JP2012066834A - In-mold label container, and in-mold label container with lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thinned in-mold label container, especially an in-mold label container in which strength of a flange is increased and sealing performance between the flange and a lid is excellent.SOLUTION: The in-mold label container 10 includes: a trunk 1; the flange 4 formed on an upper end of the trunk 1; and a bottom 3 connected to the trunk 1. A belt-like label 5 extends from an outer surface of the trunk 1 to the flange 4. A thickness of the trunk 1 is 0.30 to 0.50 mm, and a thickness of the flange 4 is 1.4 to 2.1 times the thickness of the trunk 1. On un upper surface of the flange 4, a plurality of annular ribs 9 projecting upward are formed.

Description

  The present invention relates to an in-mold label container and an in-mold label container with a lid, and more specifically, with an in-mold label container and a lid having excellent drop strength and excellent sealing properties even if light and thin. The present invention relates to an in-mold label container.

  In recent years, in-mold label containers have been widely used as containers for containing beverages and solids. In-mold label containers have many advantages such as being lighter and more formable than other glass containers and metal containers, but there is a need for further lighter containers.

  The in-mold label container is formed into a desired shape by injection molding or blow molding. For example, when a plastic container having a truncated cone shape is formed by injection molding, a container having a desired shape can be formed by pouring molten resin into a mold and cooling and solidifying the resin. To reduce the weight of the container, it can be realized by reducing the amount of resin poured into the mold of the injection molding machine and making the container thinner.

JP 2006-315726 A JP 2009-227316 A

  However, a thinned in-mold label container has a problem of poor mechanical strength. In particular, since the weight of the container increases when the contents are stored in the in-mold label container, if the container falls while the contents are stored, the vicinity of the flange in the container may be damaged. It was.

  The present invention has been made in consideration of the above points, and has an in-mold label container having a flange having excellent drop strength even when being light and thin, and having excellent sealing performance with a lid, and a lid. It aims at providing the in-mold label container with a material.

  The present invention, in an in-mold label container composed of a label and an injection resin injected on the surface of the label, includes a body, a flange provided at the upper end of the body, and a bottom connected to the body. The label extends from the outer surface of the body part to the flange, the thickness of the body part is 0.30 to 0.50 mm, and the thickness of the flange is 1.4 to 2.1 times the thickness of the body part. A plurality of annular ribs projecting upward are provided on the upper surface of the flange.

  The present invention is an in-mold label container characterized in that 2 to 6 annular ribs projecting upward are provided on the upper surface of the flange.

  The present invention is an in-mold label container with a lid material comprising the in-mold label container described above and a lid material bonded to the upper surface of the flange of the in-mold label container.

  As described above, according to the present invention, since the thickness of the body portion is 0.30 to 0.50 mm, the weight of the entire in-mold label container can be reduced, and the thickness of the flange can be reduced. By making the thickness 1.4 to 2.1 times the thickness of the part, the mechanical strength of the flange can be improved. Furthermore, by providing a plurality of annular ribs on the top surface of the flange, the flatness of the top surface of the flange can be improved, and when the cover material is bonded to the top surface of the flange, the sealing performance between the flange and the cover material can be improved. it can.

FIG. 1 is an overall side sectional view showing an embodiment of an in-mold label container and an in-mold label container with a lid according to the present invention. FIG. 2 is an enlarged side cross-sectional view showing a body portion and a flange of an in-mold label container. FIG. 3 is a plan view showing a flange of the in-mold label container. FIG. 4 is a side sectional view showing an injection resin and a label. FIG. 5 is a diagram showing a side drop test.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 are views showing an embodiment of an in-mold label container and an in-mold label container with a lid according to the present invention.

  As shown in FIG. 1, the in-mold label container 10 includes a body 1, a flange 4 provided at the upper end of the body 1, a bottom 3 connected to the body 1, and a peripheral edge 3 a of the bottom 3 downward. And a protruding thread end 2.

