WO2022202857A1

WO2022202857A1 - Multilayer label

Info

Publication number: WO2022202857A1
Application number: PCT/JP2022/013337
Authority: WO
Inventors: 直紀田矢; 慶一佐藤; 壮宮田
Original assignee: リンテック株式会社
Priority date: 2021-03-25
Filing date: 2022-03-23
Publication date: 2022-09-29
Also published as: JPWO2022202857A1; TW202302362A

Abstract

The present invention pertains to a multilayer label having a base material, a resin layer, and an adhesive layer in the stated order. The base material and the resin layer are detachably adhered. The resin layer contains a biodegradable resin (A) and a filler (B).

Description

multilayer label

The present invention relates to multilayer labels.

Conventionally, multi-layered labels with a multi-layered structure have been widely used for delivery slips used to deliver packages. This multilayer label usually consists of a base material such as thermal paper on which information is printed, a resin layer (hereinafter also referred to as an "intermediate resin layer") detachably adhered to the base material, and an adhesive for affixing to a package. A layer is provided, and the substrate and the intermediate resin layer are difficult to adhere to each other after being separated once. In addition, although the layers laminated under specific conditions can be separated by delamination, adhesion in a mode that does not exhibit re-adhesiveness and adhesiveness after separation is referred to as "pseudo-adhesion". Sometimes.

The base material and intermediate resin layer of a multilayer label are required to have both good pseudo-adhesiveness, that is, adhesiveness to the extent that it does not come off unintentionally, and releasability to the extent that it can be easily removed by hand. Furthermore, when managing the peeled base material as a slip, various performances are required even after peeling, such as the ease of handling the peeled base material, the ease of disposal of the base material and the members remaining after peeling the base material, etc. is sometimes requested.

In Patent Document 1, a pseudo-adhesion laminate having a good pseudo-adhesion property of the pseudo-adhesion layer includes a substrate and a pseudo-adhesion layer laminated on one surface of the substrate, and the pseudo-adhesion layer discloses a pseudo-adhesive laminate containing an olefinic resin, an emulsifier having a melting point of 25° C. or higher, and a release agent.

JP 2019-147898 A

By the way, in recent years, due to the growing awareness of environmental issues, environmental pollution when disposing of petroleum-derived plastic materials has been viewed as a problem. There is concern that the olefinic resin used in the pseudo-adhesive laminate and the like of Patent Document 1 may affect the environment when disposed of by incineration, landfilling, or the like. Therefore, it is desired to form the intermediate resin layer using a material with less environmental load while maintaining the peel strength between the substrate and the resin layer within a favorable range.

In addition, delivery slips may be affixed to a position where they are stacked on both the packaging material such as cardboard and the tape that seals the packaging material. In that case, after peeling off the base material, the intermediate resin layer remains in a state straddling over the packing material and the tape. If an attempt is made to peel the tape from the packing material in this state, the intermediate resin layer may become an obstacle and the tape may not be easily peeled off. In order to be able to easily open the packing material even when the delivery slip is attached as described above, when the tape is peeled off, the intermediate resin layer itself must be separated from the part attached on the tape and the part attached on the packaging material. It is desirable to be torn into two parts. However, resins having moderate peel strength in the practical temperature range tend to have high initial tear strength, which triggers tearing. Therefore, it is desired to achieve both moderate peel strength and excellent tearability.

The present invention has been made in view of the above problems, and has a base material, a resin layer, and an adhesive layer in this order, and the base material and the resin layer are releasably adhered. The object of the present invention is to provide a multi-layer label which has a low environmental load of a material forming a resin layer, has an appropriate peeling force between a substrate and a resin layer, and is excellent in tearability.

The present inventors have found that the above problems can be solved by using a biodegradable resin and a filler as materials for forming the resin layer, and have completed the present invention.

That is, the present invention relates to the following [1] to [12].
[1] having a substrate, a resin layer, and an adhesive layer in this order,
The base material and the resin layer are adhered in a detachable manner,
A multilayer label, wherein the resin layer contains a biodegradable resin (A) and a filler (B).
[2] The multilayer label according to [1] above, wherein the biodegradable resin (A) has crystallinity.
[3] The multilayer label according to [1] or [2] above, wherein the biodegradable resin (A) has a glass transition temperature of 0° C. or lower and a melting point of 40° C. or higher.
[4] The multilayer label according to any one of [1] to [3] above, wherein the biodegradable resin (A) is a polybutylene succinate resin.
[5] The multilayer label according to any one of [1] to [4] above, wherein the filler (B) is an inorganic filler.
[6] The multilayer label according to [5] above, wherein the inorganic filler is calcium carbonate.
[7] The multilayer label according to any one of [1] to [6] above, wherein the filler (B) has a non-spherical shape.
[8] The multilayer label according to any one of [1] to [7] above, wherein the filler (B) is not subjected to surface modification treatment with an organic component.
[9] Any of the above [1] to [8], wherein the content of the filler (B) in the resin layer is 1 to 50% by volume with respect to the volume (100% by volume) of the resin layer. A multi-layer label according to:
[10] The multilayer label according to any one of [1] to [9] above, wherein the substrate is a paper substrate.
[11] The multilayer label according to any one of [1] to [10] above, wherein the peel force between the substrate and the resin layer is 100 to 1,000 mN/50 mm.
[12] The multilayer label according to any one of [1] to [11] above, which is used for delivery slips.

