WO2021220795A1

WO2021220795A1 - Container with label

Info

Publication number: WO2021220795A1
Application number: PCT/JP2021/015242
Authority: WO
Inventors: 英司疋田; 和樹稲川; 敏博出水; 幸敏榎谷; 智基名取
Original assignee: 株式会社フジシールインターナショナル
Priority date: 2020-04-28
Filing date: 2021-04-13
Publication date: 2021-11-04
Also published as: JPWO2021220795A1

Abstract

Provided is a container with a label that can be efficiently reused.　In the container with a label in which a label is attached, the container is a polyester-based container, and the label has a substrate layer having: a first surface and a second surface facing each other; an adhesive layer attaching the first surface of the substrate layer and the container to each other; a bonding layer laminated on the second surface of the substrate layer; and a printing layer located on the opposite side of the substrate layer when viewed from the bonding layer. The substrate layer is a polyester-based film, the adhesive layer is a polyester-based adhesive, and the bonding layer is soluble in at least one among warm water and an alkaline solution.

Description

Labeled container

The present invention relates to a labeled container.

Currently, various plastic products are on the market. Many plastic products have labels that display product information and the like. For example, many polyethylene terephthalate bottles (PET bottles) filled with beverages and the like inside have labels indicating the beverages and the like inside attached to the outer surface of the PET bottles.

In recent years, there has been a strong demand for reuse of plastic containers from the viewpoint of the environment. For example, a PET bottle reuse system with the above-mentioned label has already been constructed and is widely put into practical use. Specifically, first, the work of removing the label from the PET bottle is carried out, and then the PET bottle after the label is removed is subjected to the recycling process. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2013-527813) discloses an apparatus for continuously removing labels from a plurality of PET bottles.

Special table 2013-527813

However, the work of removing the label is complicated and is one of the factors that hinder the efficient reuse of plastic containers.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a labeled container capable of efficient reuse.

There are two types of labeled containers, one is a type in which the label is adhered to a plastic container, and the other is a type in which the label is put on the container. In the former, the work of removing the label from the container tends to be more complicated than in the latter. This is because when the adhered label is peeled off from the container, a part of the label remains on the surface of the container depending on the force applied. Therefore, the present inventors decided to focus on the realization of efficient reuse of the labeled container to which the label is adhered.

A label having a function such as product display has a printing layer for exerting the function. When such a label is subjected to a recycling process together with a container, it becomes difficult to produce resin pellets having high utility value. This is because the pigment contained in the printing layer affects the physical characteristics and color of the resin pellets. Therefore, in order to regenerate resin pellets having high utility value from the labeled container, it is required to surely separate the label from the container. However, the present inventors have made extensive studies and changed the way of thinking in labeled containers with labels attached, and even if a part of the label remains on the surface of the container, it can be reused more efficiently. Was found to be feasible. The embodiments of the present invention listed below are thus completed.

The labeled container according to an embodiment of the present invention is a labeled container to which a label is adhered, the container is a polyester-based container, and the label is a group having a first surface and a second surface facing each other. The material layer, the adhesive layer that adheres the first surface of the base material layer and the container to each other, the bonding layer laminated on the second surface of the base material layer, and the position on the side opposite to the base material layer when viewed from the bonding layer. It has a printing layer and a printing layer. The base material layer is a polyester-based film, the adhesive layer is a polyester-based adhesive, and the bonding layer is soluble in at least one of warm water and an alkaline solution.

According to the labeled container, the bonding layer is soluble in at least one of hot water and alkaline solution. Therefore, by a simple operation of bringing the labeled container into contact with warm water or an alkaline solution, the bonding layer and the printing layer located on the opposite side of the base layer from the bonding layer can be separated from the labeled container. It can be easily separated.

Further, in the past, in order to recycle a container, the label and the container had to be completely separated as described above, so sufficient care was required in the work of peeling the label from the labeled container. .. On the other hand, according to the labeled container, the bonding layer and the printing layer can be removed from the container even when a part of the label remains on the surface of the container. Since the base material layer and the adhesive layer are made of the same material (polyester resin) as the container, they can be used together with the container in the recycling process.

As described above, according to the above-mentioned labeled container, it is possible to properly recycle the labeled container without paying excessive attention to the complicated work of peeling the label from the labeled container. Therefore, according to the labeled container, efficient reuse can be achieved.

In the above-labeled container, the bonding layer is preferably not soluble in warm water, but soluble in an alkaline solution. According to this, it is possible to sufficiently suppress the layer separation of the label at an unintended timing, and it is possible to efficiently reuse the label when it is used for recycling using an alkaline solution.

In the above-mentioned labeled container, the label preferably has a supporting layer that is located on the side opposite to the base material layer when viewed from the bonding layer and supports the printing layer. According to this, even after the printed layer is separated from the base material layer, the supported layer can support the printed layer, thereby suppressing fine dispersion of the printed layer in warm water or an alkaline solution. Can be done.

In the labeled container, the printing layer is preferably located between the supporting layer and the bonding layer. According to such a labeled container, the supporting layer can function as a protective layer of the printing layer.

According to the present invention, it is possible to provide a labeled container that enables efficient reuse.

