AU2006277422B2

AU2006277422B2 - Sealed container with resealability

Info

Publication number: AU2006277422B2
Application number: AU2006277422A
Authority: AU
Inventors: Osamu Horii; Masaki Nakaya
Original assignee: Kirin Brewery Co Ltd
Current assignee: Kirin Brewery Co Ltd
Priority date: 2005-08-05
Filing date: 2006-07-28
Publication date: 2011-08-11
Anticipated expiration: 2026-07-28
Also published as: AU2006277422A1; CN101238042A; RU2363630C1; CN100564176C; WO2007018055A1; JP4757563B2; KR101227299B1; KR20080044832A; JP2007039117A

Abstract

A fit-on type sealed container well recyclable, transparent, manufacturable at low cost, eliminating the need of chemical reforming, hard to crack and leak, and enabling resealing. The sealed container with resealability comprises a container body with a tubular mouth part and a cover formed in a tubular shape with a top face and sealing the mouth part by fitting to the container body from the outside of the mouth part. The container body is formed of a PET resin in such a structure that the deformation of the mouth part is suppressed by limiting the deformation of the body part inside the body part when a stress is applied to the body part. The mouth part comprises an annular projected part continuously formed along the periphery of the tube outer wall of the mouth part, and the cover comprises an annular recessed part continuously formed for fitting the annular projected part therein along the periphery of the tube inner wall of the cover and is formed of an amorphous PET resin having a density of 1.320 to 1.340 g/cm, and its wall thickness is 80 to less than 390 μm.

