JP5177390B2 - Cup-shaped container - Google Patents

Description

  The present invention relates to a synthetic resin cup-shaped container in which a label is affixed to an outer peripheral surface of a side wall by an in-mold, and a vertical rib having a function of heat insulation or the like is projected.

Conventionally, the outer peripheral surface of the side wall of a cup-shaped container made of synthetic resin for the purpose of providing a heat insulation function so that it can be held by hand even with a liquid content such as hot water, or for the purpose of improving the rigidity of the container or preventing slipping A method of projecting a large number of ribs is employed. Patent document 1 is one of the conventional examples, and there is a description of a cup-shaped plastic container in which a large number of protruding piece-like vertical ribs are provided on the outer peripheral surface.
JP-A-6-32379

  In such containers, even if decorations with patterns, designs, etc., or display of designs or characters on the outer peripheral surface of the container itself, there are cases where decoration or display function cannot be performed well due to irregularities due to many ribs. Many. In view of this, the heat-shrinkable plastic film preprinted on the outer side of the ribs is heat-shrinked and is applied, or labels are adhered and pasted along the upper end surfaces of a plurality of ribs. Further, the rib may protrude from a limited range of the outer peripheral surface of the product, and a flat surface area where the rib is not protruded may be decorated or displayed.

  An object of the present invention is to sufficiently perform a decoration or display function in a wide region including a portion where ribs are formed on the outer peripheral surface of a side wall of a cup-shaped container provided with a large number of ribs. The purpose of the present invention is to provide a cup-shaped container with high merchantability that has functions related to gripping properties such as heat insulation by ribs, improvement of rigidity, or prevention of slipping, as well as unprecedented decoration and display functions. To do.

The main structure according to the means of the present invention for solving the above technical problem is that the label is integrally attached to the outer peripheral surface of the side wall of the container body by in-mold injection molding, and a large number of protrusion-like vertical ribs are provided on the label. in the container,
The outer surface portion of the label, and the synthetic resin forming the container body is made of heat-weldable synthetic resin,
The vertical rib has an upper end integrally connected to the side wall via a flange above the upper edge of the label, and the base end surface of the vertical rib is welded to the outer surface of the label except for the integrally connected portion. It is said that it is set as the structure fixed by adhesion.

The cup-shaped container having the above-described configuration is a state in which the label is integrally attached to the outer peripheral surface of the side wall of the container body by in-mold molding, and a plurality of vertical ribs in a state in which at least the upper end portion is integrally connected to the side wall Is formed.
According to in-mold injection molding in which a label is attached by in-mold, the upper end of the vertical rib is integrally connected to the side wall via a portion directly above the upper end of the label, for example, a flange provided around the upper end of the cup-shaped container. be able to.
In addition, in the said structure or the following description, let the surface of the side in contact with the side wall outer peripheral surface of a container main body be an inner surface, and let the surface on the opposite side be an outer surface.

  Moreover, according to in-mold injection molding, the outer surface side portion of the label is made of a synthetic resin that can be thermally welded, so that the base end surface of the vertical rib can be securely adhered and fixed to the outer surface of the label. It is possible to reliably prevent the vertical rib from being damaged or dropped due to insufficient adhesion to the outer surface of the label when an external force such as is applied. Or it can be used in peace without worrying about deterioration of the function related to gripping properties such as non-slip.

When a cup-shaped container is injection-molded, generally, the molten resin is injected from a portion corresponding to the center of the bottom bottom surface of the cup-shaped container in the mold, via a side wall portion and an integral connecting portion at the upper end portion. Therefore, the flow length in the mold becomes long and the temperature of the molten resin is considerably lowered, so that it contacts the outer surface of the label. The adhesive strength will be low,
By making the outer surface side portion of the label made of a synthetic resin that can be thermally welded, it is possible to obtain a sufficient adhesive strength even when the temperature of the molten resin is considerably lowered.

  Here, a synthetic resin such as polypropylene (hereinafter referred to as PP), polyethylene, polystyrene, polyethylene terephthalate, etc. can be used for the container body of the cup-shaped container of the present invention, depending on the purpose. For the heat-weldable synthetic resin that forms at least the outer surface side portion of the label, among the synthetic resins, synthetic resins having a relatively low melting point and softening temperature, or other components such as a copolymer component and a rubber component are used. A synthetic resin having a lower melting point and softening temperature is used.

  In the cup-shaped container having the above-described configuration, patterns, designs, designs, characters, and the like are partially cut off by the vertical ribs in a predetermined region including a large number of vertical ribs, but are displayed on a surface having no unevenness as a whole. Therefore, by taking into account the shape of vertical ribs, the distance between adjacent vertical ribs, or the size, arrangement, etc. of patterns, designs, designs, characters, etc., the decoration or display effect that can be recognized as an entire area can be achieved. Providing a cup-like container suitable for applications such as hot beverages such as hot coffee, in combination with functions related to gripping properties such as heat insulation effect, rigidity improvement, or slip prevention it can.

