Ring for beverage extraction pod, and beverage extraction 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

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

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

[0002] Generally, an extraction pod for producing a beverage is constructed by heat-sealing a reinforcing ring and a filter for containing an extracting material. 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.

[0003] Special table 2017-522150 publication

[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, Cited Document 1 does not disclose a beverage extraction pod that includes a filter and a ring, in which the beverage extraction pod itself is home compostable and in which the ring and the filter have good heat sealing properties.

[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.

[0006] The present inventors conducted extensive research and experimentation to solve the above-mentioned problems. As a result, they discovered that if the same type of 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 capacity for containing an extracting material, a cylindrical side wall adapted to be bonded to the filter 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) primarily containing a thermoplastic resin A, which is different from a thermoplastic resin composition (b) primarily 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] The ring for a beverage extraction pod according to 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] The ring for a beverage extraction pod according to [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 to be 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 the ring for a beverage extraction pod according to any one of [1] to [4], and a filter bonded to the flange surface of the ring and having a capacity for containing 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] The 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 a nonwoven fabric. [9] The air permeability of the filter is 10 cm ３ / (cm ２

[10] The beverage extraction pod according to any one 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.

[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.

[0009] 1A and 1B are perspective schematic views of a ring for a beverage brewing pod according to one embodiment of the present invention, and a schematic view of a beverage brewing pod according to one embodiment of the present invention, including a ring;

[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 capacity for containing an extracting material, a cylindrical side wall adapted to be bonded to the filter 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) primarily containing a thermoplastic resin A, which is different from the thermoplastic resin composition (b) primarily 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). Hereinafter, the "flange surface" of the "ring for a beverage extraction pod" will also be referred to as the "flange portion."

[0012] Figure 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 along 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 sidewall 11 and flange portion 12 may be manufactured as a single piece, for example by hot and / or injection molding, compression processing, or thermoforming.

[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 portion of the side wall 11 is, for example, not less than 41.0 mm and not more than 43.0 mm.

[0018] The inner diameter of the widest part of the side wall 11 is, for example, not less than 44.0 mm and not more than 45.0 mm.

[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 may be a polygonal shape, such as a triangular, square, rectangular, pentagonal, hexagonal, octagonal, or dodecagonal. 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 in the flange portion 12, a portion of the contour of 12 in FIG. 1 may be missing. The flange portion 12 may also 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 thereof. 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 viewpoint 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) primarily comprising thermoplastic resin A" means that the thermoplastic resin composition (a) contains 50% by mass or more of the thermoplastic resin A.

[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 achieve the 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 PBS 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 melting point difference 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 to set the ratio of the thickness difference between the flange surface of the ring and the filter (nonwoven fabric) within a specific range. Here, the ratio of the thickness difference between the flange surface of the ring and the filter (nonwoven fabric) is a value calculated using the following formula: {(thickness of the flange surface of the beverage extraction pod ring) - (thickness of the filter)} / (thickness of the flange surface of the beverage extraction pod ring) x 100. By setting the ratio of the thickness difference 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 standpoints of the ease of heat transfer during heat sealing and the adhesive strength between thermoplastic resin A and thermoplastic resin B, the ratio of the thickness difference 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 transferred 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, it is preferable that the ratio of the difference in thickness between the flange surface of the ring and the filter be 99% or less. Furthermore, if the thickness of the flange surface of the ring itself is small, the ring may deform during heat sealing. If the flange surface of the ring is thick, the amount of resin in the thermoplastic resin composition (a) required for adhesion to the filter increases, which may result in a longer cooling time after heat sealing the ring and the filter, resulting 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-sealability. By setting the crystallinity to 70% or less, a home-compostable ring with excellent heat-sealability to the filter can be obtained.

[0032] 2 is a schematic diagram of 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 the material to be brewed in obtaining the 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 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 (B) 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 composting, moldability of the nonwoven fabric, heat resistance, and adhesion to the ring, it is preferable to select PBSA, PBAT, PBS, or a combination thereof as the main component of thermoplastic resin B, and from the viewpoint of home composting, 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 comprising thermoplastic resin B" means that thermoplastic resin composition (b) contains thermoplastic resin B in an amount of 50% by 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 long-fiber nonwoven fabric made by the spunbond method, and M means an ultrafine nonwoven fabric made by the meltblown method. 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 a C-shape, a Y-shape, or a 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 appropriately selected depending on the material to be extracted, but from the viewpoint of thickness and breathability, it is preferable that the basis weight is 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 appropriately selected 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, 20 cm 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 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 6 μm or more and 35 μm or less. 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] The beverage extraction pod of this embodiment, for example, when the filter is made of nonwoven fabric, can be manufactured by a method including the following steps: bringing the flange portion of the ring into surface contact with a thermoformable nonwoven fabric; applying heat from the nonwoven fabric side to heat-seal the nonwoven fabric and the flange portion; and molding the nonwoven fabric so that the nonwoven fabric passes through the ring, thereby forming a volume for storing the material to be extracted.

