Composite member and method for manufacturing the same, and beverage container and method for manufacturing the same

Abstract

To provide a composite member including a silicone rubber surface and a polypropylene surface bonded to each other and a method for manufacturing the same, and a beverage container and a method for manufacturing the same.SOLUTION: A method for manufacturing a composite member including a first member and a second member includes a bonding step of bonding a silicone rubber surface of the first member being a silicone rubber molding and a polypropylene surface of the second member being a polypropylene molding.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite member and a method for manufacturing the same, and a beverage container and a method for manufacturing the same. [Background technology]

[0002] Patent Document 1 describes an inner plug of a plug member that closes the opening of a food or beverage container, and that includes an inner plug rubber that fits tightly against the inner periphery of the opening, a rubber holder into which the inner plug rubber is fitted, and a restraining part that is formed integrally with the rubber holder and restrains the inner plug rubber so that it cannot be separated from the rubber holder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-007296 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, the inventors of the present invention have conducted extensive research into a technical means for bonding the silicone rubber surface of the inner plug gasket and the polypropylene surface of the inner plug base material when a silicone rubber molded body is used as the inner plug gasket and a polypropylene molded body is used as the inner plug base material that supports the inner plug gasket, in relation to an inner plug member for a beverage container.

[0005] The present invention has been made in consideration of the above-mentioned problems, and one of its objects is to provide a composite member including a silicone rubber molded body and a polypropylene molded body bonded to each other, a method for manufacturing the same, and a beverage container and a method for manufacturing the same. [Means for solving the problem]

[0006] According to one embodiment of the present invention, there is provided a method for producing a composite member comprising a first member and a second member, the method comprising a bonding step of bonding a silicone rubber surface of the first member, which is a silicone rubber molded body, to a polypropylene surface of the second member, which is a polypropylene molded body. The present invention provides a method for producing a composite member comprising a silicone rubber molded body and a polypropylene molded body bonded together.

[0007] The method may further include a surface modification step of surface-modifying the polypropylene surface of the second member and a primer application step of applying a primer to the surface-modified polypropylene surface of the second member, and the bonding step may bond the silicone rubber surface of the first member to the primer-coated polypropylene surface of the second member. The bonding step may also bond the silicone rubber surface of the first member to the polypropylene surface of the second member by insert molding. The bonding step may also bond the silicone rubber surface to the polypropylene surface with a peel strength of 3.0 N / mm or more as measured by a method in accordance with JIS K6256-2.

[0008] In addition, in the above method, the composite member may be an inner plug member of a beverage container including an insulated double container, the first member may include an inner plug gasket that is in close contact with the inner surface of the upper opening of the insulated double container, and the second member may include an inner plug base material that supports the inner plug gasket.

[0009] According to one embodiment of the present invention, there is provided a composite member comprising a first member that is a silicone rubber molded body and a second member that is a polypropylene molded body, wherein the silicone rubber surface of the first member is bonded to the polypropylene surface of the second member.

[0010] In the composite member, the silicone rubber surface of the first member and the polypropylene surface of the second member may be bonded via a primer-derived component. In this case, the second member may have a modified polypropylene surface. The composite member may be an insert-molded body. In the composite member, the silicone rubber surface and the polypropylene surface may be bonded with a peel strength of 3.0 N / mm or more as measured by a method in accordance with JIS K6256-2.

[0011] The composite member may also be an inner plug member of a beverage container including an insulated double container, and the first member may include an inner plug gasket that adheres to the inner surface of the upper opening of the insulated double container, and the second member may include an inner plug base material that supports the inner plug gasket.

[0012] According to one embodiment of the present invention, a beverage container includes an insulated double container and the inner plug member, the inner plug member including an inner plug packing and an inner plug base material bonded to each other.

[0013] According to one embodiment of the present invention, a method for manufacturing a beverage container includes a step of attaching the inner plug member to an insulated double container. The method includes a step of attaching the inner plug member to an insulated double container. According to the present invention, a method for manufacturing a beverage container provided with an inner plug member including an inner plug gasket and an inner plug base material bonded to each other is provided.

[0014] The method for manufacturing a beverage container may further include a step of manufacturing the inner plug member by the method for manufacturing an inner plug member. [Effects of the Invention]

[0015] According to the present invention, there are provided a composite member including a silicone rubber molded body and a polypropylene molded body bonded to each other, a method for producing the same, and a beverage container and a method for producing the same. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view of an example of a beverage container according to an embodiment of the present invention. [Figure 2] 2 is a perspective cross-sectional view of the stopper of the beverage container shown in FIG. 1. FIG. [Figure 3A] 2 is an explanatory view showing a surface modification step included in an example of a method for producing the inside plug member shown in FIG. 1. FIG. [Figure 3B] 2 is an explanatory view showing a primer coating step included in the example of a method for manufacturing the inside plug member shown in FIG. 1. FIG. [Figure 3C] 2 is an explanatory view showing a bonding step included in an example of a manufacturing method of the inside plug member shown in FIG. [Figure 3D] FIG. 3D is a cross-sectional view of an example of an inner plug member manufactured by a manufacturing method for an inner plug member including the steps shown in FIGS. 3A to 3C. [Figure 4] 10 is a cross-sectional view of a portion of another example of a beverage container according to an embodiment of the present invention. FIG. [Figure 5A] 5 is an explanatory view showing a surface modification step included in the example of a method for producing the inside plug member shown in FIG. 4. FIG. [Figure 5B] 5 is an explanatory view showing a primer application step included in the example of a method for manufacturing the inside plug member shown in FIG. 4. FIG. [Figure 5C] 5 is an explanatory view showing a bonding step included in the example of a manufacturing method of the inside plug member shown in FIG. 4. FIG. [Figure 5D] FIG. 5B is a cross-sectional view of an example of an inner plug member manufactured by a method for manufacturing an inner plug member including the steps shown in FIGS. 5A to 5C. [Figure 6] FIG. 10 is an explanatory diagram showing the results of measuring the peel strength of a test piece in Example 2 according to the present embodiment by a method conforming to JIS K6256-2. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described below, although the present invention is not limited to this embodiment.

