JP2007136827A - In-mold label sheet, in-mold label and in-mold label container - Google Patents

Abstract

An in-mold label sheet, an in-mold label, and a container with an in-mold label are provided.
An in-mold label sheet 1 includes resin films 12A and 12B made of a thermoplastic resin as raw materials laminated on both surfaces of a nonwoven fabric 11, and a print layer 21 is provided on the upper surface of the resin film 12A. The thickness is 0.7 mm or less, the apparent specific gravity is 0.3 or less, and the curl degree is 10 mm or less. The in-mold label obtained from this in-mold label sheet 1 has less curl and is excellent in workability during in-mold molding. Furthermore, the in-mold label container is excellent in heat insulation.
[Selection] Figure 1

Description

  The present invention relates to an in-mold label sheet, an in-mold label, and an in-mold label container.

2. Description of the Related Art Conventionally, polystyrene foam containers have been widely used as food containers that are used with a heated liquid such as cup ramen. However, recently, the use of such foamed polystyrene has been regarded as a problem from the viewpoint of environmental load.
Therefore, switching to non-foamable containers made of synthetic resin such as polypropylene is also increasing. However, in a container having a general structure, since the heat of the contents is easily transmitted to the outer peripheral surface of the container, an attempt has been made to impart heat insulation properties such as the shape of the container so that the user can directly hold it. Specifically, a container has been proposed in which ribs are raised on the outer peripheral surface of the container main body (for example, Patent Document 1), or a heat insulating material made of a nonwoven fabric is wound around the outer peripheral surface (for example, Patent Document 2). The non-woven fabric is a material that contains air between fibers and can have appropriate heat insulation properties by controlling the thickness and the like.

  On the other hand, when manufacturing a molded product by injection molding, a method of placing a label cut into a predetermined shape in a mold in advance and attaching the label to the molded product simultaneously with injection molding is also known. A label used for such an application is called an in-mold label. In that case, if a nonwoven fabric is used as an in-mold label, a molded article with an in-mold label can be easily obtained (for example, Patent Document 3). And it can also utilize as an in-mold label container which utilized the heat insulation of the nonwoven fabric.

JP 2000-226079 A Japanese Utility Model Publication No. 51-89003 JP 2004-270089 A

  However, in order to manufacture the container described in Patent Document 1, a special injection mold for forming the rib is required, and there is a problem that it is difficult to cope with various shapes of the container. Moreover, in patent document 2, it is necessary to make a strip | belt-shaped nonwoven fabric beforehand, and there exists a problem that the process of adhering this to a cup outer peripheral surface is needed separately. In the method described in Patent Document 3, although an in-mold labeled molded product that makes use of the thermal insulation of the nonwoven fabric can be easily obtained, the injection resin is impregnated between the fibers of the nonwoven fabric by the injection pressure during molding, There is a problem that voids inherent to the nonwoven fabric are reduced and the heat insulation is impaired.

  An object of the present invention is to provide a sheet for an in-mold label that can provide heat insulation that can be held with human hands, for example, in a container containing a hot beverage such as hot coffee or a frozen food such as ice cream. There is to do. It is another object of the present invention to provide an in-mold label and an in-mold label container that are excellent in molding workability made of such a sheet.

  In order to solve the above-described problems, the sheet for in-mold label of the present invention has a resin film made of a thermoplastic resin as a raw material on both sides of a nonwoven fabric, and the sheet has a thickness of 0.7 mm or less and an apparent specific gravity of 0. .3 or less, and the curl degree is 10 mm or less.

