JP2019059483A - In-mold label container and method of manufacturing the same - Google Patents

Abstract

An object of the present invention is to suppress the generation of bubbles and welds in an injection resin.
An in-mold label container (10) comprises at least a label (4) and an injection resin (8) injected onto the label (4). The injection resin 8 constituting the bottom 12 has a thick region 51 extending in the longitudinal direction X from the gate and another region 52, and the thickness of the thick region 51 is larger than the thickness of the other region 52.
[Selected figure] Figure 2

Description

  The present invention relates to an in-mold label container capable of eliminating molding defects by suppressing the generation of air bubbles and welds in an injection resin, and a method of manufacturing the same.

  The in-mold label container is obtained by setting a label having a heat seal layer in advance in a mold at the time of injection molding and fusing the heat seal layer of the label to the surface of the injection resin by the heat of the resin at the time of molding. .

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

  Generally, in an in-mold label container, the bottom, in particular, has a rectangular shape with longitudinal and latitudinal directions. For this reason, when the injection resin is injected into the mold, the injection resin flows smoothly in the short side direction of the bottom, but the flow in the longitudinal direction of the bottom becomes staggering, and a uniform flow of the injection resin is ensured. It is difficult. For this reason, bubbles or welds may be generated in the injection resin to cause molding defects.

JP-A-8-325317

  The present invention has been made in consideration of these points, and it is an object of the present invention to provide an in-mold label container capable of suppressing the generation of air bubbles or welds in an injection resin and a method for producing the same.

According to the present invention, there is provided an in-mold label container comprising a body, a longitudinal direction and a transverse direction perpendicular to each other, a bottom including a gate, and a body connected to the bottom.
A label comprising at least a bottom label and a torso 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 injection resin at the bottom, and the thick region is thicker than other regions of the injection resin at the bottom including the gate. In-mold label container.

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

  In the in-mold label container according to the present invention, an intermediate area is formed between the thick area of the injection resin and the other area, in which the thickness of the injection resin gradually increases from the other area toward the thick area. It is.

The present invention uses a mold having a core and a cavity, and has a bottom including a gate and having a longitudinal direction and a short direction orthogonal to each other, and a body connected to the bottom, and a label and this surface In a method of manufacturing an in-mold label container for manufacturing an in-mold label container having an injection resin injected onto a label surface,
Providing a mold in which a thick region forming recess extending in the longitudinal direction from the gate side is formed in at least one of the core and the cavity;
Inserting the label into the mold;
And a step of injecting the injection resin into the mold and providing the injection resin on the label surface.

According to the present invention, prior to the step of injecting the injection resin into the mold, a sheet molding including a body sheet and a bottom sheet and having a container shape is inserted and attached.
It is a manufacturing method of the in-mold label container which injects the said injection resin between the said label and the said sheet molded object.

  As described above, according to the present invention, the generation of air bubbles and welds in the injection resin can be suppressed, and molding defects can be eliminated.

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

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A to 9C show an embodiment of the present invention.

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

  Further, the in-mold label container 10 has the sheet molded body 3 having the gas barrier property, the label 4 having the gas barrier property, and the injection resin 8 interposed between the sheet molded body 3 and the label 4 .

  Among them, the sheet molded body 3 is located inside the injection resin 8, and the body portion sheet 3 a corresponding to the body portion 11, the bottom portion sheet 3 b corresponding to the bottom portion 12, and the flange portion sheet 3 c corresponding to the flange portion 14 It has a container shape that includes the gas barrier property as a whole. Further, at the central portion of the bottom sheet 3b of the sheet molded body 3, a gate receiving portion 33 described later is formed. Although the in-mold label container 10 according to the present embodiment includes the sheet molded body 3, the sheet molded body 3 may not necessarily be provided.

  The label 4 is located outside the injection resin 8 and 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. Further, at the center of the bottom label 7, a gate hole 7a for injecting the injection resin 8 is formed (see FIGS. 6 to 8). The gas barrier property referred to herein has at least oxygen barrier property, but may have a water vapor barrier.

  Further, as shown in FIGS. 6 and 7, the body label 5 and the bottom label 7 constituting the label 4 are integrally formed. The body label 5 has four side labels 5a, 5b, 5c and 5d extending outward from the peripheral edge of the bottom label 7. The 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.

  Further, no trunk label 5 is present between the side labels 5a, 5b, 5c and 5d of the trunk label 5, and a gap 5A is formed.

  Since the body label 5 and the bottom label 7 both include a layer 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 with each other, and a gap 5A is formed between the side labels 5a, 5b, 5c and 5d of the body label 5.

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

  The 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 sealed.

  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 configuration as shown in FIG.

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

    Then, by subjecting the sheet-like laminated body 23 configured in this manner to vacuum forming, the sheet molded body 3 having a container shape can be obtained.

  Next, the label 4 including the body label 5 and the bottom label 7 will be described below.

  The label 4 having the body label 5 and the bottom label 7 comprises a laminate 24 having a layer configuration as shown in FIG.

