and the nonwoven fabric because it could not be set in a tensile tester, it was measured using the following procedure. (i) Preparation of resin plate The amount of thermoplastic resin composition (a) in chip form required for the flange portion of the ring was measured and poured into a rectangular mold heated to a temperature higher than the melting point of the thermoplastic resin composition (a). After visually confirming that the thermoplastic resin composition (a) had melted, the mixture was left at room temperature until it completely cooled and solidified, thereby obtaining a resin plate. When two or more types of thermoplastic resin composition (a) were used, they were dry-blended at any mass ratio. (ii) Heat sealing of resin plate and nonwoven fabric Two samples, each 30 mm wide and 20 cm long, were cut from the nonwoven fabric and the resin plate. The nonwoven fabric and resin plate samples were aligned widthwise with the nonwoven fabric sample on top, overlapped by approximately 8 mm lengthwise, and the overlapping area was heat-sealed. Heat sealing was performed using a flat heat press from above the nonwoven fabric under conditions of 1 MPa pressure, 110°C temperature, 1 MPa pressure, and 2 seconds. (iii) Peel strength evaluation The heat-sealed sample was attached to a tensile tester with a grip distance of 10 cm so that the heat-sealed portion was positioned in the center and peeled at a 180-degree angle, and the peel strength (N / 30 mm) was measured at a pulling speed of 100 m / min. Two measurements were taken for different samples, and the average value was used as the peel strength (N / 30 mm). The higher the peel strength, the better the heat-sealability.

[0049] (2)-2. Evaluation method by sensory evaluation Ten pieces were made by heat-sealing the ring and filter, and two people separated them by hand, five pieces per person. The number of pieces separated was counted and evaluated according to the following criteria. (Evaluation criteria) 5 points: No separation at all. 4 points: Two pieces separated. 3 points: 4 pieces separated. 2 points: 6 pieces separated. 1 point: 8 or more particles separated.

[0050] (3) Home compostability The home compostability of the target materials was evaluated in accordance with ISO 14855-1. The biodegradation test of the resin was carried out in a composting environment at 28°C, and the evaluation criteria were as follows: (Evaluation criteria) ◎: Absolute biodegradability within 12 months is 95% or more. 〇: Absolute biodegradability within 12 months is 90% or more but less than 95%. △: Absolute biodegradability within 12 months is 70% or more but less than 90%. ×: Absolute biodegradability within 12 months is less than 70%.

[0051] (4) Ring thickness The thickness of the ring was measured at four symmetrical points on the circle using a digital caliper. Each measurement was recorded and the average value was calculated.

[0052] (5) Thickness of nonwoven fabric The thickness of the nonwoven fabric was measured according to the following procedure. (i) Sections measuring 5 cm x 5 cm were obtained from five different locations on the nonwoven fabric. (ii) The thickness of each section was measured using an ABS Digimatic Indicator ID-CX (manufactured by Mitutoyo Corporation), with a flat probe of 15 mm diameter. (iii) The average value of the five points obtained in step (ii) was taken as the thickness of the nonwoven fabric. The ratio of the difference in thickness between the flange surface of the ring and the filter (nonwoven fabric) was calculated using the following formula: Ratio of the difference in thickness between the flange surface of the ring and the filter (nonwoven fabric) = {(thickness of the flange surface of the ring for the beverage extraction pod) - (thickness of the filter)} / (thickness of the flange surface of the ring for the beverage extraction pod) × 100

[0053] (6) Breathability of nonwoven fabric The measurement was performed using the method specified in JIS L1096 Air Permeability Method A (Fragile method).

[0054] [Manufacturing Ring A] Rings were fabricated by conventional injection molding. Specifically, granular PBSA resin (FORZEAS®, manufactured by Mitsubishi Chemical Corporation) was fed into a heated cylinder as the thermoplastic resin composition (a). The temperature of the heated cylinder was set to 80°C above the melting point of the thermoplastic resin composition (a). The thermoplastic resin composition (a) was melted and delivered to the nozzle at the tip of the screw by rotating the screw. The screw was then advanced, and the molten thermoplastic resin composition (a) was injected from the injection nozzle at the tip of the screw into the cavity of a closed mold (designed to have ring dimensions of "side wall: inner diameter 43 mm, outer diameter 45 mm, length 8 mm, flange: inner diameter 45 mm, outer diameter: 52 mm, thickness: 3 mm"). After the thermoplastic resin composition (a) was cooled and solidified within the cavity, the mold was opened, and the molded product adhering to the inner surface of the mold was removed using an ejector pin or the like to fabricate Ring A. The resulting Ring A had the appearance shown in Figure 1. The shapes of each part are shown in Table 1 below.

