JP6928899B2 - Manufacturing method of in-mold label container and in-mold label container - Google Patents

Description

The present invention relates to an in-mold label container manufacturing method and an in-mold label container that can suppress appearance defects and molding defects.

The in-mold label container is obtained by setting a label having a heat-sealing layer in a mold in advance at the time of injection molding, and fusing the heat-sealing layer of the label to the surface of the injection resin by the heat of the resin at the time of molding. .. The label used for such an in-mold label container is generally formed by punching a label material into a predetermined shape, and at this time, a gate hole for injecting an injection resin is formed in the label (at this time, a gate hole for injecting an injection resin is formed. For example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-200919

However, when the label is punched out from the label material, the residue of the label material may adhere to the peripheral edge of the label or the edge of the gate hole for injecting the injection resin. When the in-mold label container is continuously molded using the label with such debris attached, the debris of the label material may be accumulated in the mold. In this case, transfer marks of the residue may be formed on the surface of the in-mold label container, which may lead to poor appearance. In addition, the accumulation of label material residue in the mold may cause molding defects and reduce productivity.

Further, when the label is set in the mold, the label may come into close contact with the mold when the label is aligned, which may make it difficult to align the label. If the in-mold label container is molded in a state where the label is not set in a predetermined position, wrinkles of the label may occur on the surface of the in-mold label container, which also leads to poor appearance.

The present invention has been made in consideration of such a point, and a method for manufacturing an in-mold label container and an in-mold label container capable of suppressing an appearance defect of the in-mold label container and suppressing a molding defect can be obtained. The purpose is to provide.

In the present invention, in the method for manufacturing an in-mold label container, a step of preparing a mold having a core and a mold with a cavity and a label having a gate hole through which the injection resin passes are mounted in the mold. A step of injecting the injection resin onto the label mounted in the mold is provided, and the label is mounted on at least one of the core of the mold and the mold with a cavity. This is a method for manufacturing an in-mold label container, characterized in that a surface treatment is applied to a position straddling at least one of the peripheral edge of the label and the gate hole in the finished state.

The present invention is a method for manufacturing an in-mold label container, characterized in that a fine uneven shape is formed on at least one of the core of the mold and the mold with a cavity by the surface treatment. be.

The present invention is a method for manufacturing an in-mold label container, characterized in that at least one of the core and the mold with a cavity is coated with a release layer by the surface treatment.

The present invention is a method for manufacturing an in-mold label container, wherein the release layer contains a fluororesin.

The present invention is formed on an in-mold label container having a body and a bottom, a label having at least a bottom label corresponding to the bottom and a body label corresponding to the body, and a label having the body label. A gate hole for injecting the injection resin is formed in the bottom label of the label, and the glossiness of at least one of the periphery of the label and the periphery of the gate hole is the same as that of the label. It is an in-mold label container characterized by having a lower gloss than other parts.

As described above, according to the present invention, it is possible to suppress the appearance defect of the in-mold label container and the molding defect.

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 an in-mold label container according to an embodiment of the present invention. FIG. 2 is a developed view showing a label having a body label and a bottom label. FIG. 3A is an assembly view showing a label having a body label and a bottom label. FIG. 3B is an assembly view showing a label having a body label and a bottom label. FIG. 4 is a side sectional view showing a laminated structure of the sheet molded body. FIG. 5 is a side sectional view showing a laminated structure of labels. FIG. 6 is a side sectional view showing a mold. FIG. 7A is an enlarged view showing an example of the mold of FIG. FIG. 7B is an enlarged view showing another example of the mold of FIG. FIG. 8A is a diagram showing a method for manufacturing an in-mold label container according to the present invention. FIG. 8B is a diagram showing a method for manufacturing an in-mold label container according to the present invention. FIG. 9A is a diagram showing a method for manufacturing an in-mold label container according to the present invention. FIG. 9B is a diagram showing a method for manufacturing an in-mold label container according to the present invention. FIG. 9C is a diagram showing a method for manufacturing an in-mold label container according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

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

As shown in FIGS. 1A and 1B, the in-mold label container 10 includes a substantially square tubular body portion 11 having a flange portion 14 and a bottom portion 12 connected below the body portion 11.

Further, the in-mold label container 10 is formed on the sheet molded body 3, the label 4 having at least the body label 5 and the bottom label 7, and the label 4, and is interposed between the sheet molded body 3 and the label 4. It has the injection resin 8 which has been made.

