JP7621809B2 - Hinge Cap - Google Patents

Description

The present invention relates to a hinge cap, and in particular to a hinge cap with improved adhesion and bonding properties.

Conventionally, hinge caps that are attached to container bodies have been widely used in which a partition wall with a cork removal section defined by a thin, weakened section is provided on the cap body that is attached to the mouth of the container body to keep the inside of the container sealed until it is opened, and the cork removal section is opened by pulling up on it with a pull ring to open the spout.

In addition, in order to keep the inside of a container clean, the container body may be filled with a liquid content heated to a high temperature for sterilization and then capped, or the container may be capped and then sterilized by heating to a high temperature from the outside. For this reason, hinge caps have been known that prevent the cap from coming off the container body even if the inside of the container body becomes hot and the pressure rises (see, for example, Patent Document 1).

JP 2009-179385 A

As shown in FIG. 4, the hinge cap described in Patent Document 1 above has a U-shaped connection between the periphery of the partition 100 and the lower part of the inner tube 101 with a connecting wall 102 so that the inner tube 101 of the cap body Ao, which is in close contact with the inner circumference of the mouth 1, will not come loose even if the partition 100 of the cap body Ao that closes the mouth 1 of the container body D is pressed from below due to an increase in pressure inside the container body D after the cap is plugged. The connecting wall 102 prevents the inner tube 101 from deforming, ensures close contact with the inner circumference of the mouth 1, and prevents the plugged hinge cap from coming loose from the container body D.

However, the hinge cap described in Patent Document 1 above requires that the inner tube 101 and the connecting wall 102 be formed in a U-shape in order to ensure close contact between the inner tube 101 of the cap body Ao and the mouth 1 of the container body D, which increases the amount of resin used.

The present invention aims to solve the above problems by providing a hinge cap that can ensure adhesion between the mouth of the container body and the cap body without increasing the amount of resin used, and that will not come off the mouth of the container body even if the internal pressure rises.

In order to solve the above-mentioned problems, the present invention provides a hinge cap comprising a cap body to be attached to the mouth of a container body and a top lid connected to the cap body via a hinge, wherein the cap body comprises a partition wall that seals the mouth of the container body and a mounting part that is connected to the outer edge of the partition wall and is attached to the mouth, and the mounting part comprises an inner tube whose outer periphery is in close contact with the inner periphery of the mouth of the container body, and the hinge cap is molded from a resin in which low-density polyethylene is a base resin blended with a polyolefin-based adhesive resin as a mixed resin, the base resin being linear low-density polyethylene, and 5 to 50% by weight of maleic acid-modified polyethylene is blended as the mixed resin relative to the total amount of resin, so that the outer periphery of the inner tube of the mounting part of the cap body is in close contact with the inner periphery of the mouth of the container body with added adhesiveness.

As an embodiment of the hinge cap, a configuration is adopted in which the mixed resin is blended at 10 to 30% by weight, the partition wall is defined by a breakable thin-walled weakened portion and has a pull-out portion that opens the spout and a pull ring provided on the upper surface of the pull-out portion via a support, and the partition wall is defined by a breakable thin-walled weakened portion and has a transition plug portion that opens the spout and a pull-up wall erected on the upper surface of the transition plug portion, and the top cover has a top wall that engages with the pull-up wall of the transition plug portion by ultrasonic welding.

The hinge cap of the present invention is molded from a resin in which a low-density polyethylene base resin is blended with a polyolefin-based adhesive resin as a mixed resin, and the base resin is linear low-density polyethylene. By blending 5 to 50% by weight of maleic acid-modified polyethylene as the mixed resin relative to the total amount of resin , the outer periphery of the inner tube of the attachment part of the cap body is adhered to the inner periphery of the mouth of the container body with added adhesiveness, so that adhesion to the inner periphery of the mouth can be ensured without increasing the amount of resin used, and the cap body can be prevented from coming off the mouth of the container body during high-temperature filling.