[0018] One aspect of the method according to the present embodiment is a method for producing a composite member comprising a first member and a second member, and includes a bonding step of bonding a silicone rubber surface of the first member, which is a silicone rubber molded body, to a polypropylene surface of the second member, which is a polypropylene molded body.

[0019] Furthermore, the composite member according to this embodiment includes a first member that is a silicone rubber molded body and a second member that is a polypropylene molded body, and the silicone rubber surface of the first member is bonded to the polypropylene surface of the second member.

[0020] The composite member according to the present invention is not particularly limited as long as it includes a first member and a second member bonded to each other. In this specification, however, an example will be mainly described in which the composite member is an inner plug member of a beverage container including an insulated double container, the first member including an inner plug gasket that is in close contact with the inner peripheral surface of the upper opening of the insulated double container, and the second member including an inner plug base material that supports the inner plug gasket.

[0021] Fig. 1 shows a cross section of an example of a beverage container 1 including an inner plug member 21. In the example shown in Fig. 1, the beverage container 1 includes an insulated double container 10 and a plug 20 that opens and closes an upper opening 11 of the insulated double container 10, and the plug 20 includes an inner plug member 21.

[0022] Figure 2 shows a perspective cross-sectional view of the stopper 20 of the beverage container 1 shown in Figure 1. Figures 3A, 3B, and 3C show the main steps included in an example of a method for manufacturing the inner stopper member 21 shown in Figure 1, and Figure 3D shows the inner stopper member 21 manufactured by this method.

[0023] Figure 4 shows a cross section of a portion of another example of beverage container 1. Figures 5A, 5B, and 5C show the main steps included in an example of a method for manufacturing inner plug member 21 shown in Figure 4, and Figure 5D shows inner plug member 21 manufactured by that method.

[0024] In this specification and drawings, the same or similar components are denoted by the same reference numerals. In this specification, the direction along the axis A (FIGS. 1 and 4) of the beverage container 1 is referred to as the "axial direction," the direction from the bottom surface 12 of the insulated double container 10 toward the upper opening 11 in the axial direction is referred to as the "upward direction," and the opposite direction is referred to as the "downward direction." In addition, the direction perpendicular to the axis A of the beverage container 1 is referred to as the "radial direction," and in the radial direction, the direction from the center of the insulated double container 10 toward the outside is referred to as the "radial outward direction," and the opposite direction is referred to as the "radial inward direction."

[0025] First, we will explain the manufacturing method of the inner plug member 21. The inner plug member 21 is a composite member including an inner plug gasket (first member) 30 that is in close contact with the inner peripheral surface 11a of the upper opening 11 of the thermally insulated double container 10 of the beverage container 1, and an inner plug base material (second member) 40 that supports the inner plug gasket 30.

[0026] The inside plug packing 30 is a silicone rubber molded body and has a silicone rubber surface (hereinafter referred to as the "rubber surface") 31. The inside plug base material 40 is a polypropylene molded body and has a polypropylene surface (hereinafter referred to as the "PP surface") 41.

[0027] The manufacturing method of the inside plug member 21 includes a bonding step of bonding the rubber surface 31 of the inside plug packing 30 to the PP surface 41 of the inside plug substrate 40. In the bonding step, the rubber surface 31 of the inside plug packing 30 and the PP surface 41 of the inside plug substrate 40 are bonded to each other with such adhesive strength that they are inseparable during normal use of the inside plug member 21.

[0028] Specifically, in the bonding process, it is preferable that the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40 are bonded together with a peel strength (hereinafter simply referred to as "peel strength") of 3.0 N / mm or more, as measured by a method in accordance with JIS K6256-2 "Vulcanized rubber and thermoplastic rubber -- Determination of adhesion -- Part 2: 90° peel strength from rigid plate."

[0029] In this case, the adhesive strength between the rubber surface 31 and the PP surface 41 achieved in the bonding step is not particularly limited as long as the peel strength is in the range of 3.0 N / mm or more, but the peel strength is, for example, preferably 4.0 N / mm or more, more preferably 5.0 N / mm or more, even more preferably 5.5 N / mm or more, and particularly preferably 6.0 N / mm or more. Since a high peel strength between the rubber surface 31 and the PP surface 41 does not cause any particular problems, the upper limit of the peel strength is not particularly limited.

[0030] The peel strength (N / mm) is calculated by dividing the maximum peel force (N) measured according to JIS K6256-2 by the width of the test piece (25 mm). The maximum peel force (N) is the maximum force (N) required to peel, measured according to JIS K6256-2. The maximum peel force is calculated as the arithmetic mean of the measurements obtained for four samples.

[0031] In the bonding step, the method for bonding the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40 is not particularly limited as long as it achieves the desired adhesive strength (for example, adhesive strength with a peel strength equal to or greater than the above-mentioned predetermined value). However, it is preferable that the manufacturing method of the inside plug member 21 further includes a surface modification step of applying a surface modification treatment to the PP surface 41 of the inside plug substrate 40, and a primer application step of applying a primer to the surface-modified PP surface 41 of the inside plug substrate 40, and that in the bonding step, the rubber surface 31 of the inside plug gasket 30 and the primer-applied PP surface 41 of the inside plug substrate 40 are bonded together.

