Transition plug cap

Abstract

To provide a transition plug cap that can be easily opened by a rotational movement of a screw cap even if formed from a resin material including a petroleum-derived polyolefin and a plant-derived polyolefin.SOLUTION: A transition plug cap A includes a cap body B that is attached to a mouth of a container body and has a removable transition plug body 6 and a screw cap C mounted by screwing the same onto the cap body B and capable of engaging a removed transition plug body 6. At least the cap body B is formed from a resin material including 40 wt.% or more of a petroleum-derived polyolefin and 60 wt.% or less of a plant-derived polyolefin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a transition stopper cap that can be opened by rotating a screw cap, and more particularly to a transition stopper cap that uses a resin material containing a plant-derived polyolefin. [Background technology]

[0002] Conventionally, for food containers that contain liquid contents such as dressings and seasonings, transfer plug caps have been known that can be opened by rotating a screw cap in order to keep the inside of the container sealed until it is opened. Moreover, in recent years, due to growing awareness of preventing global warming and reducing the use of petroleum, a defunct resource, attempts have been made to switch from conventional petroleum-derived resin materials to carbon-neutral plant-derived resin materials, and containers made from resin materials containing plant-derived polyolefins are also known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-199513 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1 above, resin materials containing plant-derived polyolefins can be used as containers, but when used as transition stopper caps that are opened by rotating a screw cap, there is a problem that they cannot be opened as easily as conventional transition stopper caps made of petroleum-derived polyolefin resins. For this reason, a transfer plug cap using a resin material containing a plant-derived polyolefin is not yet known.

[0005] The present invention has an objective of solving the above problems and providing a transition plug cap that can be easily opened by rotating a screw cap, even if it is made of a resin material containing a petroleum-derived polyolefin and a plant-derived polyolefin. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a transition stopper cap comprising a cap body that is attached to the mouth of a container body and has a removable transition stopper body, and a screw cap that is screwed onto the cap body and can engage the removed transition stopper body when opened by rotation, wherein at least the cap body is formed from a resin material containing 40% or more by weight of petroleum-derived polyolefin and 60% or less by weight of plant-derived polyolefin.

[0007] As an embodiment of the transition plug cap, a configuration is adopted in which the plant-derived polyolefin is made of plant-derived low-density polyethylene, and the petroleum-derived polyolefin is made of petroleum-derived linear low-density polyethylene, and the petroleum-derived linear low-density polyethylene and the plant-derived low-density polyethylene have a melt flow rate of 7 to 9, and the petroleum-derived linear low-density polyethylene and the plant-derived low-density polyethylene have a flexural modulus of 70 to 660 MPa. Effect of the Invention

[0008] By adopting the above-mentioned configuration, the transition plug cap of the present invention can be easily opened by rotating the screw cap, even if at least the cap body is formed from a resin material containing petroleum-derived polyolefin and plant-derived polyolefin. [Brief description of the drawings]

[0009] [Figure 1]1A and 1B are diagrams showing the state after the screw cap and the cap body in the transition plug cap according to an embodiment of the present invention have been set, where (a) is a side cross-sectional view and (b) is an enlarged view of the main part of (a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A transition plug cap according to the present invention will be described with reference to the drawings, showing an embodiment. In Figure 1, A is a transition stopper cap, which is attached to the mouth of a container body (not shown) and comprises a cap body B having a removable transition stopper body 6, and a screw cap C which is attached by screwing onto the cap body B and can engage with the removed transition stopper body 6.

[0011] As shown in Figure 1, the cap body B is composed of an attachment part 1 that is attached to the mouth of the container body, a threaded wall part 2 that stands up from the attachment part 1, a partition wall 3 that extends inward from the upper end of the inner circumference of the threaded wall part 2 and has an opening 3a of diameter α drilled in the center, a pouring tube 4 that stands up from the edge of the opening 3a of the partition wall 3, and a transition stopper body 6 that is integrally connected to the lower end of the inner circumference of the opening 3a via a thin-walled weakened part 5 formed around the entire circumference.