According to the sheet for in-mold labels of the present invention, since it has a non-woven fabric layer and has an apparent specific gravity of 0.3 or less, it has excellent heat insulating properties. Therefore, when an in-mold label container is molded based on an in-mold label obtained by punching this sheet into a predetermined shape, even if a high-temperature liquid is put into the container, its outer peripheral surface does not become high temperature, The user can hold the container directly by hand. In addition, since the resin film is laminated on both sides of the nonwoven fabric, the in-mold label has an appropriate rigidity and very little curling, and the workability during in-mold molding (placement in a mold, etc.) is extremely high. Excellent. And since the surface of a nonwoven fabric layer is covered with the resin film, when shape | molding a container with an in-mold label, molten resin does not impregnate a nonwoven fabric layer, and the heat insulation of a nonwoven fabric is not impaired. Furthermore, since this resin film is a thermoplastic resin, it can be easily joined to the container body. Moreover, since the resin film located in both layers of a nonwoven fabric is a thermoplastic resin and has covered the nonwoven fabric, it becomes easy to laminate | stack the film with various functions including a printing layer.
Furthermore, since the sheet has a thickness of 0.7 mm or less and a curl degree of 10 mm or less, the sheet is not bulky even when an in-mold label is used, and the design of the in-mold label container is not hindered. When the thickness exceeds 0.7 mm, the thickness of the container is relatively reduced and the strength of the container is reduced. Further, since the curl degree is 10 mm or less, the sheet is difficult to curl even when it is used as an in-mold label, and is excellent in workability at the time of in-mold molding (such as placing in a mold). The curl degree is preferably 5 mm or less, and more preferably 2 mm or less.
Here, the curl degree is measured by the following method. A 10 cm × 10 cm rectangular sample 1A is cut out from the in-mold label sheet and placed on a flat floor surface F in an environment of 23 ° C. and 50% RH as shown in FIG. After 1 minute has passed, the height L of the most raised end is measured in mm to obtain the “curl degree”.
In addition, as the thermoplastic resin that is a raw material of the resin film located in both layers of the nonwoven fabric, at least one is preferably the same type of thermoplastic resin as the container body from the viewpoint of heat-fusibility during in-mold molding. .

In this invention, it is preferable that the raw material of the said nonwoven fabric is a thermoplastic resin.
According to this invention, since the raw material of the nonwoven fabric which is an intermediate layer of the sheet for in-mold labels is a thermoplastic resin, it is excellent in heat fusion with the thermoplastic resin constituting both layers of the nonwoven fabric.
In this case, if both thermoplastic resins and the resin constituting the in-mold label container body are the same type, it is not necessary to separate the in-mold label from the container when the in-mold label container is discarded. Excellent convenience.

In the present invention, the nonwoven fabric is preferably a spunbonded nonwoven fabric.
According to this invention, since the spunbond nonwoven fabric is composed of continuous long fibers, the nonwoven fabric is excellent in flexibility and strength. Moreover, since it is excellent also in productivity, it can manufacture at low cost. Furthermore, since fiber waste is not generated when the in-mold label is punched out, it is suitable for the present invention.
As a raw material for the spunbonded nonwoven fabric, a polypropylene resin is preferable from the viewpoint of strength and heat-fusibility with a resin film.

In this invention, it is preferable that the raw material of the said resin film is a polypropylene resin.
According to this invention, since the resin film which comprises both layers of a nonwoven fabric is a polypropylene resin, high intensity | strength is obtained when it is set as an in-mold label.
In particular, when the raw material of the nonwoven fabric is a polypropylene-based resin, thermal fusion can be easily performed, and an in-mold label sheet can be easily formed by a thermal lamination method.

In this invention, it is preferable that the said nonwoven fabric and the said resin film are laminated | stacked without using an adhesive agent.
According to this invention, since the nonwoven fabric and the resin film are laminated without using an adhesive, no solvent measures are required at the time of lamination, and the burden on the environment is small. As the laminating method, an extrusion laminating method or a thermal laminating method is preferable because it is simple and has high adhesive strength.

In this invention, it is preferable that the printing layer is provided in the single side | surface.
According to the present invention, since the printed layer is provided on one side of the in-mold label, an in-mold label having a high decorative property can be obtained without impairing the in-mold formability. In particular, in the present invention, since the resin film layers are present in both layers of the nonwoven fabric, the printing layer can be easily laminated on any surface. For example, by applying so-called back printing to a biaxially stretched polyester film (OPET) and laminating it on a resin film layer, an in-mold label that makes use of the gloss and back printing effect of OPET can be obtained.