  According to another configuration of the present invention, in addition to the main configuration described above, the melting point of a heat-synthesizable synthetic resin is in the range of 80 to 140 ° C.

In the injection molding of the container main body, the molten resin is generally injected at a temperature exceeding 200 ° C. Therefore, by setting the melting point of the synthetic resin forming the outer surface side portion of the label to 140 ° C. or lower, The outer surface of the label and the longitudinal rib base end surface can be bonded and fixed at the formed flow end.
Here, when the melting point is less than 80 ° C., problems such as blocking of labels occur, and therefore the melting point is preferably in the range of 80 to 140 ° C.

  Still another configuration of the present invention is that the label is a laminated film composed of at least three layers, and the outer layer is made of a heat-weld synthetic resin film.

With the above configuration, heat-sealable synthetic resins generally have low rigidity and heat distortion resistance, but by laminating aluminum foil, paper, resin films, etc. that exhibit a function as a base material on the intermediate layer, A label having high heat resistance and suitable for in-mold molding can be obtained.
Further, by adding a gas barrier layer such as an aluminum foil, a printing layer, or a nylon resin to the intermediate layer, functions such as a higher degree of decoration and barrier properties can be imparted.

  According to still another configuration of the present invention, in addition to the above configuration, the inner layer is made of a synthetic resin film that can be thermally welded.

  With the above configuration, the inner layer of the label is also made of a synthetic resin that can be heat-welded, so that the label is firmly bonded and fixed to the outer peripheral surface of the side wall of the container body. Thus, the rigidity of the entire container and the strength of the vertical ribs can be improved more effectively.

  Still another configuration of the present invention is that a heat-sealable synthetic resin film is a low-density polyethylene resin film.

Low density polyethylene (hereinafter referred to as LDPE) has a low melting point and can firmly adhere and fix the outer surface of the label and the base end surface of the vertical rib even at the flow end where the vertical rib is formed.
Note that LDPE includes linear low density polyethylene (LLDPE).

  Still another configuration of the present invention is that the heat-weldable synthetic resin film is an unstretched film made of an ethylene-propylene copolymer resin.

  An unstretched film made of an ethylene-propylene copolymer resin (hereinafter sometimes referred to as a CPP film) exhibits a strong heat-welding property particularly when the container body is made of a PP resin.

  Still another configuration of the present invention is that the heat-sealable synthetic resin film is a laminated film in which a polypropylene or polyethylene-based heat-sealable synthetic resin is laminated on a stretched film made of propylene resin. .

  The laminated film having the above structure is obtained by laminating a polypropylene-based or polyethylene-based heat-weldable synthetic resin on an OPP film that functions as a label base material. Heat resistance can be achieved at a high level.

The cup-shaped container of the present invention has the above-described configuration, and has the following effects.
In other words, the base end surface of the vertical rib is securely bonded to the outer surface of the label, and when the external force such as impact is applied, the vertical rib is damaged or dropped due to insufficient adhesion to the outer surface of the label. It can be surely prevented, and can be used with confidence without worrying about the appearance due to breakage or dropout of the vertical ribs, the heat insulation effect, the improvement of rigidity, or the deterioration of the functions related to gripping such as anti-slip.

  And since the whole label is in a state of being integrally stuck along the outer peripheral surface of the side wall without unevenness by in-mold molding, regardless of the presence of vertical ribs, in a wide area including many vertical ribs, It is possible to provide a cup-shaped container with an unprecedented high merchantability that can display patterns, designs, designs, characters, and the like printed on a label in advance without distortion, and that can fully exhibit decoration and display functions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 4 show a first embodiment of a cup-shaped container which is an in-mold injection molded product of the present invention. FIG. 1 is a front view of a half longitudinal section of a container, FIG. 2A is a front view showing a label 8 used in this embodiment in an expanded state, and FIG. 2B is a cross-sectional view showing a layer structure of the label 8. 3 is an enlarged longitudinal sectional view of the main part in the vicinity of the longitudinal rib 6, and FIG. 4 is a plan sectional view of the body 2. The container body 1 has a cylindrical body portion 2 that is slightly enlarged in diameter upward, and a flange 7 is attached to the upper end.

The container body 1 is made of PP resin.
The label 8 is a 6-layer laminated film as shown in FIG. 2B, and a LLDPE resin film, which is a synthetic resin that can be heat-welded on the OPP film, is laminated on the outside and inside by coextrusion. The laminated film fc is laminated.
In the upper and lower laminated films fc, the outer layer 8a and the inner layer 8f are LLDPE resin films that can be thermally welded to the container body 1 made of PP resin, and the layers 8b and 8e are made of OPP film.
The intermediate layer 8c is a printed layer, and the layer 8d is an aluminum foil layer.

