JP2011081100A - In-mold label and method of manufacturing in-mold label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-mold label stably laminating a sealant film in the in-mold label on the whole surface of a substrate back surface and capable of imparting adequate strength and high design flexibility to the in-mold label. <P>SOLUTION: The in-mold label to be used for an in-mold molding device has: a base layer 20; a temporal tacking layer 30 made by forming an ultra-violet curable adhesive 31 (or adhesive material) onto the back surface of the base layer 20; and a sealant layer 40 made by forming a sealant film onto the back surface of the temporal tacking layer 30. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an in-mold label used in an in-mold molding machine and a method for producing the in-mold label.

  Conventionally, there are in-mold labels used in in-mold molding, and among these, there are those in which the base material of the in-mold label melts and exhibits adhesiveness. In this case, when an in-mold label is placed in a mold at the time of in-mold molding and a molten resin is injected, the in-mold label itself is melted by the heat of the molten resin and has adhesiveness. For this reason, molten resin and a base material are comprised integrally.

  However, since the base material is not made of only the adhesive material, if it relies on the adhesive property of the base material only, the adhesive force may be insufficient for a molded product such as a bottle at the time of molding. For this reason, it was necessary to give adhesive strength to a base material. Recently, there has been an increase in the number of substrates that print. Thus, when printing is performed on the base material, the printing is disturbed if the base material is melted.

  For this reason, there is a multilayer in-mold label in which an adhesive layer having adhesive properties is laminated on the opposite surface or the same surface of the substrate so as not to affect the printing on the substrate (for example, patents) Reference 1 to Patent Document 3).

  There are various types of materials that constitute the adhesive layer, but it is also possible to use a sealant film that exhibits an adhesive force when heated.

Japanese Patent No. 3163645 JP 2005-91594 A Japanese Utility Model Publication No. 06-055727

  However, actually, even if the sealant film is laminated on the substrate with hot pressure, wrinkles, distortion, curl, etc. are generated in the sealant film due to the effect of heat shrinkage. For this reason, there existed a problem that it was difficult to laminate | stack stably a sealant film with respect to the whole region of a base material back surface.

  If the sealant film is not evenly formed on the entire area of the substrate and the in-mold label is placed in the mold and molded, the adhesion of the in-mold label to the resin molded product such as a container is improved. There may be unevenness.

  Moreover, when time passes immediately after molding a resin molded product, the resin molded product is cooled, its volume is reduced, and its surface contracts. At this time, if the base material of the in-mold label was directly attached to the sealant film, the base material also contracted with the volume shrinkage of the resin molded product, so that wrinkles were generated on the surface of the in-mold label.

  For this reason, an object of the present invention is to stably laminate a sealant film in an in-mold label on the entire back surface of the substrate, and to give sufficient strength and high designability to the in-mold label.

  The configuration of the in-mold label of the present invention for achieving the above object is an in-mold label for use in an in-mold molding machine, and a base material layer and an ultraviolet curable adhesive material on the back surface of the base material layer or An in-mold label comprising: a temporary fixing layer formed of an adhesive; and a sealant layer formed of a sealant film on a back surface of the temporary fixing layer.

  The pattern formed of the ultraviolet curable pressure-sensitive adhesive material or adhesive in the temporary fixing layer may be a pattern having a gap.

  The method for producing an in-mold label is a method for producing an in-mold label, wherein a temporary fixing layer forming step of applying an ultraviolet curable adhesive or an adhesive to the back surface of the base material layer, and the ultraviolet curable adhesive An in-mold label manufacturing method comprising: an ultraviolet irradiation process for irradiating a material or an adhesive with ultraviolet light; and a film pressing process for pressing a sealant film on the back surface of the temporary fixing layer.

  In addition, the said ultraviolet irradiation process and the said sealant film press-contact process may be reverse.

  According to the above structure and manufacturing method, a sealant film can be stably laminated | stacked on the whole surface of a base material back surface. Moreover, when the sealant film is laminated on the entire area of the back surface of the base material, a sufficient adhesive force can be exerted on the back surface of the in-mold label.