  The body portion 1 of the in-mold label container 10 includes a belt-like label 5 that is wound and an injection resin 6 that is injected onto the surface of the belt-like label 5. Further, the belt-like label 5 extends upward from the outer surface of the body portion 1 toward the flange 4 side and also extends toward the yarn tail portion 2 side. As described above, the yarn bottom portion 2 and the flange 4 include the strip-shaped label 5 and the injection resin 6 on the strip-shaped label 5.

That is, as the belt-like label 5, a label composed of at least two layers of a printing base material layer and a heat seal layer can be used, and a gas barrier layer can be provided as necessary. For example, the following layer structure can be used. The numbers indicate the thickness of each layer.
(1) OPP (stretched polypropylene) 20 μ / VMPET (aluminum-deposited polyethylene terephthalate) 12 μ / OPP (stretched polypropylene) 20 μ, or (2) OPP 30 μ / VMPET 12 μ / OPP 30 μ
(3) OPP 30μ / OPP 30μ
(4) OPP 30μ / AL (aluminum foil) 7μ / OPP 30μ
(5) OPP 30μ / PET (polyethylene terephthalate) 12μ / OPP 30μ

  As shown in FIG. 4, the strip-shaped label 5 has an OPP layer 5a, a VMPET layer 5b, and an OPP layer 5c. Of these, the OPP layer 5a is a heat seal layer, and the VMPET layer 5b and the OPP layer 5c. Are non-heat-sealing layers that function as a gas barrier layer and a printing substrate layer, respectively.

As shown in FIGS. 1 and 2, a plurality of, for example, four annular ribs 9 projecting upward are provided on the upper surface of the flange 4. Furthermore, it is preferable that the thickness l ₂ of the trunk portion 1 is 0.30 to 0.50 mm as described later.

Further, as shown in FIG. 2, the thickness l ₁ of the flange 4, the relationship between the thickness l ₂ of the body 1,
It is preferable that 1.4 × l ₂ ≦ l ₁ ≦ 2.1 × l ₂ is satisfied.

  The in-mold label container 10A having a lid material is filled by filling the in-mold label container 10 having such a configuration with contents (not shown) and bonding the lid material 11 to the upper surface of the flange 4 by heat sealing. Is obtained.

In the in-mold label container 10, the body portion 1 occupies most of the area, and the thickness l ₂ of the body portion 1 is dominant in weight. In the current in-mold label container 10, the thickness l ₂ of the body portion 1 is generally 0.50 to 0.80 mm. As described above, by setting the thickness l ₂ of the body portion 1 to 0.30 to 0.50 mm, the in-mold label container 10 can be reduced in weight while maintaining the moldability of the in-mold label container 10. be able to.

That is, when the thickness l ₂ of the body portion 1 is less than 0.30, the injection resin cannot be sufficiently distributed in the molding die, and it is difficult to mold the in-mold label container 10 itself.

On the other hand, when the thickness l ₂ of the body part 1 is 0.50 mm or more, it is difficult to reduce the weight of the entire in-mold label container 10.

Moreover, the mechanical strength of the flange 4 can be improved by setting the thickness l ₁ of the flange 4 to 1.4 to 2.1 times the thickness l ₂ of the body 1.

That is, if the thickness l ₁ of the flange 4 is less than 1.4 times the thickness l ₂ of the body 1, the mechanical strength of the flange 4 cannot be improved. In particular, when a side drop test is performed on the in-mold label container 10, breakage occurs in the flange 4 particularly in the vicinity of the end face 5A of the strip-shaped label 5 (FIG. 5). This is because the end surface 5A of the belt-like label 5 does not adhere to the injection resin 6, and the boundary between the end surface 5A and the injection resin 6 plays a role like a notch.