In the present invention, it is preferable that the resin films laminated on both surfaces of the nonwoven fabric have the same raw material and substantially the same thickness.
According to the present invention, since the resin films laminated on both surfaces of the nonwoven fabric have the same raw materials and substantially the same thickness, the front and back surfaces of the in-mold label sheet have a symmetrical structure, and curl is very small. Become. Therefore, the in-mold label obtained from such an in-mold label sheet also has very little curling and is excellent in workability at the time of in-mold molding.

The in-mold label of the present invention is characterized by using the above-described in-mold label sheet.
Since the in-mold label of the present invention uses the above-mentioned sheet for in-mold label, it is difficult to curl and has excellent workability during in-mold molding, and also has excellent heat insulation.

The in-mold label container of the present invention uses the above-described in-mold label.
Since the in-mold label container of the present invention uses the above-mentioned in-mold label, the in-mold label container is excellent in heat insulating properties. For example, even if hot water is poured into the container, the user can hold it by hand.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view of an in-mold label sheet 1 according to an embodiment of the present invention. The in-mold label sheet 1 includes a resin film 12A made of a thermoplastic resin on both sides of a nonwoven fabric 11, 12B is laminated, and a printed layer 21 is provided on the surface of the resin film 12A.

  The raw material of the nonwoven fabric 11 is arbitrarily selected from those that can be used as a raw material for the continuous long-fiber nonwoven fabric, such as polyethylene resin, polypropylene resin, polyester resin, and polyamide resin. However, when the raw material of the resin films 12A and 12B described later is a polypropylene resin, the polypropylene resin is preferable from the viewpoint of heat-fusibility. Also, from the viewpoint of reducing the weight of the in-mold label container, a polypropylene resin is preferable as a raw material for the nonwoven fabric 11. Furthermore, at the time of in-mold label molding, since the nonwoven fabric 11 is melted if the nonwoven fabric 11 does not have a certain degree of heat resistance under high temperature and high pressure of the injection resin, effective heat insulation cannot be obtained. Polypropylene resin having excellent heat resistance is also suitable. In the present embodiment, both the nonwoven fabric 11 and the resin films 12A and 12B use a polypropylene resin. As the polypropylene resin, any of homopolypropylene, block polypropylene, and random polypropylene may be used.

Although there is no restriction | limiting in particular in the fabric weight of the nonwoven fabric 11, It is preferable that it is 25 g / m < ² > or more from a viewpoint of maintaining the heat insulation of a final in-mold label container, and it is more preferable that it is especially 30 g / m < ² > or more. . If the basis weight is less than 25 g / m ² , effective heat insulation cannot be obtained. Moreover, although there is no restriction | limiting in particular in the apparent specific gravity of the nonwoven fabric 11, 0.3 or less is preferable. If it exceeds 0.3, effective heat insulation cannot be obtained.

As such a nonwoven fabric 11, a well-known thing can be employ | adopted. However, when used as an in-mold label, fraying of the fibers becomes a problem, and a nonwoven fabric made of thermoplastic continuous long fibers such as a spunbond nonwoven fabric is preferable. Since both surfaces of the nonwoven fabric 11 are covered with the resin films 12A and 12B and there is no fiber fraying from the surface, the in-mold label sheet 1 is cut (punched) to form an in-mold label. This is because the fibers fall off from the metal, causing problems such as adhesion to the mold and contamination of the container.
In addition to the spun bond method, methods such as a melt blow method, a spun lace method, a hot air card method, a hot emboss card method, and a flash bond method may be employed.

Here, although the nonwoven fabric 11 in the present embodiment is a spunbond nonwoven fabric, it can be easily manufactured by, for example, a manufacturing apparatus 5 as shown in FIG.
The manufacturing apparatus 5 includes a spinning process, a stretching process, a fiber opening process, and a collecting process. Specifically, the hopper 40, an extruder 41, a die 42, a spinning traction machine 43, The conveyor 44, the winding roll 50, and the bonding apparatus 6 are provided.

  The hopper 40 has an opening into which the raw material of the nonwoven fabric 11 described above is placed. From here, the raw material is injected into the extruder 41. The extruder 41 is, for example, a 45 mmφ single-screw extruder. As the die 42, a known die for performing the spunbond method can be used, and the size and shape thereof can be appropriately changed according to the purpose.