According to the present invention, a multilayer label has a base material, a resin layer, and an adhesive layer in this order, and the base material and the resin layer are releasably adhered, and the resin layer is It is possible to provide a multi-layer label that has a low environmental load due to the material to be formed, has an appropriate peeling force between the base material and the resin layer, and is excellent in tearability.

It is a cross-sectional schematic diagram which shows an example of a structure of the multilayer label of this embodiment. FIG. 3 is a schematic cross-sectional view showing another example of the configuration of the multilayer label of the present embodiment; It is a schematic diagram for demonstrating the peelability evaluation method.

Hereinafter, the present invention will be described in detail using embodiments.

In this specification, for preferred numerical ranges (for example, ranges of content etc.), the lower and upper limits described stepwise can be independently combined. For example, from the statement "preferably 10 to 90, more preferably 30 to 60", combining "preferred lower limit (10)" and "more preferred upper limit (60)" to "10 to 60" can also
In the numerical ranges described herein, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.
Mechanisms of action described herein are speculations and do not limit the mechanisms by which the effects of the present invention are achieved.

[Multilayer label]
The multilayer label of this embodiment is
Having a substrate, a resin layer, and an adhesive layer in this order,
The base material and the resin layer are adhered in a detachable manner,
The resin layer contains a biodegradable resin (A) and a filler (B),
It is a multilayer label.

Hereinafter, the configuration of the multilayer label according to this embodiment will be described more specifically with reference to the drawings.
FIG. 1 shows a schematic cross-sectional view of a multilayer label 1 that is an example of the present embodiment.
The multilayer label 1 has a structure in which a substrate 10, a resin layer 20, and an adhesive layer 30 are directly laminated in this order. In the multilayer label 1, the interlayer S between the substrate 10 and the resin layer 20 is detachably adhered. The adhesion between the base material 10 and the resin layer 20 corresponds to pseudo-adhesion, which does not exhibit re-adhesiveness or stickiness after peeling.
Also, FIG. 2 shows a schematic cross-sectional view of a multilayer label 2 that is another example of the present embodiment. The multilayer label 2 has a configuration in which a release sheet 40 is attached to the surface of the pressure-sensitive adhesive layer 30 of the multilayer label 1 shown in FIG.
Each constituent member of the multilayer label of this embodiment will be described in detail below.

<Base material>
The base material of the multilayer label according to this embodiment is not particularly limited, and is appropriately selected according to the purpose of use of the multilayer label.
Examples of substrates include paper substrates such as woodfree paper, kraft paper, glassine paper, parchment paper, rayon paper, gravure paper, art paper, coated paper, recycled paper, and synthetic paper; Resin films such as resins, polyvinylidene chloride-based resins, and polyolefin-based resins; laminated sheets obtained by laminating two or more layers of these; and the like.
Among these, the substrate is preferably a paper substrate, more preferably thermal paper, kraft paper, fine paper, or glassine paper, and still more preferably thermal paper.

In the multilayer label according to the present embodiment, the substrate is preferably an information display substrate that displays information about the adherend. For example, when the adherend is an article to be delivered, the information on the adherend includes the sender, the destination, the name or name of the delivery company, the address, the telephone number, the contents of the article to be delivered, a two-dimensional barcode, and the like. .

The substrate of the multilayer label according to the present embodiment preferably has thermochromic properties from the viewpoint of use as an information display substrate. Printing and printing by a thermal printer or the like become possible when the base material has thermochromic properties.
It is preferable that the substrate having thermochromic properties has a thermochromic layer provided on the surface of the substrate opposite to the resin layer. Examples of the thermosensitive coloring layer include those containing a leuco dye and a developer that reacts with the leuco dye.
The thermosensitive color-developing layer is formed, for example, by applying a coating liquid containing the leuco dye and the developer as well as a binder, wax, solvent, etc., to the surface of the substrate opposite to the resin layer. It is formed.

(Basic weight of base material)
When a paper base material is used as the base material, the basis weight of the paper base material is not particularly limited, but is preferably 10 to 100 g/m ² , more preferably 20 to 90 g/m ² , still more preferably 40 to 80 g/m 2 . ² . When the basis weight of the paper base is within the above range, the strength of the base and the peel strength between the base and the resin layer tend to be better.