[0032] In the surface modification step, a surface modification treatment is applied to the PP surface 41 of the preformed stopper substrate 40, thereby introducing reactive functional groups that have the property of chemically reacting with the primer to form a chemical bond (e.g., a covalent bond) into the PP surface 41 (FIGS. 3A and 5A). The surface modification treatment is not particularly limited as long as it is a treatment that introduces reactive functional groups into the PP surface 41 of the stopper substrate 40, but it is preferably one or more treatments selected from the group consisting of plasma discharge treatment, corona discharge treatment, flame treatment, itro treatment, and ultraviolet irradiation treatment.

[0033] The reactive functional group introduced onto the PP surface 41 of the stopper substrate 40 may be, for example, a polar functional group, preferably a polar functional group containing an oxygen atom, and particularly preferably one or more selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), and a carbonyl group (-C(=O)-). In the surface modification step, the portion of the PP surface 41 of the stopper substrate 40 that comes into contact with the rubber surface 31 of the stopper packing 30 is subjected to a surface modification treatment to introduce a reactive functional group.

[0034] In the primer application step, a primer is applied to the surface-modified PP surface 41 of the inside plug substrate 40 (FIGS. 3B and 5B). The primer is not particularly limited as long as it has a reactive functional group capable of forming a chemical bond (e.g., a covalent bond) with the silicone rubber that constitutes the rubber surface 31 of the inside plug packing 30, and a reactive functional group capable of forming a chemical bond (e.g., a covalent bond) with the reactive functional group on the modified PP surface 41 of the inside plug substrate 40.

[0035] Examples of reactive functional groups of the primer include alkoxy groups, but are not particularly limited as long as they are one or more types of reactive functional groups that form chemical bonds with the silicone rubber and modified PP surface 41 as described above.

[0036] The method for applying the primer to the PP surface 41 of the inside plug member 40 is not particularly limited, but is preferably one or more methods selected from the group consisting of spray application, brush application, printing, and dipping. In the primer application step, the primer is applied to part or all of the portion of the modified PP surface 41 of the inside plug substrate 40 that comes into contact with the rubber surface 31 of the inside plug packing 30.

[0037] In the bonding step, the rubber surface 31 of the inside plug gasket 30 is bonded to the PP surface 41 of the inside plug substrate 40 to which a primer has been applied in the primer application step (FIGS. 3C and 5C). The method for bonding the rubber surface 31 of the inside plug gasket 30 to the PP surface 41 of the inside plug substrate 40 is not particularly limited as long as it is a method that bonds the rubber surface 31 to the PP surface 41 via a primer, but in the bonding step, it is preferable to bond the rubber surface 31 of the inside plug gasket 30 to the PP surface 41 of the inside plug substrate 40 by insert molding.

[0038] In insert molding, as shown in FIGS. 3C and 5C, inside a heated mold 100, inside plug gasket 30 is molded from silicone rubber raw material composition M on PP surface 41 of inside plug substrate 40.

[0039] That is, under heating, a silicone rubber raw material composition M (specifically, an amorphous composition containing a silicone rubber raw material and a vulcanizing agent (e.g., an organic peroxide)) is pressed between a PP surface 41 (specifically, a modified PP surface 41 coated with a primer) of a center plug substrate 40 fixed to a part (lower mold 101) of an insert molding mold 100 and another part (upper mold 102) of the mold 100.

[0040] As a result, in the heated mold 100, the vulcanization of the silicone rubber proceeds on the PP surface 41 of the inner plug substrate 40 to form the inner plug gasket 30, and the PP surface 41 and the rubber surface 31 of the inner plug gasket 30 are bonded together via a primer.

[0041] Specifically, the modified polypropylene that constitutes the PP surface 41 of the inner plug substrate 40 and the primer form a chemical bond (e.g., a covalent bond) through a chemical reaction, and the primer and the silicone rubber that constitutes the rubber surface 31 of the inner plug gasket 30 form a chemical bond (e.g., a covalent bond) through a chemical reaction, thereby firmly adhering the PP surface 41 and the rubber surface 31.

[0042] The heating temperature in insert molding is not particularly limited as long as it is within a range in which the vulcanization of the silicone rubber progresses, the chemical bond formation reaction between the primer and the rubber surface 31 and the PP surface 41 progresses, and the inside plug substrate 40 does not undergo thermal deformation to the extent that its function is impaired.

[0043] The heating temperature is determined, for example, as a range that overlaps the temperature range suitable for the vulcanization reaction by the vulcanizing agent contained in the silicone rubber raw material composition M, the temperature range suitable for the chemical bond formation reaction by the primer, and the heat resistance temperature range of the polypropylene that constitutes the inside plug substrate 40. Specifically, the heating temperature is preferably set, for example, depending on the type of vulcanizing agent used, at a temperature at which the vulcanization reaction by the vulcanizing agent proceeds sufficiently (for example, the recommended temperature for the vulcanizing agent).

[0044] The time for which the mold 100 is maintained at the above-mentioned heating temperature during insert molding is not particularly limited as long as it is within a range that allows the insert-molded body, the center plug member 21, to be obtained. However, for example, depending on the type of vulcanizing agent used, it is preferable to use a time that allows the vulcanization reaction by the vulcanizing agent to proceed sufficiently (for example, the recommended time for that vulcanizing agent).

[0045] The manufacturing method of the inside plug member 21 may further include a secondary vulcanization step of performing a secondary vulcanization of the inside plug member 21 obtained in the bonding step. That is, when the inside plug member 21 is molded by insert molding, the inside plug member 21 removed from the mold 100 is held under heat to perform the secondary vulcanization.

[0046] The heating temperature of the inner plug member 21 in the secondary vulcanization step is not particularly limited as long as it is within a range in which the effect of the secondary vulcanization can be obtained, but is preferably, for example, the recommended temperature for the vulcanizing agent. The time for which the inner plug member 21 is held at the heating temperature in the secondary vulcanization step is not particularly limited as long as it is within a range in which the effect of the secondary vulcanization can be obtained, but is preferably, for example, the recommended time for the vulcanizing agent.