Of these, the sheet molded body 3 is located inside the injection resin 8, and has 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. Has a container shape that includes. Such a sheet molded body 3 may have a gas barrier property as a whole. Further, 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.

Further, the label 4 is located outside the injection resin 8 and has a body label 5 corresponding to the body 11 and a bottom label 7 corresponding to the bottom 12. Such a label 4 may have a gas barrier property as a whole. A gate hole 7a for injecting the injection resin 8 is formed in the center of the bottom label 7. The gas barrier property referred to here means at least an oxygen barrier property, but may be a water vapor barrier property in addition to the oxygen barrier property.

Further, as shown in FIG. 2, the body label 5 and the bottom label 7 constituting the label 4 are integrally formed. The body label 5 has a plurality of portions 5a, 5b, 5c, and 5d extending outward from the peripheral edge of the bottom label 7. In this way, the peripheral edge 4a of the label 4 is defined by the bottom label 7 and the four portions 5a, 5b, 5c, 5d of the body label 5. Such a label 4 can be produced by punching a laminate 24, which will be described later, with a laser or the like.

Further, the body label 5 does not exist between the portions 5a, 5b, 5c, and 5d of the body label 5, and a gap is formed. In this case, as shown in FIGS. 3A and 3B, in the in-mold label container 10, the portions 5a, 5b, 5c, and 5d do not overlap each other, and the portions 5a, 5b, 5c, and 5d of the body label 5 do not overlap each other. A gap is formed in.

In such an in-mold label container 10, as shown in FIG. 3B, the glossiness around the peripheral edge 4a and the gate hole 7a of the label 4 is lower than the glossiness of the other parts of the label 4. In this case, for example, the 60-degree mirror glossiness around the peripheral edge 4a and the gate hole 7a of the label 4 measured by the mirror glossiness measuring method based on JIS-Z-8741 can be 70 or less. Further, the 60-degree mirror glossiness of the other portion can be 70 or more. In FIG. 3B, the areas around the peripheral edge 4a of the label 4 and the gate hole 7a where the glossiness is low are shaded. The region having low glossiness (low gloss region) extends in a band shape along the peripheral edge 4a of the label 4 and the peripheral edge of the gate hole 7a. The glossiness can be measured with a gloss meter (for example, 1G-331 manufactured by Higashiba Seisakusho Co., Ltd.).

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 an injection resin 8 injected onto the flange portion sheet 3c.

The contents are filled in the in-mold label container 10 having such a structure. Next, the lid material 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.

Next, the sheet molded body 3 will be further described with reference to FIGS. 1A and 4.

As shown in FIG. 1A, the sheet molded body 3 receives the gate 22a described later of the mold 20 described later on the surface on the label 4 side (see FIGS. 6 to 7B), and the injection resin 8 from the gate 22a. A gate receiving portion 33 for receiving is provided. The gate receiving portion 33 is formed in a concave shape having a tapered shape so as to be pulled toward the core 21 side of the mold 20 described later. Further, the core 21 of the mold 20 is formed with a recess 21a having a shape corresponding to the gate receiving portion 33. As a result, the gate receiving portion 33 of the sheet molded body 3 can be fitted into the recess 21a of the core 21, and the sheet molded body 3 can be reliably mounted on the core 21 (FIGS. 6 to 6 to 6). See FIG. 7B).

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

That is, as shown in FIG. 4, the laminate 23 constituting the sheet molded body 3 has a polypropylene layer (PP) 23a as a synthetic resin layer sequentially arranged from the outside and ethylene vinyl as a gas barrier layer having a gas barrier property. It contains an alcohol copolymer layer (EVOH) 23b and a polypropylene layer (PP) 23c as an adhesive layer.

Then, by vacuum-molding the sheet-shaped laminated body 23 configured in this way, the sheet-shaped body 3 having a container shape can be obtained.

Next, the label 4 having the body label 5 and the bottom label 7, and the injection resin 8 will be described below.

First, label 4 will be described. The label 4 having the body label 5 and the bottom label 7 is composed of a laminated body 24 having a layer structure as shown in FIG.