(Thickness of base material)
Although the thickness of the substrate is not particularly limited, it is preferably 10 to 250 μm, more preferably 20 to 200 μm, still more preferably 30 to 150 μm. When the thickness of the base material is at least the above lower limit, it tends to be possible to suppress the occurrence of wrinkles, tears, and the like in the base material. Further, when the thickness of the base material is equal to or less than the above upper limit value, the base material tends to be economically efficient, and the rigidity does not become too high, and the transportability and handleability when performing printing and printing with a printer or the like tend to be excellent.
In addition, the "thickness of the base material" means the thickness of the entire base material. means.

<Resin layer>
The resin layer of the multilayer label according to this embodiment contains a biodegradable resin (A) and a filler (B).

(Biodegradable resin (A))
The biodegradable resin (A) is not particularly limited as long as it is a biodegradable resin, and may be a biodegradable resin derived from organisms or a biodegradable resin derived from petroleum. .
Since the multilayer label according to the present embodiment uses the biodegradable resin (A) in the resin layer, there is no concern about environmental pollution when discarded, unlike conventional polyethylene resins, etc., and the environmental load is small. .
In addition, in this embodiment, "biodegradability" means a property capable of being chemically decomposed by the action of hydrolysis, enzymatic decomposition, microbial decomposition, or the like.
The biodegradable resin (A) may be used alone or in combination of two or more.

The biodegradable resin (A) is preferably a crystalline resin. Since the biodegradable resin (A) has crystallinity, it is possible to suppress the occurrence of tack on the surface of the resin layer in the operating temperature range, improve workability, and improve the peeling force between the base material and the resin layer. becomes too large. Furthermore, the biodegradable resin (A) having crystallinity tends to make the resin layer more excellent in tearability.
Whether or not the biodegradable resin (A) has crystallinity can be confirmed by differential scanning calorimetry (DSC), specifically by the method described in Examples.

Examples of the biodegradable resin (A) include polyesters such as aliphatic polyesters, aliphatic polyester carbonates, aliphatic polyester amides, and aliphatic polyester ethers; polyvinyl alcohol; polyamino acids; cellulose, cellulose acetate, hydroxyethyl cellulose, hydroxyl polysaccharides such as propylcellulose, starch, chitin, chitosan, mannan; and other thermoplastic resins. Among these, polyesters are preferred, and aliphatic polyesters and derivatives thereof are more preferred.

Examples of aliphatic polyesters and derivatives thereof include polybutylene succinate resins, polycaprolactone, polybutylene adipate terephthalate, polylactic acid, and polyesters containing 3-hydroxyalkanoic acid as monomer units. Among these, polybutylene succinate-based resins are preferred from the viewpoint of moldability and biodegradability.

Examples of polybutylene succinate-based resins include polybutylene succinate, polybutylene succinate adipate, and polybutylene succinate lactate.

[Melting point of biodegradable resin (A)]
Although the melting point of the biodegradable resin (A) is not particularly limited, it is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 80°C or higher. When the melting point of the biodegradable resin (A) is equal to or higher than the above lower limit, it is possible to prevent the resin layer from melting under the general usage environment of the multilayer label according to the present embodiment. As a result, unintentional separation of the substrate from the resin layer due to melting of the resin layer can be suppressed.
Although the upper limit of the melting point of the biodegradable resin (A) is not particularly limited, it is preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 130°C or lower. When the melting point of the biodegradable resin (A) is equal to or lower than the above upper limit, the biodegradable resin (A) can be easily processed, and the productivity of the multilayer label tends to be excellent.
The melting point of the biodegradable resin (A) can be measured by the method described in Examples.

[Glass transition temperature (Tg) of biodegradable resin (A)]
The glass transition temperature (Tg) of the biodegradable resin (A) is not particularly limited, but is preferably 0°C or lower, more preferably -10°C or lower, and still more preferably -20°C or lower. When the glass transition temperature (Tg) of the biodegradable resin (A) is equal to or lower than the above upper limit, the resin layer has appropriate flexibility under the general usage environment of the multilayer label according to the present embodiment. becomes. As a result, unintended separation between the substrate and the resin layer due to bending, impact, or the like can be suppressed.
The lower limit of the glass transition temperature (Tg) of the biodegradable resin (A) is not particularly limited, but in consideration of the balance with other physical properties, it may be, for example, -150°C or higher, or -100°C. or higher, or -50° C. or higher.
The glass transition temperature of the biodegradable resin (A) can be measured by the method described in Examples.

From the same point of view as above, the biodegradable resin (A) preferably has a glass transition temperature of 0°C or lower and a melting point of 40°C or higher. When the glass transition temperature and the melting point of the biodegradable resin (A) are within the above ranges, it is possible to achieve a high degree of compatibility between the effects obtained from both physical properties.