[0012] The transition plug body 6 comprises a cylindrical peripheral tubular portion 10 whose outer periphery lower end is connected to the inner periphery of the thin-walled weakened portion 5, and a bottom wall 11 shaped to seal the inner periphery lower end of the peripheral tubular portion 10, and at a predetermined position on the upper outer periphery of the peripheral tubular portion 10, a fitting recess 12 is cut out from the outer periphery to form a first fitting portion that fits with a second fitting portion provided on the screw cap C described later.

[0013] The screw cap C comprises a disk-shaped top wall 20 and an outer peripheral wall 21 extending vertically from the outer periphery of the top wall 20. On the inner surface of the top wall 20, there are extending vertically from near the center, an attachment portion 22 which is inserted into the inner periphery of the peripheral tube portion 10 of the transition stopper body 6 of the cap body B, and, from the outer periphery side of the attachment portion 22, there are extending vertically, in order, a sealing tube portion 23 whose outer periphery lower part is in close contact with the inner periphery of the pouring tube 4 to seal the inward, and a threaded tube portion 24 whose inner periphery screws into the outer periphery of the threaded wall portion 2. On the inner circumference of the sealing tube portion 23, there are arranged the same number of mating protrusions 25 as the mating recesses 12, which protrude radially inward from the upper part of the inner circumference and constitute a second mating portion that fits from above into the mating recesses 12 of the transition plug body 6.

[0014] Next, the manner of use and the effects of this embodiment will be described. In the present embodiment, the transition stopper cap A is formed by first molding the cap body B and the screw cap C separately, then aligning and capping the screw cap C from the top of the cap body B, setting it as the transition stopper cap A, and then fitting the attachment portion 1 of the cap body B to the mouth of the container body filled with the liquid content by capping.

[0015] First, when using the liquid contents in the container body, the screw cap C is rotated in the opening direction relative to the cap body B, causing the mating protrusion 25 of the sealing cylindrical portion 23 of the screw cap C to rotate, and the mating recess 12 of the transition stopper body 6 of the cap body B, which mating with the mating protrusion 25, is also rotated. As the screw cap C rotates, the transition plug 6 is rotated relative to the cap body B, so that the thin-walled weakened portion 5 connecting the transition plug 6 to the inner circumferential lower end of the opening 3a of the partition wall 3 is broken. Furthermore, when the screw cap C is rotated, the screw tube portion 24 of the screw cap C and the screw wall portion 2 of the cap body B are unscrewed, and the screw cap C, together with the transition stopper body 6 attached by the attachment portion 22, is lifted up relative to the cap body B and opens, and the opening 3a of the partition 3 of the cap body B opens, allowing the liquid contents in the container body to be guided and poured out by the pouring tube 4. Furthermore, by screwing the screw cap C onto the cap body B, the sealing cylindrical portion 23 of the screw cap C can close the pouring cylinder 4 to form a lid.

[0016] The resin materials forming the cap body B and the screw cap C of the transition plug cap A of this embodiment are as follows. In the transition plug cap A of this embodiment, the cap body B and the screw cap C are formed from a resin material containing petroleum-derived polyolefin and plant-derived polyolefin, but it is not necessary for both the cap body B and the screw cap C to be formed from a resin material containing petroleum-derived polyolefin and plant-derived polyolefin, and the screw cap C may be formed only from plant-derived polyolefin. In this way, if the screw cap C is formed only from plant-derived polyolefin, the biomass content is increased and consideration can be given to the global environment. Examples of petroleum-derived polyolefins include: Petroleum-derived PE (1) Linear low-density polyethylene (LLDPE) Flexural modulus: 270MPa (JIS K 7171), MFR (melt flow rate): 25 (g / 10min, 190℃, 2.16kg), density: 0.926g / cm 3 (Prime Polymer Neozex) Petroleum-derived PE (2) Linear low-density polyethylene (LLDPE) Flexural modulus: 660MPa (JIS K 7171), MFR: 7 (g / 10min, 190℃, 2.16kg), density: 0.945g / cm 3 (Prime Polymer Urutzex) Petroleum-derived PE (3) Low-density polyethylene (LDPE) Flexural modulus 180MPa (JIS K 7171), MFR7 (g / 10min, 190℃, 2.16kg), density 0.921g / cm 3 (Mitsui Dow Polychemicals, Mirason) Either of the above is used.