In addition, the hinge cap of the present invention is molded from a resin in which a polyolefin-based adhesive resin is blended as a mixed resin with a low-density polyethylene base resin, and the base resin is linear low-density polyethylene. By blending 5 to 50% by weight of maleic acid-modified polyethylene as the mixed resin relative to the total amount of resin , when the pull-up wall erected on the upper surface of the transition plug portion is ultrasonically welded to the top wall of the upper lid, the adhesion is strengthened, thereby increasing the fusion strength and preventing the pull-up wall of the transition plug portion from peeling off from the top wall of the upper lid.

1 is a side cross-sectional view of a hinge cap according to a first embodiment of the present invention; 1A and 1B are diagrams showing a hinge cap according to a first embodiment of the present invention in an open state, in which FIG. FIG. 11 is a diagram showing a hinge cap according to a second embodiment of the present invention, in which (a) is a side cross-sectional view of the closed lid after molding, and (b) is an enlarged view of the main part of (a) after the transition plug portion has been processed to prevent it from slipping out of the upper lid. FIG. 1 is a side cross-sectional view of a hinge cap according to a conventional example of the present invention.

Next, the hinge cap of the present invention will be described with reference to the drawings in the following embodiments.
In the following description, in FIG. 1 , the left side is the "front side (opposite the hinge)", the right side is the "rear side (hinge side)", the upward direction is the "upper", and the downward direction is the "lower".

In Figs. 1 and 2, A denotes a cap body that is attached to a container body D, and B denotes an upper lid that connects the cap body A with a hinge C and opens and closes.
The container body D has a mouth portion 1 at the top, and an engaging ridge 2 is provided on the outer periphery of the mouth portion 1.

The cap body A is composed of a partition wall 5 that seals the mouth 1 of the container body D, a pouring tube 6 that stands upright from the upper surface of the outer edge of the partition wall 5, and an attachment part 7 that is connected to the outer edge of the partition wall 5 and is attached to the mouth 1.

The partition 5 has an uncorking section 10 defined by a breakable thin-walled weakened section 9 on the inner periphery of the pouring tube 6 to open the pouring outlet when in use, and the uncorking section 10 has a pull ring 11 attached to a support 12 on the top surface of the hinge C side.

The mounting portion 7 comprises a ring-shaped upper wall 14 connected to the outer peripheral edge of the partition 5, an inner tube 15 suspended from the underside of the inner edge of the upper wall 14 and whose outer periphery is inserted into the inner periphery of the mouth 1 of the container body D, an outer tube 16 connected to the outer edge of the upper wall 14 and whose inner periphery engages with the outer periphery of the mouth 1, a lid engagement cylindrical portion 17 erected from the upper surface of the upper wall 14, and a lid abutment cylindrical portion 18 erected from the outer edge of the upper wall 14, and a lid locking protrusion 19 is provided at the outer peripheral upper end of the lid engagement cylindrical portion 17.
An engaging protrusion 20 that engages with the engaging protrusion 2 of the mouth portion 1 is provided on the inner periphery of the outer cylinder 16 .

As shown in FIG. 2( a ), an outer tube 16 has an outer peripheral cutout 21 that is approximately V-shaped in plan view cut from above near either the left or right side of the hinge C, and a slit groove 22 is recessed from above so as to extend a predetermined range in the circumferential direction on the back side (hinge C side) starting from a position separated by a thin-walled portion at the upper part on the inner peripheral side of the outer peripheral cutout 21.
Therefore, when the top lid B is pulled down via the hinge C when the hinge cap is disposed of, the outer peripheral cut portion 21 forms a vertical tear line and the slit groove 22 forms a circumferential tear line, the outer tube 16 is broken circumferentially starting from the outer peripheral cut portion 21, and the engagement between the engaging protrusion 20 of the broken portion and the mouth 1 of the container body D is released, allowing the hinge cap to be easily pulled off from the container body D and separated for disposal.

The top lid B is composed of a flat top wall 25, a side peripheral wall 26 hanging down from the periphery of the top wall 25, a sealing tube 27 hanging down from the underside of the top wall 25, the outer periphery of which comes into close contact with the inner periphery of the pouring tube 6 of the cap body A when the lid is closed, sealing the inside of the pouring tube 6, and an engagement tube 28 hanging down from the outside of the sealing tube 27, the inner periphery of which engages with the outer periphery of the lid engagement tube 17 of the cap body A when the lid is closed, and the lower surface of which abuts against the upper surface of the lid abutment tube 18.

