JP7112664B2 - In-mold label container and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to an in-mold label container capable of suppressing the occurrence of air bubbles and welds in the injected resin to eliminate molding defects, and a method of manufacturing the same.

An in-mold label container is obtained by setting a label with a heat-seal layer in advance in the mold during injection molding, and fusing the heat-seal layer of the label to the surface of the injected resin using the heat of the resin during molding. .

An in-mold label container having a body portion and a bottom portion is known as an in-mold label container using a gas barrier label. In such an in-mold label container, a label having strong stiffness and high gas barrier properties is fixed to the body and bottom as an insert material. As a result, it is possible to provide an in-mold labeled container having a barrier property in which the mechanical strength of the entire container is enhanced due to the rigidity of the label. Here, as the label, a laminate of a base layer made of stiff paper or synthetic paper and a barrier layer made of a gas-barrier synthetic resin material is used.

Generally, in an in-mold label container, the bottom, among other things, has a rectangular shape with a longitudinal direction and a lateral direction. For this reason, when injected resin is injected into the mold, the injected resin flows smoothly in the short direction of the bottom, but it becomes difficult to flow in the longitudinal direction of the bottom, ensuring a uniform flow of the injected resin. is difficult. As a result, air bubbles or welds may occur in the injected resin, resulting in poor molding.

JP-A-8-325317

SUMMARY OF THE INVENTION It is an object of the present invention to provide an in-mole label container capable of suppressing the generation of air bubbles or welds in the injected resin, and a method of manufacturing the same.

The present invention provides an in-mold label container comprising a body, a bottom having a longitudinal direction and a width direction perpendicular to each other and including a gate, and a body connected to the bottom,
a label including at least a bottom label and a body label;
and an injection resin injected onto the label surface,
A thick region extending in the longitudinal direction from the gate side is formed in the injected resin of the bottom portion, and the thick region is thicker than other regions of the injected resin of the bottom portion including the gate. It is an in-mold label container.

The present invention is an in-mold label container in which the thick region of the injected resin is defined by a pair of straight lines or curved lines extending radially from the gate.

The present invention provides an in-mold label container, wherein an intermediate region is formed between the thick-walled region of the injected resin and the other region, in which the thickness of the injected resin gradually increases from the other region toward the thick-walled region. is.

The present invention employs a mold having a core and a cavity, comprising a bottom having longitudinal and lateral directions perpendicular to each other and including a gate, and a body connected to the bottom, wherein a label and its surface are formed. In a method for manufacturing an in-mold label container for manufacturing an in-mold label container having an injection resin injected onto the label surface,
preparing a mold in which at least one of the core and the cavity is formed with a recess for forming a thick region extending in the longitudinal direction from the gate side;
inserting the label into the mold;
and a step of injecting the injection resin into the mold to provide the injection resin on the surface of the label.

In the present invention, before the step of injecting the injection resin into the mold, a container-shaped sheet molded body including a body sheet and a bottom sheet is inserted,
It is a method for manufacturing an in-mold label container, in which the injection resin is injected between the label and the sheet molding.

As described above, according to the present invention, it is possible to suppress the occurrence of air bubbles and welds in the injection resin, and to eliminate molding defects.

1A is a side sectional view showing an in-mold label container according to an embodiment of the present invention; FIG. 1B is a plan view showing an in-mold label container according to an embodiment of the present invention; FIG. FIG. 2 is a top view showing an in-mold label container; FIG. 3 is a partial side cross-sectional view showing an in-mold label container; FIG. 4 is a partial side cross-sectional view of the in-mold label container viewed from a direction different from that of FIG. 3 by 90°. FIG. 5 is a side cross-sectional view showing the laminated structure of the sheet molded body. FIG. 6 is an exploded view showing a label having a body label and a bottom label; FIG. 7 is an assembly drawing showing a label having a body label and a bottom label; FIG. 8 is a side sectional view showing the laminated structure of the label. FIG. 9A is a diagram showing a method of manufacturing an in-mold label container according to the present invention; 9B is a diagram showing a method of manufacturing an in-mold label container according to the present invention; FIG. 9C is a diagram showing a method of manufacturing an in-mold label container according to the present invention; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1A to 9C are diagrams illustrating embodiments of the present invention.