  That is, as shown in FIG. 8, the label 4 having the body label 5 and the bottom label 7 is (i) an adhesive layer 24a with an injection resin, (ii) a synthetic resin layer 24b, and (iii) a gas barrier layer 24c. And (iv) A printed substrate layer 24d (here, the layer of (i) and the layer of (ii) can be used together). Each of these layers 24a, 24b, 24c, 24d is independently formed into a film and bonded (dry lamination) through an adhesive or melt extrusion (EC, coextrusion) of a part or all of the layers. It can also be formed by Also, the printing substrate layer can be omitted depending on the application and purpose.

  The adhesive layer 24 a is not particularly limited as long as it adheres to the injection resin, but usually, the adhesion of a plastic made of the same material as the injection resin, polyethylene such as EVA (ethylene-vinyl acetate copolymer), etc. The resin which it has, or the plastic film etc. which co-extrusion process or coating process of those resin can be used suitably.

  The film as the printing substrate layer 24d is not particularly limited as long as it is generally printable, and, 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) metal or metal oxide laminated on plastic film by vapor deposition etc., for example, silicon oxide vapor deposited plastic film, aluminum oxide vapor deposited Plastic films, aluminum-deposited plastic films, (c) others, polyacrylonitrile resins, EVOH (ethylene vinyl alcohol copolymer), PVDC (polyvinylidene chloride) films, PVDC coated biaxially stretched plastic films, etc. may be mentioned. It may be selected appropriately depending on the performance. When the sheet molded body 3 has sufficient gas barrier properties, the label 4 does not necessarily have to have the gas barrier layer 24 c.

  In addition, polypropylene (PP) can be used as the synthetic resin layer 24 b.

  The above layers are formed by a dry lamination method, an extrusion lamination method, an extrusion coating method or other coating method according to a conventional method.

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

(1) Heat seal oriented polypropylene layer (HSOPP) 30μ / aluminum foil 7μ / oriented polypropylene layer (OPP) 30μ
(2) Heat seal oriented polypropylene layer (HSOPP) 30μ / VM-PET 12 / oriented polypropylene layer (OPP) 30μ
(3) Heat sealing agent coating / oriented polypropylene layer (OPP) 30μ / aluminum foil 7μ / oriented polypropylene layer (OPP) 30μ
Moreover, as the injection resin 8 used for the in-mold label container 10 of this invention, the injection moldable thermoplastic resin, for example, a polypropylene, polyethylene, a polystyrene, etc. may 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 molded body 3 and the label 4 to form the trunk 11 and the bottom 12 having the flange 14 of the in-mold label container 10. Among them, the injection resin 8 constituting the bottom 12 has a gate mark (also referred to as a gate) 8 a corresponding to the gate hole 7 a of the bottom label 7.

As shown in FIG. 2, the bottom 12 is formed in a rectangular shape corresponding to the square cylindrical trunk 11 having four side surfaces 11a, 11b, 11c, 11d as described above, and the longitudinal direction X and the short With hand direction Y. In this case, the injection resin 8 constituting the bottom 12 extends from the gate 8a in the longitudinal direction X and does not include the gate 8a, and includes the pair of thick regions 51 and the gates 8a other than the pair of thick regions 51. And the thickness of the thick region 51 is larger than the thickness of the other region 52. For example, the thickness of each thick region 51 of the injection resin 8 is 1.15 mm, the thickness of the other region 52 is 0.95 mm, and the difference between the thicknesses is 0.20 mm.
Each thick region 51 of the injection resin 8 constituting 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 51 a and 51 a defining the thick region 51 and the other region 52, the thickness of the injection resin 8 gradually increases from the other region 52 toward the thick region 51. An intermediate region 53 is formed. Although each thick region 51 is defined by a pair of radial straight lines 51a, 51a radially extending from the gate 8a, the thick region 51 may be defined by a pair of radially extending curves.

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

  The other region 52 is formed by another 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 is a thick region forming recess 22A and an intermediate region formation It protrudes toward the core 21 side compared with the recessed part 22B.

  For this reason, 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, and the injection resin 8 is thus moved to the thick region forming recess 22A. It is easy to flow in. Further, in another region forming portion 22C provided in cavity 22, the gap between core 21 and cavity 22 is relatively small, and in intermediate region forming recess 22B, between core 21 and cavity 22. The gap gradually changes between the gap in the thick region forming recess 22A and the gap in the other region forming portion 22C, and gradually from the other region forming portion 22C toward the thick region forming recess 22A. The value increases.

  Next, a method of 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 subjected to vacuum forming to obtain a sheet molded 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 sheet compact 3 is adsorbed to the core 21 of the mold 20.

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

  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 port 22a of the injection resin provided in the cavity 22 (FIG. 9C). In this case, the spout 22a is formed in the protrusion 22b formed in the cavity 22, and the spout 22a formed in the protrusion 22b penetrates the gate hole 7a of the bottom label 7 and is inserted into the mold 20. It protrudes. Further, the injection resin 8 injected from the injection port 22 a penetrates between the sheet molded body 3 and the label 4 from the gate hole 7 a provided in the label 4, and the sheet molded body 3 and the label 4 are made by the injection resin 8. Are adhered, and in this way, the in-mold label container 10 is obtained.