[Content of biodegradable resin (A)]
The content of the biodegradable resin (A) in the resin layer is not particularly limited, but is preferably 50 to 99% by volume, more preferably 55 to 98% by volume, based on the volume of the resin layer (100% by volume). , more preferably 60 to 97% by volume. When the content of the biodegradable resin (A) in the resin layer is at least the above lower limit, the peel strength between the substrate and the resin layer tends to be better. Moreover, when the content of the biodegradable resin (A) in the resin layer is equal to or less than the above upper limit, the tearability tends to be better.

The content of the biodegradable resin (A) with respect to the total amount (100 parts by mass) of the resin contained in the resin layer is not particularly limited, but from the viewpoint of further reducing the environmental load, it is preferably 80 to 100 mass. %, more preferably 90 to 100 mass %, still more preferably 95 to 100 mass %, still more preferably 99 to 100 mass %.

(Filler (B))
The filler (B) is not particularly limited, and known materials can be used.
Since the resin layer contains the filler (B), the multilayer label according to the present embodiment has excellent tearability, and is less likely to become an obstacle when the packing material is opened. In addition, since the filler (B) promotes the biodegradability of the biodegradable resin (A), the multilayer label according to this embodiment has a much smaller environmental load.
A filler (B) may be used individually by 1 type, and may be used in combination of 2 or more type.

The filler (B) may be an inorganic filler or an organic filler. It is preferably an inorganic filler from the viewpoint of having and promoting hydrolysis of the biodegradable resin (A).
Examples of inorganic fillers include silica, alumina, glass, metal oxides, sodium carbonate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, magnesium silicate, calcium silicate, zirconium silicate, titanium Barium oxide, potassium titanate, calcium titanate, mica, vermiculite, zeolite, barium sulfate, silicon carbide, silicon nitride and the like. Among these, calcium carbonate is preferred.

The filler (B) may have been subjected to surface modification treatment, but is preferably not subjected to surface modification treatment with an organic component.
When the filler (B) is not subjected to a surface modification treatment with an organic component, excessive adhesion between the biodegradable resin (A) and the filler (B) is suppressed, and tearability is improved. tend to be better.

[Average particle size (D ₅₀ ) of filler (B)]
The average particle size (D ₅₀ ) of the filler (B) is not particularly limited, but is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, still more preferably 0.8 to 10 μm. When the average particle size (D ₅₀ ) of the filler (B) is at least the above lower limit, the tearability of the resin layer tends to be better. In addition, when the average particle diameter (D ₅₀ ) of the filler (B) is equal to or less than the above upper limit, it tends to be possible to suppress the peeling force between the base material and the resin layer from becoming too small due to the unevenness of the filler (B). It is in.
The average particle size (D ₅₀ ) of the filler (B) in the present embodiment is the volume-median particle size (D ₅₀ ), which can be measured by the method described in Examples.

[Shape of filler (B)]
Although the shape of the filler (B) is not particularly limited, it is preferably non-spherical. The non-spherical shape of the filler (B) tends to improve the tearability of the resin layer.
The term "non-spherical" as used in the present embodiment means a three-dimensional shape other than a spherical shape, such as polygonal, plate-like, flake-like, angular, needle-like, rod-like, and the like. In addition, "spherical" in the present embodiment means a true sphere or an elliptical sphere, and an elliptical sphere having an aspect ratio (major axis diameter/minor axis diameter) of 1.2 or more is classified as "non-spherical". shall be Among these, the filler (B) preferably has a polygonal shape. The polygonal filler (B) preferably has an irregular shape, more preferably a crushed shape.
The shape of the filler (B) can be confirmed, for example, with a scanning electron microscope (SEM).

[Content of filler (B)]
The content of the filler (B) in the resin layer is not particularly limited, but is preferably 1 to 50% by volume, more preferably 4 to 45% by volume, and even more preferably 100% by volume of the resin layer. is 7 to 40% by volume. When the content of the filler (B) in the resin layer is at least the above lower limit, the tearability tends to be better. In addition, when the content of the filler (B) in the resin layer is equal to or less than the above upper limit, it tends to be possible to prevent the peeling force between the base material and the resin layer from becoming too small due to the unevenness of the filler (B). It is in.

(Content of biodegradable resin (A) and filler (B))
The total content of the biodegradable resin (A) and the filler (B) in the resin layer is not particularly limited, but is preferably 50 to 100% by mass, more preferably 50 to 100% by mass, based on the mass of the resin layer (100% by mass). is 70 to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass.
When the total content of the biodegradable resin (A) and the filler (B) is within the above range, the environmental load of the material forming the resin layer is sufficiently reduced, and excellent tearability tends to be easily obtained. .