[0047] Next, we will explain the inside plug member 21 and beverage container 1 according to this embodiment. The beverage container 1 includes an insulated double container 10. The insulated double container 10 includes an inner container 13 and an outer container 14, with an insulated space 15 formed between the inner container 13 and the outer container 14.

[0048] Although there are no particular limitations on the materials that make up the inner container 13 and the outer container 14, the inner container 13 and the outer container 14 are preferably made of, for example, metal or glass. In the example shown in Figures 1 and 4, the inner container 13 and the outer container 14 of the double-insulated container 10 are both made of stainless steel.

[0049] The inner container 13 and the outer container 14 are connected so as to form a sealed space therebetween. In the example shown in Figures 1 and 4, the upper end of the inner container 13 and the upper end of the outer container 14 are connected by welding, and a heat-insulating space 15, which is a decompressed sealed space, is formed between the inner container 13 and the outer container 14. The heat-insulating double container 10 obtained in this way is a so-called vacuum heat-insulating container.

[0050] The beverage container 1 includes an inner plug member 21. That is, in the example shown in Figures 1, 2 and 4, the beverage container 1 includes a plug 20 that opens and closes the upper opening 11 of the insulated double container 10, and the plug 20 includes the inner plug member 21 and a cover member 22 that supports the inner plug member 21.

[0051] The cover member 22 is manufactured separately from the inner plug member 21, and the inner plug member 21 is attached to the cover member 22. The cover member 22 includes a canopy portion 22a disposed above the upper opening 11 of the insulated double container 10, and a cylindrical portion 22b covering the outer peripheral surface 11b of the upper opening 11.

[0052] The cover member 22 is attached to the insulated double container 10 by engaging the inner peripheral surface 22c of the cylindrical portion 22b with the outer peripheral surface 11b of the upper opening 11 of the insulated double container 10. Specifically, in the example shown in Fig. 1 and Fig. 4, the inner peripheral surface 22c of the cylindrical portion 22b of the cover member 22 and the outer peripheral surface 11b of the upper opening 11 of the insulated double container 10 are screwed together.

[0053] The cover member 22 may accommodate the inside plug member 21. That is, in the example shown in Figures 1, 2 and 4, the cover member 22 is formed in a cylindrical shape with a bottom including a canopy portion 22a and a cylindrical portion 22b, and the inside plug member 21 is accommodated in a space surrounded by the canopy portion 22a and the cylindrical portion 22b.

[0054] The inner plug member 21 includes an inner plug packing 30 which is a silicone rubber molded body, and an inner plug base material 40 which is a polypropylene molded body. In this embodiment, the inner plug member 21 is composed of the inner plug packing 30 and the inner plug base material 40.

[0055] The inner plug member 21 is arranged in the beverage container 1 so that the inner plug gasket 30 thereof is in close contact with the inner peripheral surface 11a of the upper opening 11 of the insulated double container 10. Specifically, a portion of the outer peripheral surface 32 of the inner plug gasket 30 (more specifically, the lower end of the outer peripheral surface 32) is in close contact with the inner peripheral surface 11a of the upper opening 11 of the insulated double container 10.

[0056] In the beverage container 1, the inner stopper gasket 30 adheres tightly to the inner surface 11a of the upper opening 11 of the insulated double container 10, effectively preventing the beverage in the insulated double container 10 from leaking between the inner stopper gasket 30 and the inner surface 11a.

[0057] As shown in Figures 1, 2 and 4, the stopper gasket 30 of this embodiment has a base 33 supported from above by the stopper substrate 40, and a cylindrical extension portion 34 extending downward from the radially outer end of the base 33, and the outer surface 34b of the extension portion 34 (part of the outer surface 32 of the stopper gasket 30) is in close contact with the inner surface 11a of the upper opening 11 of the insulated double container 10.

[0058] In addition, in the example shown in Figures 1 and 4, the inner plug gasket 30 is in close contact with the portion (reduced diameter portion) of the inner surface 11a of the insulated double container 10 that protrudes radially inward so as to reduce the inner diameter of the insulated double container 10.

[0059] When the inside plug gasket 30 is in close contact with the inner peripheral surface 11a of the upper opening 11 of the thermally insulated double container 10, the lower surface 35 of the inside plug gasket 30 is exposed inside the upper opening 11. Specifically, in the example shown in FIGS. 1 and 4, the lower surface 35 of the inside plug gasket 30 and the inner peripheral surface 34a of the extension portion 34 are exposed inside the upper opening 11 of the thermally insulated double container 10.

[0060] One of the features of the inside plug member 21 according to the present invention is that the inside plug packing 30 and the inside plug base material 40 are bonded together in a manner that makes them inseparable during normal use of the beverage container 1.

[0061] That is, for example, when a user of the beverage container 1 attempts to separate the inner plug gasket 30 and the inner plug base material 40 in order to clean the inner plug member 21, the inner plug gasket 30 and the inner plug base material 40 are firmly bonded to each other to such an extent that the user can recognize that the inner plug gasket 30 and the inner plug base material 40 cannot be separated.

[0062] In this regard, in the past, in the inner plug member of a beverage container, including an insulated double container, a resin inner plug base material and a rubber inner plug gasket have been separably fitted together so that when a user of the beverage container 1 washes the inner plug member, the inner plug gasket and the inner plug base material can be separated and washed separately.

[0063] However, for example, it is inevitable that a gap will form between the separable inner plug gasket and the inner plug base material, and as a result of using the beverage container, dirt may accumulate in the gap.