  Meanwhile, the injection resin 8 injected from the injection port 22a into the mold 20 having the core 21 and the cavity 22 intrudes between the sheet forming body 3 and the label 4 from the gate hole 7a of the bottom label 7 and thereafter It flows into the mold 20. In this case, since the thick region forming recess 22A is provided in the cavity 22, the injection resin 8 injected into the mold 20 can easily flow toward the thick region forming recess 22A.

  As described above, the body portion 11 of the in-mold label container 10 has a square 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 short direction Y direction, but it takes time to flow in the longitudinal direction X, and the smooth operation It is difficult to flow. In addition, with a rectangular shape, not only the rectangle in a strict meaning but the thing of the shape similar to a rectangle is also included.

  According to the present embodiment, the thick region forming recess 22A is provided in the cavity 22, and the thick region forming recess 22A is a pair of radial straight lines 51a, 51a radially extending from the spout 22a (see FIG. 2). The injection resin 8 which is injected from the injection port 22a into the mold 20 and spreads radially can be smoothly introduced to the thick region forming recess 22A. Furthermore, the gap between the core 21 and the cavity 22 is directed from the other region forming portion 22C to the thick region forming recess 22A between the thick region forming recess 22A and the other region forming portion 22C. Since the intermediate region forming recess 22B which gradually spreads is provided, the injection resin 8 can be more smoothly guided from the other region forming recess 21C to the thick region forming recess 22A.

  As described above, according to the present embodiment, the injection resin 8 injected from the injection port 22a into the mold 20 can be smoothly guided in any of the longitudinal direction X and the transverse 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 a sheet molded body 3 having gas barrier properties and a container shape, a label 4 having gas barrier properties, and an injection resin interposed between the sheet molded body 3 and the labels 4. Even if a gap is generated at the end edge of the label 4, the gas barrier properties of the entire in-mold label container 10 can be maintained by the sheet molded body.

  Moreover, while the label 4 is arrange | positioned on the outer side of the injection | emission resin 8, since the printing base material layer 24d is included, the designability of the in-mold label container 10 can be improved.

  In the above embodiment, an example is shown in which the sheet molded body 3 is located inside the injection resin 8 and the label 4 is located outside the injection resin 8, but the invention is not limited to this. The label 4 may be disposed on the outside of 8 and the label 4 may be disposed on the inside of the injection resin 8.

  Also, although the example shows that the body 11 of the in-mold label container 10 has a square cylindrical shape and the bottom 12 has a rectangular shape, the present invention is not limited thereto and the body 11 has an elliptical cylindrical shape, and the bottom 12 may have an elliptical shape with a longitudinal direction and a latitudinal direction.

3 sheet molded body 3a body part sheet 3b bottom part sheet 3c flanged part sheet 4 label 5 body part label 5a, 5b, 5c, 5d side label 7 bottom part label 8 injection resin 10 in-mold label container 11 body part 12 bottom part 14 flanged part 20 Mold 21 Core 22A Recess for forming thick region 22B Recess for forming intermediate region 22C Other region forming portion
22 cavity 22a inlet 23 laminate 23a synthetic resin layer 23b gas barrier layer 23c adhesive layer 24 laminate 24a adhesive layer 24b synthetic resin layer 24c gas barrier layer 24d printing substrate layer 51 thick region 51a radial straight line 52 other region 53 intermediate region

Claims (5)

An in-mold label container comprising a body, a longitudinal direction and a transverse direction orthogonal to each other, a bottom including a gate, and a body connected to the bottom.
A label comprising at least a bottom label and a torso 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 injection resin at the bottom, and the thick region is thicker than other regions of the injection resin at the bottom including the gate. Yes, in-mold label containers.   The in-mold label container according to claim 1, wherein the thick region of the injection resin is defined by a pair of straight lines or curves extending radially from the gate.   The in-region according to claim 1 or 2, wherein an intermediate region is formed between the thick region of the injection resin and the other region, in which the thickness of the injection resin gradually increases from the other region toward the thick region. Mold label container. A mold having a core and a cavity, having a bottom including a gate and having a longitudinal direction and a transverse direction orthogonal to each other and including a gate, and a body connected to the bottom, and emitting on the label and the surface label surface In a method of manufacturing an in-mold label container for manufacturing an in-mold label container having the injected resin
Providing a mold in which a thick region forming recess extending in the longitudinal direction from the gate side is formed in at least one of the core and the cavity;
Inserting the label into the mold;
And a step of injecting the injection resin into the mold and providing the injection resin on the label surface. Prior to the step of injecting the injection resin into the mold, a sheet molded body having a container shape, including a body sheet and a bottom sheet, is inserted and attached.
The method for producing an in-mold label container according to claim 4, wherein the injection resin is injected between the label and the sheet molded body.

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