FIG. 1 is a side view showing an embodiment of a labeled container according to the first embodiment. FIG. 2 is a cross-sectional view showing an example of a label laminated structure according to the first embodiment. FIG. 3 is a partial cross-sectional view showing a state in which a part of the label is separated in the labeled container according to the first embodiment. FIG. 4 is a cross-sectional view showing a laminated structure of labels according to the second embodiment. FIG. 5 is a cross-sectional view showing a laminated structure of labels according to the third embodiment. FIG. 6 is a side view showing another example of the labeled container.

In the present specification, the numerical range represented by "lower limit value A to upper limit value B" means a lower limit value A or more and an upper limit value B or less. When a plurality of the numerical values are described separately, it is possible to select an arbitrary lower limit value and an arbitrary upper limit value and set "arbitrary lower limit value to arbitrary upper limit value". The dimensions, scale and shape of the layers and members shown in each figure may differ from the actual ones. Hereinafter, an example of the present disclosure will be described with reference to the drawings.

<First Embodiment>
[Labeled container]
FIG. 1 is a perspective view showing an embodiment of a labeled container according to the present invention. In FIG. 1, the labeled container 1 includes a container 10, a label 20, and a cap 30.

[container]
The container 10 has an internal space for accommodating an object to be contained such as food, beverage, and medicine. The label 20 is adhered to the outer surface of the container 10. The cap 30 closes the internal space partitioned by the container 10 by covering the opening portion of the container 10.

The configuration of the labeled container 1 is not limited to this, as long as the object to be stored can be stored in the internal space of the container 10 and the product label or the like is indicated by the label 20. For example, the internal space may or may not be blocked by other closing members such as a spout, a zipper, and a lid seal instead of the cap 30. Other shapes of the labeled container 1 include, for example, a bowl shape.

Further, the sticking position of the label 20 on the labeled container 1 is not particularly limited. For example, as shown in FIG. 6, a part of the label 20 may not be adhered to the surface of the container 10 (a part of the label 20 may be separated from the container 10). In FIG. 6, the label 20 is attached to the body portion of the container 10, but a part thereof may be adhered to the shoulder portion of the container 10 and the cap 30 so as to be separated from the surface of the container 10. Further, the shape of the label 20 is not particularly limited.

In this embodiment, the container 10 is a polyester-based container. The polyester-based container is a container containing a polyester-based resin as a main component. The main component means a material having a weight of 50% or more of the total weight of the container 10. Preferred polyester-based resins include polylactic acid, polyethylene terephthalate (PET), polybutylene terephthalate and the like.

[cap]
The cap 30 covers the opening of the container 10 and closes the internal space of the container 10. The labeled container 1 of the present embodiment may or may not have the cap 30 as described above. When the labeled container 10 has a cap 30, it is preferable that the cap 30 contains a polyester resin as a main component. In this case, it can be used in the reuse system together with the container 10 without removing it from the container 10.

[label]
The label 20 is adhered to the outer surface of the container 10 and exerts a function such as displaying a product. FIG. 2 is a cross-sectional view showing an example of a label laminated structure according to the present embodiment. With reference to FIG. 2, the label 20 includes a base material layer 21 having a first surface 21a and a second surface 21b facing each other, and an adhesive layer 22 for adhering the first surface 21a of the base material layer 21 and the container 10 to each other. It has a bonding layer 23 laminated on the second surface 21b of the base material layer 21, and a printing layer 24 located on the side opposite to the base material layer 21 when viewed from the bonding layer 23. The shape of the label 20 is not particularly limited, and may be any shape as long as the target display is shown within the area observed from the outside. In FIG. 1, a substantially rectangular label 20 is shown. The thickness of the label 20 is not particularly limited, and may have characteristics such as rigidity and flexibility required for the label 20, for example, 20 to 170 μm, preferably 20 to 120 μm, and more preferably 30. It is ~ 100 μm.

(Base layer)
The base material layer 21 is the basic skeleton of the label 20 and functions as a carrier for other layers to be laminated. That is, the shape of the base material layer 21 is a layer that bears the overall shape of the label 20. The thickness of the base material layer 21 can be, for example, 10 to 80 μm. As a result, it is possible to prevent the label 20 from becoming unnecessarily thick while having a function as a carrier.

The base material layer 21 is a polyester-based film. The polyester-based film is a film containing a polyester-based resin as a main component. Preferred polyester-based resins include polylactic acid, polyethylene terephthalate (PET), polybutylene terephthalate and the like. The base material layer 21 is preferably made of a polyester resin made of the same material as the container 10. For example, when the container 10 is a PET-based container, the base material layer 21 is preferably a PET-based film, and when the container 10 is a polylactic acid-based container, the base material layer 21 may be a polylactic acid-based film. preferable. When the container 10 and the base material layer 21 are made of the same material, the recyclability is further enhanced.

(Adhesive layer)
The adhesive layer 22 adheres the first surface 21a of the base material layer 21 and the container 10 to each other. That is, the adhesive layer 22 is interposed between the container 10 and the base material layer 21 to bond both the container 10 and the label 20 to each other. The adhesive strength of the adhesive layer 22 to the container 10 and the label 20 is preferably 5 N / 25 mm or more, and more preferably 20 N / 25 mm or more. As a result, unintentional peeling of the label 20 can be suppressed.