An arcuate knob 29 is provided on the outer periphery of the side peripheral wall 26 at the lower end on the front side, and a hinge C is connected to the lower end on the rear side.
The engaging cylinder 28 has an engaging portion 30 at its inner circumferential lower end that engages with the lid engaging projection 19 of the lid engaging cylinder portion 17 to maintain the lid in the closed state.
In addition, the hinge cap of this embodiment may have a shrink label, a sealing member, or the like provided between the cap body A and the top lid B to prevent unauthorized opening before use.

The hinge cap of the present invention has improved flexibility and adhesion by being molded using a resin in which a low-density polyethylene base resin is blended with a polyolefin-based adhesive resin as a mixed resin in a predetermined mixing ratio.
In this embodiment, a low-density polyethylene such as linear low-density polyethylene (LLDPE) is used as the base resin, and a maleic acid-modified polyethylene (maleic acid-modified PE) is used as the polyolefin-based adhesive resin. Examples of maleic acid-modified PE include Modic (registered trademark) from Mitsubishi Chemical Corporation and Admer (registered trademark) from Mitsui Chemicals, Inc.

Next, the manner of use and the effects of this embodiment will be described.
First, as shown in FIG. 2, in the open state, the hinge cap of this embodiment is molded by using a resin in which a cap body A, a top cover B and a hinge C are blended with LLDPE as a base resin and maleic acid-modified PE as a mixed resin as an adhesive resin.
After molding the hinge cap, the top cover B is closed onto the cap body A, and the mouth 1 of the container body D is plugged as shown in FIG.

In order to evaluate the heat resistance, opening property and moldability of the hinge cap of this embodiment, comparative experiments were carried out by varying the compounding ratio of the base resin and the adhesive resin. The results are shown in Table 1.
In a comparative experiment, a hinge cap was manufactured by injection molding using linear low density polyethylene (LLDPE) as the base resin of the hinge cap and maleic acid modified polyethylene (maleic acid modified PE) as the mixed resin.
Base resin: LLDPE (Prime Polymer 25200J)
Mixed resin: Maleic acid modified polyethylene (Modic M506, manufactured by Mitsubishi Chemical Corporation)
Blending ratio: Weight% (wt%)

"Heat resistance" was determined by filling the container body D with a liquid content heated to 85°C for sterilization or the like, and then fitting a hinge cap, and checking the tightness of the seal between the inner circumference of the mouth 1 of the container body D and the outer circumference of the inner tube 15 of the attachment part 7 of the cap body A (decompression test/drop test). Those in which tightness was ensured in all tests were given an "O", those in which tightness was generally ensured were given an "△", and those in which tightness was not ensured in any of the tests were given an "X".
"Openability" was determined using a push-pull gauge to confirm whether the thin-walled weakened portion 9 could be broken and the uncorking portion 10 could be opened from the bulkhead 5 without any problems with an opening strength of around 20N (the general strength used when opening). Those that could be opened were marked with "O" and those that could not be opened (significantly exceeding 20N) were marked with "X".
Regarding "moldability," those which could be molded without any problems were rated "◯," those which could be molded with almost no problems were rated "△," and those which could not be molded were rated "×."

Experimental Example 1 is a reference example in which only the base resin is used without blending any mixed resin.
In Experimental Examples 2 to 6, the base resin LLDPE was blended with the adhesive resin maleic acid-modified polyethylene at 5 wt%, 10 wt%, 20 wt%, 30 wt%, and 50 wt%, respectively, as a mixed resin, and the adhesive resin blended into the resin increased the flexibility and adhesion of the hinge cap.
In the above experimental examples 7 and 8, the base resin LLDPE was blended with 60% by weight and 70% by weight of maleic acid modified polyethylene as a mixed resin. When the blending ratio of adhesive resin is high, the resin of the hinge cap becomes too warm and soft when the container is filled at a high temperature after plugging, and it is no longer able to maintain its shape, causing the hinge cap to easily come loose.
Furthermore, if the resin of the hinge cap becomes too soft, it will become impossible to break the thin weakened portion 9 to open the package, and the adhesiveness will become too strong, making it difficult to release the package from the mold during molding, resulting in poor moldability.
For these reasons, the mixing ratio of the maleic acid modified polyethylene to be blended with the LLDPE is preferably 5 to 50% by weight, more preferably 10 to 30% by weight, based on the total amount of the resin.