[0064] Furthermore, for example, if a user separates the inner plug gasket from the inner plug base material, cleans it, and then forgets to reattach the inner plug gasket to the inner plug base material, the beverage container may be used without the inner plug gasket, resulting in beverage leakage from the top opening of the insulated double-walled container. Furthermore, for example, when beverage containers are displayed for sale, the inner plug gasket of the beverage container may be removed from the inner plug base material and stolen. In contrast, in the inner plug member 21 according to the present invention, the inner plug gasket 30 and the inner plug base material 40 are inseparably bonded together, effectively avoiding the above-mentioned problems.

[0065] Another characteristic feature of the inside plug member 21 according to the present invention is that a silicone rubber molded body is used as the inside plug packing 30 and a polypropylene molded body is used as the inside plug base material 40 .

[0066] Silicone rubber is superior to other rubber materials as a material for forming the inside plug packing 30 in that it has low water absorption, maintains sufficient elasticity at high and low temperatures, and has sufficient chemical resistance.

[0067] Furthermore, polypropylene has low water absorption, sufficient strength and chemical resistance, and is inexpensive, making it an excellent material for forming the inside plug substrate 40 compared to other resins such as ABS resin, nylon, and polycarbonate.

[0068] The inventors of the present invention therefore conducted extensive research into technical means for inseparably bonding silicone rubber and polypropylene, which had previously been considered difficult to achieve strong bonding, and have now completed the present invention.

[0069] Specifically, in the inside plug member 21 according to the present invention, the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40 are preferably bonded with a peel strength of 3.0 N / mm or greater. In this case, the adhesive strength between the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40 is not particularly limited as long as the peel strength is within a range of 3.0 N / mm or greater. However, the peel strength is preferably, for example, 4.0 N / mm or greater, more preferably 5.0 N / mm or greater, even more preferably 5.5 N / mm or greater, and particularly preferably 6.0 N / mm or greater. Because a high peel strength between the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40 does not pose any particular problems, the upper limit of the peel strength is not particularly limited.

[0070] In addition, inner plug member 21 may be fixed to cover member 22 in an inseparable manner (for example, by force-fitting with resin). In this case, for example, when a user of beverage container 1 attempts to separate inner plug member 21 and cover member 22 in order to clean stopper 20, inner plug member 21 and cover member 22 are firmly fixed to each other to such an extent that the user can recognize that inner plug member 21 and cover member 22 cannot be separated.

[0071] When inside plug member 21 is manufactured using a primer as described above, rubber surface 31 of inside plug packing 30 and PP surface 41 of inside plug substrate 40 are bonded via a component derived from the primer.

[0072] In other words, in this case, a chemical bond (e.g., a covalent bond) is formed between the silicone rubber that constitutes the rubber surface 31 of the stopper gasket 30 and the primer-derived component, and a chemical bond (e.g., a covalent bond) is also formed between the primer-derived component and the polypropylene that constitutes the PP surface 41 of the stopper substrate 40.

[0073] The primer-derived component is a chemical structure corresponding to a portion of the primer molecule remaining between rubber surface 31 and PP surface 41 as a result of a chemical bond being formed by a chemical reaction between the primer and the silicone rubber that constitutes rubber surface 31 of inner plug gasket 30 and the modified polypropylene that constitutes PP surface 41 of inner plug substrate 40 (more specifically, reactive functional groups introduced into PP surface 41 by the surface modification treatment). This chemical structure corresponds to a portion of the primer molecule that remains between rubber surface 31 and PP surface 41 (for example, the chemical structure of a portion of the primer molecule that is not changed by the chemical reaction that forms the chemical bond).

[0074] Specifically, for example, when alkoxysilane is used as a primer, a chemical structure corresponding to a part of the alkoxysilane molecule is contained between the rubber surface 31 of the inside plug gasket 30 and the PP surface 41 of the inside plug substrate 40.

[0075] The inside plug substrate 40 may have a modified PP surface 41. That is, when the PP surface 41 of the inside plug substrate 40 is subjected to a surface modification treatment during the manufacturing process of the inside plug member 21, the inside plug substrate 40 included in the manufactured inside plug member 21 has the modified PP surface 41.

[0076] The modified PP surface 41 of the stopper substrate 40 contains, for example, the above-mentioned primer-derived component as well as a reactive functional group-derived component introduced by the surface modification treatment. The reactive functional group-derived component has a chemical structure corresponding to a portion of the reactive functional group remaining on the PP surface 41 as a result of the reactive functional group on the PP surface 41 of the stopper substrate 40 forming a chemical bond with the primer through a chemical reaction.

[0077] Furthermore, for example, reactive functional groups that are not consumed in the chemical reaction with the primer may remain on PP surface 41 of inside plug substrate 40 that is bonded to rubber surface 31 of inside plug packing 30.

[0078] Furthermore, for example, if reactive functional groups are introduced by surface modification treatment into portions of the PP surface 41 of the stopper substrate 40 that are not bonded to the rubber surface 31 of the stopper gasket 30 during the manufacturing process of the stopper member 21, the stopper substrate 40 may have a modified PP surface 41 (PP surface 41 with the reactive functional groups introduced) that is not bonded to the rubber surface 31.

[0079] The reactive functional group contained in the PP surface 41 of the inside plug substrate 40 may be, for example, a polar functional group, preferably a polar functional group containing an oxygen atom, and particularly preferably one or more selected from the group consisting of a hydroxyl group (-OH), a carboxyl group (-COOH), and a carbonyl group (-C(=O)-). The PP surface 41 that has been subjected to the surface modification treatment has higher hydrophilicity than the PP surface 41 that has not been subjected to the surface modification treatment.

[0080] The inner plug member 21 is preferably an insert-molded body. That is, the inner plug member 21 is preferably manufactured by insert molding as described above (FIGS. 3C and 5C).