Further, the labeled container 10 of the present disclosure does not require excessive attention to the peeling work of the label 20 when reusing it. When it is necessary to completely peel off the label 20 from the container 10 in order to reuse the labeled container 20, it becomes necessary to finely adjust the adhesive strength. On the other hand, according to the labeled container 10 of the present disclosure, such fine adjustment is not necessary.

In the present specification, the adhesive strength means a value measured by a method according to JIS Z 0237 180 degree peeling. Specifically, the adhesive strength is such that a laminate in which the first member (container) and the second member (base material layer) to be measured are adhered is cut out to a size of 100 mm × 25 mm, and the temperature of the first member is 23 ±. It refers to the maximum strength when peeled 180 degrees at a speed of 2 ° C., humidity 50 ± 5% RH, and 300 mm / min.

The adhesive layer 22 is a polyester-based adhesive. The polyester-based adhesive is an adhesive containing a polyester-based resin as a main component. Preferred polyester-based resins include polylactic acid, polyethylene terephthalate (PET), polybutylene terephthalate and the like. The adhesive layer 22 is preferably made of the same polyester-based adhesive as the container 10. For example, when the container 10 is a PET-based container, the adhesive layer 22 is preferably a PET-based adhesive, and when the container 10 is a polylactic acid-based container, the adhesive layer 22 may be a polylactic acid-based adhesive. preferable. When the container 10 and the adhesive layer 22 are made of the same material, the recyclability is further enhanced.

(Joining layer)
The bonding layer 23 is laminated on the second surface 21b of the base material layer 21. That is, the bonding layer 23 is interposed between the base material layer 21 and another layer located on the side opposite to the base material layer 21 when viewed from the bonding layer 23, and connects the base material layer 21 and the other layer. They are joined to each other and fixed. In the present embodiment, the bonding layer 23 fixes the base material layer 21 and the printing layer 24.

Further, the bonding layer 23 has a property of being soluble in at least one of hot water and an alkaline solution. Specifically, when a laminated structure (length x width: 1 cm x 1 cm) having a bonding layer sandwiched between two layers is immersed in water at 85 ° C. and stirred for 15 minutes, the two layers are separated. When the condition is reached, the bonding layer is considered to be soluble in warm water. Similarly, a laminated structure (length x width: 1 cm x 1 cm) having a bonding layer sandwiched between two layers is immersed in an alkaline solution (1.5 wt% NaOH aqueous solution) at 85 ° C. and stirred for 15 minutes. When the two layers are separated from each other, the bonding layer is considered to be soluble in an alkaline solution. The stirring speed depends on the stirring volume, but can be, for example, about 1000 rpm.

When the bonding layer 23 is soluble, the bonding layer 23 is dissolved in at least one of hot water and an alkaline solution, and the bonding property of the bonding layer 23 itself to other adjacent layers is reduced (disappeared). In this case, when the bonding layer 23 and the other layer are separated from each other due to the permeation (penetration) of water into the interface between the bonding layer 23 and the other adjacent layer, the bonding layer 23 swells to cause the bonding layer. It is conceivable that its own bondability decreases (disappears).

The bonding layer 23 of the present embodiment is preferably a base layer. The base layer is a layer in which a resin composition containing at least a binder resin becomes a solid layer through a drying treatment or the like to fix another layer in contact with itself. That is, the base layer does not have the adhesiveness of the adhesive layer (described later). The resin composition may further contain a solvent, additives and the like, if necessary.

When the bonding layer 23 is a base layer, it is preferable that the base layer further contains a curing agent in addition to the binder resin. Thereby, the water resistance of the bonding layer 23 can be improved.

The binder resin is preferably a polyester resin from the viewpoint of recycling suitability. The curing agent is selected according to the type of binder resin, but is preferably a carbodiimide-based curing agent, an aziridine-based curing agent, an isocyanate-based curing agent, or an oxazoline-based curing agent. For example, when the binder resin is a resin having a carboxyl group, it is preferable to use a carbodiimide-based curing agent as the curing agent, and when the binder resin is a resin having a sulfonic acid group, an isocyanate-based curing agent is used as the curing agent. Is preferable.

In the above resin composition, when the curing agent is a carbodiimide-based curing agent and the binder resin is a polyester-based resin, the solid content ratio (X: Y) of the curing agent (X) and the binder resin (Y) in the base layer. Is preferably 100: 4 to 100:30, more preferably 100:10 to 100:30, and particularly preferably 100:20 to 100:30. In this case, the water resistance of the bonding layer 23 itself, the adhesion to the base material layer 21, and the solubility in an alkaline solution are good. In the present specification, water resistance means resistance to water at room temperature (23 ° C.).

(Print layer)
The printing layer 24 is located on the side opposite to the base material layer 21 when viewed from the bonding layer 23. In FIG. 2, the print layer 24 is adjacent to the junction layer 23. The print layer 24 is a layer formed by one or more kinds of inks, and indicates a visible product display or the like. The printing layer 24 may be formed on the entire surface of the base material layer 21, or may be formed on a part of the base material layer 21.

The ink constituting the print layer 24 is not particularly limited, and examples thereof include oil-based inks, water-based inks, and UV curable inks. In particular, from the viewpoint of environmental compatibility, the ink constituting the print layer 24 is preferably a water-based ink or a UV curable ink. Among them, the ink constituting the print layer 24 is preferably a UV curable ink. This is because it does not contain an organic solvent and has a quick-drying property. The UV curable ink also has high decorativeness.