That is, as shown in FIG. 5, the label 4 having the body label 5 and the bottom label 7 has (i) an adhesive layer 24a with the injection resin 8, (ii) a synthetic resin layer 24b, and (iii) a gas barrier layer. It is composed of 24c and (iv) a printing substrate layer 24d (here, the layer (i) and the layer (ii) can be used in combination). Each of these layers 24a, 24b, 24c, and 24d is independently formed into a film and bonded (dry lamination) via an adhesive, or a part or all of the layers are melt-extruded (EC, co-extruded). It can also be formed by. Further, the printing base material 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 8, but usually, a plastic made of the same material as the injection resin 8 or polyethylene containing EVA (ethylene-vinyl acetate copolymer) is adhered. A resin having properties, or a plastic film in which the resin is co-extruded or coated, can be preferably used.

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

The gas barrier layer 24c includes, for example, (a) an 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, for example, a silicon oxide vapor deposition plastic film or aluminum oxide vapor deposition. Plastic film, aluminum vapor-deposited plastic film, (c) and others, polyacrylonitrile-based resin, EVOH (ethylene vinyl alcohol copolymer), PVDC (polyvinylidene chloride) film, PVDC-coated biaxially stretched plastic film and the like can be mentioned as desired. It can be appropriately selected according to the performance. When the sheet molded product 3 has sufficient gas barrier properties, the label 4 does not necessarily have to have the gas barrier layer 24c.

The film as the print base 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 appropriately used.

Each of the above layers is formed by a dry lamination method, an extrusion lamination method, an extrusion coating method or another 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 seal stretched polypropylene layer (HSOPP) 30 μm / aluminum foil 7 μm / stretched polypropylene layer (OPP) 30 μm
(2) Heat seal stretched polypropylene layer (HSOPP) 30 μm / VM-PET 12 μm / stretched polypropylene layer (OPP) 30 μm
(3) Heat sealant coating / stretched polypropylene layer (OPP) 30 μm / aluminum foil 7 μm / stretched polypropylene layer (OPP) 30 μm

Further, as the injection resin 8 used in 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 mold 20 for in-mold molding will be described.

As shown in FIG. 6, the mold 20 has a core 21 for adsorbing the sheet molded body 3 and a cavity 22 for adsorbing the label 4. Of these, the core 21 is formed with a recess 21a having a tapered shape corresponding to the gate receiving portion 33 of the sheet molded body 3 described above (see FIG. 7A). As a result, the gate receiving portion 33 of the sheet molded body 3 is fitted into the recess 21a of the core 21, and the sheet molded body 3 can be reliably mounted on the core 21.

The mold 22 with a cavity is formed with a protrusion 22b that penetrates the gate hole 7a of the label 4 when the label 4 is mounted. An injection port 22a for injecting the injection resin 8 is formed on the protrusion 22b, and the injection resin is formed on the label 4 by injecting the injection resin 8 from the injection port 22a.

Further, the cavity-attached mold 22 is surface-treated at a position straddling the peripheral edge 4a and the gate hole 7a of the label 4 in a state where the label 4 is attached. That is, the peripheral edge 4a of the label 4 and the peripheral edge of the gate hole 7a are located inside in the width direction of the surface-treated region. As a result, the slipperiness of the cavity-attached mold 22 can be improved, and the adhesion between the cavity-attached mold 22 and the label 4 can be reduced. Therefore, it is possible to prevent the label 4 from sticking to a position other than the desired position in the mold 20. In FIG. 6, the surface-treated area is shaded.

As shown in FIG. 7A, the mold 22 with a cavity is coated with a release layer 25 by surface treatment. The release layer 25 may contain, for example, a fluorine-based resin or ceramic. Since the release layer 25 is coated on the mold 22 with a cavity by surface treatment, the non-adhesiveness of the mold 22 with a cavity can be improved, and the in-mold label container 10 (label) from the mold 20 can be improved. The releasability of 4) can be improved. Therefore, it is possible to prevent the residue of the laminated body 24 adhering to the label 4 from adhering to the mold 20 and accumulating.

Further, when the release layer 25 contains a fluororesin, the non-adhesiveness of the cavity-attached mold 22 can be effectively improved, and the in-mold label container 10 (label 4) from the mold 20 can be used. The releasability can be improved. Therefore, it is possible to further suppress the problem that the residue of the laminated body 24 adhering to the label 4 adheres to the mold 20 and accumulates. Further, when the release layer 25 contains a fluororesin, the slipperiness of the cavity-attached mold 22 can be improved. As a result, the adhesion between the cavity-attached mold 22 and the label 4 can be reduced, and it is possible to prevent a problem that the label 4 adheres to a position other than a desired position in the mold 20. Therefore, it is possible to suppress the occurrence of wrinkles on the label 4 on the surface of the in-mold label container 10, and it is possible to suppress poor appearance.