  In addition, since the temporary fixing layer with a gap exists, the volume shrinkage of the resin molded product narrows the gap of the temporary fixing layer, but does not directly shrink the base material layer. For this reason, the influence of the shrinkage | contraction of a resin molded product can be relieved, and the wrinkle on the surface of an in-mold label can be relieved as a result. As a result, the design property is high.

  Moreover, when the pattern formed with the said ultraviolet curing adhesive material or an adhesive material in a temporary fixing layer is a pattern which has a clearance gap, the intensity | strength of the in-mold label formed through the in-mold process can be raised. This is because when the in-mold label is molded in-mold, the sealant film fills the gap in the pattern formed by the UV-curing adhesive or adhesive by heat, and the sealant layer directly bonds the base material layer and the resin molded product. It is to do.

Explanatory drawing of a structure of an in-mold label. Explanatory drawing of the manufacturing method of an in-mold label. Explanatory drawing of the use state of an in-mold label. Explanatory drawing of the modification of the manufacturing method of an in-mold label.

  Embodiments of the present invention will be described with reference to the drawings.

(Configuration of in-mold label 1)
FIG. 1 is an explanatory diagram of the configuration of the in-mold label 1.

  As shown to Fig.1 (a), the in-mold label 1 is continuously formed in roll shape. When placed in the mold of the in-mold molding machine, it may be cut and inserted according to the pattern of the print 10, or the print 10 may be placed at an appropriate position in the mold without cutting. You may send it.

  As shown in FIG.1 (b), the cross section of the in-mold label 1 is the base material layer 20 by which the printing 10 was given to the surface, and the ultraviolet curable adhesive material (or adhesive material) on the back surface of the base material layer 20. And a sealant layer 40 formed of a sealant film on the back surface of the temporary seal layer 30.

  The print 10 has a pattern or letters on the surface of the base material layer 20, and a protective layer may be further applied to the surface of the print 10. Moreover, when the pattern is formed in the base material layer 20, the printing 10 is not necessarily required and only a protective layer may be formed on the surface.

  Although the base material layer 20 will not be specifically limited if it can be put into an in-mold molding machine, For example, there exist PET, PP, PE, PP synthetic paper. Moreover, not only a single layer but a multilayer may be sufficient.

  The temporary fixing layer 30 is obtained by partially applying an ultraviolet curable adhesive material 31 to the entire back surface of the base material layer 20 with a flexographic printing machine or the like. The partial application may be a regular pattern such as a dot shape (see FIG. 1C), a linear shape, a lattice shape (see FIG. 2B), but is not limited to this, and is random. It does not matter if it is a pattern.

  Moreover, it is preferable that the pattern of the temporary fixing layer 30 formed by the ultraviolet curable adhesive material 31 is a pattern having a gap S. This is to increase the strength of the in-mold label 1 by filling the gap of the pattern formed by the ultraviolet curable adhesive material with heat when the in-mold label 1 is integrally molded with the container. .

  The sealant layer 40 is obtained by laminating and laminating a sealant film having a property of being bonded by hot pressure on the back surface of the temporary fixing layer 30.

(Method for producing in-mold label 1)
FIG. 2 is an explanatory view of a method for producing an in-mold label.

  As shown in FIG. 2A, the in-mold label manufacturing apparatus 100 used for manufacturing the in-mold label 1 includes a base material feed roll 120 that sends out the base material layer 20 and ultraviolet curing for forming the temporary fixing layer 30. A mold adhesive material coating device 130, a sealant film feed roll 140 that feeds the sealant layer 40, and an in-mold label winding roll 101 that winds the formed in-mold label 1.