[Manufacturing method of labeled container]
The above-mentioned labeled container 1 can be manufactured by appropriately combining conventionally known methods.

An example of a method for manufacturing the labeled container 1 when the bonding layer 23 is composed of a base layer will be described. First, a base material laminate 21 in which a base material layer 21 made of a polyester film, an adhesive layer 22 made of a polyester adhesive, and a release paper are laminated in this order is prepared. Next, on one surface of the base material layer 21 (the side of the second surface 21b where the adhesive layer 22 and the release paper are not provided), a resin composition used as a material for the bonding layer 23 (base layer) is applied. It is applied and dried if necessary to form a bonding layer 23 (underlayer). The method for applying the resin composition is not particularly limited, and a conventionally known method can be used.

Next, the print layer 24 is formed on the surface of the bonding layer 23 opposite to the surface in contact with the base material layer 21. The method for forming the print layer 24 is not particularly limited, and a conventionally known method can be used. Finally, if necessary, the base material layer 21 or the like on the release paper is punched into a label shape to remove unnecessary portions from the release paper. As a result, the label 20 provided with the release paper is manufactured. Next, the label 20 is removed from the release paper, and the exposed adhesive surface (adhesive layer 22) is adhered to the surface of the container 10. In this way, the labeled container 1 is manufactured. Further, by forming the laminate as described above on the long release paper, it is possible to manufacture a label continuum in which a plurality of labels 20 are continuously adhered along the longitudinal direction of the release paper. ..

The method for producing the label 20 is not limited to the above. For example, the bonding layer 23 and the printing layer 24 are formed in this order on the base material layer 21 by the same method as described above, and then the base material layer 21 is exposed. A polyester-based adhesive may be applied to the surface (first surface 21a) to be formed to form the adhesive layer 22.

[How to reuse labeled containers]
The labeled container 1 after being used by consumers and the like is brought into contact with warm water or an alkaline solution after the label 20 is peeled off, and the bonding layer 23 becomes soluble accordingly. .. This solubilization treatment can be easily carried out, for example, by immersing the labeled container 1 in a bathtub containing warm water or an alkaline solution and stirring it.

As a result, the bonding layer 23 is dissolved in warm water or an alkaline solution, and accordingly, the bonding layer 23 and each layer arranged at a position farther from the bonding layer 23 as viewed from the container 10 are separated from the container 10. Will be done. FIG. 3 is a partial cross-sectional view showing a state in which a part of the label is separated in the labeled container according to the present embodiment, and shows the labeled container after the labeled container 1 has been solubilized. .. The labeled container 1 does not have to be peeled off as described above.

The labeled container shown in FIG. 3 (hereinafter, also referred to as “solubilized container”) is composed of a container 10, an adhesive layer 22, and a base material layer 21, all of which are made of polyester resin. Therefore, the solubilized container can be used for a recycling process such as a reuse system already constructed.

[effect]
According to the labeled container 1 described above, the bonding layer 23 is soluble in at least one of hot water and an alkaline solution. Therefore, by a simple operation of bringing the labeled container 1 into contact with warm water or an alkaline solution, the bonding layer 23 and the printing layer 24 located on the side opposite to the base material layer 21 when viewed from the bonding layer 23 are separated. , Can be easily separated from the labeled container 1. The solubilized container from which a part of the label 20 is separated in this way can be directly used in the recycling step. Therefore, according to the above-mentioned labeled container 1, efficient reuse is possible without paying excessive attention to the peeling operation. In particular, when the bonding layer 23 is the above-mentioned base layer, it can be soluble in an alkaline solution.

More notably, the label 20 has been discarded in the past, but according to the above-mentioned labeled container 1, the base material layer 21 which occupies most of the label 20, and the base material layer 21 and the container 10 are adhered to each other. The adhesive layer 22 to be used can also be used for the recycling process.

In the labeled container 1, the bonding layer 23 is preferably not soluble in warm water but soluble in an alkaline solution. This is because the situation where the labeled container 1 is immersed in the alkaline solution is not assumed except for the recycling process, while the labeled container 1 is assumed to be unintentionally immersed in warm water. That is, when the bonding layer 23 is soluble in warm water, it is possible that the label 20 is layer-separated at an unintended timing.

Particularly preferable configurations of the labeled container 1 are a container 10 made of a PET-based film, an adhesive layer 22 made of a PET-based adhesive, a base material layer 21 made of a PET-based film, and a binder resin made of a carbodiimide-based curing agent and a polyester-based resin. It is a configuration having a base layer (bonding layer 23) including. In this case, the adhesion between the base material layer 21 and the bonding layer 23, the water resistance of the bonding layer 23, the alkali solubility of the bonding layer 23, and the adhesion between the bonding layer 23 and the printing layer 24 are all good. Therefore, unintended layer separation of the label 20 and the like are suppressed, and the label 20 can be easily separated by the alkali solubilization treatment. Further, since the bonding layer 23 is not soluble in warm water, unintended separation of the label 20 can be suppressed. The unintended separation of the label 20 is a case where, for example, the labeled container 1 comes into contact with warm water for which the purpose of dissolution treatment is not intended, and the label 20 is separated accordingly.