  The thermoplastic resin that is a raw material for the resin films 12A and 12B is preferably selected from the viewpoints of thermal fusion with the nonwoven fabric 11 and thermal fusion with the injection resin (container raw material). Further, from the viewpoint of curling reduction when an in-mold label is formed, the resin films 12A and 12B are preferably made of the same kind of raw material. In general, since polypropylene is often used as a raw material for plastic containers, it is preferable that both the raw material for the nonwoven fabric 11 and the raw materials for the resin films 12A and 12B are polypropylene resins.

The thickness of resin film 12A, 12B does not have a restriction | limiting in particular, What is necessary is just to be able to laminate | stack with a nonwoven fabric. However, since the manufacturing cost of an in-mold label or a container with an in-mold label increases when it is unnecessarily thick, both are preferably 0.05 mm or less. Moreover, when it becomes an in-mold label, it is preferable that the thickness of resin film 12A, 12B is substantially the same from a viewpoint of curl reduction.
Here, the “film” is a concept including a so-called “sheet” having a relatively large thickness.

  The lamination method (laminating method) between the nonwoven fabric 11 and the resin films 12A and 12B is not particularly limited as long as the lamination strength can be ensured. For example, when a biaxially stretched polypropylene film (OPP), an unstretched polypropylene film (CPP), a polyethylene film, or the like previously formed as the resin films 12A and 12B is used, a dry laminating method, a polysand laminating method, a heat Laminating methods and other laminating methods are applicable. Moreover, it is also possible to make resin films 12A and 12B by coating the nonwoven fabric 11 with a resin film such as polypropylene or polyethylene by an extrusion laminating method without using a film formed in advance.

  Here, if an adhesive is used when laminating the nonwoven fabric 11 and the resin films 12A and 12B, high-temperature heat is applied during molding (injection) of the in-mold label container, so the adhesives are so-called hard-bonded. . At the same time, the constituent fibers of the nonwoven fabric 11 to which the adhesive is attached are also bonded together. Therefore, the space | gap of the nonwoven fabric 11 reduces and the heat insulation effect tends to deteriorate. Moreover, when heated as a container for beverages or foods, there is also a problem of odor (adhesive odor). In general, a dry lamination method is used for laminating films. However, since there is no void in the laminate layer, the adhesive does not leak out from the laminate. However, in the case of a nonwoven fabric in which the intermediate layer is a continuous layer of air, the adhesive odor may leak from the end of the in-mold label. Therefore, thermal lamination or extrusion lamination without using an adhesive is preferred.

  In addition, when manufacturing the sheet | seat 1 for in-mold labels, it is preferable from a viewpoint of curl reduction that the two lamination methods which use the nonwoven fabric 11 as an intermediate | middle layer are the same. Furthermore, it is also preferable to laminate in one step instead of two steps. For example, the in-mold label sheet 1 can be obtained in a single step by passing the resin film 12A, the nonwoven fabric 11, and the resin film 12B between a pair of metal heat rolls. In the present embodiment, the above-described three-layer laminate is obtained in one step using a heat laminating method.

Moreover, since the printed layer 21 is provided on the upper surface of the resin film 12A, the in-mold label sheet 1 can provide an in-mold label that is rich in decorativeness without impairing the in-mold formability. For example, if what is called back printing is used for the biaxially-stretched polyester film (OPET) as the printing layer 21, the in-mold label which utilized the glossiness and back printing effect of OPET can be obtained. Alternatively, printing may be performed directly on the resin film 12A. In this case, it is effective to perform pretreatment such as corona treatment on the resin film 12A as necessary. In addition, what is necessary is just to provide such a printing layer 21 as needed.
Moreover, when further product aesthetics, barrier property, etc. are requested | required, you may laminate | stack an aluminum vapor deposition film, a barrier film, etc. The raw material of the nonwoven fabric 11 and the resin films 12A and 12B is preferably chemically the same because it can be recycled without separation when the in-mold label container is discarded.