[0017] Examples of plant-derived polyolefins include: Plant-derived PE Low-density polyethylene (LDPE) Flexural modulus 70MPa (ASTM D790), MFR 8.1 (g / 10min, 190℃, 2.16kg), density 0.918g / cm 3 , biomass content over 95% (Braskem) We are using. In the transition plug cap A used in the evaluation, the aperture α of the opening 3a was 10 mm, and the width β and thickness γ of the thin-walled weakened portion 5 were each 0.2 mm. Next, evaluation tests were conducted on examples of mixed resins with different blend ratios of petroleum-derived PE and plant-derived PE, comparative examples of petroleum-derived PE used in conventional transfer plug caps, and comparative examples of mixed resins with different blend ratios for comparison with the examples. The results are shown and explained in Table 1. In Table 1, the blending ratios are expressed in percent by weight (wt%), and in the openability section, × indicates that the package cannot be opened, and ○ indicates that the package can be opened.

[0018] [Table 1]

[0019] Comparative example 1 was a conventional transition plug cap made of 100% petroleum-derived PE (1). For comparison, when rotated to open, the thin-walled weakened portion 5 broke with an opening torque of 67 [N·cm] (average of three experiments) and could be opened with a normal rotational force (100 [N·cm] or less). The opening torque was measured using a torque meter manufactured by Imada Co., Ltd., and the maximum torque at the time of opening was measured.

[0020] Example 1 was a mixed resin containing 70% petroleum-derived PE (1) and 30% plant-derived PE. When rotated to open, the thin-walled weakened portion 5 broke at an opening torque of 80 [N·cm] (average), and the package could be opened with normal rotational force.

[0021] Comparative Example 2 was made of 100% petroleum-derived PE (3). However, due to the soft resin material with a flexural modulus of 180 MPa and MFR of 7 (g / 10 min), the opening torque exceeded 100 [N cm] when rotating the package when opening, and the package could not be opened with normal rotational force. Comparative Example 3 was a mixture of 70% petroleum-derived PE (3) and 30% plant-derived PE, and was a mixed resin of petroleum-derived PE (3) and a softer plant-derived PE with a flexural modulus of 70 MPa and MFR of 8.1 (g / 10 min). As a result, the opening torque was over 100 N cm, and it could not be opened with normal rotational force.

[0022] Comparative Example 4 is a mixed resin containing 20% ​​petroleum-derived PE (2) and 80% petroleum-derived PE (3). The petroleum-derived PE (2) was fairly hard, with a flexural modulus of 660 MPa and MFR of 7 (g / 10 min). However, the proportion of petroleum-derived PE (3) was too high, so the opening torque was over 100 N cm and it could not be opened with normal rotational force. However, in the mixed resin of Comparative Example 5, which was a blend of 30% petroleum-derived PE (2) and 70% petroleum-derived PE (3), the blend ratio of petroleum-derived PE (2), which has a high flexural modulus, was high, and when rotated to open, the thin-walled weakened portion 5 broke at an opening torque of 77 [N cm] (average), and the package could be opened with a normal rotation force.

[0023] Example 2 is a mixed resin containing 70% petroleum-derived PE (2) and 30% plant-derived PE. When rotated to open, the thin-walled weakened portion 5 broke at an opening torque of 65 [N·cm] (average), and the package could be opened with normal rotational force. Example 3 was a mixed resin containing 50% petroleum-derived PE (2) and 50% plant-derived PE. When rotated to open, the thin-walled weakened portion 5 broke at an opening torque of 81 [N·cm] (average), and the package could be opened with normal rotational force. Example 4 is a mixed resin containing 40% petroleum-derived PE (2) and 60% plant-derived PE. When rotated to open, the thin-walled weakened portion 5 broke at an opening torque of 94 [N·cm] (average), and the package could be opened with normal rotational force.

[0024] However, in the case of a mixed resin containing 30% petroleum-derived PE (2) and 70% plant-derived PE, as in Comparative Example 6, the proportion of plant-derived PE, which has a low flexural modulus, was high, so the opening torque exceeded 100 N·cm and the package could not be opened with normal rotational force. Furthermore, when the package was made of 100% plant-derived PE as in Comparative Example 7, the flexural modulus was too low, so that the opening torque required to rotate the package when opening exceeded 100 [N·cm] and the package could not be opened with normal rotational force.

