Liquid carton closures

Abstract

To provide a plug that has a good sealing properties and can be easily opened and reopened even by a relatively weak user such as an elderly person.SOLUTION: In a plug 1 made of plastic resin that is attached to a paper container for liquid and including a spout 20 and a cap 10, resin constituting the spout includes a polyethylene resin as a main component, and contains 5 wt.% or more of biomass polyethylene resin. The spout is provided with: an external thread 24 on an outer side surface; and a sealing plate 22 sealing an opening portion and a first engagement portion 26 connected to the sealing plate on an inner side surface. The sealing plates is connected to the inner side surface of the spout via a circumferential thin portion 23. The cap is provided with an inner screw 14 screwing an outer screw of the spout and a second engagement portion 16 engaging with the first engagement portion. When the outer screw and the inner screw are released, the first engagement portion and the second engagement portion are engaged with each other, and the sealing plate is rotated along with the cap to break the circumferential thin portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a plug consisting of a spout and a cap that is provided at the spout of a paper container for liquid, and relates to a plug that has a tight seal and can be opened with little force. [Background technology]

[0002] Conventionally, paper containers for liquids used for food and non-food liquid contents have been used across a wide range of applications, with the body shaped like a rectangular pillar and a gable-roofed sloping top panel on which a spout and cap protrude, taking ease of use into consideration.

[0003] This plug has a cap screwed onto a spout dispensing tube that protrudes from a plug mounting hole in a container, or connected with an openable hinge, but to ensure complete sealing and virginity during distribution, and to make it easy to open when in use, a sealing plate is provided below the inside of the spout dispensing tube to seal it. To open the sealing plate, a support with a pull ring at its tip is provided on the sealing plate, and a widely used system is one in which the plate is broken by pulling the pull ring to open the container when in use (for example, Patent Document 1).

[0004] However, in order to open such stoppers, two actions are required: first, remove the cap, and then pull the pull ring to break the closure plate and open the stopper. In addition, pulling the pull ring requires a considerable amount of force. Therefore, in recent years, stoppers that can be opened in a single action have been proposed to make opening easier (for example, Patent Document 2).

[0005] In this type of plug, when a user rotates the cap in the direction to remove it, the sealing plate or a part connected to the sealing plate engages with the cap in the rotational direction, and as the cap rotates, the thin part of the sealing plate is torn off, opening the sealing plate. Even when the cap is removed from the plug, the sealing plate, which is engaged with the cap in the vertical direction, can be removed without falling.

[0006] Such stoppers are convenient in that they can be opened with a single action of rotating the cap. However, on the other hand, the cap must be rotated with a large torque to tear the closure plate, which requires a large force to tear the closure plate, making them difficult to open for elderly people and women who have weaker strength. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-84078 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-209103 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the problems of the prior art as described above, and its object is to provide a closure for a liquid paper container that has good sealing properties, can be opened with a single action, and can be easily opened and re-opened even by users with relatively weak strength, such as elderly people. [Means for solving the problem]

[0009] In order to solve the above problem, the invention according to claim 1 of the present invention is as follows: A plastic resin stopper that is attached to a liquid paper container and consists of a spout and a cap. And, The resin constituting the spout is mainly composed of polyethylene resin and contains 5% by weight or more of biomass polyethylene resin, The spout has an external thread on its outer surface, and a sealing plate that seals the opening and a first engagement portion connected to the sealing plate on its inner surface, and the sealing plate is connected to the inner surface of the spout via a circumferential thin portion, The cap has an internal thread that threadably engages with the external thread of the spout and a second engagement portion that engages with the first engagement portion, This is a stopper for a paper container for liquid, characterized in that when the external thread and the internal thread are unthreaded, the first engagement portion and the second engagement portion engage with each other, the sealing plate rotates together with the cap, and the peripheral thin portion is broken.

[0010] The invention according to claim 2 of the present invention is as follows: 2. The stopper for a paper container for liquids according to claim 1, wherein the resin constituting the spout contains 50% by weight or more of biomass polyethylene resin.