  Since such an in-mold label sheet 1 has an apparent specific gravity of 0.3 or less, it has excellent heat insulation. The apparent specific gravity is preferably 0.28 or less. Moreover, since the thickness of the sheet | seat 1 for in-mold labels is 0.7 mm or less, even when it is set as an in-mold label, it does not become bulky and does not become a problem on the design of an in-mold label container. Further, the in-mold label sheet 1 has a curl degree (L) shown in FIG. 3 of 10 mm or less. When the curl degree (L) exceeds 10 mm, the in-mold label described later becomes too curled and the workability at the time of in-mold molding is deteriorated. The curl degree is preferably 5 mm or less, and more preferably 2 mm or less.

  The in-mold label sheet 1 can be made into, for example, a fan-shaped in-mold label 100 as shown in FIG. 4 by appropriate cutting (punching), and is used for in-mold molding, for example, An in-mold label container 200 as shown in FIG. 5 can be obtained.

According to the in-mold label sheet 1, the in-mold label 100, and the in-mold label container 200 of the present embodiment as described above, there are the following effects.
(1) Since the in-mold label sheet 1 uses a laminate having a three-layer structure in which the resin films 12A and 12B are laminated on both sides of the nonwoven fabric 11, and the curl degree is 10 mm or less, the in-mold label with less curl 100 can be obtained.
(2) Since the resin films 12A and 12B are laminated on both sides of the nonwoven fabric 11, the in-mold label sheet 1 has an appropriate rigidity and has little curling of the in-mold label 100. Mounting in the mold becomes easy, and the molding operation becomes efficient.

(3) Since the sheet 1 for in-mold labels has a nonwoven fabric layer and an apparent specific gravity is 0.3 or less, it is excellent in heat insulation when it is set as an in-mold label container. That is, even if a high-temperature liquid is put in the container, the outer peripheral surface thereof does not become high temperature, and the user can directly hold the container by hand.
(4) Since the resin films 12A and 12B are laminated on both sides of the non-woven fabric 11, the non-woven fabric 11 is not impregnated with the molten resin when forming a container with an in-mold label, and the heat insulation of the non-woven fabric 11 is impaired. It will not be.

(5) Since the raw material of the resin films 12A and 12B is a thermoplastic resin, the resin films 12A and 12B can be easily joined to the container body. Moreover, it becomes easy to laminate | stack the film which has various functions including the printing layer on resin film 12A, 12B.
(6) Since the raw material of the nonwoven fabric 11 is a polypropylene resin and the raw materials of the resin films 12A and 12B are also a polypropylene resin, they are excellent in mutual heat bondability.

(7) Since the nonwoven fabric 11 is a spunbond nonwoven fabric and is composed of continuous long fibers, the nonwoven fabric is excellent in flexibility and strength. Moreover, since it is excellent also in productivity, it can manufacture at low cost. Furthermore, fiber waste is not generated when the in-mold label is punched out.
(8) The nonwoven fabric 11 and the resin films 12A and 12B are laminated by a heat laminating method that does not use an adhesive, and has a low environmental load and high adhesive strength.

(9) Since the printing layer is provided on the resin film 12A, an in-mold label rich in decorativeness can be obtained without impairing the in-mold moldability.
(10) Since the thickness of the in-mold label sheet 1 is 0.7 mm or less and the curl degree is 10 mm or less, the in-mold label is not bulky and does not hinder the design of the in-mold label container.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications and improvements as long as the object of the present invention can be achieved are included in the present invention. In addition, the specific structure, shape, and the like when carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.
For example, in the above-described embodiment, the spunbond nonwoven fabric is manufactured by using the manufacturing apparatus of FIG. 2 as the manufacturing method of the nonwoven fabric 11, but the manufacturing apparatus of FIG. 2 is not used to obtain the spunbond nonwoven fabric. Alternatively, a melt blow method, a spun lace method, a hot air card method, a hot emboss card method, a flash bond method, or the like may be used without using a spun bond nonwoven fabric as the nonwoven fabric 11.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not restrict | limited at all by the content of these Examples.
[Example 1]
An unstretched polypropylene film (Unilux RS595C, manufactured by Idemitsu Unitech Co., Ltd.) having a basis weight of 100 g / m ^2, a polypropylene spunbonded nonwoven fabric (Stratex RW2100 manufactured by Idemitsu Unitech Co., Ltd., thickness 0.58 mm, apparent specific gravity 0.17). Two sheets of 02 mm and an apparent specific gravity of 0.91) were used and laminated by a thermal laminating method to obtain a three-layer laminate. Here, specifically, as the heat laminating method, the three materials described above are laminated and passed between a pair of rolls composed of a metal roll having projections and depressions (the area ratio of the projections is 20%) and a mirror metal roll. (Both roll surface temperature: 140 ° C., linear pressure 30 kgf / cm).
The obtained laminate had a curl degree of 1 mm, a thickness of 0.60 mm, and an apparent specific gravity of 0.23.