(other ingredients)
The resin layer may contain other components other than the biodegradable resin (A) and the filler (B) as long as the effects of the present invention are not impaired.
Other components include, for example, resins other than the biodegradable resin (A); additives such as antioxidants, lubricants, ultraviolet absorbers, colorants, and antiblocking agents; and the like.
For each of the other components, one type may be used alone, or two or more types may be used in combination.
When the resin layer contains other components, the content of the other components is not particularly limited. More preferably 0.0005 to 15% by mass, still more preferably 0.001 to 10% by mass.

(thickness of resin layer)
Although the thickness of the resin layer is not particularly limited, it is preferably 5 to 50 μm, more preferably 10 to 40 μm, still more preferably 15 to 30 μm. When the thickness of the resin layer is at least the above lower limit, it tends to be easy to form a resin layer with a uniform thickness, and to easily adjust the peeling force between the base material and the resin layer within an appropriate range. Further, when the thickness of the resin layer is equal to or less than the above upper limit, the environmental load can be further reduced, and the peeling force between the substrate and the resin layer tends to be better.

<Adhesive layer>
The pressure-sensitive adhesive layer of the multilayer label according to this embodiment is a layer for attaching the multilayer label to an adherend, and is appropriately selected according to the application of the multilayer label.
The adhesive layer is formed from, for example, an acrylic adhesive, a natural rubber adhesive, a synthetic rubber adhesive, a silicone adhesive, or the like. Among these, acrylic pressure-sensitive adhesives are preferred from the viewpoint of weather resistance and economy.
Examples of acrylic pressure-sensitive adhesives include solvent-type acrylic pressure-sensitive adhesives and water-based emulsion-type acrylic pressure-sensitive adhesives.
One type of adhesive may be used alone, or two or more types may be used in combination.

The adhesive preferably contains a tackifier. Examples of tackifiers include rosin resins, terpene phenol resins, terpene resins, aromatic hydrocarbon-modified terpene resins, aliphatic petroleum resins, aromatic petroleum resins, hydrogenated petroleum resins, coumarone-indene resins, styrene resins, phenolic resins, xylene resins, and the like. These tackifiers may be used alone or in combination of two or more.
When the adhesive contains a tackifier, the content is not particularly limited, but is preferably 0.1 to 20 parts by mass, more preferably 1 to 15 parts by mass, relative to 100 parts by mass of the main polymer of the adhesive. parts, more preferably 5 to 10 parts by mass.

The pressure-sensitive adhesive may or may not contain additives for pressure-sensitive adhesives used in general pressure-sensitive adhesives, other than the base polymer and the tackifier, as long as the effects of the present invention are not impaired. good too.
Examples of adhesive additives include fillers, softeners, heat and light stabilizers, antioxidants, and cross-linking agents. Each of these adhesive additives may be used alone or in combination of two or more.
When the adhesive contains a pressure-sensitive adhesive additive, the content is not particularly limited, but is preferably 0.0001 to 20 parts by mass, more preferably 0.0001 to 20 parts by mass, based on 100 parts by mass of the main polymer of the adhesive. 01 to 15 parts by mass, more preferably 1 to 10 parts by mass.

(Thickness of adhesive layer)
Although the thickness of the pressure-sensitive adhesive layer is not particularly limited, it is preferably 1 to 50 μm, more preferably 5 to 40 μm, still more preferably 10 to 30 μm. When the thickness of the pressure-sensitive adhesive layer is at least the above lower limit, it tends to be easy to form a pressure-sensitive adhesive layer with a uniform thickness and to obtain stable adhesive strength. Moreover, when the thickness of the pressure-sensitive adhesive layer is equal to or less than the above upper limit, productivity and economy tend to be excellent.

<Peel strength between substrate and resin layer>
In the multilayer label according to this embodiment, the peel force between the substrate and the resin layer is preferably 100 to 1,000 mN/50 mm, more preferably 200 to 850 mN/50 mm, still more preferably 250 to 700 mN/50 mm, and even more preferably. is 300 to 650 mN/50 mm. When the peel strength between the substrate and the resin layer is equal to or higher than the above lower limit, there is a tendency that unintentional peeling of the substrate from the resin layer can be suppressed. Further, when the peel strength between the base material and the resin layer is equal to or less than the above upper limit value, the base material tends to be easily peeled off by hand, and the base material tends to be prevented from tearing when the base material is peeled off from the resin layer.
The peel strength between the base material and the resin layer is a value measured in accordance with JIS Z 0237:2000 "180° peeling adhesive strength to test plate", and is specifically described in Examples. can be measured by the method

<Other layers>
The multilayer label according to this embodiment may or may not have layers other than the substrate, resin layer, and pressure-sensitive adhesive layer.
Even when the multilayer label according to the present embodiment has other layers, the substrate and the resin layer are directly laminated, and the positions of the other layers are not particularly limited. When there are two or more other layers, they may have the same composition or may have different compositions.
Other layers include, for example, the heat-sensitive coloring layer described above and a release sheet provided on the surface of the pressure-sensitive adhesive layer opposite to the resin layer.