  A label 8 shown in FIG. 2 is attached integrally by in-mold injection molding over the entire height range of the outer peripheral surface of the side wall 3 of the body portion 2 of the container body 1. Further, on the outer surface of the label 8, a large number of thin strips and ridge-like vertical ribs 6 are provided protruding symmetrically with respect to the central axis in a height range of about 1/3 of the total height from the upper end.

  The formation state of the vertical ribs 6 on the outer surface of the label 8 is as shown in the sectional views of FIGS. 3 and 4, and each vertical rib 6 has an upper end at the upper end edge of the label 8. While being integrally connected to the side wall 3 via the flange 7, the base end face 6 a of the vertical rib 6 is bonded and fixed to the outer surface of the label 8 in a welded manner in a portion excluding the integrally connected portion.

  Further, the inner surface of the label 8 is also bonded and fixed to the outer peripheral surface of the side wall 3 of the container main body 1 so that the side wall 3 and the vertical rib 6 are integrated via the label 8. As a result, the overall rigidity of the container can be increased even if it is thin as a whole, and it is possible to reliably prevent the vertical ribs 6 that are thin pieces from being damaged or dropped when an external force such as an impact is applied. It can be used with confidence without impairing functions such as appearance and gripping.

  Further, as can be seen from FIG. 4, in the region between the adjacent vertical ribs 6, the film-like label 8 is laminated in a state of being in close contact with the outer peripheral surface of the side wall 3 (adhered and fixed in a molten state). As can be seen, when the entire container is seen, the stylized letter H by the printed layer (layer 8c) is not distorted in the metallic glossy surface by the aluminum foil layer (layer 8d). It can be clearly recognized as an integrated design over almost the entire area.

  And although the stylized letter H is divided by the longitudinal ribs 6, since each longitudinal rib 6 is a thin piece, the letters can be clearly recognized as a design having continuity. The division of the design by the vertical rib 6 gives an unprecedented visual effect.

  And in a cup-shaped container like a present Example, it can grip by a hand, without touching the outer peripheral surface of a container directly using the heat insulation effect of the vertical rib 6, and it is highly rigid even if it is thin. For this reason, it can be used with confidence in applications for hot beverages such as hot coffee.

  Next, an in-mold injection molding method for molding the cup-shaped container of the present invention will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view showing an outline of a mold 11 for in-mold injection molding the cup-shaped container of the present invention. The mold 11 is composed of a cavity mold 13 and a core mold 12, and a label 8 on which a pattern, characters, etc. are printed in advance in the cavity 13a of the cavity mold 13 is vacuum suctioned by means of a slit 13b or by means such as static electricity. The core portion 12a of the core mold 12 is inserted and clamped, the molten resin is injected from the gate portion 18, the bottom wall forming portion 17, the side wall forming portion 14, the vertical rib forming portion 15, and the flange forming portion. 16 is filled to form the container body 1 and at the same time, the label 8 and the container body 1 are integrated.

  6 and 7 show the flow state of the molten resin (see arrows in FIGS. 6 and 7) in the mold at the portion corresponding to the upper end of the container where the vertical rib 6 is formed. FIG. 7 shows a state in a portion between adjacent vertical ribs 6, and the molten resin is a label 8 positioned in close contact with the core portion 12 a of the core mold 12 and the cavity 13 a of the cavity mold 13. It flows through the formed side wall forming part 14 and reaches the flange forming part 16 which is the flow end.

On the other hand, FIG. 6 shows a state in a portion where the vertical rib 6 is formed, and the molten resin flowing through the side wall forming portion 14 passes through the vicinity of the base end portion of the flange forming portion 16 and the vertical rib forming portion 15. Flows in the opposite direction and fills the flange forming portion 16.
8 is a plan sectional view of the mold shown in FIG. 5 taken along the line BB in FIG. 6, and an enlarged main portion thereof is shown.

Here, as can be seen from the flow form of the molten resin shown in FIG. 6, the bottom portion forming portion 17, the side wall forming portion 14, the vicinity of the base end portion of the flange forming portion 16, and the longitudinal rib forming portion 15. The flow length of the molten resin is increased, and the flow path of the vertical rib forming portion 15 that forms the flaky vertical rib 6 is a narrow flow path, so that the temperature of the molten resin is considerably reduced. Since the vertical rib forming portion 15 is filled with and contacts the outer surface of the label 8, the adhesive force of the base end surface 6a of the vertical rib 6 to the outer surface of the label 8 is inevitably reduced.
As in this example, the outer layer 8a of the label 8 is made of an LLDPE resin film having a melting point of about 120 ° C., so that sufficient adhesive strength can be obtained even when the temperature of the molten resin is considerably reduced as described above. Can be obtained.