As shown in FIGS. 1A and 1B, the in-mold label container 10 includes a trunk portion 11 having a substantially polygonal tubular shape, for example, a square tubular shape, having a flange portion 14, and a bottom portion 12 connected to the lower portion of the trunk portion 11. ing. In this case, the body 11 has four flat side surfaces 11a, 11b, 11c, and 11d. Furthermore, the bottom portion 12 is formed in a rectangular shape corresponding to the rectangular cylindrical body portion 11, so that the bottom portion 12 has a longitudinal direction X and a lateral direction Y (see FIG. 2).

Further, the in-mold label container 10 has a sheet molding 3 having gas barrier properties, a label 4 having gas barrier properties, and an injection resin 8 interposed between the sheet molding 3 and the label 4. .

Of these, the sheet molding 3 is positioned inside the injection resin 8, and includes a body sheet 3a corresponding to the body 11, a bottom sheet 3b corresponding to the bottom 12, and a flange sheet 3c corresponding to the flange 14. It has a container shape that contains gas, and has gas barrier properties as a whole. A gate receiving portion 33, which will be described later, is formed in the central portion of the bottom sheet 3b of the sheet molded body 3. As shown in FIG. Although the in-mold label container 10 according to the present embodiment has the sheet molded body 3, the sheet molded body 3 may not necessarily be provided.

The label 4 is positioned outside the injected resin 8, includes a body label 5 corresponding to the body 11 and a bottom label 7 corresponding to the bottom 12, and has gas barrier properties as a whole. A gate hole 7a for injecting the injection resin 8 is formed in the center of the bottom label 7 (see FIGS. 6 to 8). The term "gas barrier property" as used herein means at least oxygen barrier property, but may also have water vapor barrier property.

Further, as shown in FIGS. 6 and 7, the body label 5 and the bottom label 7 which constitute the label 4 are integrally formed. The body label 5 has four side labels 5a, 5b, 5c and 5d extending outwardly from the periphery of the bottom label 7. As shown in FIG. These four side labels 5a, 5b, 5c and 5d correspond to the flat side surfaces 11a, 11b, 11c and 11d of the in-mold label container 10, respectively.

Furthermore, between the side labels 5a, 5b, 5c, and 5d of the body label 5, there is no body label 5 and a gap 5A is formed.

Since both the body label 5 and the bottom label 7 include layers having gas barrier properties, the label 4 having the body label 5 and the bottom label 7 has high gas barrier properties.

In this case, the side labels 5a, 5b, 5c and 5d of the body label 5 do not overlap each other, and a gap 5A is formed between the side labels 5a, 5b, 5c and 5d of the body label 5. FIG.

By the way, as shown in FIGS. 1A and 1B, the body portion 11 of the in-mold label container 10 has a flange portion 14 . The flange portion 14 has a flange portion sheet 3c provided at the upper end of the body portion sheet 3a of the sheet molded body 3, and injection resin 8 injected onto the flange portion sheet 3c.

Contents are filled in the in-mold label container 10 having such a configuration. Next, the lid member 30 composed of the aluminum layer 30a and the heat seal layer 30b is adhered to the flange portion 14 of the in-mold label container 10, and the in-mold label container 10 is hermetically sealed.

By the way, the sheet molded body 3 includes the body sheet 3a having the flange sheet 3c and the bottom sheet 3b as described above, and has a container shape. In this case, the sheet molded body 3 is composed of a sheet-like laminate 23 having a layer structure as shown in FIG.

That is, as shown in FIG. 5, the laminate 23 constituting the sheet molded body 3 includes a polypropylene layer (PP) 23a as a synthetic resin layer and an ethylene-vinyl alcohol copolymer as a gas barrier layer having gas barrier properties, which are sequentially arranged. It includes a coalescence layer (EVOH) 23b and a polypropylene layer (PP) 23c as an adhesive layer that adheres to the injection resin.

By subjecting the sheet-like laminate 23 thus constructed to vacuum forming, the sheet molded body 3 having the shape of a container can be obtained.