  The in-mold label manufacturing apparatus 100 includes an ultraviolet irradiation device 150 on the downstream side of the ultraviolet curable adhesive application device 130 and on the upstream side of the sealant film delivery roll 140. Further, the pressure roller pair 160 is provided as a pressure contact means for pressing the sealant layer 40 against the temporary fixing layer 30. Thus, in this embodiment, the application | coating operation | work of the ultraviolet curable adhesive material 31 is performed in-line with the formation process of the in-mold label 1. FIG.

  The in-mold label 1 is manufactured by the apparatus having the above-described configuration as follows.

  First, a base material is sent out from the base material feed roll 120 (base material sending step). This becomes the base material layer 20. In this step, the printing 10 may be performed on the surface side of the base material layer 20 by the printing machine 110.

  When the base material reaches the ultraviolet curable adhesive material application device 130, the ultraviolet curable adhesive material 31 is applied to the back surface of the base material layer 20. Thereby, the temporary fixing layer 30 is formed in the back surface of the base material layer 20 (temporary fixing layer formation process).

  FIG. 2B is an enlarged perspective view of the ultraviolet curable adhesive material application device 130, and shows an example in which the temporary fixing layer 30 is formed by applying the ultraviolet curable adhesive material 31 in a lattice shape. In the present embodiment, the ultraviolet curable adhesive coating device 130 uses a flexographic printing machine.

  Next, ultraviolet rays are irradiated from the ultraviolet irradiation device 150 in a state where the temporary fixing layer 30 is formed on the back surface of the base material layer 20. Then, an adhesive force is developed in the ultraviolet curable adhesive material 31 (ultraviolet irradiation process).

  In this state, the sealant film separately delivered from the sealant film delivery roll 140 joins the continuous film formed by the base material layer 20 and the temporary fixing layer 30 and is pressed by the pressure roller pair 160 (film Pressure welding process). Then, the base material layer 20 and the sealant layer 40 are temporarily fixed integrally by the adhesive force developed in the temporary fixing layer 30. In this way, the base material layer 20, the temporary fixing layer 30, and the sealant layer 40 are laminated. Finally, the in-mold label 1 is wound up by the in-mold label winding roll 101.

  Thus, in the present embodiment, the temporary fixing layer 30 is formed on the base material layer 20, and the sealant layer 40 is laminated after being irradiated with ultraviolet rays. For this reason, when the in-mold label 1 is laminated, the sealant film can be prevented from being wrinkled, distorted, curled, etc., and the state where the sealant film is laminated on the entire back surface of the substrate can be maintained.

  In addition, since the sealant film is stably laminated on the entire back surface of the base material, the winding operation by the in-mold label winding roll 101 can be smoothly performed.

  Furthermore, since the sealant film is stably laminated on the entire back surface of the base material, a sufficient adhesive force can be exerted on the back surface of the in-mold label at the time of in-mold molding.

(Use state of in-mold label 1)
FIG. 3 is an explanatory diagram of the use state of the in-mold label. As shown in FIG. 3, the in-mold label 1 is integrally formed with a resin molded product B such as a bottle container.

  The resin molded product B may be blow-molded or injection-molded. In either case, the high-temperature molten resin is injected into the mold with the in-mold label 1 placed in the mold. Go through the process. For this reason, the sealant film is melted by the heat of the molten resin and has an adhesive force, and the base material layer 20 is bonded to the resin molded product B through the sealant layer 40.

  In the present embodiment, the sealant film is stably laminated on the entire back surface of the base material layer 20 due to the presence of the temporary fixing layer 30. For this reason, sufficient adhesive force can be exhibited on the back surface of the in-mold label 1.

  In addition, since the sealant film is melted, the melted sealant film fills the gap S of the pattern formed on the temporary fixing layer 30 and the sealant layer 40 directly bonds the base material layer 20 and the resin molded product B ( Bridge structure). For this reason, the strength of the in-mold label 1 can be increased.

  As described above, according to the present embodiment, the base material layer 20 and the sealant layer 40 are stably temporarily fixed over the entire back surface of the base material layer 20 by the ultraviolet curable adhesive material 31 of the temporary fixing layer 30. Therefore, the in-mold label 1 having a high adhesive strength with a molded product and having no visual defects can be manufactured.

