JP2012025415A - In-mold label container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-mold label container which prevents a gap from being made between adjacent labels in the formation of the in-mold label container and which makes the label bring about a new function not intrinsically belonging to a container body.SOLUTION: The in-mold label container includes a part overlapping the adjacent label. The molding wall-thickness of the overlapping part is set greater by 1-5 times of thickness of the label for use than the molding wall-thickness of other parts not overlapping the adjacent label. Thus, thermal energy required for uniform adhesion of the label is supplied from a molten resin, so that the label can bring about the new function not intrinsically belonging to the container body.

Description

  The present invention relates to an in-mold label container obtained by carrying out formation of a container body and labeling in one step in packaging containers for drugs, detergents, toiletries, foods, etc. Thus, an in-mold label container that provides a new function to the container body is proposed.

  In-mold label containers that perform labeling at the same time as molding are used to increase the added value of the container in combination with a functional film, in addition to improving efficiency and efficiency by reducing manufacturing processes and reducing costs. That is, the skeleton of the container is a three-dimensional molded body such as blow molding or injection molding. For example, as a functional film, a barrier film that prevents the permeation of gases such as oxygen and water vapor is used as an in-mold label. As a new function that cannot be supplemented by this function, it is possible to reduce the oxidation and deterioration of the contents, which can greatly contribute to the protection of the contents, which is the mission of the container.

  For example, in an in-mold label container using a barrier film as an in-mold label, a barrier that prevents the transmission of gas such as oxygen and water vapor to the function of the container itself by attaching the in-mold label to the surface of the molding container without any gap. The container which has property can be provided.

  In the pasting of the in-mold label, the following factors can be considered as a factor causing a gap between adjacent labels. For example, the dimensional accuracy of the label, the positional accuracy of the label, and the deformation of the label due to molding can be improved. In particular, in the injection in mold formation, the molten resin flows on the label surface at a high speed. It greatly affects the displacement. Therefore, the label gap area varies from molding to molding, and there is a risk that variations in container performance, particularly barrier properties, will increase.

  In addition to the barrier property, the functions expected by the in-mold label overlaying include high light-shielding properties and design properties. As with the barrier property, the in-mold label can be applied to the surface of the container body without any gaps. Thus, it is possible to provide an in-mold label container that has a function that is not originally provided in the container body.

  As a method for affixing an in-mold label to the surface of a molding container without a gap, for example, in Patent Document 1, 0.5 mm is laminated on an adjacent label as a means for preventing oxygen from entering through a gap between labels having a barrier property. Proposals have been made.

  However, the above method has two major problems. The first is the labeling position accuracy. The method of laminating 0.5 mm between adjacent labels described in Patent Document 1 can overlay adjacent labels with relatively high accuracy when the container to which the label is applied has a simple shape. In a rectangular tray-shaped container in which a gap is formed between the side surfaces, it is quite difficult to apply the labels with a dimensional accuracy of 0.5 mm.

The second is the adhesive force due to non-uniform heat conduction to the in-mold label. In forming the in-mold label container, a heat sealant is applied to the label in advance, or a film that melts at a relatively low temperature is used as a sealant layer to form a label. Is used. That is, in the formation of the in-mold label container, the label placed in advance in the mold at the time of container molding and the molten resin forming the container body are in direct contact with each other so that the label surface is bonded. Accordingly, the overlapped portion of the label is farther from the molten resin forming the container body as a heat source than the other non-overlapping portions, and accordingly, the amount of heat that reaches is reduced, and the adhesion becomes unstable.

JP 2002-255185 A

  The present invention has been made in view of the problems of the background art, and in forming an in-mold label container, it prevents a gap between adjacent labels from being generated, and is more reliably attached inside the mold. The present invention proposes an in-mold label container having a new function which is not originally provided in the main body of the container.

  The invention according to claim 1 for solving the above-mentioned problem is an in-mold label container having a portion overlapping with an adjacent label, wherein the thickness of the molded product of the overlapping portion is that of other non-overlapping portions. An in-mold label container characterized by being 1 to 5 times thicker than the thickness of the label to be used with respect to the thickness of the molded product.

  The invention according to claim 2 for achieving the above object is an in-mold label container, wherein the in-mold label container is formed by injection molding or blow molding.

  The invention described in claim 3 for achieving the above object is characterized in that the material of the front and back of the label is made of the same material as the molding resin of the in-mold label container body. The in-mold label container described in 1.

  In forming the in-mold label container, by making the molded product thickness of the portion overlapping with the adjacent label 1-5 times thicker than the thickness of the molded product thickness of the portion not overlapping with the adjacent label, The adhesion of the entire label can be optimized and the quality can be stabilized.

Container front view Container bottom view <FIG. 3-1> Container AA cross-sectional view (when not overlapping with adjacent label) <FIG. 3-2> Container AA cross-sectional view (when overlapping with adjacent label)

  Below, one Embodiment of this invention is described using FIGS. 1-3.

  FIG. 1 is a front view of an in-mold label container according to the present invention, wherein 1 is a flange part for sealing the container with the contents and 2 is a corner part of the container, and 3 is a side part. Show.

  FIG. 2 is a bottom view of the in-mold label container according to the present invention, and 4 indicates a bottom portion.