<Second Embodiment>
The labeled container according to the second embodiment will be described with reference to FIG. In FIG. 4, a label 20A further provided with a supporting layer 25 is shown with respect to the label 20 according to the first embodiment. That is, in the labeled container according to the second embodiment, in addition to the configuration of the labeled container according to the first embodiment, the label further includes a supporting layer.

[Labeled container]
The label 20A has a structure in which a supporting layer 25 is further provided with respect to the label 20. The carrier layer 25 is located on the side opposite to the base material layer 21 when viewed from the bonding layer 23. Further, the printing layer 24 is located between the supporting layer 25 and the bonding layer 23.

[Supported layer]
The supporting layer 25 is a layer that supports the printing layer 24. That is, the printed layer 24 cannot form a layer by itself, but can form a layer shape on the surface of a solid layer such as a film as a carrier, and the supported layer 25 is such a printed layer 24. It is a layer that functions as a carrier of. Further, the supporting layer 25 is preferably a film having at least one of a film having a specific gravity smaller than the specific gravity of water or an alkaline aqueous solution or a film having heat shrinkage. For example, the supporting layer 25 is preferably a polyolefin-based film such as polyethylene or polypropylene, and more preferably a polypropylene film. In this case, the supporting layer 25 can have a specific density smaller than that of the aqueous solution of water or alkaline solution. Examples of the heat-shrinkable film include polystyrene-based films in addition to the above-mentioned polyolefin-based films.

The thickness of the carrier layer 25 is not particularly limited. Since the supporting layer 25 only needs to function as a carrier for the printing layer 24, it is preferably smaller than the thickness of the base material layer 21 which is the base material of the label, and can be set to 10 to 30 μm. This is to avoid unnecessarily increasing the total amount of material of the label 20. The supported layer 25 may have the same shape as the base material layer 21, or may have a different shape, for example, a shape smaller than that of the base material layer 21.

[Joining layer]
In the present embodiment, the bonding layer 23 may be, for example, the above-mentioned base layer or an adhesive layer. The adhesive layer is a layer made of an adhesive, and is a layer that adheres a layer in contact with itself due to its own adhesiveness.

When the bonding layer 23 is an adhesive layer, the adhesive strength of the adhesive layer is preferably 2 to 25 N / 25 mm. This is to suppress unintended separation of label 20A. Examples of the pressure-sensitive adhesive having excellent adhesion to the base material layer 21 made of a polyester-based resin and being soluble in at least one of hot water and an alkaline solution include an acrylic emulsion-type pressure-sensitive adhesive.

[Manufacturing method of labeled container]
The labeled container provided with the label 20A can be produced by appropriately combining conventionally known methods.

An example of a method for manufacturing a labeled container according to the present embodiment when the bonding layer 23 is composed of a base layer will be described. First, in the same manner as in the first embodiment, the base material laminate is prepared, and the bonding layer 23 and the printing layer 24 are formed on the second surface 21b of the base material layer 21 of the base material laminate. Next, the printing layer 24 and the supporting layer 25 are adhered to each other by a known laminating method using an arbitrary adhesive (not shown). Optional adhesives include UV curable adhesives, solvent adhesives, hot melt adhesives and the like. As a result, the label 20A provided with the release paper is manufactured. Next, the release paper is removed from the label 20A, and the exposed adhesive surface (adhesive layer 22) is adhered to the surface of the container 10. As described above, a labeled container having the label 20A is manufactured. The adhesive layer 22 may be formed by applying a polyester-based adhesive to the exposed surface (first surface 21a) of the base material layer 21 without using the base material laminate, and the label continuum. The manufacturing method is the same as that of the first embodiment.

An example of a method for manufacturing a labeled container according to the present embodiment when the bonding layer 23 is composed of an adhesive layer will be described. First, in the same manner as in the first embodiment, a base material laminate is prepared, and an adhesive is applied on the second surface 21b of the base material layer 21 of the base material laminate to form a bonding layer 23 (adhesive layer). Form. From the viewpoint of facilitating handling, it is preferable to attach a second release paper to the surface of the bonding layer 23 (adhesive layer). Next, the carrier layer 25 is prepared, and the print layer 24 is formed on one surface of the carrier layer 25. The method for forming the print layer 24 is not particularly limited, and a conventionally known method can be used. Next, the second release paper on the bonding layer 23 (adhesive layer) is removed, and the supporting layer 25 is adhered onto the exposed bonding layer 23. At this time, the printing layer 24 is laminated so as to be arranged between the bonding layer 23 and the supporting layer 25. As a result, the label 20A provided with the release paper is manufactured. Next, the release paper is removed from the label 20A, and the exposed adhesive surface (adhesive layer 22) is adhered to the surface of the container 10. As described above, a labeled container having the label 20A is manufactured. The adhesive layer 22 may be formed by applying a polyester-based adhesive to the exposed surface (first surface 21a) of the base material layer 21 without using the base material laminate, and the label continuum. The manufacturing method is the same as that of the first embodiment.

[effect]
According to the labeled container according to the present embodiment, in addition to the effect of the labeled container 1 according to the first embodiment, the effect of providing the supporting layer 25 can be further exerted. Specifically, the carrier layer 25 is a film, which itself functions as a carrier. That is, the adhesive layer 22 and the printed layer 24 are layers that can maintain the shape for the first time on the surface of another layer having a constant shape, whereas the base material layer 21 and the supported layer 25 are themselves constant. The shape of can be maintained.