The resin blended with the adhesive resin in the preferred ratio of this embodiment has a good balance of shape retention, flexibility, and adhesion, and the flexibility and adhesion are also added to the inner tube 15 of the mounting part 7 of the cap body A. Therefore, unlike the conventional hinge cap made only of LLDPE shown in Figure 4, where a connecting wall 102 is provided between the inner tube 101 and the partition wall 100 and the inner tube 101 is processed into a U-shape and pressed outward to seal, it is possible to ensure adhesion between the inner circumference of the mouth 1 of the container body A and the outer circumference of the inner tube 15, and the amount of resin used can be reduced compared to the conventional method.

When using the hinge cap, after opening the top lid B, a finger is hooked on the pull ring 11 on the partition 5 and pulled to break the thin-walled weakened portion 9 via the support 12, thereby opening the uncorking portion 10 from the partition 5, and an opening is made in the partition 5 to pour out the liquid contents in the container body D through the pouring tube 6.
Furthermore, after all the liquid content has been used, by pulling down the top lid B via the hinge C, the hinge cap can be easily detached from the container body D and separated for disposal.

Next, a second embodiment in which the cap body A and the top cover B of the first embodiment are modified will be described.
In the following, the same components as those in the first embodiment are given the same reference numerals, and only different components are given different reference numerals, and differences will be mainly described.

In FIG. 3, Aa denotes a cap body that is attached to a container body D, and Ba denotes an upper lid that connects the cap body Aa with a hinge C and opens and closes.
The container body D has a mouth portion 1 at the top, and an engaging ridge 2 is provided on the outer periphery of the mouth portion 1.

The cap body Aa is composed of a partition 35 that seals the mouth 1 of the container body D, a pouring tube 36 that stands upright from the upper surface of the outer edge of the partition 35, and an attachment part 37 that is connected to the outer edge of the partition 35 and is attached to the mouth 1.

The partition 35 is provided with a transition plug portion 40 defined by a breakable thin-walled weakened portion 39 on the inner peripheral side of the pouring tube 36 in order to open the pouring outlet during use.
The transition plug portion 40 has a bottom wall 41 connected to the partition wall 35 via a thin-walled weakened portion 39, and an approximately cylindrical pull-up wall 42 is erected on the upper surface of the bottom wall 41 on the front side, and a retaining upright wall 43 is erected along the thin-walled weakened portion 39 on the hinge C side.
A reinforcing rib 44 is provided on the hinge C side of the lifting wall 42 from its upper portion toward the upper surface of the bottom wall 41 .

As shown in FIG. 3A , a mountain-shaped locking protrusion 46 is provided on the upper surface of the lifting wall 42 via a step portion 45 so as to cover the lifting wall 42 .
In this embodiment, the upper surface of the locking projection 46 is flat, but it may be rounded.

The mounting portion 37 is suspended from the outer edge of the partition wall 35 and includes an inner tube 15 whose outer circumference is inserted into the inner circumference of the mouth 1 of the container body D, an outer tube 16 whose inner circumference engages with the outer circumference of the mouth 1, and an annular lid engaging portion 47 connected to the upper ends of the inner tube 15 and outer tube 16, and an annular bulge 48 that protrudes outward is provided at the top of the lid engaging portion 47.

The top cover Ba is rotatably attached to the outer periphery of the outer tube 16 of the cap body Aa via a hinge C, and has a flat top wall 50 and a side wall 51 depending down from the periphery of the top wall 50 .
On the underside of the top wall 50, there are provided a sealing tube 52 whose outer periphery is in close contact with the inner periphery of the pouring tube 36 of the cap body Aa when the lid is closed, an engagement wall 53 is provided on the inside of the sealing tube 52 near the front side, and a retaining receiving wall 54 on the inside hinge C side of the sealing tube 52, whose lower inner periphery fits into the upper outer periphery of the retaining vertical wall 43 of the transition plug portion 40, and further, an engagement hole portion 55 is opened in the top wall 50 which communicates with the inner surface of the engagement wall 53.