Further, in the mold 22 with a cavity, in addition to the release layer 25, a fine uneven shape 26 is formed by surface treatment. The release layer 25 covers the uneven shape 26. Alternatively, the uneven shape 26 is formed on the surface of the release layer 25. By forming the fine uneven shape 26 on the mold 22 with a cavity, the contact area between the mold 20 and the label 4 can be reduced, and the adhesion between the mold 20 and the label 4 can be reduced. Can be done. In this case, the surface roughness of the concave-convex shape 26 depends on the configuration of the mold 22 with a cavity and the label 4 to be used, but for example, the maximum height roughness Rz of the concave-convex shape 26 is set to 1 μm or more and 50 μm or less. Can be done. The maximum height roughness conforms to JIS-B0601-2013.

It is preferable that such a surface treatment is performed within a range of 1 mm or more from the peripheral edge 4a of the label 4 or the gate hole 7a in the state where the label 4 is attached. By setting the range to which the surface treatment is applied to 1 mm or more from the peripheral edge 4a of the label 4 or the gate hole 7a in the state where the label 4 is attached, the residue of the laminated body 24 adhering to the label 4 has a cavity as described later. Adhesion to the mold 22 can be effectively suppressed. The surface treatment may be applied to the entire surface of the cavity-attached mold 22. In this case, the adhesion between the cavity-attached mold 22 and the label 4 can be reduced, and a problem that the label 4 adheres to a position other than a desired position in the mold 20 can be prevented.

As shown in FIG. 7B, only the concave-convex shape 26 may be formed without coating the release layer 25 on the cavity-attached mold 22. In this case, for example, the concave-convex shape 26 can be formed by subjecting the die 22 with a cavity to a shot peening process.

Next, a method for manufacturing the in-mold label container will be described with reference to FIGS. 8A to 9C.

First, the sheet-shaped laminated body 23 is vacuum-molded to obtain a sheet-shaped body 3 having a container shape.

Further, in parallel with producing the sheet molded body 3, a label 4 having a body label 5 and a bottom label 7 is prepared. At this time, first, the laminated body 24 is prepared. Next, the laminate 24 is punched out with a laser or the like to obtain the label 4.

Next, as shown in FIG. 8A, a mold 20 having a core 21 and a mold 22 with a cavity is prepared.

Next, as shown in FIG. 8B, the sheet molded body 3 is mounted in the mold 20. In this case, the sheet molded body 3 is adsorbed on the core 21 of the mold 20.

Next, as shown in FIG. 9A, a label 4 having a gate hole 7a through which the injection resin 8 passes is mounted in the mold 20. In this case, the label 4 is attracted to the cavity-equipped mold 22 of the mold 20. At this time, the mold 22 with a cavity is coated with a release layer 25 by surface treatment, and the release layer 25 contains a fluorine-based resin. As a result, the slipperiness of the cavity-attached mold 22 is improved, and the adhesion between the cavity-attached mold 22 and the label 4 is reduced. Further, the mold 22 with a cavity is formed with a fine uneven shape 26 by surface treatment. As a result, the contact area between the mold 20 and the label 4 is reduced, and the adhesion between the mold 22 with a cavity and the label 4 is reduced. Therefore, when the label 4 is attached to the cavity-attached mold 22, the label 4 becomes easy to move on the cavity-attached mold 22, and the problem that the label 4 adheres to a position other than the desired position in the mold 20 is prevented. NS. As a result, it is possible to suppress the occurrence of wrinkles on the label 4 on the surface of the in-mold label container 10, and it is possible to suppress poor appearance.

Next, the injection resin 8 is injected onto the label 4 attached to the mold 20. At this time, first, the core 21 is brought close to the cavity-attached mold 22, the core 21 is inserted into the cavity-attached mold 22, and the cavity-attached mold 22 and the core 21 are molded. Next, in this state, the injection resin 8 is injected into the space between the cavity-attached mold 22 and the core 21 from the gate (injection port) 22a of the injection resin 8 provided in the cavity-attached mold 22 (FIG. 9B). In this case, the spout 22a is formed in the protrusion 22b formed on the mold 22 with a cavity, penetrates the gate hole 7a of the bottom label 7, and protrudes into the mold 20. The injection resin 8 injected from such an injection port 22a penetrates between the sheet molded body 3 and the label 4 through the gate hole 7a provided in the label 4, and the injection resin 8 allows the sheet molded body 3 and the label to enter. 4 is adhered to and the in-mold label container 10 is molded.