Therefore, the print layer 24 is separated from the container 10 by the above-mentioned solubilization treatment. However, according to the label 20A, the print layer 24 is supported on the carrier layer 25 in warm water or an alkaline solution. Can exist in. Therefore, according to the labeled container provided with the label 20A, in addition to the effect of the labeled container 1 provided with the label 20 described above, it is possible to suppress the printing layer 24 from being finely dispersed in warm water or an alkaline solution.

Further, in the label 20A, since the printing layer 24 is protected from external factors by the supporting layer 25, it is possible to suppress unintended damage to the printing layer 24.

Further, the supporting layer 25 is preferably a film having a specific density smaller than that of the aqueous solution of water or an alkaline solution. In this case, since the container 10, the adhesive layer 22, and the base material 21 are polyester-based resins and have a higher specific density than that of water or an alkaline aqueous solution, the support layer 25 that supports the printing layer 24, the adhesive layer 22, and the base material layer The container 10 to which the 21 is attached can be easily separated by specific gravity separation in water or an alkaline solution.

Further, the carrier layer 25 may be, for example, a film having heat shrinkage. In this case, the supporting layer 25 can be shrunk so as to involve the printing layer 24 in warm water or an alkaline solution. The printing layer 24 caught in the shrinking and curled supporting layer 25 is less frequently contacted with warm water or an alkaline solution. As a result, it is possible to significantly prevent the printing layer 24 from being finely dispersed in warm water or an alkaline solution. Further, it is expected that the base material layer 21 and the printing layer 24 are more easily separated due to the heat shrinkage of the supported layer 25.

When the supported layer 25 has a specific gravity smaller than that of the water or alkaline aqueous solution and has heat shrinkage, both easy separation by specific gravity separation and marked suppression of dispersion of the printed layer 24 are both made. Is possible.

Similar to the first embodiment, it is preferable that the bonding layer 23 is not soluble in warm water but soluble in an alkaline solution. Further, in the present embodiment, the bonding layer 23 may be the above-mentioned base layer or an adhesive layer. When the bonding layer 23 is a base layer, the preferred base layer is a base layer containing a carbodiimide-based curing agent and a binder resin made of a polyester-based resin, as in the first embodiment. When the bonding layer 23 is an adhesive layer, the preferable adhesive layer is an adhesive layer having an adhesive strength of 2 to 25 N / 25 mm.

<Third Embodiment>
The labeled container according to the third embodiment will be described with reference to FIG. In FIG. 5, a label 20B further provided with a supporting layer 25 is disclosed with respect to the label 20 according to the first embodiment. That is, in the labeled container according to the third embodiment, in addition to the configuration of the labeled container according to the first embodiment, the label further includes a supporting layer. Further, in the labeled container according to the third embodiment, the arrangement of the printing layer and the supporting layer is different from the configuration of the labeled container according to the second embodiment.

[Labeled container]
The label 20B has a structure in which a supporting layer 25 is further provided with respect to the label 20. The carrier layer 25 is located on the side opposite to the base material layer 21 when viewed from the bonding layer 23. Further, the supporting layer 25 is located between the printing layer 24 and the bonding layer 23. The carrier layer 25 is the same as the carrier layer 25 according to the second embodiment. The bonding layer 23 is preferably a base layer or an adhesive layer as in the second embodiment. Other configurations are the same as those in the first embodiment.

[Manufacturing method of labeled container]
The labeled container provided with the label 20B can be produced by appropriately combining conventionally known methods.

An example of a method for manufacturing a labeled container according to the present embodiment when the bonding layer 23 is composed of a base layer will be described. First, in the same manner as in the first embodiment, the base material laminate is prepared, and the bonding layer 23 (base layer) is formed on the second surface 21b of the base material layer 21 of the base material laminate. On the other hand, the supporting layer 25 is prepared, and the printing layer 24 is formed on one surface of the supporting layer 25. The method for forming the print layer 24 is not particularly limited, and a conventionally known method can be used. Next, the bonding layer 23 (base layer) and the supporting layer 25 are adhered to each other by a known laminating method using an arbitrary adhesive. Optional adhesives include UV curable adhesives, solvent adhesives, hot melt adhesives and the like. At this time, the printing layer 24 formed on the supporting layer 25 is arranged so as not to be arranged between the bonding layer 23 and the supporting layer 25, that is, to be located on the exposed surface side of the label 20B. As a result, the label 20B provided with the release paper is manufactured. Next, the release paper is removed from the label 20B, and the exposed adhesive surface (adhesive layer 22) is adhered to the surface of the container 10. As described above, a labeled container having the label 20B is manufactured. The adhesive layer 22 may be formed by applying a polyester-based adhesive to the exposed surface (first surface 21a) of the base material layer 21 without using the base material laminate, and the label continuum. The manufacturing method is the same as that of the first embodiment.