  When time elapses immediately after molding the resin molded product B, the resin molded product B cools and its volume shrinks. At this time, if there is no temporary fixing layer and the base material of the in-mold label is directly attached to the resin molded product B, the base material also contracts as the volume of the resin molded product B shrinks. Wrinkles will be generated on the surface. On the other hand, according to the present embodiment in which the temporary fixing layer 30 having the gap S exists, the volume shrinkage of the resin molded product B narrows the gap S of the temporary fixing layer 30, but directly the base material layer 20. Will not shrink. For this reason, the influence of the shrinkage | contraction of the resin molded product B can be relieved, and the wrinkle on the surface of the in-mold label 1 can be relieved as a result. As a result, the design property is high.

  FIG. 4 is an explanatory view of a modification of the method for producing an in-mold label. In the above-described embodiment, before the temporary fixing layer 30 and the sealant layer 40 are pressed, the temporary irradiation layer 30 is irradiated with ultraviolet rays by the ultraviolet irradiation device 150. However, the present invention is not limited to this. That is, as shown in FIG. 4, the temporary fixing layer 30 and the sealant layer 40 may be pressed by the pressure roller pair 160 before the ultraviolet irradiation by the ultraviolet irradiation device 150 is performed.

  Moreover, although the temporary fixing layer 30 in this embodiment was comprised with the ultraviolet curing adhesive, it does not restrict to this. That is, any other adhesive material / adhesive other than the ultraviolet curable material can be used as long as it exhibits the adhesive force / adhesive force by ultraviolet irradiation.

  Moreover, in this embodiment, although it was set as the structure which has the printing 10 on the surface of the base material layer 20, it is not restricted to this. That is, it is good also as a structure which makes the base material layer 20 transparent or semi-transparent, and forms the printing 10 in the back surface.

  The present invention can be used for an in-mold label used in an in-mold molding machine and a method for producing the in-mold label.

B ... Resin molding S ... Gap 1 ... In-mold label 10 ... Printing 20 ... Base material layer 30 ... Temporary stop layer 31 ... UV curable adhesive 40 ... Sealant layer 100 ... In-mold label manufacturing apparatus 101 ... In-mold label winding Take roll 110 ... Printer 120 ... Substrate delivery roll 130 ... UV curable adhesive coating device 140 ... Sealant film delivery roll 150 ... UV irradiation device 160 ... Pressure roller pair

Claims (4)

An in-mold label for use in an in-mold molding machine,
A base material layer;
A temporary fixing layer formed of an ultraviolet curable adhesive material or an adhesive on the back surface of the base material layer;
A sealant layer formed of a sealant film on the back surface of the temporary fixing layer;
An in-mold label characterized by comprising:   The in-mold label according to claim 1, wherein the pattern formed of the ultraviolet curable pressure-sensitive adhesive material or adhesive in the temporary fixing layer is a pattern having a gap. It is a manufacturing method of the in-mold label according to claim 1 or 2,
A temporary fixing layer forming step of applying an ultraviolet curable pressure-sensitive adhesive or adhesive on the back surface of the base material layer;
An ultraviolet irradiation step of irradiating the ultraviolet curable pressure-sensitive adhesive material or adhesive with ultraviolet rays;
A film press-contacting process in which a sealant film is press-contacted to the back surface of the temporary fixing layer;
A method for producing an in-mold label, comprising: It is a manufacturing method of the in-mold label according to claim 1 or 2,
A temporary fixing layer forming step of applying an ultraviolet curable pressure-sensitive adhesive or adhesive on the back surface of the base material layer;
A film press-contacting process in which a sealant film is press-contacted to the back surface of the temporary fixing layer;
An ultraviolet irradiation step of irradiating the ultraviolet curable pressure-sensitive adhesive material or adhesive with ultraviolet rays;
A method for producing an in-mold label, comprising:

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