Label 4, including body label 5 and bottom label 7, will now be described.

A label 4 having a body label 5 and a bottom label 7 consists of a laminate 24 having a layer structure as shown in FIG.

That is, as shown in FIG. 8, the label 4 having the body label 5 and the bottom label 7 includes (i) an adhesive layer 24a for injection resin, (ii) a synthetic resin layer 24b, and (iii) a gas barrier layer 24c. and (iv) a printing substrate layer 24d (here, the layer (i) and the layer (ii) can be used together). Each of these layers 24a, 24b, 24c, and 24d is formed independently and laminated via an adhesive (dry lamination), or a part or all of the layers are melt extruded (EC, co-extrusion). It can also be formed by Moreover, the printing substrate layer can be omitted depending on the application and purpose.

The adhesive layer 24a is not particularly limited as long as it adheres to the injection resin, but usually plastics of the same material as the injection resin, polyethylene containing EVA (ethylene-vinyl acetate copolymer), etc., have adhesive properties. resins, or plastic films obtained by co-extrusion processing or coating processing of these resins can be preferably used.

The film as the printing substrate layer 24d is not particularly limited as long as it is generally printable. For example, a polyester film, a polypropylene film, a nylon film, or the like can be used as appropriate.

As the gas barrier layer 24c, for example, (a) aluminum foil (7 to 25 μm), (b) a metal or metal oxide laminated on a plastic film or the like by vapor deposition or the like, such as silicon oxide vapor deposited plastic film, aluminum oxide vapor deposited. Plastic films, aluminum-deposited plastic films, (c) and others, polyacrylonitrile-based resins, EVOH (ethylene-vinyl alcohol copolymer), PVDC (polyvinylidene chloride) films, PVDC-coated biaxially oriented plastic films, etc., can be mentioned. It can be selected as appropriate according to performance. If the sheet molded body 3 has sufficient gas barrier properties, the label 4 does not necessarily have the gas barrier layer 24c.

Polypropylene (PP) can be used as the synthetic resin layer 24b.

Each of the above layers is formed by a dry lamination method, an extrusion lamination method, an extrusion coating method or other coating method according to a conventional method.

Specifically, as the label 4 having the body label 5 and the bottom label 7, for example, a label having the following layer structure can be used.

(1) Heat-sealed oriented polypropylene layer (HSOPP) 30 μm / aluminum foil 7 μm / oriented polypropylene layer (OPP) 30 μm
(2) Heat seal oriented polypropylene layer (HSOPP) 30 μ / VM-PET12 / oriented polypropylene layer (OPP) 30 μ
(3) Heat sealing agent coating/oriented polypropylene layer (OPP) 30μ/aluminum foil 7μ/oriented polypropylene layer (OPP) 30μ
As the injection resin 8 used for the in-mold label container 10 of the present invention, an injection-moldable thermoplastic resin such as polypropylene, polyethylene, polystyrene, or the like can be used.

Next, the injection resin 8 of the in-mold label container 10 will be further described. As described above, the injection resin 8 is injected between the sheet molding 3 and the label 4 to form the body portion 11 and the bottom portion 12 having the flange portion 14 of the in-mold label container 10 . Of these, the injection resin 8 forming the bottom portion 12 has gate traces (also referred to as gates) 8a corresponding to the gate holes 7a of the bottom portion label 7 .

As shown in FIG. 2, the bottom portion 12 is formed in a rectangular shape corresponding to the square tube-shaped trunk portion 11 having the four side surfaces 11a, 11b, 11c, and 11d as described above, and is arranged in the longitudinal direction X and the lateral direction. It has a hand direction Y. In this case, the injection resin 8 forming the bottom portion 12 forms a pair of thick regions 51 that extend in the longitudinal direction X from the gate 8a side and does not include the gate 8a, and the gate 8a other than the pair of thick regions 51. The thickness of the thick region 51 is greater than the thickness of the other regions 52 . For example, the thickness of each thick region 51 of the injection resin 8 is 1.15 mm, the thickness of the other regions 52 is 0.95 mm, and the difference in thickness is 0.20 mm.
Each thick region 51 of the injected resin 8 forming the bottom portion 12 is defined by a pair of radial straight lines 51a, 51a radially extending from the gate 8a. Furthermore, between the pair of radial straight lines 51a, 51a defining the thick region 51 and the other region 52, the thickness of the injected resin 8 gradually increases from the other region 52 toward the thick region 51. An intermediate region 53 is formed. Each thick region 51 is defined by a pair of radial straight lines 51a, 51a extending radially from the gate 8a, but the thick region 51 may be defined by a pair of curved lines extending radially.