Description

Description TITLE OF THE INVENTION RESEALABLE SEALED CONTAINER TECHNICAL FIELD [0001] The present invention is related to a resealable sealed container in which a container body made from polyethylene terephthalate (hereafter, referred to as PET) resin for containing contents such as foods or beverages is sealed by a lid made from PET resin having a good recyclability and transparency. In this regard, resealable refers to the characteristic in which sealability is obtained to the extent that at least water will not leak at the time the lid is fitted again when used under a load applied to the container, for example, in situations where the container is held by hand or is carried in a bag or the like. PRIOR ART TECHNOLOGY [0002] As for a sealed container, for example, as for a beverage container, various containers such as bottles, cans, plastic containers and the like are known. In recent years, plastic containers, especially containers made from PET resin (PET bottles) have been widely used from the viewpoint of convenience such as a good handling 1 performance thereof and the like. [0003] Further, in order to recycle the container, preferably the lid of the PET bottle is formed from the same material, that is, PET resin. However, from the fact that the PET resin lid cracks easily and is difficult to ensure sealability (e.g., see Patent Document 1), a plastic material which has plenty of flexibility and extensibility such as polypropylene resin mainly, as well as polyethylene or the like is used as a material for the lid (e.g., see Patent Document 2). [00041 In using PET resin for the lid, substantial chemical modification of the PET resin such as a copolymer with polyethylene or the like is required (e.g., see Patent Document 3). [0005] Further, in PET bottles, a method in which a lid is screwed on a bottle mouth portion is used as a sealing method (e.g., see Patent Document 1). [0006] Patent Document 1: Japanese Laid-Open Patent Publication No. HEI 10-139061 Patent Document 2: Japanese Laid-Open Patent Publication No. 2002-348326 2 Patent Document 3: Japanese Laid-Open Patent Publication No. 2002-302133 [10007] However, starting with the technology disclosed in 5 Patent Document 2, in the case where the lid is made from polypropylene resin, the container body and the lid have to be separated in order for recycling, and this consumes time. Further, the transparency of the lid is inferior compared to the container body. 10 [0008] Further, in the case where PET resin is modified to form a lid like the technology disclosed in Patent Document 3, costs accompanying modification will rise, and there are cases where recyclability is insufficient. 15 [0009] Furthermore, starting with the lid disclosed in Patent Document 1, because the screw-on type lid is given a large thickness which imparts stiffness, the lid forms a main cause of large cost increases in the whole container. 20 [0010] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were 3 common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application. [0010A) 5 Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, 10 or group of elements, integers or steps. SUMMARY OF THE INVENTION (0011] From a diligent examination of the problems described above, the present inventors discovered that it is possible 15 to (1) form the container body from a hard PET resin, form the lid from a soft PET resin, and use a fit-on type instead of a screw-on type as the sealing method, and completed the present invention. According to the present invention, there is provided a resealable sealed container equipped 20 with a container body which has a cylindrically shaped mouth portion, and a lid which is formed in a cylindrical shape with a top surface, and which seals said mouth portion by being fitted on from the outside of said mouth portion, wherein said container body has a structure in which the 4 deformation of said mouth portion is suppressed by restricting deformation of a body part to the inside of said body part when a stress is applied to said body part, and is formed from polyethylene terephthalate resin, wherein said 5 mouth portion has a continuous annular protrusion part along the circumferential direction of the cylindrical outer wall, wherein said lid has a continuous annular concavity for fitting on said annular protrusion part along the circumferential direction of the cylindrical inner wall, is 10 formed from amorphous polyethylene terephthalate resin having a density of 1.320 - 1.340 g/cm 3 , and has a thickness which is greater than or equal to 80 ym and less than 390 y m; and wherein a rib-shaped neck ring is provided on the cylindrical outer wall of said mouth portion toward the body 15 part side than said annular protrusion part, a flange facing the outside is provided on the cylindrical end part of said lid, and said neck ring and said flange are fused. [0012] In the resealable sealed container, said lid is 20 preferably formed by an air pressure forming method or a vacuum forming method. The lid formed by an air pressure forming method or a vacuum forming method has a small thickness and a low cost. [0013] 5 In the resealable sealed container, said container body is preferably formed by a blow molding or injection molding method. By forming it with a blow molding or injection molding method, it is easy to obtain a structure in which 5 the deformation of the mouth portion is suppressed. [0014] In the resealable sealed container, when the top surface of said lid is pulled up, the measured bonding force of said lid until said lid is opened is preferably greater 10 than or equal to 9.8 N. This makes it difficult for contents to fly out, and makes it easy to obtain sufficient sealability when the opened lid is fitted again. [0015] In the resealable sealed container, said structure in 15 which the deformation of said mouth portion is restricted is preferably a structure in which said container body has a body part with a grip part which is formed at a part where the body diameter is maximum or roughly maximum, and is separated from said mouth portion by 30 mm or further, and 20 has a shoulder part between said body part and said mouth portion. By providing a grip part, it becomes easy for stress to be applied to only the body part which is the grip part, and even if the body part is deformed by stress, the transmission of deformation is blocked by the provision of 6 the shoulder part. In this way, because it is possible to prevent the deformation of the mouth portion, as a result, the contents are difficult to leak. [0016] 5 In the resealable sealed container, said shoulder part preferably has a shape in which the ratio of the reducing diameter from said body part to said mouth portion is changed. Even in the case where the amount of the deformation of the body part which is the grip part is 10 large, the transmission of the deformation is blocked by the shoulder part, and this makes it possible to prevent the deformation of the mouth portion. [0017] In the resealable sealed container, said structure in 15 which the deformation of said mouth portion is restricted is preferably a structure in which at least said shoulder part is formed with a thicker wall compared to said body part, or a structure in which at least said shoulder part is crystallized, or a structure in which a rib-shaped 20 reinforcement ring is provided along the circumferential direction on the outer wall of said mouth portion or said shoulder part, or a combination of these structures. Even if the stress applied to the body part is large, because the stiffness of the shoulder part itself is raised by the 7 structure described above, it is possible to prevent the deformation of the mouth portion. [0018] In the resealable sealed container, preferably said 5 container body is formed in a cup shape, and said structure in which the deformation of said mouth portion is restricted is a structure in which at least a lower part from said mouth portion is formed with a thicker wall compared to said body part, or a structure in which at least the lower part 10 from