On the other hand, when the thickness l ₁ of the flange 4 is 1.4 times or more than the thickness l ₂ of the body portion 1, the injection resin 6 becomes difficult to reach the flange 4 portion of the molding die. A non-uniformity occurs in the filling density of the injection resin 6. This is because the injection resin 6 is injected from the bottom 3 side, so that the injection resin 6 reaches the flange 4 after passing through the body portion 1. As a result, sink marks (dents) occur at locations where the filling density of the flange 4 is low, and the flatness of the upper surface of the flange 4 deteriorates. When the flatness of the upper surface of the flange 4 is deteriorated, a problem occurs in the appearance of the flange 4, and when the lid member 11 is bonded to the upper surface of the flange 4 by heat sealing, the sealing performance between the flange 4 and the lid member 11 is improved. Problems can also arise. This is because the upper surface of the flange 4 is melted and flattened to some extent by the heat of the heat seal, but sink marks are randomly generated on the upper surface of the flange 4 and the depths thereof are not uniform, so that the flattening is not completely achieved. However, in the present invention, sink marks on the upper surface of the flange 4 can be suppressed by providing the annular rib 9 on the upper surface of the flange 4 as described later. When the thickness l ₁ of the flange 4 is 2.1 times or more than the thickness l ₂ of the body portion 1, the injection resin 6 is solidified before it reaches the flange 4 portion of the molding die, It cannot be molded.

According to the present invention, the in-mold label container 10 can be reduced in weight by setting the thickness l ₂ of the body portion 1 to 0.30 to 0.50 mm, and the thickness l ₁ of the flange 4 can be reduced. The mechanical strength of the flange 4 can be improved by setting the thickness l ₂ of the body portion 1 to 1.4 to 2.1 times.

  Further, a plurality of, for example, four annular ribs 9 projecting upward are provided on the upper surface of the flange 4. In this case, by providing the four annular ribs 9 on the upper surface of the flange 4, even if the thickness of the flange 4 is increased, the area of the flat surface on the upper surface of the flange 4 can be suppressed. Flatness can be maintained well.

  Since each annular rib 9 is continuously formed on the upper surface of the flange 4, when the lid member 11 is bonded to the upper surface of the flange 4 by heat sealing, the entire circumferential direction between the annular rib 9 and the lid member 11 is reduced. Can be bonded over the circumference. For this reason, the sealing performance between the upper surface of the flange 4 and the lid member 11 can be improved.

  When the lid 11 is bonded to the upper surface of the flange 4 by heat sealing, each annular rib 9 is generally crushed by a heat sealing device (not shown) and flattened on the flange 4.

Next, the structure of each part of the in-mold label container 10 will be described in detail. As the shape of the in-mold label container 10, the overall height of the container is preferably 90 to 120 mm, the outer diameter of the flange 4 is 50 to 100 mmφ, and the thickness l ₂ of the body 1 is preferably 0.30 to 0.50 mm. The thickness l ₁ of the flange 4 is 1.4 to 2.1 times the thickness l ₂ of the body 1.

  As shown in FIG. 1, the entire bottom section 3 has a convex shape that protrudes in the direction of the yarn bottom 2. Thus, since the bottom part 3 has the convex shape which protrudes below a container, the force which acts on the downward direction (gravity direction) of the bottom part 3 is disperse | distributed to the inner side of the trunk | drum 1, and generation | occurrence | production of distortion is suppressed. Is done. Moreover, since the trunk | drum 1 thru | or the thread | yle bottom part 2 will be pressed on the bottom part 3 by the force of the trunk | drum 1 inner side direction, the periphery 3a of the bottom part 3 will not be damaged by the impact at the time of dropping.

  The bottom portion 3 is formed such that an angle θ formed by the cross section of the trunk portion 1 and the cross section of the bottom portion 3 is an obtuse angle at the intersection (the peripheral edge 3a of the bottom portion 3) between the trunk portion 1 and the bottom portion 3. By making the bottom part 3 convex so that the peripheral edge 3a of the bottom part 3 has a downward curvature of the container, the stress in the gravitational direction acting on the bottom part 3 is dispersed in the inner direction of the body part 1 to suppress the occurrence of distortion. Is done.