At this time, the injection resin 8 that has entered between the sheet molded body 3 and the label 4 from the gate hole 7a spreads radially between the bottom sheet 3b of the sheet molded body 3 and the bottom label 7 of the label 4. To go. In this case, since the sheet molded body 3 is provided with the gate receiving portion 33 having a tapered shape for receiving the injection resin 8, the injection resin 8 ejected from the injection port 22a is received by the gate receiving portion 33, and then the gate receiving portion 33 is provided. The tapered gate receiving portion 33 can smoothly guide the injection resin 8 between the sheet molded body 3 and the label 4 in the horizontal direction.

Then, as shown in FIG. 9C, the obtained in-mold label container 10 is taken out from the mold 20 to the outside.

By the way, in the in-mold label container 10 according to the present embodiment, as described above, the glossiness of at least one of the peripheral edge 4a of the label 4 and the periphery of the gate hole 7a is lower than the glossiness of the other portion of the label 4. It has become. This is considered to be due to the following reasons. That is, the mold 22 with a cavity is coated with the release layer 25 by surface treatment, and the concave-convex shape 26 is formed. As a result, the surface of the label 4 follows the shape of the uneven shape 26 during in-mold molding. Therefore, the surface roughness of the label 4 in the surface-treated region is rougher than the surface roughness of the label 4 in the unsurface-treated region. As a result, it is considered that the glossiness of the label 4 is lower in the surface-treated region than in the non-surface-treated region.

As described above, according to the present embodiment, the surface treatment is applied to the cavity-equipped mold 22 of the mold 20 at a position straddling the peripheral edge 4a of the label 4 and the gate hole 7a in a state where the label 4 is attached. ing. As a result, it is possible to prevent the residue of the laminated body 24 adhering to the label 4 from adhering to the mold 20 and accumulating. Further, the slipperiness of the cavity-attached mold 22 can be improved, and the adhesion between the cavity-attached mold 22 and the label 4 can be reduced. Therefore, it is possible to prevent the label 4 from sticking to a position other than the desired position in the mold 20.

Further, according to the present embodiment, a fine uneven shape 26 is formed on the mold 22 with a cavity of the mold 20 by surface treatment. Thereby, the slipperiness of the cavity-attached mold 22 can be effectively improved.

Further, according to the present embodiment, the mold 22 with a cavity of the mold 20 is coated with the release layer 25 by surface treatment. As a result, the non-adhesiveness of the cavity-attached mold 22 can be improved, and the releasability of the in-mold label container 10 (label 4) from the mold 20 can be improved. Therefore, it is possible to prevent the residue of the laminated body 24 adhering to the label 4 from adhering to the mold 20 and accumulating.

Further, according to the present embodiment, the release layer 25 contains a fluororesin. As a result, the non-adhesiveness of the cavity-attached mold 22 can be effectively improved, and the releasability of the in-mold label container 10 (label 4) from the mold 20 can be effectively improved. .. Therefore, it is possible to prevent the residue of the laminated body 24 adhering to the label 4 from adhering to the mold 20 and accumulating. Further, in this case, the slipperiness of the cavity-attached mold 22 can be effectively improved, and the adhesion between the cavity-attached mold 22 and the label 4 can be effectively reduced. As a result, it is possible to more effectively suppress the problem that the label 4 adheres to a position other than the desired position in the mold 20. Therefore, it is possible to suppress the occurrence of wrinkles on the label 4 on the surface of the in-mold label container 10, and it is possible to suppress poor appearance.

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 present invention is not limited to this, and the sheet molded body 3 is an injection resin. The label 4 may be arranged on the outside of the injection resin 8 and may be arranged on the inside of the injection resin 8. In this case, the surface treatment described in the above embodiment may be applied to the core 21. Even in this case, it is possible to prevent the residue of the laminated body 24 adhering to the label 4 from accumulating in the mold 20.

Further, in the above embodiment, the example in which the in-mold label container 10 includes the sheet molded body 3 is shown, but the present invention is not limited to this, and the in-mold label container 10 does not include the sheet molded body 3, and the label 4 and It may be composed of the injection resin 8. In this case, the surface treatment described in the above embodiment may be applied to one of the core 21 and the mold 22 with a cavity, or may be applied to both.