[0055] [Manufacturing Ring B] A resin prepared by blending PBSA resin (FORZEAS®, manufactured by Mitsubishi Chemical Corporation) and PBS resin (FORZEAS®, manufactured by Mitsubishi Chemical Corporation) in a ratio of 90:10 as thermoplastic resin composition (a) was molded in the same manner as for ring A, except that a mold designed so that the flange thickness of the ring would be 1 mm was used, to obtain ring B. The shape of ring B obtained had the appearance shown in FIG. 1, and the shapes of each part are shown in Table 1 below.

[0056] [Manufacturing of Ring C] Ring C was obtained by molding in the same manner as Ring B, except that a mold designed to have dimensions such that the thickness of the flange portion of the ring would be 3 mm was used. The shape of Ring C obtained was as shown in Figure 1, and the shapes of each part are shown in Table 1 below.

[0057] [Manufacturing of Ring D] Ring D was obtained by molding in the same manner as Ring B, except that a mold designed to have dimensions such that the thickness of the flange portion of the ring would be 6 mm was used. The shape of Ring D obtained was as shown in Figure 1, and the shapes of each part are shown in Table 1 below.

[0058] [Manufacturing of Ring E] Ring E was obtained by molding in the same manner as ring C, except that thermoplastic resin composition (a) obtained by blending PBSA resin (FORZEAS (registered trademark) manufactured by Mitsubishi Chemical Corporation) and PBS resin (FORZEAS (registered trademark) manufactured by Mitsubishi Chemical Corporation) in a ratio of 80:20 was used as thermoplastic resin A. The shape of the obtained ring B had the appearance shown in FIG. 1, and the shapes of each part are shown in Table 1 below.

[0059] [Manufacturing of Ring F] Ring F was obtained by molding in the same manner as ring C, except that thermoplastic resin composition (a) prepared by blending PBSA resin (FORZEAS, manufactured by Mitsubishi Chemical Corporation) and PBS resin (FORZEAS, manufactured by Mitsubishi Chemical Corporation) in a 50:50 ratio was used as thermoplastic resin A. Ring B obtained had the appearance shown in FIG. 1, and the shapes of each part are shown in Table 1 below.

[0060] [Manufacturing of Ring G] Ring H was obtained by molding in the same manner as Ring A, except that PLA (Nature Works, 6202D) was used as thermoplastic resin A. The shape of Ring H obtained had the appearance shown in Figure 1, and the shapes of each part are shown in Table 1 below.

[0061] [Manufacturing of Ring H] Ring I was obtained by molding in the same manner as Ring A, except that PBS (FORZEAS (registered trademark) manufactured by Mitsubishi Chemical Corporation) was used as thermoplastic resin A. The shape of the obtained Ring I was as shown in Figure 1, and the shapes of each part are shown in Table 1 below.

[0062] [Manufacture of Ring I] Ring J was obtained by molding in the same manner as Ring A, except that PHA (H1009-H, manufactured by Danimer Scientific) was used as thermoplastic resin A. The shape of the obtained Ring J was as shown in Figure 1, and the shapes of each part are shown in Table 1 below.

[0063] [Nonwoven fabric manufacturing a] Polybutylene adipate terephthalate (PBAT) was used as the thermoplastic resin composition (b), which was melted and kneaded in a single-screw extruder and extruded using the spunbonding method at a throughput rate of 0.9 g / min·Hole and a spinning temperature of 210°C. The filaments were pulled using a high-speed air jet pulling device and deposited on a moving collection surface to prepare a biodegradable long-fiber web (circular cross section). Next, using a pair of embossing rolls consisting of a roll with a concave-convex pattern on the surface and a roll with a smooth surface, the fabric was heat-pressed under the conditions of a pressure-bonding area ratio of 11%, a temperature of 95°C for both rolls, and a roll linear pressure of 20 N / mm, resulting in a basis weight of 130 g / m 2 The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[0064] [Nonwoven fabric manufacturing b] Ventilation is 15cm 3 / (cm 2 Nonwoven fabric b was obtained by the same method as nonwoven fabric a, except that the fiber diameter was adjusted to be s. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[0065] [Nonwoven Fabric Manufacturing c] Breathability is 63cm 3 / (cm 2 Nonwoven fabric c was obtained by the same method as nonwoven fabric a, except that the fiber diameter was adjusted to be s. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[0066] [Nonwoven Fabric Manufacturing] Weight is 250g / m 2 Nonwoven fabric d was obtained by the same production method as nonwoven fabric a, except that the speed of the moving collection surface was adjusted so that the nonwoven fabric d was 0.05 mm. The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[0067] [Nonwoven fabric manufacturing] Nonwoven fabric e was obtained in the same manner as nonwoven fabric a, except that polybutylene succinate resin (PBS) was used as thermoplastic resin composition (b). The physical properties of the obtained nonwoven fabric are shown in Table 1 below.