said mouth portion is crystallized, or a structure in which a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of said mouth portion or the lower part from said mouth portion, or a combination of these structures. In the case where the 15 container body is formed in a cup shape, the deformation of the body part is easily transmitted to the mouth portion when a stress is applied to the body part. However, by using either structure of the structures in which the deformation of the mouth portion is restricted described 20 above, even when the container body is formed in a cup shape, the deformation of the body part is difficult to be transmitted to the mouth portion. [0019] In the resealable sealed container, when a stress is 8 applied and said body part is crushed 10% in the body diameter direction, the deformation ratio calculated by (Equation 1) in the mouth diameter direction of said mouth portion is preferably 0.50% or lower. By providing a 5 structure in which the deformation of the mouth portion is suppressed so that the deformation ratio becomes 0.50% or lower, it is possible to ensure the sealability of the lid, and this makes it possible to practically eliminate the leaking of the contents. 10 (Equation 1): Deformation Ratio (%) = {(Minimum Value of Mouth Diameter at The Time of No Load - Minimum Value of Mouth Diameter at The Time of Deformation) / Minimum Value of Mouth Diameter at The Time of No Load} X 100 [0020] 15 In the resealable sealed container, the amount of the deformation of said mouth portion is preferably smaller than the amount of the deformation of said lid when a prescribed load is applied to the peripheral part of the overlapping area of said lid and said mouth portion. By making the 20 mouth portion stiffer than the lid, it is possible to ensure the sealability of the lid, and this makes it possible to practically eliminate the leaking of the contents. [0021] In an embodiment of the present invention, even when the 9 contents are a carbonated beverage for example, it is possible to prevent the lid from popping off. Further, it is also possible to confirm whether or not it has been opened. 5 [0022] The resealable sealed container is preferably equipped with a mechanism that prevents said lid from popping off by providing a tab on said lid, providing a rib-shaped neck ring having a cutout on the cylindrical outer wall of said 10 mouth portion toward the body part side than said annular protrusion part, and hooking said tab in said cutout. Even when the contents are carbonated beverage for example, it is possible to prevent the lid from popping off. [0023] 15 The resealable sealed container preferably has a shrink film cover which covers said mouth portion and said lid sealing said mouth portion. It is possible to prevent the lid from popping off until it reaches a consumer. Further, it is also possible to confirm whether or not it has been 20 opened. [0024] In the resealable sealed container, a gas barrier property thin film is preferably formed on at least one side of the surface of said container body or said lid. By 10 improving the gas barrier property of the container, it is possible to extend the expiration date or the freshness date. [0025] The sealed container according to embodiments of the 5 present invention has a good recyclability, has transparency, is low-cost, does not require chemical modification, is difficult to crack and difficult to leak, and can be resealed while ensuring sealability. BRIEF DESCRIPTION OF THE DRAWINGS 10 [0026] Fig. 1 is a schematic drawing of a vertical cross section of one embodiment of a resealable sealed container according to the present embodiments. Fig. 2 shows a molding process for the lid using an air 15 pressure forming method, wherein (a) shows a sheet heating step, (b) shows an air pressure forming step, and (c) shows a removing step. Fig. 3 is a schematic drawing which shows illustratively the deformation state when a stress is applied to the sealed 20 container 100 shown in Fig. 1, wherein (a) shows the state before deformation, and (b) shows the state after deformation. Fig. 4 is a schematic drawing of a vertical cross section of another embodiment of a resealable sealed container according to the present embodiments, wherein (a) 11 is the case where it has a shoulder part shape in which the ratio of the reducing diameter from the body part to the mouth portion is changed, (b) is the case where it has a shoulder part that is formed with a thicker wall compared to the body part, (c) is the case where it has a crystallized shoulder part, and (d) is the case where a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of the mouth portion or the shoulder part. Fig. 5 is a schematic drawing of a vertical cross section of a resealable sealed container which has a cup shaped container body according to the present embodiments, wherein (a) is the case where reinforcement is carried out by adding thickness to the wall, (b) is the case where reinforcement is carried out by crystallization of the wall, and (c) is the case where reinforcement is carried out with a rib-shaped reinforcement ring. Fig. 6 is a schematic drawing which shows another embodiment of a lid pop-off prevention mechanism. Fig. 7 is a schematic drawing which shows an example embodiment in which the sealed container 100 is covered with a shrink film cover. DESCRIPTION OF SYMBOLS [0027] 1, container body 12 2, lid 3, mouth portion 4, body part 5, top surface of lid 6, 6a, 6b, annular protrusion part 7, 7a, 7b, annular concavity part 8, shoulder part 10, stress 11, crush 12, reinforcement ring 13, ring 14, 32, neck ring 15, 30 tab 16, flange 18, hooking part 19, closely attached part 21, heating plate 22, metal mold 23, sheet 24, compressed air 25, lower part from the mouth portion 31, cutout 40, shrink film cover 100, 200, 300, 400, 500, 600, 700, 800, 900, sealed container 13 X, axis of container DETAILED DESCRIPTION OF THE INVENTION [0028] (OPERATION) In the resealable sealed container according to the present embodiments, the container body and the lid are both formed from PET resin in order to enhance recyclability. In this regard, when a screw-on type lid is formed by injection molding from PET resin in order to ensure resealability, chemical modification of the PET resin is required because the sealability is insufficient and cracks form easily. Accordingly, assuming that a general-purpose PET resin is used, in order to both ensure sealability and prevent cracks, the container body, especially the mouth portion thereof is made stiff, and the lid is made soft. Further, the lid is made a fit-on type instead of a screw-on type. The destruction of the sealability due to deformation is prevented by making the mouth portion stiff, and cracks in the lid are reduced by making the lid soft. In the case where the lid is made soft, because it is difficult to make a screw-on type lid, a fit-on type lid is used. In this regard, means for making the thickness of the wall of the mouth portion large in order to make the mouth portion stiff have been considered, but there is a limit to the increased stiffness 14 of the mouth portion by these means. Accordingly, the deformation of the mouth portion is suppressed by giving the container body a structure in which the deformation of the mouth portion is suppressed by restricting deformation of the body part to the inside of the body part when a stress is applied to the body part. [0029] The present invention is described in detail below with reference to preferred embodiments, but it should not be interpreted that the present invention is limited to these descriptions. First, a resealable sealed container according to the present embodiments will be described with reference to Fig. 1 ~ Fig. 7. Further, the same symbols are applied to the same members or same parts. [0030] A schematic drawing of a vertical cross section of one embodiment of a resealable sealed container according to the present embodiments is shown in Fig. 1. The sealed container 100 shown in Fig. 1 is equipped with a container body 1 which has a