[0081] In the inside plug member 21, the inside plug base material 40 preferably has a flange portion 42 that extends downward and penetrates into the inside plug packing 30. That is, in the examples shown in Figures 1, 2, and 4, the inside plug base portion 40 has a cylindrical flange portion 42 that extends downward.

[0082] The flange portion 42 of the inside plug substrate 40 penetrates into the inside of the inside plug gasket 30, and as a result, the inside plug gasket 30 (specifically, the base portion 33) covers the flange portion 42. In other words, the surface of the flange portion 42 of the inside plug substrate 40 is part of the PP surface 41, and is adhered to the rubber surface 31 of the inside plug gasket 30. Therefore, the presence of the flange portion 42 in the inside plug substrate 40 effectively increases the adhesion area between the PP surface 41 of the inside plug substrate 40 and the rubber surface 31 of the inside plug gasket 30.

[0083] Furthermore, flange portion 42 preferably has a tapered shape in which the radial thickness increases upward from its lower end (tip) (see, for example, FIG. 2). By forming flange portion 42 in such a tapered shape, a primer can be easily and reliably applied to the surfaces of flange portion 42 (the lower end face, the radially outer surface, and the radially inner surface), and the adhesive strength between inside plug substrate 40 and inside plug packing 30 can be effectively increased.

[0084] The inside plug substrate 40 may not have a flange portion that extends radially (for example, radially outward) and penetrates into the inside plug gasket 30. That is, in conventional inside plug components in which the inside plug gasket and the inside plug substrate are separable, the inside plug substrate has been provided with a flange portion that extends radially and penetrates into the inside plug gasket to prevent the inside plug gasket from axially detaching from the inside plug substrate when the inside of the insulated double container is cooled and decompressed.

[0085] However, in the inside plug member 21 according to the present invention, the inside plug packing 30 and the inside plug base material 40 are inseparably bonded together, so there is no need to provide the conventional flange portion extending in the radial direction.

[0086] Furthermore, for example, in insert molding, not only the silicone rubber raw material composition M but also the inside plug substrate 40 is pressed vertically under heat (FIGS. 3C and 5C), so if the inside plug substrate 40 has a flange portion extending in the radial direction, the flange portion may be deformed by the insert molding. For this reason, the inside plug substrate 40 may have a flange portion extending in the radial direction, but preferably has a flange portion 42 extending downward.

[0087] The plug substrate 40 may have bridge portions 44 that extend radially and are sandwiched from above and below by the plug gasket 30 (see FIGS. 2 and 3D). That is, during insert molding, the silicone rubber raw material composition M penetrates into gaps (not shown) formed above and below the bridge portions 44 of the plug substrate 40 and hardens, whereby the bridge portions 44 are embedded in the plug gasket 30 in the resulting plug member 21. The plug substrate 40 having the bridge portions 44 increases the adhesive area between the plug substrate 40 and the plug gasket 30 in the plug member 21, effectively increasing adhesive strength and effectively preventing the plug gasket 30 from detaching from the plug substrate 40 in the axial direction.

[0088] The inside plug substrate 40 may have a bank portion 43 that extends downward and covers a portion (specifically, the upper end portion of the outer peripheral surface 32) of the inside plug packing 30 (specifically, the base portion 33). In this case, the lower surface 43a of the bank portion 43 may not be covered by the inside plug packing 30. The bank portion 43 of the inside plug substrate 40 functions to hold back the silicone rubber raw material composition M so that the silicone rubber raw material composition M does not protrude radially outward during insert molding, for example.

[0089] The inside plug packing 30 may have an annular protrusion 36 that protrudes radially outward in an annular shape on the outer peripheral surface 32. It is preferable that the annular protrusion 36 does not protrude radially outward beyond the outer peripheral surface 34b of the extension portion 34. In other words, it is preferable that the radially outer end (protruding tip) of the annular protrusion 36 is located radially inward beyond the outer peripheral surface 34b of the extension portion 34. The annular protrusion 36 of the inside plug packing 30 is formed by the silicone rubber raw material composition M slightly protruding radially outward at the interface between the lower mold 101 and the upper mold 102 during the insert molding shown in Figures 3C and 5C.

[0090] In the beverage container 1, the inner plug member 21 may be a member capable of blocking the entire radial cross section of the upper opening 11 of the insulated double container 10, or may be a member capable of blocking only a portion of the radial cross section of the upper opening 11.

[0091] 1 , the inner plug member 21 closes the entire radial cross section of the upper opening 11 of the insulated double container 10. Specifically, the base 33 of the inner plug packing 30 has a central portion 37 that covers the radial central portion of the upper opening 11 of the insulated double container 10, and is in close contact with the inner peripheral surface a of the upper opening 11, thereby closing the entire radial cross section of the upper opening 11.

[0092] In this way, the inside plug gasket 30 having the central portion 37 covers the entire PP surface 41 below the inside plug base material 40. As a result, the adhesive area between the inside plug gasket 30 and the inside plug base material 40 is increased compared to when the inside plug gasket 30 does not have the central portion 37, and adhesive strength is effectively increased.

[0093] 4, the inner plug member 21 closes only a portion of the radial cross section of the upper opening 11 of the insulated double container 10. Specifically, a communication hole 23 that axially penetrates the inner plug packing 30 and the inner plug base material 40 is formed in the radial center portion of the inner plug member 21. Therefore, the inner plug member 21 closes only the radial outer periphery of the upper opening 11 of the insulated double container 10, and does not close the radial center portion of the upper opening 11.

[0094] In the beverage container 1, the stopper 20 may be attached to the insulating double container 10 in its entirety so as to be openable and closable, or may be attached to the insulating double container 10 in its part so as to be openable and closable.