[0011] The invention according to claim 3 of the present invention is as follows: 3. The plug for a paper container for liquids according to claim 1 or 2, characterized in that the resin constituting the cap is mainly composed of polyethylene resin and contains 5% by weight or more of biomass polyethylene resin.

[0012] The invention according to claim 4 of the present invention is as follows: 4. The plug for a paper container for liquids according to any one of claims 1 to 3, characterized in that the resin constituting the cap contains 50% by weight or more of biomass polyethylene resin.

[0013] The invention according to claim 5 of the present invention is as follows: A stopper for a paper container for liquid as described in any one of claims 1 to 4, characterized in that the first engagement portion and the second engagement portion have any of the following structures: reverse thread, undercut, flap, or ratchet. [Effects of the Invention]

[0014] According to the present invention, even in a closure in which the sealing plate is torn at the same time as the cap is unscrewed, if the polyethylene resin that is the main component of the spout contains a specified proportion or more of biomass polyethylene resin, the amount of low molecular weight components increases compared to when only petroleum-derived polyethylene resin is used, and the tensile breaking strength decreases, thereby reducing the breaking strength of the sealing plate that seals the spout opening, and it becomes possible to break the peripheral thin portion 23 with less force when unscrewing the cap, thereby providing a closure for a liquid paper container that can be opened with a single action of removing the cap even by users with relatively weak strength such as the elderly, children, and women.

[0015] Furthermore, when the cap is resealed after opening and then opened again, the low molecular weight components bleed out, increasing the slipperiness at the contact points between the threads that screw the spout and cap together and the inner ring, thereby reducing the resistance to removing the cap and providing a stopper for a liquid paper container that can be removed with less force.

[0016] Furthermore, by using polyethylene resin as the main component of the cap and including a certain proportion of biomass polyethylene resin, it becomes possible to remove the cap with even less force, providing a closure for a liquid paper container that can be opened more smoothly even by users with relatively weaker strength, such as the elderly, children, and women.

[0017] The plug of the present invention is made of a resin containing plant-derived biomass polyethylene resin. Therefore, they are all plant-derived and are environmentally friendly even when incinerated. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional schematic view of one embodiment of the plug of the present invention. [Figure 2] 1 is a schematic cross-sectional view of a state in which a cap of one embodiment of the plug of the present invention is being unscrewed. [Figure 3] 10A and 10B are top views of configuration examples of a first engagement portion and a second engagement portion. [Figure 4]FIG. 2 is a cross-sectional schematic view of a second embodiment of the plug of the present invention. [Figure 5] FIG. 2 is a cross-sectional view of a third embodiment of the plug of the present invention. [Figure 6] 1 is a schematic diagram of one embodiment of a paper container for liquids using a stopper of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below. Furthermore, in the following, the same reference numerals will be used to designate equivalent components, and their description may be omitted.

[0020] Figure 1 is a schematic cross-sectional view of one embodiment of the stopper of the present invention, showing the cap and spout screwed together. The stopper 1 comprises a cap 10 and a spout 20. A flange 28 that extends flat outward is integrally formed at the lower end of the spout 20. The spout 20 is molded from a resin whose main component is polyethylene resin and contains 5% by weight or more of biomass polyethylene resin. For example, as shown in Figure 6, the spout 20 is inserted into a hole in the inclined plate 102 of a paper container for liquid 100 having a rectangular prism-shaped body 101 and adhered from the inside. If the inner surface of the paper container for liquid is a thermoplastic resin layer, it can also be welded to that thermoplastic resin layer.

[0021] The spout 20 has a cylindrical dispensing tube 21 rising from a flange portion 28, with an opening at the top end and an external thread 24 on its outer circumferential surface for threading onto the cap 10. A sealing plate 22 that seals the dispensing tube 21 is provided inside the dispensing tube 21, and a V-shaped groove is provided around the bottom surface of the sealing plate 22, forming a circumferential thin-walled portion 23 where the sealing plate 22 is thinned. The V-shaped groove may be provided on the top surface of the sealing plate 22, or on both the top and bottom surfaces. A cylindrical first engagement portion 26 rises from the inside of the circumferential thin-walled portion 23 on the sealing plate 22 of the spout 10, and a first engagement structure 25 is formed on the inner surface of the first engagement portion 26.