cylindrically shaped mouth portion 3, and a lid 2 which is formed in a cylindrical shape with a top surface 5, and which seals the mouth portion 3 by being fitted on from the outside of the mouth portion 3, wherein the container body 1 has a structure in which the deformation of the mouth portion 3 is suppressed by 15 restricting deformation of a body part 4 to the inside of the body part 4 when a stress is applied to the body part 4, and is formed from polyethylene terephthalate resin, wherein the mouth portion 3 has a continuous annular protrusion part 6 along the circumferential direction of the cylindrical outer wall, and wherein the lid 2 has a continuous annular concavity part 7 for fitting on the annular protrusion part 6 along the circumferential direction of the cylindrical inner wall, is formed from amorphous polyethylene terephthalate resin having a density of 1.320 ~ 1.340 g/cm 3 , and has a thickness which is greater than or equal to 80g m and less than 390gm. [0031] The container body 1 has a so-called bottle shape, and the mouth portion 3 has a cylindrical shape. The cylindrical shape stated here is not only a cylindrical shape, but also includes the case where the mouth diameter along the X-axis direction becomes large and the case where it becomes small. Further, the shape of a horizontal cross section with respect to the X-axis is not only a circle, but also includes the case where it is an ellipse, a rectangle or a polygon. Further, the container body 1 may be formed in a cup shape (e.g., Fig. 5), and in this case as well the mouth portion 3 has a cylindrical shape. 16 [0032] The container body 1 is formed by a well-known molding method, for example, a blow molding or injection molding method using polyethylene terephthalate resin (PET resin). In the present embodiments, the PET resin includes modified PET resin such as glycol modified polyethylene terephthalate (PETG) resin or the like which can be handled in the same way as PET resin in recycling. [0033] The contents filled in the container body 1 are mainly various beverages such as beer, sparkling wine, carbonated beverages, soft drinks and the like, but may also be condiments, cooking oils or foods. The sealed container according to the present embodiments has adaptability to being filled with contents requiring resealability, namely, the characteristic in which sealability is obtained to the extent that at least water will not leak at the time the lid is fitted again when used in a state where a load is applied to the container such as in the case where the container is held by hand or is inserted and carried in a bag or the like. Accordingly, it also has adaptability as a large-capacity container of 1 liter or more. [0034] In the mouth portion 3, a continuous annular protrusion part 6 is provided along the circumferential 17 direction on the cylindrical outer wall. In the resealable sealed container 100 shown in Fig. 1, the case where an annular protrusion part 6a at the cylinder end side and an annular protrusion part 6b provided below that are provided as two annular protrusion parts 6 is shown, but only one annular protrusion part 6 may be provided, or three or more may be provided. Because the bonding force of the lid 2 increases as the number of annular protrusion parts 6 becomes greater, it is suitably determined in accordance with the desired pressure resistance strength. Further, that number is limited by the cylinder length of the mouth portion 3. (0035] The lid 2 is formed in a cylindrical shape with a top surface 5, and seals the mouth portion 3 by being fitted on from the outside of the mouth portion 3. Because the side surface part of the cylinder of the lid 2 forms a shape that makes contact with the side surface of the mouth portion 3, the cylindrical shape stated here forms almost the same shape as the side surface of the mouth portion 3. Accordingly, it is not only a cylindrical shape, but also includes the case where the mouth diameter along the X-axis direction becomes large and the case where it becomes small. Further, the shape of a horizontal cross section with respect to the X-axis is not only a circle, but also 18 includes the case where it is an ellipse, a rectangle or a polygon. In the lid 2, a continuous annular concavity part 7 for fitting on the annular protrusion part 6 is provided along the circumferential direction in the cylindrical inner wall thereof. [0036] The lid 2 is formed using amorphous polyethylene terephthalate resin having a density of 1.320 ~ 1.340 g/cm 3 . The lid 2 has transparency, and this makes it possible to confirm the contents through the lid 2. As for the amorphous polyethylene terephthalate resin, in general there are a material called A-PET and a material called PETG, and amorphous conversion is carried out by including a crystallization inhibitor inside the PET resin or carrying out polymerization for one part of the structure inside the PET crystal structure. By using this resin and forming the thickness to be greater than or equal to 80pm and less than 390gm, and preferably 150 - 300gm, a lid with a good sealability and plenty of flexibility without cracking is formed. Because it has a moderate flexibility, when the lid 2 is fitted again on the mouth portion 3 of the container body 1, the deformation of the lid 2 forms a plastic deformation range, and this makes it possible to obtain resealability while ensuring sealability. When the thickness of the lid 2 is less than 80gm, because 19 it has flexibility but is thin, there are cases where it cracks in the case where the internal pressure is high such as in the case where the contents are a carbonated beverage or the like, on the other hand when it is greater than or equal to 390pm, the flexibility becomes inadequate, and there are cases where it cracks. Further, profitability is lowered because the amount of resin increases. [0037] In order to form the thickness to be greater than or equal to 80pm and less than 390pm, the lid 2 is preferably formed by an air pressure forming method or a vacuum forming method. A lid formed by an air pressure forming method or a vacuum forming method can be formed in the thickness range described above, and is low-cost. Fig. 2 shows a molding process for the lid 2 using an air pressure forming method, wherein (a) shows a sheet heating step, (b) shows an air pressure forming step, and (c) shows a mold removing step. For example, a sheet 23 made from amorphous polyethylene terephthalate resin having a thickness greater than or equal to 80gm and less than 390gm and a density of 1.320 ~ 1.340 g/cm 3 is prepared and heated by a heating plate 21 (see Fig. 2(a)). Next, the sheet 23 is held between a metal mold 22 and the heating plate 21, and compressed air 24 is blown out from the surface of the heating plate 21 to press the sheet 23 against the inside 20 surface of the metal mold 22 (see Fig. 2(b)). After the sheet 23 has been deformed in the shape of a lid 2, the lid 2 is taken out from the metal mold 22 (see Fig. 2(c)). Because a large number of lids 2 can be formed from one sheet 23, the lids 2 are cut out one by one and separated (not shown in the drawings). [0038] Next, the relationship between the annular protrusion part 6 of the container body 1 and the annular concavity part 7 of the lid 2 will be described. The shape of the annular protrusion part 6 preferably forms a semicircular shaped protrusion on the vertical end surface of the container as shown in Fig. 1. Alternatively, it may be semi-elliptical. When the surface of the annular protrusion part 6 is square, there are cases where opening the lid and closing the lid can not be carried out smoothly. In order to enhance the sealability, the shape of the annular protrusion part 6 preferably has an inverse relationship with the shape of the annular concavity part 7 so as to fit in the annular concavity part 7. In the sealed container 100 shown in Fig. 1, the shape of the annular protrusion part 6a has an inverse relationship with the annular concavity part 7a, and the shape of the annular protrusion part 6b has an inverse