  Moreover, it is preferable that the thread | yarn bottom part 2 is formed in the taper shape so that a lower end may be thin and it may become thick gradually toward the bottom part 3 direction. In this way, by forming the thread tail portion 2 in a tapered shape, the mold releasability can be improved while making the bottom portion 3 convex so that the in-mold label container 10 has a downward curvature. That is, if the yarn bottom portion 2 is not formed in a tapered shape, the yarn bottom portion 2 may be caught by the mold when the container 10 is released from the mold during container molding. The taper is preferably such that the slope γ of the side surface inside the container 10 of the yarn bottom 2 is 1 to 2 °. Moreover, it is preferable that the yarn bottom part 2 shall be 2.0-5.0 mm in height, and 0.6-0.8 mm in thickness.

  Further, in the present invention, the body 1 of the container 10 may have an inclination, and a horizontal stack rib that is convex inward may be provided on the inner peripheral surface below the body 1. Since the stack rib is provided in a horizontal direction that is convex on the inner peripheral surface below the side portion, when stacking empty containers 10 having an inclination on the body 1, the thread rib portion 2 of the container is placed on the stack rib. Since it does not fit tightly, so-called stacking separation is good and suitability of the filling machine can be improved.

  Therefore, by adopting the above-described configuration, the productivity of the transparent in-mold label container 10 is further improved in terms of impact resistance and also in terms of moldability, heat resistance, water resistance, and food safety. It can be provided well and economically.

  The injection resin 6 used for the in-mold label container 10 of the present invention has a melt flow rate (MFR) (meaning a value measured by a test method based on JIS K7210) from 45 to 120 g from the viewpoint of moldability. A range of / 10 minutes is preferable. In the in-mold label container 10 according to the present invention, the thin container 10 can be easily injection-molded by using such a resin having a low melt viscosity. When the MFR is less than 45 g / 10 minutes, when pouring into a mold of an injection molding machine with a narrow gap to make the container 10 thin, the heat fluidity is low, so that the moldability is inferior. This is not preferable because a short circuit is likely to occur. When the MFR exceeds 120 g / 10 minutes, the low-viscosity resin generally has a lower molecular weight than the high-viscosity resin, and thus the container 10 using the low-viscosity resin is inferior in mechanical strength. Moreover, since heat fluidity is high and burrs are likely to be generated in, for example, a flange portion during injection molding, it is not preferable.

  In addition, the flexural modulus of the resin (meaning a value measured by a test method in accordance with JIS K7171) is preferably in the range of 200 to 2000 MPa, and when it is less than 200 MPa, the resin fluidity decreases and thin-wall molding cannot be performed. On the other hand, when it exceeds 2000 MPa, it becomes too hard when the container is molded, and the impact resistance is reduced.

  In the present invention, the injection resin 6 is excellent in fluidity with respect to the metal mold when thinned, excellent in moldability, and excellent in mechanical strength. Olefin-based resins such as polypropylene resins and polyethylene resins Resins, polystyrene resins, and polyester resins can be suitably used. Among these, the ones that are suitable for use conditions such as the contents stored in the container and the presence or absence of heat treatment after storage and sealing. It can be appropriately selected and used. Among these, it is preferable to use a resin made of polypropylene which is excellent in moldability even when it is thinned, can maintain strength, and is excellent in heat resistance.

  Examples of the polypropylene-based resin include a propylene-only polymer, a random copolymer of propylene and ethylene or ethylene and butene-1, a block copolymer of propylene-ethylene obtained by copolymerizing ethylene in a block form, Can use a polypropylene-based blend resin obtained by blending polypropylene with another polymer, an elastomer, or the like.

  It is relatively easy to adjust the flexural modulus of the polypropylene resin within the above range, and it is also easy to set the melt flow rate (MFR) to a range of 45 to 120 g / 10 minutes. If necessary, a transparent nucleating agent such as sorbitol can be added to such a polypropylene resin to improve transparency.

  The polypropylene resin is also excellent in rigidity, heat resistance, water resistance, and the like, and is excellent in safety with respect to these foods even when the contents are various beverages and other dessert foods. Moreover, since impact resistance at low temperatures can be modified by copolymerization or the like, it can be widely used for various contents and use conditions.