[0022] The cap 10 has a top surface 11 and a cylindrical side wall 12 that hangs down from the periphery of the top surface 11. An internal thread 14 is formed on the inner surface of the side wall 12 to threadably engage with an external thread 24 of the pouring tube 21 of the spout 20, and a cylindrical inner ring 13 hangs down from the top surface 11 so as to fit closely against the inner surface of the pouring tube 21. The outer diameter of the inner ring 13 is slightly larger than the inner diameter of the pouring tube 21. A cylindrical second engagement portion 16 hangs down from the top surface 11 of the cap 10 so as to be inserted into the first engagement portion 26 of the spout 20, and a second engagement structure 15 is formed on the outer surface of the second engagement portion 16.

[0023] The first engagement structure 25 and the second engagement structure 15 are configured to engage at least in the rotational direction when the external thread 24 and the internal thread 14 are unthreaded to remove the cap 10. The first engagement portion 26 and the second engagement portion 16 may also have a structure that engages in the vertical direction, and although not particularly limited, may have, for example, a structure such as an undercut 27 shown in FIG. 1, a flap, a ratchet, or the like. Alternatively, the first engagement structure 25 and the second engagement structure 15 may have a structure or shape that engages with each other in both the rotational direction and the vertical direction.

[0024] 2 is a cross-sectional view of the plug 1 in the state of unscrewing the cap. When the cap 10 is rotated to unscrew the internal thread 14 and the external thread 24 in order to open the plug 1, The first engagement structure 25 of the engagement portion 26 and the second engagement structure 15 of the second engagement portion 16 engage in the rotational direction, and a rotational torque is applied to the first engagement portion and the closing plate 22 connected thereto so as to rotate together with the cap 10. The rotational torque acts as a force to thread off a portion of the circumferential thin portion 23, causing the circumferential thin portion 23 to break, and the closing plate 22 is separated from the spout 20. Because the first engagement portion 26 and the second engagement portion 16 are also engaged in the vertical direction by the undercut 27, the closing plate 22 will not fall and can be removed together with the cap 10. By removing the closing plate 22, the opening of the dispensing tube 21 communicates with the interior of the container, allowing the contents to be poured out.

[0025] 3 is a top view of an example of the configuration of the first engagement portion and the second engagement portion. The first engagement structure 25 and the second engagement structure 15 have a structure that engages in the rotational direction indicated by the black arrow, and can be, for example, any of (a) flap structures 15a, 25a, (b) undercut structures 15b, 25b, and (c) ratchet structures 15c, 25c, as shown in FIG. 3. In addition, a reverse-thread structure in which the rotational direction of the thread engagement is opposite to that of the internal thread 14 and the external thread 24 can be used, but is not limited to these.

[0026] Spout 20 can be made entirely of biomass polyethylene resin, but biomass polyethylene resin is generally expensive, so in consideration of production costs, it can be used in blend with fossil fuel-derived polyethylene resin. If it contains at least 5% by weight, and more preferably 50% by weight or more, biomass polyethylene resin causes low molecular weight components to bleed out, reducing the breaking strength. Whereas previously a rotational torque of about 100 N·cm was required, the thin peripheral portion 23 of sealing plate 22 can now be broken with less force, making it easier for even users with relatively weak strength, such as the elderly, to open it.

[0027] As mentioned above, the outer diameter of the inner ring 13 is slightly larger than the inner diameter of the dispensing tube 21, and this difference is also called the "protrusion amount." When there is a "protrusion amount," the inner ring 13 is elastically deformed due to the natural elasticity of the resin when inserted into the dispensing tube 21, and after insertion, the inner ring 13 is pressed against the inner surface of the dispensing tube 21 due to its elasticity, and the inner ring 13 tightly contacts the inner surface of the dispensing tube 21, sealing the contents to prevent leakage. Generally, increasing the "protrusion amount" improves the sealing performance, but the pressing force also increases, which increases the sliding resistance when removing the cap, making it difficult for users with weak strength to open the cap.