relationship with the annular concavity part 7b. Further, the annular protrusion 21 part 6a fits in the annular concavity part 7a, and the annular protrusion part 6b fits in the annular concavity part 7b. [0039] In the resealable sealed container according to the present embodiments, when the top surface of the lid 2 is pulled up, the measured bonding force of the lid until the lid 2 is opened is preferably greater than or equal to 9.8 N, and preferably greater than or equal to 20 N. This reduces the flying out of contents, and with the opened lid, resealing is easy to carry out while ensuring sealability. The bonding force of the lid becomes larger as the height of the annular protrusion part 6 and the corresponding depth of the annular concavity part 7 become larger, it becomes larger as the surfaces of the annular protrusion part 6 and the annular concavity part 7 become square, and it becomes larger as the set number of annular protrusion parts 6 and annular concavity parts 7 become greater. Further, because more force is required at the time of resealing as the bonding force of the lid becomes larger, the bonding force of the lid is preferably 50 N or less. [0040] As for the measurement of the bonding force of the lid, the container body of the sealed container fitted with 22 the lid is fixed, a metal jig is bonded to the top surface of the lid, the metal jig is pulled at a speed of 50 mm/min by a tensile tester, and the stress at the point in time where any part of the annular concavity part 7 comes off from the annular protrusion part 6 is measured. [0041] In the resealable sealed container according to the present embodiments, when a prescribed load is applied to the peripheral part of the overlapping area of the lid 2 and the mouth portion 3, preferably the amount of the deformation of the mouth portion 3 is smaller than the amount of the deformation of the lid 2. By making the mouth portion 3 stiffer than the lid 2, it is possible to ensure the sealability of the lid 2, and this makes it possible to practically eliminate the leaking of the contents. The stiffness of the mouth portion 3 can be raised by making the wall thicker or crystallizing the mouth portion 3. [0042] Further, as shown in Fig. 1, by forming the lid 2 so that the end surface of the cylinder tip of the mouth portion 3 and the inner surface of the lid 2 are bonded when the annular protrusion part 6 is fitted in the annular concavity part 7, it is possible to further improve the sealability of the contents. 23 [0043] As shown by the sealed container 100 shown in Fig. 1, in the resealable sealed container according to the present embodiments, preferably the lid 2 is provided with a pop-off 5 prevention mechanism by hooking a hooking part 18 provided on one end of a flange 16 on a neck ring 14, and hooking and locking a tab 15 provided on the other end of the flange 16 on a ring 13. [0044] 10 Next, various embodiments related to a structure which suppresses the deformation of the mouth portion 3 by restricting the deformation of the body part 4 to the inside of the body part 4 when a stress is applied to the body part 4 are shown and described in detail in Fig. 1, Fig. 3 and 15 Fig. 4. [0045] Fig. 3 is a schematic drawing which shows illustratively the deformation state when a stress is applied to the sealed container 100 shown in Fig. 1, wherein 20 (a) shows the state before deformation, and (b) shows the state after deformation. As shown in Fig. 3, the structure which restricts the deformation of the mouth portion 3 is, concretely, a structure in which even if a crush 11 is produced and deformation occurs in the body part 4 when a 25 stress 10 is applied at any place of the body 24 part 4 of the container body 1 (Fig. 3(a)), the crush 11 is blocked by a shoulder part 8 and is not transmitted to the mouth portion 3 (Fig. 3(b)), whereby it is difficult for deformations to occur in the mouth portion 3. [0046] In order to form a structure in which the deformation of the mouth portion 3 is restricted, first of all, like the structure shown in Fig. 1, preferably a structure is formed in which the container body 1 has a body part 4 with a grip part which is formed at a part where the body diameter is maximum or roughly maximum, and is separated from the mouth portion 3 by 30 mm or further, and has a shoulder part 8 between the body part 4 and the mouth portion 3. This is a structure in which the container body 1 forms a so-called bottle shape, and the mouth portion 3 and the body part 4 are separated. By providing a grip part, it becomes easy for stress to be applied to only the body part 4 which is the grip part. This is because bumping frequently occurs at the place where the body diameter is maximum. Further, even if the body part is deformed by stress, the transmission of deformation is blocked by the provision of the shoulder part 8. The effect of blocking the transmission of the deformation increases as the separation between the mouth portion 3 and the body part 4 increases. In this regard, the separation 25 between the mouth portion 3 and body part 4 is preferably 30 mm or higher. Because it is possible to prevent the deformation of the mouth portion 3 by using this structure, as a result, the contents filled in the container body 1 are difficult to leak. [0047] Fig. 4 is a schematic drawing of a vertical cross section of another embodiment of a resealable sealed container according to the present embodiments, wherein (a) is the case where it has a shoulder part 8 shape in which the ratio of the reducing diameter from the body part 4 to the mouth portion 3 is changed, (b) is the case where it has a shoulder part 8 that is formed with a thicker wall compared to the body part 4, (c) is the case where it has a crystallized shoulder part 8, and (d) is the case where a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of the mouth portion 3 or the shoulder part 8. In this regard, in Figs. 4(a) ~ (c), because the left part is symmetrical with respect to the X-axis of the container, a description is omitted. Further, the mouth portion 3 when the lid 2 is not fitted is shown in Fig. 4(d). [0048] The shoulder part 8 preferably has a shape in which the ratio of the reducing diameter from the body part 4 to 26 the mouth portion 3 is changed like the sealed container 200 shown in Fig. 4(a). For example, by making the ratio of the reducing diameter from the body part 4 to the mouth portion 3 large in the beginning, and then gradually changing the ratio to be smaller, there is the case where the shoulder part 8 forms a high shoulder. In contrast with the shoulder part 8 of the sealed container 100 which is a shoulder in which the body part 4 and the mouth portion 3 are connected smoothly, because the shoulder part 8 of the sealed container 200 has a shape in which the ratio of the reducing diameter from the body part 4 to the mouth portion 3 is changed, even in the case where the amount of the deformation of the body part 4 which is the grip part is larger, the transmission of the deformation is blocked by the shoulder part 8, and this makes it possible to prevent the deformation of the mouth portion 3. [0049] The shoulder part 8 preferably has a structure formed by a thicker wall compared to the body part 4 like the sealed container 300 shown in Fig. 4 (b). Even if the stress applied to the body part 4 is large, because the stiffness of the shoulder part 8 itself is raised by the structure described above, it is possible to prevent the deformation of the mouth portion 3. [0050] 27 Preferably, a structure in which at least the shoulder part 8 is crystallized is formed like the sealed container 400 shown in Fig. 4(c). The dots in Fig. 4(c) show crystallization. Even if the stress applied to the body part 4 is large, because the stiffness of the shoulder part 8 itself is raised by the structure described above, it is possible to prevent the deformation of the mouth portion 3. In the sealed container 400 shown in Fig. 4(c), only the shoulder part 8 is shown in a crystallized form, but the body part 4 or the mouth portion 3 also