[0045] The manufacturing method of the beverage extraction pod of this embodiment may further include the following steps: filling the inside of the filter with the material to be extracted; and heat-sealing the lid so that the material to be extracted is enclosed.

[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 (°C) and Crystallinity (%) of Ring and Filter Thermoplastic resin composition (a) for the ring and thermoplastic resin composition (b) for the filter were used as samples. Using a PerkinElmer DSC6000 differential scanning calorimeter, 3 to 6 mg of 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 quantities of the cold crystallization portion and the melting portion were calculated, and the crystallinity (%) was determined using the following formula: Crystallinity (%) = (ΔHm - ΔHc) / ΔHf × 100 (Formula 1) {where ΔHm and ΔHc represent the enthalpy of endotherm and the enthalpy of exotherm due to crystallization in the DSC measurement, respectively, and ΔHf is a value described in the literature.}

[0048] (2) Heat Sealability (2)-1. Evaluation Method by Peel Strength Heat sealability was evaluated by the peel strength between the flange portion of the ring and the nonwoven fabric. However, since it was not possible to set it in a tensile tester, it was difficult to directly measure the peel strength between the flange portion of the ring and the nonwoven fabric. Therefore, it was measured using the following procedure. (i) Preparation of Resin Plate Chip-shaped thermoplastic resin composition (a) was measured and poured into a rectangular mold heated to a temperature higher than the melting point of the thermoplastic resin composition (a), in the amount of resin required for the flange portion of the ring. After visually confirming that the thermoplastic resin composition (a) had melted, it 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 Between Resin Plate and Nonwoven Fabric Two samples measuring 30 mm in width and 20 cm in length were cut from each of the nonwoven fabric and the resin plate. The nonwoven fabric and resin plate samples were placed with the nonwoven fabric sample on top, with both ends aligned in the width direction and overlapped by approximately 8 mm in the length direction, and the overlapping portion 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 180 degrees, and the peel strength (N / 30 mm) was measured at a tensile speed of 100 m / min. Measurements were performed twice for different samples, and the average value was taken 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 rings and filters were heat-sealed and separated by hand by two people, five per person. The number of separated pieces was counted and evaluated according to the following evaluation criteria. (Evaluation criteria) 5 points: none separated. 4 points: 2 pieces separated. 3 points: 4 pieces separated. 2 points: 6 pieces separated. 1 point: 8 pieces or more separated.

[0050] (3) Home Compostability The home compostability of the target object was evaluated in accordance with ISO 14855-1. A biodegradation test was conducted on the resin in a compost environment at 28°C, and the results were evaluated according to the following criteria: (Evaluation criteria) ◎: Absolute biodegradability of 95% or more within 12 months. ○: Absolute biodegradability of 90% or more but less than 95% within 12 months. △: Absolute biodegradability of 70% or more but less than 90% within 12 months. ×: Absolute biodegradability of less than 70% within 12 months.

[0051] (4) Ring Thickness The thickness of the ring was measured at four symmetrical points on a circle using a digital caliper. Each measurement value 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) 5 cm x 5 cm sections were obtained from five different positions on the nonwoven fabric. (ii) The thickness of each section was measured using an ABS Digimatic Indicator ID-CX (manufactured by Mitutoyo Corporation). A flat probe with a diameter of 15 mm was used. (iii) The average value of the five points obtained in procedure (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 as follows: 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) Air permeability of nonwoven fabric: Measured using the method specified in JIS L1096 Air Permeability Method A (Fragile type method).