[0068] [Manufacturing beverage extraction pods] [Example 1] A beverage pod was produced using ring A and nonwoven fabric a. The nonwoven fabric was placed on top of the ring, and then heat-sealed at a temperature of 110°C and a pressure of 0.2 MPa with the upper side of the nonwoven fabric as the heated surface. The nonwoven fabric was then passed through the ring and thermoformed to fit the inner diameter of the ring, resulting in a capsule-shaped beverage extraction pod. The heat-sealing properties of the resulting pods were evaluated by sensory evaluation, and the results are shown in Table 1 below.

[0069] [Examples 2 to 10, Comparative Examples 1 to 4] Capsule-type beverage extraction pods were obtained in the same manner as in Example 1, except that the rings and nonwoven fabrics were used in the combinations shown in Table 1. The heat-sealing properties of the obtained pods were evaluated by sensory evaluation. The results are shown in Table 1 below. In Table 1 below, the thermoplastic resin composition (a) is also referred to as the "raw material for the ring" or "raw material resin", and the thermoplastic resin composition (b) is also referred to as the "raw material resin for the filter".

[0070] [Table 1] [Industrial Applicability]

[0071] The ring for a beverage extraction pod according to the present invention is made of a home-compostable thermoplastic resin composition (a) and has good heat-sealing properties with a filter also made of a home-compostable thermoplastic resin composition (b). Therefore, it can be suitably used for home-compostable beverage extraction pods, and can be suitably used as a ring for beverage extraction pods for coffee, black tea, green tea, Chinese tea, etc. [Explanation of symbols]

[0072] 1 Beverage Pod Ring 11 Side wall 12 Flange surface (part) 2 beverage brewing pods 21 Volume for containing material to be extracted 22 filters

Claims

1. A beverage extraction pod comprising a ring for a beverage extraction pod, the ring having a cylindrical side wall and a flange surface protruding outward from the cylindrical side wall, and a filter bonded to the flange surface of the ring and having a capacity for containing a material to be extracted, wherein the filter is made of a thermoplastic resin composition (b) mainly containing at least one thermoplastic resin B selected from the group consisting of polybutylene adipate terephthalate (PBAT) and polybutylene succinate (PBS), and the ring is made of a thermoplastic resin composition (a) mainly containing a thermoplastic resin A that is a polyalkylene dicarboxylate, different from the thermoplastic resin composition (b) mainly containing thermoplastic resin B that constitutes the filter, and wherein the melting point of the thermoplastic resin composition (a) is lower than the melting point of the thermoplastic resin composition (b), the difference in melting points being 10°C or more.

2. 2. The beverage extraction pod according to claim 1, wherein the thermoplastic resin A is a polyalkylene dicarboxylate containing two or more types of at least one of an aliphatic dicarboxylic acid and a linear glycol subjected to polycondensation.

3. 3. The beverage extraction pod according to claim 1 or 2, wherein the thermoplastic resin A is polybutylene succinate adipate (PBSA).

4. A beverage extraction pod as described in claim 1 or 2, wherein the thermoplastic resin composition (a) is a blend of the thermoplastic resin A with polybutylene succinate adipate (PBSA) and polybutylene succinate (PBS), and the blend amount of the PBS (mass % of PBS relative to the total mass of the thermoplastic resin composition (a) containing PBSA and PBS) is more than 0% and not more than 30%.

5. The beverage extraction pod according to claim 1 or 2, wherein the ring has an absolute biodegradability of 70% or more within 12 months in a biodegradation test in a compost environment at 28°C in accordance with ISO 14855-1.

6. 3. The beverage extraction pod according to claim 1 or 2, wherein the thermoplastic resin B is polybutylene adipate terephthalate (PBAT).

7. 3. The beverage extraction pod according to claim 1 or 2, wherein the filter is a nonwoven fabric.

8. The air permeability of the filter is 10 cm ３ / (cm ２ 3. The beverage extraction pod according to claim 1 or 2, wherein the number of the first and second electrodes is equal to or greater than s.

9. A beverage extraction pod as described in claim 1 or 2, wherein the ratio of the difference in thickness between the ring and the filter calculated by [{(thickness of the flange surface of the ring for the beverage extraction pod) - (thickness of the filter)} / (thickness of the flange surface of the ring for the beverage extraction pod)] x 100 is 70% or more.

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