FIG. 3 is an in-mold label container according to the present invention, and shows the relationship between the thickness of the molded product and the label in the AA sectional view of FIG. FIG. 3A illustrates a case where the label does not overlap with an adjacent label, and FIG. 3B illustrates a case where the label overlaps with an adjacent label.

  As in the case of label (5) shown in FIG. 3-1, since the formation of a normal in-mold label container does not overlap adjacent labels, that is, there is no overlapping, the thermal energy necessary for adhesion between the label and the container body is Even if the thickness of the molded product of the molten resin, which is a heat energy source, is uniform, it is sufficiently supplied.

  However, as in the present invention, in the formation of an in-mold label container that requires overlapping and overlapping adjacent labels for the purpose of imparting functionality to the container body using a label, the molded product film thickness is uniform. If so, there is a difference in the thermal energy of the molten resin between the part where the label overlaps and the part where it does not overlap. As a result, there is a high possibility that the entire in-mold label cannot be evenly bonded, and quality is added to provide functionality. The problem remains.

  The present invention has been made in view of the above problems, and according to the present invention, the molded product thickness (8) corresponding to the label overlapping portion (6) shown in FIG. The thickness of the molded product corresponding to the part (5) having no gap (7) is made thicker, that is, by supplying more molten resin as a heat energy source necessary for the adhesion of the label, the adhesion between the label and the container body can be improved. Optimization is possible.

  According to the present invention, the molded product thickness (8) corresponding to the label overlapping portion (6) is thicker than the molded product thickness (7) corresponding to the portion (5) without label overlapping. Thermal energy can be supplied effectively and stable label adhesion is possible. However, in consideration of productivity and economy, the molded product thickness (8) corresponding to the label overlapped portion (6) is changed to the molded product thickness (7) corresponding to the portion (5) without label overlapped. On the other hand, it is preferable that the thickness of the label to be used is 1 to 5 times thicker. As the background, according to the experiments by the inventors, an increase in thickness less than 1 times the thickness of the label to be used depends on the molding conditions, but due to the lack of thermal energy due to the molten resin, the label overlapping part (6) adheres. Defects occur. Further, when the thickness is increased by 5 times or more the thickness of the label to be used, an economic problem arises from the molding cycle time and the increase in the amount of resin used.

  As shown in FIG. 1 (front view of container) and 2 (bottom view of container), the container cross-sectional shape is rectangular, the outer dimension of one side is 100 mm at the bottom, the top opening is 120 mm, and the height is 25 mm. The in-mold label container formed by laying a flange (1) for attaching a film to the opening was formed.

Prior to the formation of the in-mold label container, a barrier film with a thickness of 40 nm is applied to a PET film with a thickness of 12 μm under a 10 ⁻¹ Pa condition, and a polypropylene film with a thickness of 20 μm is laminated from both sides, and the thickness is combined with the adhesive layer. A 60 μm label was prepared.

  Next, using the label, the base film of the label is punched out with a punching die processed into a container development view, and the sides are connected to the respective sides around the bottom rectangle, and the outer surface of the container is removed except for the flange portion. It was produced in a shape to cover.

  In the in-mold label container mold, the molded product thickness (8) corresponding to the label overlapping portion (6) is 900 μm, and the molded product thickness (7) corresponding to the portion (5) where the label is not stacked is pasted. A mold for the entire injection molding was prepared to be 700 μm.

  The label was inserted into the injection mold and injected under the condition of a resin temperature of 210 ° C. using polypropylene resin to form an in-mold label container.

  Next, a metal plate was bonded to the flange portion, and oxygen permeability was measured. The results are shown in Table 1.

[Comparative Example 1]
For the in-mold label container mold, the molded product thickness (8) corresponding to the label overlapping portion (6) and the molded product thickness (7) corresponding to the portion (5) without label overlapping are the same 700 μm. Thus, a mold for the entire injection molding was produced.

  In-mold label containers were formed under the same conditions as in Example 1 except for the above mold, and acid permeability was measured by the same method as in Example 1. The results are shown in Table 1.

Table 1 shows the oxygen permeability of Example 1 and Comparative Example 1.

  From the results of Table 1, in forming an in-mold label container, a label to be used is a part thickness (8) that overlaps with an adjacent label from a part thickness (7) that does not overlap with an adjacent label. By making the thickness 3.3 times thicker, it was possible to optimize the adhesion of the entire label and to stabilize the quality.

DESCRIPTION OF SYMBOLS 1 ... Flange part 2 ... Corner part 3 ... Side part 4 ... Bottom face part 5 ... Label (no overlapping)
6 ... Label overlapped portion 7 ... Molded product thick portion corresponding to label non-overlaid portion 8 ... Molded product thick portion corresponding to label overlapped portion

Claims (3)

  It is an in-mold label container which has a part which overlaps with an adjacent label, Comprising: The molded product thickness of the said overlapping part is 1-5 of the thickness of the label to be used with respect to the molded product thickness of the other non-overlapping part. An in-mold label container that is twice as thick.   The in-mold label container according to claim 1, wherein the molding method is injection molding or blow molding.   The in-mold label container according to claim 1 or 2, wherein the front and back materials of the label are made of the same material as the molding resin of the in-mold label container body.

Images