Such a thick region 51 is formed by a thick region forming recess 22A provided on the cavity 22 side of the mold 20 to be described later, and the intermediate region 53 is formed on the cavity 22 side of the mold 20. It is formed by an intermediate area forming recess 22B provided adjacent to 22A.

The other region 52 is formed by the other region forming portion 22C of the cavity 22 of the mold 20, and the other region forming portion 22C provided on the cavity 22 side includes the thick region forming concave portion 22A and the intermediate region forming portion. It protrudes toward the core 21 side compared to the recess 22B.

Therefore, in the thick region forming recess 22A provided in the cavity 22, the gap between the core 21 and the cavity 22 is relatively large. It is easier to inflow. Further, in the other region forming portion 22C provided in the cavity 22, the gap between the core 21 and the cavity 22 is relatively small. The gap gradually changes between the gap in the thick region forming concave portion 22A and the gap in the other region forming portion 22C, and gradually changes from the other region forming portion 22C toward the thick forming concave portion 22A. value increases.

Next, a method for manufacturing an in-mold label container will be described with reference to FIGS. 9A, 9B and 9C.

First, the sheet-like laminated body 23 is vacuum-formed to obtain the sheet-formed body 3 having a container shape. Also, a label 4 having a body label 5 and a bottom label 7 is prepared.

Next, as shown in FIG. 9A, a mold 20 having a cavity 22 and a core 21 is prepared, and the molded sheet 3 is attracted to the core 21 of the mold 20 .

Next, the label 4 is adhered to the cavity 22 of the mold 20 as shown in FIG. 9B.

Next, the core 21 is brought close to the cavity 22, the core 21 is inserted into the cavity 22, and the cavity 22 and the core 21 are clamped (see FIG. 9C).

In this state, the injection resin 8 is injected into the space between the cavity 22 and the core 21 from the injection resin inlet 22a provided in the cavity 22 (FIG. 9C). In this case, the spout 22a is formed in a projection 22b formed in the cavity 22, and the spout 22a formed in the projection 22b penetrates the gate hole 7a of the bottom label 7 and enters the mold 20. Protruding. The injection resin 8 injected from the outlet 22a enters between the sheet molding 3 and the label 4 through the gate hole 7a provided in the label 4, and the injection resin 8 separates the sheet molding 3 and the label 4 from each other. are adhered, and the in-mold label container 10 is thus obtained.

During this time, the injection resin 8 injected into the mold 20 having the core 21 and the cavity 22 from the outlet 22a enters between the sheet formation body 3 and the label 4 through the gate hole 7a of the bottom label 7, and then It flows into the mold 20. In this case, since the cavity 22 is provided with the thick region forming recess 22A, the injection resin 8 injected into the mold 20 easily flows toward the thick region forming recess 22A.

As described above, the body portion 11 of the in-mold label container 10 has a rectangular cylindrical shape, and the bottom portion 12 has a rectangular shape accordingly. For this reason, in general, the injection resin 8 injected into the mold 20 from the gate hole 7a can flow smoothly in the lateral direction Y, but it takes time to flow in the longitudinal direction X, and the resin 8 flows smoothly. Difficult to flow. Note that the rectangular shape is not limited to a rectangle in a strict sense, and includes shapes similar to a rectangle.