Next, a printed biaxially stretched polyester film (E5100 manufactured by Toyobo Co., Ltd., thickness 12 μm, apparent specific gravity 1.40) is laminated on the above laminate by a dry laminate method to form a four-layer laminate (in-mold label). Sheet). This laminate had a curl degree of 2 mm, a thickness of 0.60 mm, and an apparent specific gravity of 0.26. The four-layer laminate was punched into a fan shape to form an in-mold label.
This in-mold label is placed in an injection mold so that the polypropylene unstretched film is in contact with the container body side, and in-mold injection molding is performed using polypropylene as the resin for injection molding. Was molded. This container has a frustoconical shape with an opening diameter of 7 cmφ at the top, a diameter of 5 cmφ at the bottom, a height of 10 cm, and a wall thickness of 2 mm.
90 ° C. hot water was put into the molded container, and the container surface temperature after 1 minute was measured with a non-contact type thermometer, which was 70 ° C. and could be held by hand. Incidentally, in the case of a container obtained by performing in-mold injection molding without placing an in-mold label, the container surface temperature measured in the same manner was 85 ° C. and could not be held by hand.

[Example 2]
An in-mold label was produced in the same manner as in Example 1 except that a spunbond nonwoven fabric made of polypropylene having a basis weight of 50 g / m ² was used as an intermediate layer (Stratex RW2050 by Idemitsu Unitech, thickness 0.32 mm, apparent specific gravity 0.16). The attached container was molded and the surface temperature was measured in the same manner.
The curl degree of the three-layer laminate is 0.5 mm, the thickness is 0.35 mm, and the apparent specific gravity is 0.25. The curl degree of the four-layer laminate is 1 mm, the thickness is 0.36 mm, and the apparent specific gravity is 0.28. there were. Moreover, the surface temperature of the obtained container with an in-mold label was 75 degreeC, and it was possible to hold it by hand.

[Example 3]
A spunlace nonwoven fabric made of polypropylene with a basis weight of 50 g / m ² (Toyobo's Celes P0050, thickness 0.57 mm, apparent specific gravity 0.08) was used as an intermediate layer, with an in-mold label in the same manner as in Example 1. A container was molded and the surface temperature was measured in the same manner.
The curl degree of the three-layer laminate was 1 mm, the thickness was 0.60 mm, and the apparent specific gravity was 0.15. The curl degree of the four-layer laminate was 1 mm, the thickness was 0.61 mm, and the apparent specific gravity was 0.17. . Further, the surface temperature of the obtained container was 65 ° C. and could be held by hand.
In addition, when the laminated body was punched into a fan shape to obtain an in-mold label, some fiber fraying was seen from the cross section of the nonwoven fabric, but it was not a defective product.

[Comparative Example 1]
An in-mold label was produced in the same manner as in Example 1 except that a spunbond nonwoven fabric made of polypropylene having a weight per unit area of 20 g / m ² was used as an intermediate layer (Stratex RW2020 made by Idemitsu Unitech, thickness 0.18 mm, apparent specific gravity 0.11). The attached container was molded and the surface temperature was measured in the same manner.
The curl degree of the three-layer laminate was 3 mm, the thickness was 0.19 mm, and the apparent specific gravity was 0.32, and the curl degree of the four-layer laminate was 8 mm, the thickness was 0.21 mm, and the apparent specific gravity was 0.34. The surface temperature of the obtained container was 83 ° C. and could not be held by hand.