As the release sheet, a release sheet subjected to double-sided release treatment, a release sheet subjected to single-sided release treatment, or the like is used.
Base materials for release sheets include, for example, papers such as woodfree paper, glassine paper, and kraft paper; polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin; plastic films such as olefin resin films; and the like.
Examples of release agents include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, fluorine-based resins, and the like.

Although the thickness of the release sheet is not particularly limited, it is preferably 10 to 200 μm, more preferably 25 to 170 μm, still more preferably 30 to 150 μm from the viewpoint of economy and handling.

<Total thickness of multilayer label>
Although the total thickness of the multilayer label according to this embodiment is not particularly limited, it is preferably 50 to 300 μm, more preferably 70 to 200 μm, still more preferably 90 to 150 μm.
When the multilayer label has a release sheet, the thickness of the release sheet is not included in the total thickness of the multilayer label.

<Shape of multilayer label>
The shape of the multilayer label when viewed from above is not particularly limited, and examples thereof include polygons such as rectangles and triangles; circles, ellipses, irregular shapes; and the like.

<Manufacturing method of multilayer label>
The multilayer label according to this embodiment can be manufactured, for example, by a manufacturing method including the following steps P1 and P2.
Step P1: A step of forming a resin layer on one surface of a base material to obtain a base material with a resin layer. Step P2: A step of laminating an adhesive layer on the resin layer of the base material with a resin layer obtained in Step P1.

(Process P1)
Step P1 is a step of forming a resin layer on one surface of a substrate to obtain a substrate with a resin layer.
The method for forming a resin layer on one side of the substrate is not particularly limited, and for example, a resin layer-forming material containing a biodegradable resin (A) and a filler (B) is melt-extruded onto the substrate. and a method of applying a resin layer-forming material onto a substrate. Among these, the method of melt extruding the resin layer-forming material is preferable from the viewpoint of productivity.

Examples of the method of melt extruding the resin layer-forming material onto the substrate include a method of extruding a melted resin layer-forming material onto the substrate to form a layer using an extruder and a T-die. .
The melt extrusion temperature of the resin layer-forming material is not particularly limited, and may be appropriately set according to the type of resin constituting the resin layer. is 180-220°C.
After the resin layer-forming material is melt-extruded, the formed resin layer may be cooled and solidified.

As a method of applying the resin layer-forming material onto the substrate, for example, a coating liquid of the resin layer-forming material obtained by dissolving and dispersing the biodegradable resin (A) and the filler (B) in a solvent is applied to the substrate. A method of forming a resin layer by coating on the surface and then drying may be mentioned.
Examples of methods for applying the coating liquid of the resin layer-forming material include roll coating, spin coating, spray coating, bar coating, knife coating, roll knife coating, blade coating, die coating, and gravure coating. law, etc.

(Process P2)
Step P2 is a step of laminating an adhesive layer on the resin layer of the substrate with a resin layer obtained in step P1.
As a method of laminating an adhesive layer on a resin layer, for example, an adhesive layer is formed by coating a release sheet with an adhesive composition containing a material constituting the adhesive layer and then drying it as necessary. and sticking the pressure-sensitive adhesive layer to the resin layer of the base material with the resin layer.
Further, as another method of laminating the pressure-sensitive adhesive layer on the resin layer, for example, after applying the pressure-sensitive adhesive composition to the surface of the resin layer of the base material with the resin layer, by drying as necessary, the resin layer A method of forming a pressure-sensitive adhesive layer on the surface of After that, if necessary, a release sheet may be attached to the surface of the pressure-sensitive adhesive layer.
The method of applying the pressure-sensitive adhesive composition includes the same method as the method of applying the coating liquid of the resin layer-forming material.

From the viewpoint of improving the adhesion between the resin layer and the adhesive layer, the adhesive layer may be formed after surface treatment or the like is applied to the surface of the resin layer on which the adhesive layer is laminated. Examples of surface treatment methods include corona discharge treatment, plasma treatment, chromic acid oxidation (wet), flame treatment, hot air treatment, ozone irradiation treatment, ultraviolet irradiation treatment, and ultraviolet-ozone treatment. oxidizing method; roughening method such as sandblasting method and solvent treatment method; and the like.

The multilayer label may be punched as appropriate. In the punching process, for example, the release sheet may be punched using a punching blade along the outline of a predetermined multilayer label, or the base material and the adhesive layer may be cut so as not to punch the release sheet, and then peeled off. A plurality of multilayer labels may be arranged on the sheet. Moreover, if necessary, unnecessary portions around the outer contour of each multilayer label may be removed from the release sheet as waste.