[0095] 1, the entire stopper 20 is attached to the insulated double container 10 so as to be openable and closable. Specifically, in this example, by removing the entire stopper 20 from the insulated double container 10, the upper opening 11 of the insulated double container 10 is connected to the outside, and the beverage container 1 is in an open state. With the beverage container 1 in an open state, a user can pour the beverage contained in the insulated double container 10 through the upper opening 11 of the insulated double container 10.

[0096] 4, the stopper 20 is attached to the insulated double container 10 so that a portion of the stopper 20 can be opened and closed. Specifically, in this example, the canopy portion 22a of the cover member 22 of the stopper 20 is attached to the cylindrical portion 22b via the hinge portion 22d so as to be rotatable.

[0097] Then, with the cylindrical portion 22b of the cover member 22 attached to the outer peripheral surface 11b of the upper opening 11 of the double insulated container 10 and the middle stopper member 21 attached to the cylindrical portion 22b (with the middle stopper gasket 30 in close contact with the inner peripheral surface 11a of the upper opening 11), by rotating the canopy portion 22a of the cover member 22, the upper opening 11 of the insulated double container 10 is connected to the outside through the communication hole 23 of the middle stopper member 21, and the beverage container 1 is in an open state.

[0098] When the beverage container 1 is in an open state, a user can pour out the beverage contained in the insulated double container 10 through the upper opening 11 of the insulated double container 10 and the communicating hole 23 of the inner stopper member 21.

[0099] In the beverage container 1, the inner stopper gasket 30 may be disposed within the upper opening 11 of the insulated double container 10, as shown in Figures 1 and 4. Specifically, in this case, the entire inner stopper gasket 30 is disposed below the upper end 11c of the upper opening 11 of the insulated double container 10 (more specifically, the upper end of the insulated double container). In addition, a portion of the inner stopper base material 40 may also be disposed within the upper opening 11 of the insulated double container 10.

[0100] Another aspect of the method according to this embodiment is a method for manufacturing a beverage container 1, which includes an attachment step of attaching an inner plug member 21 to an insulated double container 10. In the attachment step, the inner plug member 21 is attached to the insulated double container 10 so that the inner plug gasket 30 of the inner plug member 21 is in close contact with the inner circumferential surface 11a of the upper opening 11 of the insulated double container 10.

[0101] When manufacturing a beverage container 1 having a stopper 20 including an inner stopper member 21, the stopper 20 is attached to the insulated double container 10 so that the inner stopper gasket 30 adheres closely to the inner surface 11a of the upper opening 11 of the insulated double container 10.

[0102] The method for manufacturing the beverage container 1 may further include a step of manufacturing the inner plug member 21 by the method for manufacturing the inner plug member 21 described above. In this case, the method for manufacturing the beverage container 1 includes the bonding step described above. The method for manufacturing the beverage container 1 may also include the surface modification step and primer application step described above. That is, the method for manufacturing the beverage container 1 may include the surface modification step, primer application step, bonding step, and attachment step.

[0103] Next, a specific example according to this embodiment will be described. [Example]

[0104] [Example 1] The inside plug member 21 and beverage container 1 shown in Figures 1 and 2 were manufactured. First, an inside plug substrate 40 was formed by injection molding of polypropylene. Next, as shown in Figure 3A, a surface modification treatment was applied to the PP surface 41 of the inside plug substrate 40. Furthermore, as shown in Figure 3B, a primer was applied to the surface-modified PP surface 41 of the inside plug substrate 40.

[0105] Then, insert molding was performed as shown in Fig. 3C. That is, a silicone rubber raw material composition M containing a silicone rubber raw material and a vulcanizing agent was pressed onto the primer-coated PP surface 41 of the inside plug substrate 40 fixed to the lower mold 101 using the heated lower mold 101 and upper mold 102, and the temperature and time were maintained within a range where vulcanization was sufficiently advanced and the polypropylene could withstand the heat.

[0106] In this way, as shown in Fig. 3D, a center plug member 21 was obtained, which was an insert-molded body composed of a center plug gasket 30, which was a silicone rubber molded body, and a center plug base material 40, which was a polypropylene molded body. Then, the center plug member 21 was removed from the mold 100 and placed in an oven equipped with an exhaust mechanism, where it was maintained at a temperature and for a time sufficient for vulcanization to proceed, thereby carrying out secondary vulcanization.

[0107] In the manufactured inner plug member 21, the inner plug gasket 30 and the inner plug base material 40 were firmly bonded, making it virtually impossible to separate them by pulling them by hand. Then, by attaching the inner plug member 21 to a separately manufactured cover member 22, a stopper 20 as shown in Figure 2 was manufactured. Furthermore, by attaching the stopper 20 to a separately manufactured insulated double container 10, a beverage container 1 as shown in Figure 1 was manufactured.

[0108] [Example 2] In Example 2-1, the peel strength between a silicone rubber test piece and a polypropylene test piece in an insert molded article composed of the silicone rubber test piece and the polypropylene test piece was evaluated using a method in accordance with JIS K6256-2.

[0109] First, polypropylene test pieces were molded by injection molding. Next, one surface of the polypropylene test piece was subjected to a surface modification treatment. Furthermore, a primer was applied to the surface-modified surface of the polypropylene test piece.

[0110] A silicone rubber raw material composition containing a silicone rubber raw material and a vulcanizing agent was placed on the primer-coated surface of the polypropylene test piece fixed to the lower mold, and the piece was pressed using the heated lower and upper molds. The temperature and time were maintained within a range where vulcanization was sufficiently advanced and the polypropylene could withstand the heat, thereby performing insert molding.