[0028] In the plug of the present invention, the spout 20 contains a specified ratio of biomass polyethylene resin, which causes low molecular weight components to bleed out, increasing the slipperiness, and also providing the effect that the plug can be opened with a relatively small force even when the "protrusion amount" is increased to improve sealing performance.

[0029] Cap 10 can be formed by molding polypropylene resin, polyethylene resin, or the like. When polyethylene resin is used, a part or all of it can be biomass polyethylene resin, as in spout 20. In this case, the preferred content is the same as in spout 20, 5% by weight or more, more preferably 50% by weight or more.

[0030] Furthermore, if the cap 10 is also molded from polyethylene resin containing a specified ratio of biomass polyethylene resin, low molecular weight components will bleed out from the cap 10 as well as from the spout 20, making it easier to unscrew the internal thread 14 and external thread 24, and allowing the cap to be opened and re-opened with even less force.

[0031] The spout 20 and cap 10 can be formed using the resin compositions that make up each of them by known molding methods such as compression molding or injection molding, similar to conventional spouts and caps that use only petroleum-derived resins.

[0032] 4 is a cross-sectional schematic diagram of a second embodiment of the plug of the present invention. In the plug 2 of this embodiment, the first engagement portion 26 of the spout 20b extends cylindrically downward further than the sealing plate of the previous embodiment, and this cylindrical portion and the bottom surface essentially form the sealing plate 22. Accordingly, the second engagement portion 16 of the cap 10b also extends downward. In this case, the area in which the first engagement structure 25 and the second engagement structure 15 are formed can be made wider.

[0033] 5 is a cross-sectional schematic diagram of a third embodiment of the plug of the present invention. In the plug 3 of this embodiment, the first engagement portion 26 of the spout 20c is formed in a portion that extends cylindrically downward from the sealing plate of the previous embodiment, and does not extend upward. The downwardly extending cylindrical portion and the bottom portion essentially form the sealing plate 22. Accordingly, the second engagement portion 16 of the cap 10c also extends downward, and a first engagement structure 25 and a second engagement structure 15 are formed at positions facing each other.

[0034] The biomass polyethylene resin used in the plug of the present invention is obtained by chemical or biological synthesis using renewable resources such as plants as raw materials, whereas most ordinary plastic resins are made from petroleum, a non-renewable fossil resource. This material has been attracting attention in recent years as a type of biomass plastic that does not increase the CO2 concentration in the atmosphere, contributes to preventing global warming, and reduces dependence on fossil resources.

[0035] The biomass polyethylene resin used in the spout 20 and the cap 10 is plant-derived. "Plant-derived" means that it is synthesized using alcohol obtained by fermenting plants as a raw material and contains plant-derived carbon. Ethylene is synthesized from this alcohol and then polymerized to obtain the biomass polyethylene resin. Examples of plants that can be used as raw materials include, but are not limited to, corn, sugarcane, beets, and cassava.

[0036] Examples of biomass polyethylene resins include high-density polyethylene (manufactured by Braskem, product name: SHA7260, biomass content: 94.5%, density: 0.955 g / cm 3 , MFR: 20 g / 10 min) and linear low-density polyethylene (Braskem: SLL318, biomass content: 87%, density: 0.918 g / cm 3 Examples of the polyethylene resin include, but are not limited to, an antioxidant, a tackifier, a bulking agent, and various other additives, such as various fillers.

[0037] As explained above, the plug of the present invention contains a predetermined ratio of biomass polyethylene resin, making it an environmentally friendly plug. In other words, by using biomass polyethylene resin derived from plants, which is a renewable resource, the amount of fossil fuels used, which is an exhaustible resource, can be further reduced, and its carbon-neutral properties can reduce carbon dioxide emissions. [Example]

[0038] The present invention will be explained in more detail below with reference to examples.