<Uses of multi-layer labels>
The multilayer label according to this embodiment is preferably a multilayer label for delivery slips. When used as a delivery slip, a half-cut line is provided in the base material of the multilayer label so that the base material can be separated into a plurality of pieces and peeled off. One piece of base material separated by the half-cut line is used as a delivery slip, and the other piece of base material is used as a receipt slip. The receipt is usually stamped or signed by the recipient, then peeled off, taken home by the delivery company, and used for sorting slips and the like.
In addition, since the multilayer label according to the present embodiment has a small environmental load and is easy to dispose of, it is suitable for applications other than delivery slips, such as postcards and tamper-proof labels.

The present invention will be described in more detail below based on examples, but the present invention is not limited by these examples. Measurement methods and evaluation methods for various physical properties are as follows.

[Measurement of thickness of each layer]
It was measured using a constant-pressure thickness measuring instrument manufactured by Teclock Co., Ltd. (model number: "PG-02J", standard specifications: JIS K 6783, Z1702, Z1709).

[Measuring method of average particle size (D ₅₀ ) of filler]
Particle size distribution measurement is performed using a laser diffraction particle size distribution analyzer (manufactured by Malvern, product name "Mastersizer 3000"), and the cumulative volume frequency calculated from the smaller particle size of the obtained particle size distribution is 50%. The corresponding particle size was taken as the average particle size ( _D50 ).

[Measurement of melting point of resin and confirmation of crystallinity]
The melting point of the resin was measured according to JIS K 7121:1987 by the following procedure.
About 5 mg of the sample is put into an aluminum pan, and a differential scanning calorimeter (DSC) (manufactured by TA Instruments, product name "Q2000") is used to measure the temperature range from -120 to 200 ° C. under a nitrogen atmosphere. , and a temperature increase rate of 10° C./min. The melting point of the resin was obtained by analyzing the obtained DSC curve according to JIS K 7121:1987.
The presence or absence of crystallinity of the resin was determined by the presence of a melting point peak, and all the resins used in Examples and Comparative Examples described later had crystallinity.

[Measurement of glass transition temperature (Tg) of resin]
The glass transition temperature (Tg) of the resin was measured according to JIS K 7121:1987 by the following procedure.
About 5 mg of the sample is put into an aluminum pan, and a differential scanning calorimeter (DSC) (manufactured by TA Instruments, product name "Q2000") is used to measure the temperature range from -120 to 200 ° C. under a nitrogen atmosphere. , and a temperature increase rate of 10° C./min. The glass transition temperature of the resin was obtained by analyzing the obtained DSC curve according to JIS K 7121:1987.

[Preparation of multilayer label]
Examples 1 to 8, Comparative Example 1
A resin layer-forming material containing a resin and a filler having the composition of the resin layer shown in Table 1 is heated to 200 ° C., and using a T die, a paper base material (manufactured by Nippon Paper Industries Co., Ltd., thermal paper, basis weight 65 g /m ² , thickness 75 μm). Thereafter, the resin layer was cooled and solidified by a water-cooled roll adjusted to a water temperature of 23° C. to form a resin layer having a thickness of 20 μm on the paper substrate.
Next, 100 parts by mass of acrylic pressure-sensitive adhesive and 7.5 parts by mass of rosin-based tackifier were mixed to prepare a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition is applied onto a release sheet (manufactured by Lintec Corporation, trade name "8K Blue") using a roll coater, and then dried to form a pressure-sensitive adhesive layer having a thickness of 20 μm on the release sheet. formed.
Subsequently, by laminating the adhesive layer on the release sheet and the resin layer on the paper substrate, the paper substrate, the resin layer containing the resin and the filler, the adhesive layer, the release sheet, in this order to obtain a multilayer label in which the paper substrate and the resin layer are releasably adhered.

Comparative example 2
A multilayer label was obtained in the same manner as in Example 1, except that no filler was added to the resin layer-forming material.

[Evaluation of multilayer label]
The multilayer labels produced in each example were evaluated as follows. Table 1 shows the evaluation results.

(Peeling force between base material and resin layer)
The peel strength between the base material and the resin layer was measured according to the following procedure according to JIS Z 0237:2000 "180° peeling adhesive strength to test plate".
The multi-layer label produced in each example was cut into a size of 50 mm in width and 150 mm in length, and the release sheet was removed to prepare a multi-layer label for evaluation. Then, the multi-layer label for evaluation was attached and fixed to the surface of the SUS plate with the pressure-sensitive adhesive layer as the attachment surface. Subsequently, at one end of the multi-layer label for evaluation on the SUS plate, the paper substrate was peeled off from the resin layer by 40 mm. The part of the peeled paper substrate was fixed to a chuck of a tensile tester, and the paper substrate was peeled off from the resin layer using the tensile tester under the conditions of a peeling speed of 0.3 m/min and a peeling angle of 180°. , 4-point peel force was measured at 20 mm intervals. Three multilayer labels for evaluation were tested, and the peel force was calculated as the average value of the 12 measured points.