According to the present embodiment, the cavity 22 is provided with the thick region forming recess 22A, and the thick region forming recess 22A is formed by a pair of radial straight lines 51a, 51a (see FIG. 2) extending radially from the spout 22a. ), the injected resin 8, which is injected into the mold 20 from the outlet 22a and spreads radially, can be smoothly guided toward the thick region forming recess 22A. Furthermore, between the thick region forming recess 22A and the other region forming portion 22C, the gap between the core 21 and the cavity 22 extends from the other region forming portion 22C toward the thick region forming recess 22A. Since the intermediate region forming recesses 22B that gradually widen are provided, the injected resin 8 can be guided more smoothly from the other region forming recesses 21C toward the thick region forming recesses 22A.

As described above, according to the present embodiment, the injection resin 8 injected from the spout 22a into the mold 20 can be smoothly guided in either the longitudinal direction X or the lateral direction Y. As a result, no bubbles or welds are generated in the injected resin, and molding defects can be suppressed.

In addition, since the in-mold label container 10 has the sheet molded body 3 having gas barrier properties and a container shape, the label 4 having gas barrier properties, and the injection resin interposed between the sheet molded body 3 and the label 4, Even if a gap occurs at the edge of the label 4, the sheet molding can maintain the gas barrier properties of the in-mold label container 10 as a whole.

In addition, since the label 4 is arranged outside the injection resin 8 and includes the printed base material layer 24d, the design of the in-mold label container 10 can be improved.

In the above-described embodiment, an example is shown in which the sheet molded body 3 is positioned inside the injected resin 8 and the label 4 is positioned outside the injected resin 8. However, the sheet molded body 3 is not limited to this. 8 and the label 4 inside the injected resin 8 .

In the example shown, the body portion 11 of the in-mold label container 10 has a rectangular tubular shape and the bottom portion 12 has a rectangular shape. 12 may have an elliptical shape with a longitudinal direction and a lateral direction.

3 Sheet molding 3a Body sheet 3b Bottom sheet 3c Flange sheet 4 Label 5 Body labels 5a, 5b, 5c, 5d Side label 7 Bottom label 8 Injected resin 10 In-mold label container 11 Body 12 Bottom 14 Flange 20 Mold 21 Core 22A Thick region forming recess 22B Intermediate region forming recess 22C Other region forming portions
22 Cavity 22a Inlet 23 Laminated body 23a Synthetic resin layer 23b Gas barrier layer 23c Adhesive layer 24 Laminated body 24a Adhesive layer 24b Synthetic resin layer 24c Gas barrier layer 24d Print substrate layer 51 Thick region 51a Radial line 52 Other region 53 Intermediate region

Claims (3)

An in-mold label container having a longitudinal direction and a lateral direction orthogonal to each other and including a bottom portion including a centrally located gate and a body portion connected to the bottom portion,
a label including at least a bottom label and a body label;
and an injection resin injected onto the label surface,
A pair of thick regions extending in the longitudinal direction are formed in the bottom injection resin on both sides of the gate, and each thick region is thicker than the other region of the bottom injection resin including the gate. is getting bigger and
each thick-walled region of the injected resin is defined by a pair of straight lines extending radially from the gate to form a plane triangular shape,
Between each thick region of the injected resin and other regions, an intermediate region is formed in which the thickness of the injected resin gradually increases from the other regions toward the thick regions,
Each intermediate region is formed in a strip shape along the pair of straight lines of the corresponding thick region , and the other region, the intermediate region, and the thick region extend from the gate in the longitudinal direction. Placed, in-mold label container. A method of manufacturing an in-mold label container for manufacturing the in-mold label container according to claim 1, wherein the in-mold label container is manufactured using a mold having a core and a cavity. in
At least one of the core and the cavity includes another area forming recess located on the gate side, a thick area forming recess extending in the longitudinal direction from the gate side, and the thick area forming. a step of preparing a mold in which a recess for forming an intermediate region and a recess for forming an intermediate region positioned between the recess for forming another region;
inserting the label into the mold;
and a step of injecting the injection resin into the mold to provide the injection resin on the surface of the label. Before the step of injecting the injection resin into the mold, inserting a container-shaped sheet molded body including a body sheet and a bottom sheet,
3. The method of manufacturing an in-mold label container according to claim 2, wherein the injection resin is injected between the label and the sheet molding.

Images