may be crystallized to raise the stiffness of the entire container body 1. [0051] Preferably, a structure in which a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of the mouth portion 3 or the shoulder part 8 is formed like the sealed container 500 (the lid is not shown in the drawing) shown in Fig. 4(d). Because the reinforcement ring 12 has a reinforcing effect against deformation in the mouth diameter direction of the mouth portion 3, in the case where the body part (not shown in Fig. 4(d)) receives crushing stress in the body diameter direction, the transmission of the crush of the body part is easily stopped at the reinforcement ring 12. The closer the reinforcement ring 12 is to the part being sealed, namely, the closely attached part of the annular protrusion 28 part 6 and the annular concavity part 7 shown in Fig. 1, the more deformation at such closely attached part is restricted, and as a result, there are fewer cases where the seal is broken and leaking occurs, but on the other hand, because there are cases where the drinking ease is lost, it is provided at any place of the outer wall of the mouth portion 3 or the shoulder part 8 after consideration of the drinking ease and the design properties of the container. [0052] Further, the reinforcement ring 12 of the sealed container 500 shown in Fig. 4(d) may also be used in combination with the neck ring 14 shown in Fig. 1 or the ring 13 for hooking and locking the tab 15. [0053] The various structures in which the deformation of the mouth portion 3 is suppressed shown in Figs. 4(a) ~ (d) may be incorporated in the container separately, or two or more structures may be combined at the same time and incorporated in the container. [0054] In the case where the container body is formed in a cup shape, because there is no shoulder part, it is possible to suppress the deformation of the mouth portion by incorporating the various structures shown in Fig. 5 in 29 the container body. Fig. 5 is a schematic drawing of a vertical cross section of a resealable sealed container which has a cup-shaped container body according to the present embodiments, wherein (a) is the case where reinforcement is carried out by adding thickness to the wall, (b) is the case where reinforcement is carried out by crystallization of the wall, and (c) is the case where reinforcement is carried out by a rib-shaped reinforcement ring. In Fig. 5(a), because at least a lower part 25 from the mouth portion 3 is formed with a thicker wall compared to the body part 4, even if the container body is formed in a cup shape, it is difficult for deformation in the body part 4 to be transmitted to the mouth portion 3. In Fig. 5(b), because at least the lower part 25 from the mouth portion 3 is crystallized, even if the container body is formed in a cup shape, it is difficult for deformation in the body part 4 to be transmitted to the mouth portion 3. The entire container may be crystallized. In Fig. 5(c), because a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of the mouth portion 3 or the lower part 25 from the mouth portion 3, even if the container body is formed in a cup shape, it is difficult for deformation in the body part 4 to be transmitted to the mouth portion 3. The reinforcement principles of the various structures are the same as those 30 of Figs. 4(b) - (d). The various structures shown in Figs. 5(a) - (c) may be combined and incorporated. [0055] In the resealable sealed container according to the present embodiments, in either the bottle-shaped sealed container shown in Fig. 1, Fig. 3 and Fig. 4 or the cup shaped sealed container shown in Fig. 5, when a stress 10 is applied as shown in Fig. 3 for example, and the body part 4 is crushed 10% in the body diameter direction, the deformation ratio calculated by (Equation 1) in the mouth diameter direction of the mouth portion 3 is preferably 0.50% or lower. The deformation ratio in the mouth diameter direction of the mouth portion 3 allowed from the viewpoint of ensuring sealability changes depending on the capacity of the container or the size of the body diameter of the body part 4 or the mouth diameter of the mouth portion 3, for example, if there is a beverage bottle of 500 ml volume, by setting the deformation ratio at 0.50% or lower, it is possible to prevent the annular protrusion part 6 and the annular concavity part 7 from separating and the contents from leaking due to deformation. Accordingly, by providing a structure in which the deformation of the mouth portion is suppressed so that the deformation ratio becomes 0.50% or lower, it is possible to ensure the sealability of the lid 2, and this makes it possible to 31 practically eliminate the leaking of the contents. [0056] In the resealable sealed container according to the present embodiments, as shown in Fig. 1, preferably a rib shaped neck ring 14 is provided on the cylindrical outer wall of the mouth portion 3 more toward the body part 4 side than the annular protrusion part 6, a flange 16 facing the outside is provided on the cylindrical end part of the lid 2, and the neck ring 14 and the flange 16 are fused. In Fig. 1, a closely attached part 19 of the neck ring 14 and the flange 16 shows a fused part. Even when the contents are a carbonated beverage for example, it is possible to prevent the lid 2 from popping off. Further, it is also possible to confirm whether or not it has been opened until it reaches a consumer. [0057] As for the fusion of the closely attached part, preferably it is fused by a laser welding method. Compared to the case where thermal fusion is carried out with a heater as a heat source, the boundary between the fusion part and the non-fusion part is distinct, and highly precise fusion can be carried out. In order to make it easy to absorb laser light, the place prearranged for fusing which forms the fusing part, namely, the closely attached part 19 may be formed from a material that absorbs 32 laser light, or a paint that absorbs laser light may be painted on the closely attached part 19, or a body formed from a material that absorbs laser light may be arranged at the closely attached part 19. In the case where fusion is carried out by a laser welding method, even in the case where the object being fused does not absorb laser light, by applying a color that has absorptivity for the laser light on the closely attached part 19, it is possible to directly heat the closely attached part 19. In order to form the closely attached part 19 from a material that absorbs laser light, for example, a dye or a pigment is included in the plastic resin to form the container body 1 or the lid 2 or both of these. In order to paint the closely attached part 19 with a paint that absorbs the laser light, for example, the paint can be printed by various printing methods. As for the material that absorbs laser light arranged at the closely attached part 19, for example, the same material as either the container body 1 or the lid 2 is painted with a paint, or includes a dye or a pigment. By providing an absorbing part for the laser light in this way, the absorptance of the laser becomes high, and it becomes possible to carry out laser welding with a little energy. The dye or the pigment, for example, is a metal material, a ceramic or an organic pigment that absorbs laser light. Preferably, the wavelength of the 33 laser light, the laser power and the laser scanning speed are adjusted in accordance with the absorption level of the absorbing part for the laser light. [0058] The laser oscillating element used in laser welding is a semiconductor laser, a gas laser such as a carbon dioxide laser or the like, or a YAG laser, for example. The material of the container body 1 and the lid 2 which undergo laser welding is suitably selected in accordance with various parameters such as the laser irradiation moving speed, the irradiation spot shape and the like. The wavelength of the laser is preferably 800 - 1000 nm with semiconductor laser, for example. The energy density of the laser light irradiating the closely attached part 19 is 150 J per 1 cm2 of