(tearability)
The tearability of the multilayer label was evaluated by the following procedure. In addition, the schematic diagram for demonstrating the tearability evaluation method is shown in FIG. 3, and below, a procedure is demonstrated, referring this drawing.
First, a multi-layer label 1 for evaluation was prepared by cutting the multi-layer label prepared in each example into a size of 80 mm long×40 mm wide and removing the release sheet.
A cloth tape (No. 111, manufactured by Okamoto Co., Ltd.) 60 having a length of 160 mm and a width of 50 mm was attached to the surface of the cardboard 50 .
Next, as shown in FIG. 3, the multi-layer label for evaluation 1 is attached to both the corrugated cardboard 50 and the cloth tape 60 attached to the corrugated cardboard 50 with the adhesive layer as the attachment surface, and the paper The substrate was peeled off. The position where the multi-layer label for evaluation 1 is pasted is a position where the center line of the cloth tape 60 in the lateral direction coincides with the center line of the multi-layer label for evaluation 1 in the longitudinal direction. The half length of 40 mm was laminated on the cloth tape 60 and the remaining length of 40 mm was laminated on the cardboard 50 .
Next, one end of the cloth tape 60 attached to the cardboard 50 is peeled off by about 20 mm, and the peeled portion is grasped with fingers, and the cloth tape 60 is peeled from one longitudinal end to the other end (Fig. 3) at a peeling angle of about 135°. (X direction)), thereby tearing the resin layer. Thereafter, the longest distance from the boundary between the corrugated board 50 and the fabric tape 60 to the edge of the torn resin layer was measured and evaluated according to the following criteria. In addition, the evaluation was based on a test (i) in which the flow direction when the resin layer was extruded and formed was parallel to the direction in which the cloth tape 60 was peeled off, and a test (i) in which the flow direction was the direction in which the cloth tape 60 was peeled off. Both tests (ii) of application perpendicular to the
[Evaluation Criteria for Tearability]
A: The longest distance of the resin layer was less than 5 mm in both tests (i) and (ii).
B: Among tests (i) and (ii), the longest distance of the resin layer was 5 mm or more and less than 10 mm.
C: Among Tests (i) and (ii), the longest distance of the resin layer was 10 mm or more and less than 20 mm.
F: Among tests (i) and (ii), the longest distance of the resin layer was 20 mm or more. Alternatively, the resin layer was peeled off from the cardboard 50 without being torn.

From the results in Table 1, the multilayer labels of Examples 1 to 8 of the present embodiment have the same peel strength as the multilayer label of Comparative Example 1 using conventional low-density polyethylene for the resin layer, but they are biodegradable. It can be seen that the use of the flexible resin (A) has a small environmental load and is excellent in tearability. On the other hand, the multilayer label of Comparative Example 2, in which no filler was added to the resin layer, was inferior in tearability.

1, 2 Multilayer label 10 Base material 20 Resin layer 30 Adhesive layer 40 Release sheet 50 Cardboard 60 Cloth tape S Interlayer X direction

Claims

Having a substrate, a resin layer, and an adhesive layer in this order,
The base material and the resin layer are adhered in a detachable manner,
A multilayer label, wherein the resin layer contains a biodegradable resin (A) and a filler (B).
The multilayer label according to claim 1, wherein the biodegradable resin (A) has crystallinity.
The multilayer label according to claim 1 or 2, wherein the biodegradable resin (A) has a glass transition temperature of 0°C or lower and a melting point of 40°C or higher.
The multilayer label according to any one of claims 1 to 3, wherein the biodegradable resin (A) is a polybutylene succinate resin.
The multilayer label according to any one of claims 1 to 4, wherein the filler (B) is an inorganic filler.
The multilayer label according to claim 5, wherein the inorganic filler is calcium carbonate.
The multilayer label according to any one of claims 1 to 6, wherein the filler (B) has a non-spherical shape.
The multilayer label according to any one of claims 1 to 7, wherein the filler (B) is not subjected to surface modification treatment with an organic component.
The content of the filler (B) in the resin layer is 1 to 50% by volume with respect to the volume (100% by volume) of the resin layer, according to any one of claims 1 to 8. multi-layer label.
The multilayer label according to any one of claims 1 to 9, wherein the substrate is a paper substrate.
The multilayer label according to any one of claims 1 to 10, wherein the peel force between the substrate and the resin layer is 100 to 1,000 mN/50 mm.
The multilayer label according to any one of claims 1 to 11, which is for delivery slips.