An example of a method for manufacturing a labeled container according to the present embodiment when the bonding layer 23 is composed of an adhesive layer will be described. First, an adhesive is applied to one surface of the carrier layer 25 to form a bonding layer 23 (adhesive layer). In order to facilitate handling, it is preferable to attach a release paper to the exposed surface of the bonding layer 23. Next, the printing layer 24 is formed on the surface of the supporting layer 25 on which the bonding layer 23 is not formed. The method for forming the print layer 24 is not particularly limited, and a conventionally known method can be used. Next, the base material laminate is prepared, and the bonding layer 23 (adhesive layer) is adhered to one surface (second surface 21b) of the base material layer 21 (the release paper is removed before bonding). As a result, the label 20B provided with the release paper is manufactured. Next, the release paper is removed from the label 20B, and the exposed adhesive surface (adhesive layer 22) is adhered to the surface of the container 10. As described above, a labeled container having the label 20B is manufactured. The adhesive layer 22 may be formed by applying a polyester-based adhesive to the exposed surface (first surface 21a) of the base material layer 21 without using the base material laminate, and the label continuum. The manufacturing method is the same as that of the first embodiment.

[effect]
Also in the labeled container according to the present embodiment, in addition to the effect of the labeled container 1 according to the first embodiment, easy separation by specific gravity separation is possible, and / or the printing layer 24 is in warm water or an alkaline solution. It can have the effect of suppressing fine dispersion in the inside.

Also in the present embodiment, the bonding layer 23 may be the above-mentioned base layer or an adhesive layer, as in the second embodiment. When the base layer or the adhesive layer is used as the bonding layer 23, the same effect as that of the labeled container according to the second embodiment can be obtained.

Hereinafter, examples and comparative examples will be described, and the present invention will be described in more detail. However, the present invention is not limited to the following examples.

<Evaluation method>
Using the samples prepared in each example, each evaluation was carried out by the following evaluation methods.

[Adhesion evaluation]
Adhesion was evaluated by the following method. Specifically, in a standard state (23 ° C., 1 atm, 50% RH), for each label of Examples 1 to 8, an adhesive tape having a width of 24 mm (manufactured by Nichiban Co., Ltd., trade name) is applied to the surface of the printing layer. "Cellotape (registered trademark)") was strongly attached, and then the adhesive tape was peeled off in the 180-degree direction. The surface of the adhesive tape after peeling was visually observed and evaluated according to the following criteria.
AA: No ink deposits were observed on the adhesive tape, and no ink peeling was observed.
A: Ink deposits were observed on the adhesive tape, and the ink peeling area ratio of the sample piece was less than 3%.
B: Ink deposits were observed on the adhesive tape, and the ink peeling area ratio of the sample piece was 3% or more. The ink peeling area is calculated by the formula (total area of the ink peeled portion / area of the ink layer before the tape is applied) × 100.

[Water resistance evaluation]
Each label was immersed in water at room temperature (about 23 ° C.) for 24 hours. Then, each label was taken out of water, allowed to stand for 1 minute, and left to stand for 10 minutes, and then the above peel resistance test was carried out and evaluated according to the following criteria.
AA: No ink deposits were observed on the adhesive tape, and no ink peeling was observed.
A: Many ink deposits were observed on the adhesive tape, and the ink peeling area ratio of the sample piece was less than 3%.
B: Many ink deposits were observed on the adhesive tape, and the ink peeling area ratio of the sample piece was 3% or more and less than 10%.
C: Many ink deposits were observed on the adhesive tape, and the ink peeling area ratio of the sample piece was 10% or more. The ink peeling area is calculated by the formula (total area of the ink peeled portion / area of the ink layer before the tape is applied) × 100.

[Alkaline desorption test]
Each sample (10 mm × 10 mm) was immersed in a 1.5 wt% NaOH aqueous solution at 85 ° C. and stirred at 600 rpm for 15 minutes. Then, the sample was taken out from the NaOH aqueous solution and allowed to stand for 5 minutes, and then the detachment of the printed layer was visually observed and evaluated according to the following criteria.
A: No print layer was visually observed on the surface of the sample.
B: A printed layer was visually recognized on the surface of the sample.

[Evaluation of hot water desorption]
Each sample (10 mm × 10 mm) was immersed in warm water at 85 ° C. and stirred at 600 rpm for 15 minutes. Then, the sample was taken out from warm water and allowed to stand for 5 minutes, and then the detachment of the printed layer was visually observed and evaluated according to the following criteria.
A: No print layer was visually observed on the surface of the sample.
B: A printed layer was visually recognized on the surface of the sample.

<Examination 1: Alkali-soluble base layer>
[Example 1]
As a base material layer, a polyester film (thickness 38 μm, manufactured by Toyobo Co., Ltd., “E5100”) was prepared. As a material for the bonding layer, a material for the base layer (resin composition) containing a carbodiimide-based curing agent (curing agent) and a polyester-based resin (binder resin) was prepared. Specifically, a polyester resin aqueous dispersion (manufactured by Mitsubishi Chemical Co., Ltd., "WR-961") and a carbodiimide-based curing agent (manufactured by Nisshinbo Chemical Co., Ltd., "Carbodilite E-03A") are mixed in a solid content ratio ("Carbodilite E-03A"). A resin composition mixed so as to have a weight ratio of 100:10 was prepared. Then, using a bar coater, the resin composition was printed on a solid surface on the base material layer and dried (100 ° C., 20 seconds). The thickness of the bonding layer formed on the base material layer was about 1 μm.