fusion surface area. This makes it possible to complete fusion without producing thermal deformation. [0059] In the present embodiments, it is possible to apply the following welding methods in place of the laser welding method. Namely, there are cases where sealed containers are manufactured in which the closely attached part 19 is fused by an impulse sealing method, a high frequency welding method, a vibration welding method, a spin welding method, an ultrasonic welding method, a hot gas welding 34 method or a heat sealing method. [0060] The impulse sealing method is a method in which a strong electric current quickly flows to a ribbon heater to carry out heat welding of the closely attached part 19. The high frequency welding method is a welding method that depends on internal heating by the absorption of a high frequency electric current in a closely attached part 19 having a large dielectric constant and a large dielectric dissipation factor. A film having a large dielectric constant and a large dielectric dissipation factor is used. The vibration welding method is a welding method in which fusion bonding is carried out by rubbing the closely attached part 19 in place of spin to generate heat. The spin welding method is a method in which fusion welding is carried out by frictional heat from rotating and rubbing the closely attached part 19. The ultrasonic welding method is a method in which the closely attached part 19 is fusion bonded by applying ultrasonic vibration energy. The hot gas welding method is a method in which air or a gas is sent to a heated heater and then blown on the closely attached part 19 to carry out welding. The heat sealing method is a method in which welding is carried out by pressurized heating in the state where the closely attached part 19 is held between heating plates. Each welding 35 method can be suitably selected and applied to fit the shape of the container. (0061] In the resealable sealed container according to the 5 present embodiments, in order to prevent the lid from popping off more than the pop-off prevention mechanism of the lid shown in Fig. 1, a pop-off prevention mechanism of a lid shown in Fig. 6 may be provided. Fig. 6 is a schematic drawing which shows another embodiment of a lid pop-off 10 prevention mechanism. By providing a tab 30 on the lid 2, providing a rib-shaped neck ring 32 having a cutout 31 on the cylindrical outer wall of the mouth portion 3 more toward the body part 4 side than the annular protrusion part 6, and hooking the tab 30 in the cutout 31, the sealed 15 container 900 shown in Fig. 6 is further equipped with a mechanism that prevents the lid 2 from popping off. Even when the contents are a carbonated beverage for example, it is possible to prevent the lid 2 from popping off. [0062] 20 Fig. 7 is a schematic drawing which shows an example embodiment in which the sealed container according to the present embodiments is covered with a shrink film cover. In the resealable sealed container according to the present embodiments, the sealed container 100 preferably has a 25 shrink film cover 40 which covers the mouth portion 3 and 36 the lid 2 sealing the mouth portion 3 as shown in Fig. 7. This makes it possible to reliably prevent the lid from popping off until it reaches a consumer. Further, it is possible to confirm whether or not it has been opened. [0063] In the resealable sealed container according to the present embodiments, a gas barrier property thin film is preferably formed on at least one side of the surface of the container body 1 or the lid 2. By improving the gas barrier property of the container, it is possible to extend the expiration date or the freshness date. The gas barrier property thin film is a diamond-like carbon (DLC) film, a Si-containing DLC film or a SiOx film, for example. As for the method of forming a gas barrier property thin film, it is possible to use known film formation methods, for example, there is technology disclosed in Patent Number 2788412, Patent Number 3072269 or Patent Number 3115252. The formation of the gas barrier property thin film is carried out on the inner surface or the outer surface of the container body 1, and is carried out on the inner surface or the outer surface of the lid 2. More preferably, the formation of the gas barrier property thin film is carried out on the inner surface or the outer surface of both the container body 1 and the lid 2. EXAMPLE 37 [0064] (SAMPLE 1) Using a sheet made of amorphous PET resin (Denka A-PET sheet), the type of lid shown in Fig. 1 was formed by an air pressure forming method. The outer diameter of the lid was set at 21.7 mm. At this time, the surface area of the top surface was 3.71 cm 2 . At this time, the thickness of the lid was set at 485ym. The thickness of the lid was measured at the place of the annular concavity part. Three of these were prepared (n = 3). Further, the density of the lid was 1.326 g/cm 3 . Because it is difficult to accurately measure the crystallinity of the lid, the density which changes due to differences in crystallinity was set as an indicator of crystallinity. There is a relationship in which the crystallinity is high if the density is high, and the crystallinity is low if the density is low. The density was measured using a density gradient method specific gravity measuring device (Asahi Syokou, Inc.). Further, as a precondition of density measurement, a measurement sample by the DSC method showed the heat absorption properties of PET, and it was confirmed that there were no endothermic/exothermic peaks of other components (device used: DSC-60 Shimadzu Corporation). After the lid was fitted on a container body made of PET resin, the result of repeating a lid removing operation 10 38 times was evaluated as having no crack resistance (recorded as X) in the case where cracks were produced in the lid, and having crack resistance (recorded as 0) in the case where cracks were not produced in the lid. The result is shown in Table 1. [0065] (SAMPLE 2 - SAMPLE 10) The density, thickness and molding method of the lid was changed, evaluation of the cracking resistance was carried out, and the results are shown in Table 1. The conditions of the density, thickness and molding method of the lid are also shown at the same time in Table 1. [0066] TABLE 1 Density at Sample 23 Degrees Thickness Forming Cracking No. (g/cm 3 ) n (y m) Method Resistance Air Pressure 1 1.326 3 485 Forming x Air Pressure 2 1.323 3 390 Forming x Air Pressure 3 1.326 3 351 Forming 0 Air Pressure 4 1.329 3 285 Forming 0 Air Pressure 5 1.332 3 185 Forming 0 Air Pressure 6 1.335 3 89 Forming 0 Injection 7 1.369 3 1000 Molding x Injection 8 1.367 3 1000 Moldinq x Injection 9 1.354 3 1300 Molding x Injection 10 1.355 3 1300 Molding x 39 [0067] The following is understood from the results of Table 1. Preferably, the thickness of the lid is greater than or equal to 80um and less than 390y m, and it is formed from amorphous polyethylene terephthalate resin having a density of 1.320 ~ 1.340 g/cm 3 . At this time, because the lid has required sufficient flexibility, cracks are not produced by repeatedly opening and closing the lid. [0068] The type of sealed container of Fig. 1 was prepared, and after the container body was filled with water, the lid of Sample 4 was fitted. When the body part was crushed in the range 1 cm ~ 2 cm as shown in Fig. 3, the deformation ratio of the mouth portion was calculated, and the presence or absence of water leaks was examined. The deformation ratio was calculated by (Equation 1). The results are shown in Table 2. [0069] TABLE 2 Crush Mouth Diameter Deformation Presence or Amount of (Mouth Portion Ratio (/) Absence of Body Diameter) Leaks at the Portion Minimum Diameter ~ time of Cover (cm) Maximum Diameter Fitting (mm) 0(No Load) 24.88-24.91 0 No 1.0 24.80-24.98 0.32 No 1.2 24.78~-25.03 0.40 No 1.5 24.75~-25.12 0.52 Yes 2.0 24.70-25.31 0.72 Yes 40 [0070] From the results of Table 2, it was understood that cracks are not produced in the case where the deformation ratio is greater than or equal to 0% and less than 0.52%. 41