Further, in the above embodiment, the cavity-attached mold 22 is subjected to surface treatment at a position straddling the peripheral edge 4a of the label 4 and the gate hole 7a in a state where the label 4 is attached to the mold 20. However, the surface treatment is not limited to this, and the surface treatment may be applied to a position straddling only one of the peripheral edge 4a and the gate hole 7a of the label 4.

Next, a specific example of the above-described embodiment will be described.

(Example 1)
Polypropylene was used as the injection resin 8, and the laminate 24 having the following layer structure was used as the label 4. At this time, the label 4 was produced by punching the laminate 24 by laser cutting.
OPP / printing layer / adhesive layer / PET / adhesive layer / HSOPP
Here, "OPP" means a stretched polypropylene film. "PET" means a polyethylene terephthalate film. "HSOPP" means a stretched polypropylene film having a heat-sealing property.

Using these injection resins 8 and the label 4, the in-mold label container 10 according to the present embodiment was produced by the methods shown in FIGS. 8A to 9C. The in-mold label container 10 was continuously prepared for 1 hour. At this time, the mold 22 with a cavity of the mold 20 was subjected to Nifgrip (registered trademark) as a surface treatment, and the mold 22 with a cavity was coated with a release layer containing a fluorine-based resin. After that, it was confirmed whether or not the residue of the laminated body 24 was attached to the mold 20. Further, in the obtained in-mold label container 10, it was confirmed whether or not the label 4 had wrinkles. The results are shown in Table 1. In Table 1, the evaluation criterion "◎" indicates "excellent", the evaluation criterion "○" indicates "good", and the evaluation criterion "x" indicates "poor". ..

(Example 2)
The laminated body 24 is formed on the mold 20 in the same manner as in the first embodiment, except that the mold 22 with a cavity of the mold 20 is subjected to shot peening processing as a surface treatment to form a fine uneven shape 26. It was confirmed whether or not the residue was attached. Further, in the obtained in-mold label container 10, it was confirmed whether or not the label 4 had wrinkles. The results are shown in Table 1.

(Comparison example)
It was confirmed in the same manner as in Example 1 whether or not the residue of the laminated body was attached to the mold except that the mold with a cavity of the mold was not surface-treated. In addition, it was confirmed whether or not the label had wrinkles in the obtained in-mold label container. The results are shown in Table 1.

As a result, in the comparative example in which the mold with a cavity was not surface-treated, it was confirmed that a large amount of residue of the laminated body adhered to the mold. On the other hand, in Example 1 in which the mold 22 with a cavity was coated with the release layer 25 containing a fluororesin by the surface treatment, the adhesion of the residue of the laminated body 24 to the mold 20 was not confirmed. Further, in Example 2 in which the concave-convex shape 26 was formed on the cavity-attached mold 22 by the surface treatment, it was possible to reduce the adhesion of the residue of the laminated body 24 to the mold 20.

Further, in the comparative example, the occurrence of wrinkles on the label 4 was confirmed in the in-mold label container 10. On the other hand, in Examples 1 and 2, no wrinkles were confirmed on the label 4.

As described above, according to the present embodiment, according to the present embodiment, it is possible to suppress the problem that the residue of the laminated body 24 adhering to the label 4 adheres to the mold 20 and accumulates. In addition, it is possible to suppress the occurrence of wrinkles on the label 4 on the surface of the in-mold label container 10. As a result, it is possible to suppress appearance defects and molding defects.

It is also possible to appropriately combine the plurality of components disclosed in the above-described embodiment as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiment.

4 Label 4a Periphery 5 Body label 7 Bottom label 7a Gate hole 8 Injection resin 10 In-mold label container 11 Body 12 Bottom 20 Mold 21 Core 22 Cavity mold 25 Peeling layer 26 Concavo-convex shape

Claims (3)

In the manufacturing method of in-mold label containers
The process of preparing a mold having a core and a mold with a cavity,
A process of mounting a label having a gate hole through which the injection resin passes in the mold, and
The label mounted in the mold is provided with a step of injecting the injection resin.
At least one of the core of the mold and the mold with a cavity is surface-treated at a position straddling at least one of the peripheral edge of the label and the gate hole when the label is attached. Label,
A method for producing an in-mold label container , wherein at least one of the core and the mold with a cavity is coated with a release layer by the surface treatment. The production of the in-mold label container according to claim 1, wherein a fine uneven shape is formed on at least one of the core of the mold and the mold with a cavity by the surface treatment. Method. The method for manufacturing an in-mold label container according to claim 1 or 2 , wherein the release layer contains a fluororesin.

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