The inner peripheral surface of the engagement wall 53 is inclined to match the outer peripheral surface of the lower portion of the locking projection 46, and the lower surface is adapted to abut or come close to the step 45 on the upper surface of the lifting wall 42 when the lid is closed.
An engagement portion 56 is provided on the inner circumferential upper surface of the engagement wall 53 , and the lower surface of the engagement hole portion 55 is formed thereon.

In this embodiment, as shown in FIG. 3(a), when the cap is initially closed, the upper part of the locking protrusion 46 of the transition plug portion 40 of the cap body Aa reaches the engagement hole portion 55, and subsequent anti-slip processing by ultrasonic welding causes the upper part of the locking protrusion 46 to expand so as to fill the engagement hole portion 55, as shown in FIG. 3(b), and the locking protrusion 46 engages with the engagement portion 56 on the upper surface of the engagement wall 53.
An arc-shaped knob 58 is provided on the outer periphery of the lower end of the front side of the side wall 51, and an annular locking groove 59 is provided near the lower end of the inner surface of the side wall 51 into which the bulge 48 of the lid engagement portion 47 fits to maintain the lid in a closed state.

Next, the manner of use and the effects of this embodiment will be described.
The hinge cap of this embodiment manufactured by integral molding is obtained in an open state, and the top cover Ba is rotated via the hinge C to be in the closed state shown in FIG. 3(a).
At that time, the upper locking protrusion 46 of the pull-up wall 42 of the transition plug portion 40 of the cap body Aa enters into the engagement wall 53 of the upper cover Ba, with its upper portion reaching the engagement hole portion 55, and the lower outer periphery of the locking protrusion 46 fitting within the inner periphery of the engagement wall 53, and further, the lower surface of the engagement wall 53 abuts or comes into close proximity to the step portion 45 of the pull-up wall 42.

Next, the upper portion of the locking projection 46 is ultrasonically welded to prevent it from coming loose, as shown in FIG. 3B, so that the deformed locking projection 46 engages with the inner periphery of the engagement hole 55 of the top cover Ba and the upper surface of the engagement wall 53.
Furthermore, when the lid is closed, the outer periphery of the retaining vertical wall 43 of the transition plug portion 40 engages with the inner periphery of the retaining receiving wall 54 of the upper lid Ba, thereby attaching the transition plug portion 40 of the cap body Aa to the inside of the top wall 50 of the upper lid Ba.
The closed hinge cap is attached to the mouth 1 of the container body D filled with the liquid content.

When using the hinge cap of this embodiment for the first time, first, hook your fingers on the knob 58 of the top lid Ba and lift the knob 58. The top lid Ba opens using the hinge C as a fulcrum, and the locking protrusion 46 of the transition plug portion 40 attached to the top lid Ba is pulled, causing the transition plug portion 40 itself to be lifted from the front side, and the thin-walled weakened portion 39 connected to the partition wall 35 to break from the front side. By further lifting the top lid Ba, the breakage of the thin-walled weakened portion 39 progresses in the direction of the hinge C, and finally, the transition plug portion 40 is removed from the partition wall 35 and transferred to the top lid Ba.
In the partition 35 of the cap body Aa, the site of the removed transfer plug portion 40 serves as a pouring outlet, allowing the content liquid in the container body D to be poured out.

The hinge cap of this embodiment is manufactured by injection molding using resins that are blended by varying the compounding ratio of the base resin LLDPE and the mixed resin maleic acid modified polyethylene, as in the first embodiment, and the results of the openability (in this embodiment, the results of checking whether the thin-walled weakened portion 39 can be broken and the transition plug portion 40 can be opened from the bulkhead 35 without any problems at an opening strength of around 20 N) and moldability were the same as those in Table 1.