Claims

1. A resealable sealed container, comprising: a container body which has a cylindrically shaped mouth portion; and 5 a lid which is formed in a cylindrical shape with a top surface, and which seals said mouth portion by being fitted on from the outside of said mouth portion; wherein said container body has a structure in which the deformation of said mouth portion is suppressed by 10 restricting the deformation of a body part to the inside of said body part when a stress is applied to said body part, and is formed from polyethylene terephthalate resin; wherein said mouth portion has a continuous annular protrusion part along the circumferential direction of the 15 cylindrical outer wall; wherein said lid has a continuous annular concavity part for fitting on said annular protrusion part along the circumferential direction of the cylindrical inner wall, is formed from amorphous polyethylene terephthalate resin having 20 a density of 1.320 - 1.340 g/cm 3 , and has a thickness which is greater than or equal to 80ym and less than 390y m; and wherein a rib-shaped neck ring is provided on the cylindrical outer wall of said mouth portion toward the body part side than said annular protrusion part, a flange facing 25 the outside is provided on the cylindrical end part of said 42 lid, and said neck ring and said flange are fused.

2. The resealable sealed container according to claim 1, wherein said lid is formed by an air pressure forming method or a vacuum forming method. 5

3. The resealable sealed container according to claim 1 or 2, wherein said container body is formed by a blow molding or injection molding method.

4. The resealable sealed container according to claim 1, 2 or 3, wherein when the top surface of said lid is pulled 10 up, the measured bonding force of said lid until said lid is opened is greater than or equal to 9.8 N.

5. The resealable sealed container according to claim 1, 2, 3 or 4, wherein said structure in which the deformation of said mouth portion is restricted is a structure in which 15 said container body has a body part with a grip part which is formed at a part where the body diameter is maximum or roughly maximum, and is separated from said mouth portion by 30 mm or further, and has a shoulder part between said body part and said mouth portion. 20

6. The resealable sealed container according to claim 5, wherein said shoulder part has a shape in which the ratio of the reducing diameter from said body part to said mouth portion is changed.

7. The resealable sealed container according to claim 5 25 or 6, wherein said structure in which the deformation of said 43 mouth portion is restricted is a structure in which at least said shoulder part is formed with a thicker wall compared to said body part, or a structure in which at least said shoulder part is crystallized, or a structure in which a rib 5 shaped reinforcement ring is provided along the circumferential direction on the outer wall of said mouth portion or said shoulder part, or a combination of these structures.

8. The resealable sealed container according to claim 10 1, 2, 3 or 4, wherein said container body is formed in a cup shape, and said structure in which the deformation of said mouth portion is restricted is a structure in which at least a lower part from said mouth portion is formed with a thicker wall compared to said body part, or a structure in which at 15 least the lower part from said mouth portion is crystallized, or a structure in which a rib-shaped reinforcement ring is provided along the circumferential direction on the outer wall of said mouth portion or the lower part from said mouth portion, or a combination of these structures. 20

9. The resealable sealed container according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein when a stress is applied and said body part is crushed 10% in the body diameter direction, the deformation ratio calculated by (Equation 1) in the mouth diameter direction of said mouth portion is 25 0.50% or lower. 44 (Equation 1): Deformation Ratio (%) = ((Minimum Value of Mouth Diameter at The Time of No Load - Minimum Value of Mouth Diameter at The Time of Deformation) / Minimum Value of Mouth Diameter at The Time of No Load} X 100 5

10. The resealable sealed container according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the amount of the deformation of said mouth portion is smaller than the amount of the deformation of said lid when a prescribed load is applied to the peripheral part of the overlapping area of 10 said lid and said mouth portion.

11. The resealable sealed container according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, further comprising a mechanism that prevents said lid from popping off by providing a tab on said lid, providing a rib-shaped neck ring 15 having a cutout on the cylindrical outer wall of said mouth portion toward the body part side than said annular protrusion part, and hooking said tab in said cutout.

12. The resealable sealed container according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, further comprising a 20 shrink film cover which covers said mouth portion and said lid sealing said mouth portion.

13. The resealable sealed container according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein a gas barrier property thin film is formed on at least one side of 25 the surface of said container body or said lid. 45

14. A resealable sealed container substantially as hereinbefore described with reference to the accompanying drawings. 46