[Comparative Example 2]
In the same manner as in Example 1, except that a three-dimensional network continuous fiber nonwoven fabric made of polyethylene having a basis weight of 55 g / m ² (Tyvek 1056D made by DuPont, thickness 0.16 mm, apparent specific gravity 0.34) was used as the intermediate layer. A container with a mold label was molded, and the surface temperature was measured in the same manner.
The curl degree of the three-layer laminate was 9 mm, the thickness was 0.19 mm, and the apparent specific gravity was 0.48. The curl degree of the four-layer laminate was 9 mm, the thickness was 0.20 mm, and the apparent specific gravity was 0.54. . The surface temperature of the obtained container was 82 ° C. and could not be held by hand.

[Comparative Example 3]
An unstretched polypropylene film (Unilux RS595C, manufactured by Idemitsu Unitech Co., Ltd.) having a weight of 100 g / m ² as a middle layer using a spunbond nonwoven fabric made of polypropylene (Strade RW2050 manufactured by Idemitsu Unitech Co., Ltd., thickness 0.32 mm, apparent specific gravity 0.16). 02mm, apparent specific gravity 0.91) and biaxially stretched polypropylene film (Toyobo Pyrene P3162, thickness 0.02mm, apparent specific gravity 0.91) were used as the resin film laminated on both sides of the nonwoven fabric. A container with an in-mold label was formed in the same manner as in Example 1.
The curl degree of the three-layer laminate was 25 mm, the thickness was 0.59 mm, and the apparent specific gravity was 0.24. The curl degree of the four-layer laminate was 35 mm, the thickness was 0.60 mm, and the apparent specific gravity was 0.25. .
In-mold molding was performed by punching out the in-mold label from the four-layer laminate in the same manner as in Example 1. However, troubles such as misalignment due to label curl occurred frequently in the label feeding process.

  Since the sheet for in-mold label of the present invention has less curl, it is excellent in workability at the time of in-mold molding as an in-mold label. Furthermore, since the in-mold label container of this invention is excellent in heat insulation, it can be used suitably for uses, such as a cup noodle container and a hot coffee container.

It is a fragmentary sectional view which shows the sheet | seat for in-mold labels which concerns on embodiment of this invention. It is a conceptual diagram which shows the manufacturing process of the nonwoven fabric in the said embodiment. It is sectional drawing which shows the curl degree of the sheet | seat for in-mold labels in the said embodiment. It is a front view of the in-mold label in the embodiment. It is a perspective view of the in-mold label container in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet for in-mold label 11 Nonwoven fabric 12A, 12B Resin film 21 Print layer 100 In-mold label 200 In-mold label container

Claims (10)

A sheet for an in-mold label in which a resin film made from a thermoplastic resin is laminated on both sides of a nonwoven fabric,
The sheet for in-mold label, wherein the sheet has a thickness of 0.7 mm or less, an apparent specific gravity of 0.3 or less, and a curl degree of 10 mm or less. In the in-mold label sheet according to claim 1,
The in-mold label sheet, wherein the raw material of the nonwoven fabric is a thermoplastic resin. In the in-mold label sheet according to claim 2,
The in-mold label sheet, wherein the nonwoven fabric is a spunbond nonwoven fabric. In the in-mold label sheet according to any one of claims 1 to 3,
An in-mold label sheet, wherein the resin film is made of polypropylene resin. In the in-mold label sheet according to any one of claims 1 to 4,
The in-mold label sheet, wherein the nonwoven fabric and the resin film are laminated without using an adhesive. In the in-mold label sheet according to claim 5,
The sheet for in-mold labels, wherein the nonwoven fabric and the resin film are laminated by an extrusion lamination method or a heat lamination method. In the sheet for in-mold labels according to any one of claims 1 to 6,
An in-mold label sheet, wherein a printed layer is provided on one side. In the in-mold label sheet according to any one of claims 1 to 7,
The resin film laminated on both surfaces of the nonwoven fabric has the same raw material and substantially the same thickness, and is an in-mold label sheet.   An in-mold label using the in-mold label sheet according to any one of claims 1 to 8.   An in-mold label container using the in-mold label according to claim 9.

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