[0039] (Sample configuration) A polyethylene resin spout and a polypropylene resin cap with the same shape as shown in Figure 1 were fabricated, and the ratio of biomass polyethylene resin in the polyethylene resin of the spout was varied between 5% and 100%, and six samples, ten of each, were fabricated. As a comparison sample, one sample (10 pieces) was produced that did not contain biomass polyethylene resin in the polyethylene resin spout.

[0040] (evaluation) The torque required to unscrew internal and external threads is measured using a torque meter, and the average value is calculated. was calculated (opening torque). · Test samples with a lower opening torque than the comparison sample were rated as "good" (△) or "very good" (○), depending on the degree of the test. The comparative sample was also measured in the same way and evaluated as "poor" (×).

[0041] Example 1 Biomass polyethylene resin content of spout: 5%

[0042] <Example 2> Spout biomass polyethylene resin content: 20%

[0043] Example 3 Spout biomass polyethylene resin ratio: 50%

[0044] Example 4 Spout biomass polyethylene resin content: 80%

[0045] <Example 5> Spout biomass polyethylene resin content: 95%

[0046] Example 6 Spout biomass polyethylene resin ratio: 100%

[0047] The evaluation results of each of the above examples are summarized in Table 1.

[0048] [Table 1]

[0049] As can be seen from Table 1, increasing the ratio of biomass polyethylene resin in the polyethylene resin of the spout to 5% was confirmed to have the effect of reducing the unscrewing torque. Furthermore, the effect became greater until the ratio was increased to 50%, and the effect did not change even when the ratio was increased further. [Explanation of symbols]

[0050] 1, 2, 3....Stop 10, 10b, 10c... Cap 11...Top section 12 Side wall 13 Inner ring 14 Internal thread 15, 15a, 15b, 15c...Second engagement structure 16 Second engagement portion 20, 20b, 20c...Spout 21...Pour tube 22...Blocking plate 23... Circumferential thin wall part 24...External thread 25, 25a, 25b, 25c...first engagement structure 26 First engagement portion 27. Undercut 28 Flange 100 Liquid carton 101... Body 102... Inclined plate

Claims

1. A plastic resin stopper attached to a paper container for liquid, which comprises a spout and a cap, The resin constituting the spout is mainly composed of polyethylene resin and contains 5% by weight or more of biomass polyethylene resin, The spout has an outer thread on its outer surface, a sealing plate on its inner surface that seals the opening, and a cylindrical first engagement portion that is connected to the sealing plate and stands upright from the sealing plate, and the sealing plate is connected to the inner surface of the spout via a circumferential thin portion, The cap is provided with an internal thread that threadably engages with the external thread of the spout and a second engagement portion that engages with the first engagement portion, When the plug is oriented such that the spout is positioned downward and the cap is positioned upward, the first engagement portion extends downward from the position of the circumferential thin portion and further has a cylindrical portion that constitutes a part of the sealing plate, and the second engagement portion is provided at a position corresponding to the first engagement portion and ranging from a position higher than the position of the circumferential thin portion to a position lower than the position of the circumferential thin portion, A stopper for a paper container for liquid, characterized in that when the external thread and the internal thread are unthreaded, the first engaging portion and the second engaging portion engage with each other, the sealing plate rotates together with the cap, and the peripheral thin portion is broken.

2. The stopper for a paper container for liquids according to claim 1, wherein the resin constituting the spout contains 50% by weight or more of biomass polyethylene resin.

3. 3. The plug for a paper container for liquids according to claim 1, wherein the resin constituting the cap is mainly composed of polyethylene resin and contains 5% by weight or more of biomass polyethylene resin.

4. The plug for a paper container for liquids according to any one of claims 1 to 3, wherein the resin constituting the cap contains 50% by weight or more of biomass polyethylene resin.

5. The stopper for a paper container for liquids according to any one of claims 1 to 4, wherein the first engagement portion and the second engagement portion have any one of a reverse thread, an undercut, a flap, and a ratchet structure.

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