  The resin used in the present invention is not particularly limited as long as it is a resin that can be injection-molded. For example, as a polypropylene resin, BC10HRF manufactured by Nippon Polypolo, melt flow rate (MFR) 100 g / 10 min. Can be used.

  When manufacturing the in-mold label container 10 of the present invention, the band-like label 5 is set in a mold at the time of injection molding, and the belt-like label 5 and the heat seal layer are fused to the upper surface of the molded product by the heat of the resin at the time of molding. By doing so, labeling is performed simultaneously with molding.

  As a manufacturing method of the in-mold label container 10, a conventional manufacturing method of an in-mold label method can be used as it is, and it can be manufactured by an in-mold label method using an injection molding method.

  Next, the structure of the four annular ribs 9 provided on the upper surface of the flange 4 will be described in detail with reference to FIG.

  As shown in FIG. 2, the width of the flange 4 is 4.4 mm, and the four annular ribs 9 are provided on the upper surface of the flange 4. Each annular rib 9 has a height of 0.4 mm and a width of 0.3 mm at the bottom.

  The cross-section of each annular rib 9 has a taper shape that tapers upward in order to facilitate peeling of the in-mold label container 10 from the mold, and the taper angle of the annular rib 9 is 20 °. If the in-mold label container 10 can be peeled from the mold, it is not always necessary to provide a tapered shape.

  The annular ribs 9 are arranged at intervals of 1.4 mm.

  Further, the upper surface of the flange 4 is chamfered in an R shape at both ends thereof, and the both ends of the upper surface of the flange 4 are chamfered with a radius R = 0.2 mm.

  Although the number of the annular ribs 9 on the upper surface of the flange 4 is not limited to four, it is preferable to provide two to six. When one annular rib 9 is provided, the area of the flat surface on the upper surface of the flange 4 cannot be suppressed, and the flatness of the upper surface of the flange 4 cannot be improved. When seven annular ribs 9 are provided, a problem arises in the releasability from the mold.

  Next, specific examples of the present invention will be described below.

  In the Example of this invention, the following were prepared as an in-mold label container, and the side drop test was performed about each in-mold label container 10. FIG.

Example 1
The in-mold label container 10 in Example 1 uses BC10HRF manufactured by Nippon Polypolo Co., Ltd. as the injection resin 6 with a melt flow rate (MFR) of 100 g / 10 min. Molded, total height 110 mm, flange 4 outer diameter 71 mmφ, neck lower diameter 63 mm, bottom outer diameter 49 mmφ, full capacity 250 cc, barrel 1 thickness l ₂ = 0.40 mm, flange 4 thickness l ₁ = 0.70 mm. Two annular ribs 9 are provided on the upper surface of the flange 4, and the height of the annular rib 9 is 0.4 mm.

  A side drop test in which the in-mold label container 10 having such a configuration is observed on the flatness (sink state) of the upper surface of the flange 4 and the in-mold label container 10A with a lid is dropped from the flange 4 onto the floor surface. Went. The drop test method is described below with reference to FIG. The in-mold label container 10 is filled with 200 cc of water, the lid material 11 is heat-sealed to the flange 4, and the in-mold label container 10A with the lid material is manufactured. Stored for over 24 hours. Using a drop tester, place the in-mold label container 10A with a lid so that the end face 5A of the strip-like label 5 of the trunk 1 is on the lower side of the refrigerated sample (so that the trunk and the flange hit the concrete surface G). And dropped on the concrete surface G. At this time, cracks C such as cracks and defects were generated in the flange 4 from the end face 5A of the strip label 5. The drop height started from 10 cm, and the drop height was increased by 10 cm until a crack C such as a crack or a chip occurred on the flange 4, and the height when the crack occurred was recorded. The minimum crack height was the test of n = 10 times, the record of the sample damaged at the lowest height, and the average crack height was the average value of n = 10 times.

(Example 2)
An in-mold label container 10 similar to that in Example 1 was prepared except that the number of the annular ribs 9 was four.

  The planarity of the upper surface of the flange 4 was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container 10A with a lid.