Next, a print layer was formed on the joint layer. Specifically, a UV curable ink (manufactured by T & K TOKA Co., Ltd., "AF indigo") was printed solidly on the bonding layer using a flexographic coater and cured by UV irradiation. The thickness of the printing layer formed on the bonding layer was about 1 μm.

As described above, the label of Example 1 (however, there is no adhesive layer on one surface side of the base material layer) is prepared, and this is shredded into 10 mm × 10 mm to prepare a plurality of samples. bottom.

[Example 2]
As the resin composition of the material for the bonding layer, the same method as in Example 1 was used except that the mixing ratio of the binder resin and the carbodiimide-based curing agent was 100:20 in terms of solid content ratio (weight ratio). Labels and samples of 2 were prepared.

[Example 3]
As the resin composition of the material for the bonding layer, the same method as in Example 1 was used except that the mixing ratio of the binder resin and the carbodiimide-based curing agent was 100:30 in terms of solid content ratio (weight ratio). Labels and samples of 3 were prepared.

[Example 4]
The label and sample of Example 4 were prepared by the same method as in Example 1 except that the material for the bonding layer was changed. Specifically, the mixing ratio of the polyester resin aqueous dispersion (manufactured by Mitsubishi Chemical Co., Ltd., "WR-961") and the carbodiimide-based curing agent (manufactured by Stahl Polymers, "XL-732") is the solid content ratio. A resin composition having a (weight ratio) of 100: 4 was prepared.

[Example 5]
A label and a sample of Example 5 were prepared by the same method as in Example 2 except that a medium ink was further layered as a printing layer. Specifically, a UV curable varnish (“FTV varnish” manufactured by T & K TOKA Co., Ltd.) was printed solidly on an ink layer made of indigo ink using a flexographic coater and cured by UV irradiation.

[Example 6]
As the resin composition of the material for the bonding layer, the same method as in Example 1 was used except that the mixing ratio of the binder resin and the carbodiimide-based curing agent was set to a weight ratio of 100: 0 (in terms of solid content). Labels and samples of 2 were prepared. That is, a resin composition composed of only a binder resin was used as a material for the bonding layer.

Table 1 shows the results of each evaluation. With reference to Table 1, it was confirmed that each of the labels of Examples 1 to 6 had high alkali desorption while having sufficient adhesion and water resistance after 1 minute. Further, it was confirmed that each of the labels of Examples 1 to 5 had high alkali desorption while having sufficient adhesion, water resistance after 1 minute, and water resistance after 10 minutes. Therefore, it was confirmed that each of the labels of Examples 1 to 6 has a function as a label and can easily remove the ink layer by contact with an alkaline solution. It was also confirmed that each sample did not have warm water desorption.

<Examination 2: Detachable base layer with warm water>
[Example 7]
The label and sample of Example 7 were prepared by the same method as in Example 1 except that the resin composition consisting only of the polyester resin aqueous dispersion (“WR901S20WO” manufactured by Mitsubishi Chemical Corporation) was used as the material for the bonding layer. Made.

[Example 8]
The label and sample of Example 8 were prepared by the same method as in Example 7 except that "WR905S20WO" manufactured by Mitsubishi Chemical Corporation was used.

Table 2 shows the results of each evaluation. With reference to Table 2, it was confirmed that each of the labels of Examples 7 and 8 had high adhesion and water resistance after 10 minutes, and also had high hot water desorption. Therefore, it was confirmed that each of the labels of Examples 7 and 8 has a function as a label and can easily remove the ink layer by contact with warm water. It was also confirmed that each sample did not have alkali desorption.

<Examination 3>
A model of a labeled container was manufactured using the label of Example 1. Specifically, a 10 mm × 10 mm polyester film (thickness 100 μm, manufactured by Toyobo Co., Ltd., “E5100”) was regarded as a container. Of the labels of Example 1, an adhesive was applied to the surface of the exposed base material layer, and this was adhered to a polyester film. The laminate produced in this way was used as a model for a labeled container. A polyester-based adhesive was used as the material of the adhesive, and the adhesive layer was applied to the surface of the base material layer using a gravure printing machine so that the thickness of the adhesive layer after drying was 20 μm.

When an alkali desorption test was carried out using the manufactured model, no printing layer was observed on the surface of the polyester film, which was regarded as a container, and only the film, which was the base material layer, was visually observed.

1 Labeled container, 10 container, 20 label, 21 base material layer, 21a first surface, 21b second surface, 22 adhesive layer, 23 bonding layer, 24 printing layer, 25 supporting layer, 30 cap.

Claims

A labeled container with a label attached
The container is a polyester-based container.
The label is laminated on a base material layer having a first surface and a second surface facing each other, an adhesive layer for adhering the first surface of the base material layer and the container to each other, and a second surface of the base material layer. It has a bonded layer and a printed layer located on the side opposite to the base material when viewed from the bonded layer.
The base material layer is a polyester-based film,
The adhesive layer is a polyester-based adhesive and is
A labeled container in which the bonding layer is soluble in at least one of hot water and an alkaline solution.
The labeled container according to claim 1, wherein the bonding layer is not soluble in warm water but soluble in an alkaline solution.
The labeled container according to claim 1 or 2, wherein the label has a supporting layer that is located on the side opposite to the base material layer when viewed from the bonding layer and supports the printing layer.
The labeled container according to claim 3, wherein the printing layer is located between the supporting layer and the bonding layer.