  In addition, the label 8 of this embodiment has the layers 8b and 8e of the laminated film fc constituting the upper and lower portions made of an OPP film, and has high rigidity and heat distortion resistance suitable for in-mold injection molding as described above. .

Next, FIG. 9 is a front view showing a second embodiment of the cup-shaped container of the present invention, which is an example in which the vertical ribs 6 are arranged by changing the lower end position into a wave shape aiming at a unique decoration effect.
Here, the formation direction of the vertical ribs 6 is not necessarily limited to being formed in a vertical straight line, but can be formed obliquely or can be formed in a curved shape. It can be formed in various modes in consideration of the decorativeness and the functionality related to gripping.

As mentioned above, although embodiment of this invention and its effect were demonstrated along the Example, embodiment of this invention is not limited to the said Example.
For example, the label does not necessarily have to be applied over the entire outer peripheral surface of the side wall, and the application location and area can be determined according to the purpose. Further, the shape of the container body and the synthetic resin to be used are not particularly limited. In the above embodiment, the container having a cylindrical body has been described. However, the present invention also applies to cup-shaped containers having various shapes such as a polygonal cylinder. The effect of the invention is exhibited.

In addition, the layer structure of the label can be made into various layer structures in consideration of the heat-weldability to the container body, rigidity and heat-resistant deformation, decoration, functionality such as a gas barrier, and the like.
For example, when the container body is made of PP resin, a CPP film can be effectively used in addition to LLDPE for the outer layer, and when the container body is made of polyethylene resin, the use of LDPE is effective.

  As described above, the cup-shaped container of the present invention exhibits both the function of gripping by the vertical ribs and the decoration by the label including the vertical rib forming region, such as hot coffee. A wide range of usage can be expected for applications such as hot beverages.

It is a front view of 1st Example of the cup-shaped container of this invention. (A) is the front view which expands and shows the label used for the container of FIG. 1, (b) is sectional drawing which shows the layer structure of this label. FIG. 2 is an enlarged vertical sectional view showing a main part in the vicinity of a vertical rib in FIG. 1. FIG. 2 is a plan sectional view of the container shown in FIG. 1 taken along line AA in FIG. 1. It is a longitudinal cross-sectional view which shows the outline of the metal mold | die for injection-molding the container of FIG. FIG. 6 is an enlarged vertical sectional view of a main part showing the vicinity of a vertical rib forming part of the mold of FIG. 5. FIG. 6 is an enlarged vertical cross-sectional view of a main part showing the vicinity of a side wall forming part of the mold of FIG. 5. FIG. 7 is a plan sectional view of the mold shown in FIG. 5 taken along line BB in FIG. 6. It is a front view of 2nd Example of the cup-shaped container of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Container body 2; Body part 3; Side wall 6; Vertical rib 6a; Base end surface 7; Flange 8; Label 8a; Outer layer 8b, 8c, 8d, 8e; Mold 12a; Core part 13; Cavity mold 13a; Cavity 13b; Slit 14; Side wall forming part 15; Vertical rib forming part 16; Flange forming part 17; Bottom wall forming part 18; Gate part fc;

Claims (7)

The label (8) is affixed integrally to the outer peripheral surface of the side wall (3) of the synthetic resin container body (1) by in-mold injection molding, and the protruding ribs (6) are formed on the label (8). In many cup-shaped containers ,
The outer surface portion of the front Symbol label (8), is made of heat-weldable synthetic resin of the synthetic resin forming the container body (1),
The vertical rib (6) has an upper end thereof integrally connected to the side wall (3) via the flange (7) above the upper end edge of the label (8), and in a portion excluding the integrally connected portion, A cup-shaped container in which the base end face (6a) of the vertical rib (6) is bonded and fixed to the outer surface of the label (8) in a welding manner.
The cup-shaped container according to claim 1, wherein the melting point of the heat-sealable synthetic resin is in the range of 80 to 140 ° C. The cup-shaped container according to claim 1 or 2, wherein the label (8) is a laminated film composed of at least three layers, and the outer layer is made of a synthetic resin film that can be thermally welded. 4. The cup-shaped container according to claim 3, wherein the inner layer is also made of a synthetic resin film that can be thermally welded. The cup-shaped container according to claim 3 or 4, wherein the heat-sealable synthetic resin film is a low-density polyethylene resin film. The cup-shaped container according to claim 3 or 4, wherein the heat-sealable synthetic resin film is an unstretched film made of an ethylene-propylene copolymer resin. The cup-shaped container according to claim 3 or 4, wherein the heat-weld synthetic resin film is a laminated film obtained by laminating a polypropylene or polyethylene heat-weld synthetic resin on a stretched film made of propylene resin.

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