(Example 3)
And four the number of the annular rib 9, except that the thickness l ₁ of the flange 4 was 0.9mm was prepared in the same manner in-mold label container 10 as in Example 1.

  The planarity of the upper surface of the flange 4 was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container 10A with a lid.

(Comparative Example 1)
An in-mold label container similar to that of Example 1 was prepared except that the thickness l ₂ of the body 1 was 0.40 mm, the thickness l ₁ of the flange 4 was 0.5 mm, and no annular rib was provided.

  The flatness of the upper surface of the flange was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container with a lid.

(Comparative Example 2)
An in-mold label container similar to that of Comparative Example 1 was prepared except that the thickness l ₁ of the flange 4 was 0.6 mm.

  The flatness of the upper surface of the flange was observed for this in-mold label container, and a side drop test was performed on the in-mold label container with a lid.

(Comparative Example 3)
An in-mold label container similar to that of Comparative Example 1 was prepared except that the thickness l ₁ of the flange 4 was 0.70 mm.

  The flatness of the upper surface of the flange was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container with a lid.

(Comparative Example 4)
An in-mold label container similar to Comparative Example 1 was prepared except that the thickness l ₁ of the flange 4 was set to 0.90 mm.

  The flatness of the upper surface of the flange was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container with a lid.

(Comparative Example 5)
An in-mold label container similar to that of Example 1 was prepared except that the thickness l ₂ of the body 1 was 0.50 mm, the thickness l ₁ of the flange 4 was 0.70 mm, and no annular rib was provided.

  The flatness of the upper surface of the flange was observed with respect to the in-mold label container 10, and a side drop test was performed on the in-mold label container with a lid.

Hereinafter, the flatness of the flange (sink state) and side drop test results for Example 1-3 and Comparative Example 1-5 are shown in Table 1.
As a result of the determination, a case where all of the following three items are satisfied was evaluated as ◯.
1. 1. The weight of the in-mold label container 10 is 12 g or less. 2. The average crack height is higher than 50 cm. No sink marks can be confirmed on the upper surface of the flange 4 by visual inspection.

  As can be seen from Table 1 above, in Example 1-3, the weight can be reduced, the flatness of the flange is good, and when a side drop test is performed, the minimum crack height at which the flange starts to break. Will improve. In Example 1-3, when the side drop test is performed, the average crack height at which the flange breaks also increases. In Example 1-3, it was confirmed that liquid leakage did not occur when 200 cc of water was filled and the lid was heat sealed on the upper surface of the flange to check whether liquid leakage occurred.

  On the other hand, in Comparative Example 1-5, the flatness of the flange is good in Comparative Example 1, but the minimum crack height and average crack height at which the flange breaks during the side drop test are low. In Comparative Example 2-4, the minimum crack height and the average crack height are good, but the flatness of the flange is poor. Moreover, in the comparative example 5, weight reduction cannot be achieved.

DESCRIPTION OF SYMBOLS 1 trunk | drum 2 thread | yarn bottom part 3 bottom part 3a bottom part peripheral edge 4 flange 5 strip | belt-shaped label 5a heat seal layer 5b, 5c non-heat seal layer 6 injection resin 9 annular rib 10 in-mold label container 10A in-mold label container 11 with cover material cover material G Concrete surface C Crack

Claims (3)

In an in-mold label container composed of a label and an injection resin injected on the label surface,
The torso,
A flange provided at the upper end of the trunk,
A bottom connected to the body,
The label extends from the outer surface of the trunk to the flange,
The thickness of the trunk is 0.30 to 0.50 mm,
The thickness of the flange is 1.4 to 2.1 times the thickness of the body,
An in-mold label container comprising a plurality of annular ribs protruding upward on an upper surface of the flange.   The in-mold label container according to claim 1, wherein 2 to 6 annular ribs projecting upward are provided on the upper surface of the flange. An in-mold label container according to claim 1;
An in-mold label container with a lid material, comprising: a lid material bonded to the upper surface of the flange of the in-mold label container.

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