[0025] From the above, it can be seen that plant-derived PE has a lower flexural modulus than petroleum-derived PE as a low-density polyethylene, and therefore even when it is blended with petroleum-derived low-density polyethylene to form a mixed resin, the thin-walled weakened portion 5 cannot be easily broken to open the package. Furthermore, when the petroleum-derived PE to be blended with the plant-derived PE is linear low-density polyethylene, such as petroleum-derived PE (1) or petroleum-derived PE (2), if the blending rate of plant-derived PE is 60% or more, the flexural modulus of the mixed resin will be too low, making it difficult to break and open the package, so the blending rate of plant-derived PE is preferably 60% or less.

[0026] Furthermore, to form transition plug cap A from a resin material, it is preferable for the fluidity index MFR to be 7 to 9 (g / 10 min). In the above evaluation experiments, the linear low-density polyethylene of petroleum-derived PE (2) had an MFR of 7 (g / 10 min), and the low-density polyethylene of plant-derived PE had an MFR of 8.1 (g / 10 min). A mixed resin containing both has a fluidity index MFR of 7 to 9 (g / 10 min), making it preferable as a resin material for forming transition plug cap A.

[0027] In this way, when forming the transition plug cap A from a mixed resin containing plant-derived low-density polyethylene (Braskem), the MFR, which is the fluidity index of the resin material, is preferably 7 to 9 (g / 10 min). Furthermore, to enable it to be opened with a normal rotational force of 100 [N·cm] or less, it is preferable to select linear low-density polyethylene (2) derived from petroleum (Ultzek, Prime Polymer).

[0028] Furthermore, by adjusting the blending ratio of the petroleum-derived PE (2) and the plant-derived PE, a resin material with a flexural modulus of 70 to 660 MPa can be obtained. However, in order to easily break the thin-walled weakened portion 5 of the transition plug cap A, the opening torque must be 100 [N·cm] or less. For this reason, it is preferable that the blending ratio of the plant-derived PE be 60% or less. [Industrial Applicability]

[0029] The transition stopper cap of the present invention is a transition stopper cap that is attached to the mouth of a container body and comprises a cap body having a removable transition stopper body, and a screw cap that is screwed onto the cap body and can engage the removed transition stopper body.Even if at least the cap body is formed from a resin material containing petroleum-derived polyolefin and plant-derived polyolefin, when the screw cap is rotated in the opening direction, the thin-walled weakened portion breaks, allowing the transition stopper body to be removed from the cap body and transferred to the screw cap.This makes it possible to utilize plant-derived resin materials and is suitable as a transition stopper cap that can be widely used for containers of food, beverages, seasonings, etc. [Explanation of symbols]

[0030] A Transfer stopper cap B Cap body C Screw Cap α caliber β width γ Thickness 1. Mounting part 2 Threaded wall 3 Bulkhead 3a aperture 4 Pour tube 5 Thin weakened part 6 Transition plug 10 Peripheral cylinder 11 Bottom wall 12 Fitting recess (first fitting portion) 20 Top Wall 21 Outer wall 22 Attachment 23 Closed envelope section 24 Threaded cylinder 25 Fitting protrusion (second fitting portion)

Claims

1. A transition stopper cap is provided which is fitted to the mouth of a container body and has a cap body having a removable transition stopper body, and a screw cap which is screwed to the cap body and can engage with the removed transition stopper body when the cap is opened by turning the cap, A transfer plug cap, characterized in that at least a cap body is formed from a resin material containing 40% by weight or more of petroleum-derived polyolefin and 60% by weight or less of plant-derived polyolefin.

2. 2. The transfer plug cap of claim 1, wherein the plant-derived polyolefin comprises a plant-derived low-density polyethylene.

3. 3. The transfer plug cap according to claim 1, wherein the petroleum-derived polyolefin comprises petroleum-derived linear low-density polyethylene.

4. 4. The transfer plug cap according to claim 3, wherein the petroleum-derived linear low-density polyethylene and the plant-derived low-density polyethylene have a melt flow rate of 7 to 9.

5. 5. The transfer plug cap according to claim 3, wherein the petroleum-derived linear low-density polyethylene and the plant-derived low-density polyethylene have a flexural modulus of elasticity of 70 to 660 MPa.

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