[0054] [Production of Ring A] A ring was produced by general injection molding. Specifically, granular PBSA resin (FORZEAS (registered trademark) manufactured by Mitsubishi Chemical Corporation) as the raw material for the thermoplastic resin composition (a) was fed into a heating cylinder, and the temperature was set to the melting point of the thermoplastic resin composition (a) + 80 ° C. The thermoplastic resin composition (a) was melted and sent to the nozzle side at the tip of the screw by rotating a screw installed in the heating cylinder. The screw was advanced, and the molten thermoplastic resin composition (a) was injected from the injection nozzle installed at the tip of the screw into the cavity of a closed mold (designed so that the ring dimensions were "side wall: inner diameter 43 mm, outer diameter 45 mm, length 8 mm, flange portion: inner diameter 45 mm, outer diameter: 52 mm, thickness: 3 mm"). After the thermoplastic resin composition (a) was cooled and solidified in the cavity, the mold was opened, and the molded body stuck to the inner surface of the mold was removed using an ejector pin or the like to produce Ring A. The shape of the obtained ring A has the appearance shown in Figure 1. The shapes of each part are shown in Table 1 below.

[0055] [Production of Ring B] A resin 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 90:10 as the thermoplastic resin composition (a) was molded in the same manner as for Ring A, except that a mold designed so that the thickness of the flange portion of the ring would be 1 mm was used, to obtain Ring B. 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.

[0056] [Production 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 was 3 mm was used. The shape of the obtained Ring C was as shown in Fig. 1, and the shapes of each part are shown in Table 1 below.

[0057] [Production 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 was 6 mm was used. The shape of the obtained Ring D had the appearance shown in Fig. 1, and the shapes of each part are shown in Table 1 below.

[0058] [Production 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] [Production of Ring F] Ring F was obtained by molding in the same manner as Ring C, except that thermoplastic resin composition (a) obtained by blending PBSA resin (FORZEAS, manufactured by Mitsubishi Chemical Corporation) and PBS resin (FORZEAS, manufactured by Mitsubishi Chemical Corporation) in a ratio of 50:50 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.

[0060] [Production 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 the obtained Ring H was as shown in Fig. 1, and the shapes of each part are shown in Table 1 below.

[0061] [Production 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 had the appearance shown in FIG. 1, and the shapes of each part are shown in Table 1 below.

[0062] [Production 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 had the appearance shown in FIG. 1, and the shapes of each part are shown in Table 1 below.

[0063] [Production of Nonwoven Fabric a] Polybutylene adipate terephthalate (PBAT) was used as the thermoplastic resin composition (b), and the mixture was melted and kneaded in a single-screw extruder. The mixture was extruded by the spunbonding method at a throughput 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, the web was heat-pressed using a pair of embossing rolls consisting of a roll with a textured surface and a roll with a smooth surface under conditions of a pressure-bonding area ratio of 11%, both rolls at a temperature of 95°C, 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] [Production of nonwoven fabric b] Air permeability 15 cm ３ / (cm ２ Nonwoven fabric b was obtained by the same production 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 production c] Air permeability 63 cm 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] [Production of nonwoven fabric d] Nonwoven fabric with a basis weight of 250 g / m ２ Nonwoven fabric d was obtained by the same 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] [Production of Nonwoven Fabric e] Nonwoven fabric e was produced 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 of Beverage Extraction Pods] [Example 1] A beverage pod was fabricated 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 heat-molded to fit the inner diameter of the ring, resulting in a capsule-shaped beverage extraction pod. The heat-sealing properties of the resulting pod were evaluated by sensory evaluation. 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 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, thermoplastic resin composition (a) is also referred to as the "ring raw material" or "raw material resin," and thermoplastic resin composition (b) is also referred to as the "filter raw material resin."

[0070]

[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.

[0072] REFERENCE SIGNS LIST 1 Ring for beverage extraction pod 11 Side wall 12 Flange surface (portion) 2 Beverage extraction pod 21 Volume for accommodating material to be extracted 22 Filter

Claims

1. A ring for a beverage extraction pod, comprising a filter having a volume for accommodating an extracting material, 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. The ring for a beverage extraction pod according to claim 1, wherein the difference in melting point between the plastic 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 claim 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. A ring for a beverage extraction pod as described in claim 1 or 2, wherein the thermoplastic resin A is polybutylene succinate adipate (PBSA).

5. A beverage extraction pod comprising a ring for a beverage extraction pod according to claim 1 or 2, and a filter bonded to the flange surface of said ring and having a volume for containing a material to be extracted.

6. The beverage extraction pod according to claim 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. The beverage extraction pod of claim 5, wherein said thermoplastic resin B is polybutylene adipate terephthalate (PBAT).

8. The beverage extraction pod of claim 5, wherein the filter is a non-woven fabric.

9. The air permeability of the filter is 10 cm ３ / (cm ２ The beverage extraction pod of claim 5, wherein the number of the first and second electrodes is equal to or larger than the number of the second electrodes.

10. A beverage extraction pod as described in claim 5, 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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