Table 2 shows the results of comparative experiments in which the compounding ratio of the base resin and adhesive resin of the hinge cap was changed, and the upper part of the locking protrusion 46 of the transition plug portion 40 was welded using an ultrasonic welding machine (manufactured by Seidensha Electronics Co., Ltd.) to prevent it from coming loose.Then, with the transition plug portion 40 fixed, when the top lid Ba was opened, the fusion strength at which the locking protrusion 46 of the transition plug portion 40 peeled off from the top lid Ba was measured.
"Welding strength" is the strength required to open a package without any problems, which is 20N when opened. If a safety factor of two is assumed, the welding strength is 40N. Packages that do not peel off even when they exceed 40N are marked "O", packages that do not peel off at 40N are marked "△", and packages that peel off at less than 40N are marked "X". The number in the lower row is the strength at which they peel off (unit: N).

From the experimental results in Table 2, it can be seen that increasing the proportion of maleic acid-modified polyethylene mixed with the base resin LLDPE increases the flexibility of the hinge cap and the "fusion strength," making it more difficult for the locking protrusion 46 of the transition plug portion 40 to peel off from the top lid Ba.
In this example, taking into consideration the experimental results of "openability" and "moldability" in Table 1 and taking into account the openability, fusion strength, and moldability, the blending ratio of maleic acid-modified polyethylene to be blended with LLDPE is preferably 5 to 50% by weight, and more preferably 10 to 30% by weight, based on the total amount of resin.

The hinge cap of the present invention is made from a resin that is a blend of a low-density polyethylene base resin and a polyolefin adhesive resin as a mixed resin, resulting in a material with excellent flexibility and adhesiveness, making it particularly suitable as a hinge cap to be used by sealing the mouth of a container body that is filled at high temperature.

A, Aa, Ao Cap body B, Ba Top lid C Hinge D Container body 1 Mouth 2 Engagement protrusion 5, 35, 100 Partition 6, 36 Spout tube 7, 37 Mounting portion 9, 39 Thin-walled weakened portion 10 Plug removal portion 11 Pull ring 12 Support 14 Top wall 15, 101 Inner tube 16 Outer tube 17 Lid engagement tube portion 18 Lid abutment tube portion 19 Lid engagement protrusion 20 Engagement protrusion 21 Outer peripheral cut portion 22 Slit groove 25, 50 Top wall 26, 51 Side peripheral wall 27, 52 Sealing tube 28 Engagement tube 29, 58 Knob 30 Engagement portion 40 Transfer plug portion 41 Bottom wall 42 Pull-up wall 43 Retaining wall 44 Reinforcement rib 45 Step portion 46 Engagement protrusion 47 Lid engagement part 48 Swelling part 53 Engagement wall 54 Holding wall 55 Engagement hole 56 Engagement part 59 Locking groove 102 Connection wall

Claims (4)

A hinge cap including a cap body attached to the mouth of a container body and a top lid connected to the cap body via a hinge,
The cap body includes a partition wall that closes the mouth of the container body, and a mounting part that is connected to an outer edge of the partition wall and is mounted on the mouth,
The mounting portion has an inner tube whose outer periphery fits closely to the inner periphery of the mouth of the container body,
The hinge cap is made of a resin that is a blend of low-density polyethylene as the base resin and polyolefin adhesive resin as the mixed resin.
The base resin is linear low-density polyethylene, and maleic acid-modified polyethylene is blended as a mixed resin in an amount of 5 to 50% by weight based on the total amount of the resin.
A hinge cap characterized in that the outer periphery of the inner cylinder of the mounting portion of the cap body is closely adhered to the inner periphery of the mouth of the container body with the aid of adhesiveness. 2. The hinge cap according to claim 1, wherein the mixed resin is blended in an amount of 10 to 30% by weight . The hinge cap according to claim 1 or 2, characterized in that the partition is defined by a breakable thin-walled weakened portion, and is provided with a plug-removal portion that opens the spout, and a pull ring provided on the upper surface of the plug-removal portion via a support . The partition wall is defined by a breakable thin-walled weakened portion, and includes a transition plug portion that opens the spout, and a lift-up wall that is erected on the upper surface of the transition plug portion;
3. The hinge cap according to claim 1 , wherein the top cover has a top wall that is engaged with the lift-up wall of the transition plug portion by ultrasonic welding .

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