[0111] In this way, an insert molded article was obtained consisting of a silicone rubber test piece, which was a silicone rubber molded article, and a polypropylene test piece, which was a polypropylene molded article. The insert molded article was then removed from the mold and placed in an oven equipped with an exhaust mechanism, where it was maintained at a temperature and for a time sufficient for vulcanization to proceed, thereby carrying out secondary vulcanization.

[0112] Then, using a commercially available test device (Shimadzu Corporation's Autograph Precision Universal Testing Machine equipped with a Type 2 Rubber Adhesion Tester (90°) as the test jig), a 90° peel test was performed between the silicone rubber test piece and the polypropylene test piece in the insert molding, and the test force (N) per displacement (mm) was measured and recorded. The peel strength (N / mm) was calculated by dividing the maximum peel force (N) measured in the peel test by the width (25 mm) of the test piece.

[0113] In Example 2-2, a composite test piece was obtained by bonding a silicone rubber test piece and a polypropylene test piece with an adhesive, and the peel strength between the silicone rubber test piece and the polypropylene test piece was evaluated using a method in accordance with JIS K6256-2.

[0114] First, a polypropylene test piece was molded in the same manner as in Example 2-1 above. Next, a primer included with a commercially available adhesive for plastics (Aron Alpha, Toa Gosei Co., Ltd.) that can be used with polypropylene and polyethylene was applied to one surface of the polypropylene test piece. Meanwhile, a silicone rubber test piece was molded by compression molding the same silicone rubber raw material composition as used in Example 2-1 above.

[0115] Next, the primer-coated surface of the polypropylene test piece was bonded to one surface of the silicone rubber test piece using the commercially available adhesive (Aron Alpha, Toa Gosei Co., Ltd.) The peel strength between the silicone rubber test piece and the polypropylene test piece in the composite test piece was then evaluated in the same manner as in Example 2-1 above.

[0116] In Example 2-3, the peel strength between the silicone rubber test piece and the polypropylene test piece in the composite test piece was evaluated in the same manner as in Example 2-2 above, except that no primer was applied to the surface of the polypropylene test piece and a commercially available adhesive that can also be used on polypropylene and polyethylene (Scotch (registered trademark), Ultra-Strong Adhesive Premier Gold Super Multi-Purpose, 3M Japan Ltd.) was used as the adhesive.

[0117] In Example 2-4, the peel strength between the silicone rubber test piece and the polycarbonate test piece in the insert molded body was evaluated in the same manner as in Example 2-1 above, except that a polycarbonate test piece obtained by injection molding of polycarbonate was used instead of the polypropylene test piece.

[0118] Figure 6 shows the maximum peel force (N) and peel strength (N / mm) measured for each of Examples 2-1, 2-2, 2-3, and 2-4. The maximum peel force shown in Figure 6 is the arithmetic mean value of the four maximum peel forces measured using four test pieces in each example.

[0119] As shown in Figure 6, the peel strengths of Examples 2-2 and 2-3, which used an adhesive, were 1.5 N / mm and 0.8 N / mm, respectively, while the peel strengths of Examples 2-1 and 2-4, which used insert molding, were 6.2 N / mm and 5.4 N / mm, respectively. In other words, the peel strength achieved by insert molding was significantly greater than the peel strength achieved by using an adhesive.

[0120] Furthermore, the peel strength achieved in Example 2-1 using the polypropylene test piece was greater than the peel strength achieved in Example 2-4 using the polycarbonate test piece. That is, in Example 2-1, by using polypropylene suitable for the inner plug member 21 of the beverage container 1, a higher adhesive strength was achieved than when polycarbonate was used. [Explanation of symbols]

[0121] 1 beverage container, 10 insulated double container, 11 upper opening, 11a inner peripheral surface, 11b outer peripheral surface, 11c upper end, 12 bottom surface, 13 inner container, 14 outer container, 15 insulated space, 20 stopper, 21 inner stopper member, 22 cover member, 22a canopy portion, 22b cylindrical portion, 22c inner peripheral surface, 22d hinge portion, 23 communication hole, 30 inner stopper packing, 31 silicone rubber surface (rubber surface), 32 outer peripheral surface, 33 base portion, 34 extension portion, 34a inner peripheral surface, 34b outer peripheral surface, 35 lower surface, 36 annular protrusion portion, 37 central portion, 40 inner stopper base material, 41 polypropylene surface (PP surface), 42 flange portion, 43 bank portion, 43a lower surface, 44 bridge portion, 100 Mold, 101 lower mold, 102 upper mold, A axis, M silicone rubber raw material composition.

Claims

1. An inner plug member for a beverage container including an insulated double container, an inner plug packing that is a silicone rubber molded body and that is in close contact with the inner peripheral surface of the upper opening of the heat-insulating double container; an inner plug base material that is a resin molded body and supports the inner plug packing; Including, the silicone rubber surface of the inside plug packing and the resin surface of the inside plug base material are inseparably bonded together, the inside plug base material has a flange portion that extends downward and penetrates into the inside plug packing, and does not have a flange portion that extends radially outward and penetrates into the inside plug packing, the inside plug packing is a component that is insert-molded from a silicone rubber raw material composition onto a resin surface of the inside plug base material having the flange portion; Inner plug component.

2. the silicone rubber surface of the inside plug packing and the resin surface of the inside plug base material are bonded to each other via a component derived from a primer; The inside plug member according to claim 1 .

3. The inside plug substrate has the resin surface modified. The inside plug member according to claim 2.

4. the silicone rubber surface and the resin surface are bonded together with a peel strength of 3.0 N / mm or more as measured by a method in accordance with JIS K6256-2; The inside plug member according to any one of claims 1 to 3.

5. A double insulated container, An inside plug member according to any one of claims 1 to 4; Beverage containers including:

6. The method includes a step of attaching the inner plug member according to any one of claims 1 to 4 to an insulated double container. A method for manufacturing beverage containers.

Images