JP7794538B2 - Pseudo-adhesive labels - Google Patents

Description

The present invention relates to pseudo-adhesive labels.

Pseudo-adhesive labels are labels that, after being attached to an adherend, can be easily peeled from the substrate starting from the pseudo-adhesive interface. Pseudo-adhesive labels are used in practical applications, such as shipping labels and information-hiding labels.

In recent years, mail-order sales via the Internet and television shopping have become widespread, and as a result, distribution methods in which delivery companies deliver products on behalf of the product seller are becoming more common. In such distribution methods, the delivery company packs the item (product) in packaging materials such as cardboard or paper boxes, affixes a delivery label containing information about the delivery destination to the surface of the packaging, and delivers the item to the purchaser based on this information.

One such shipping label is known, for example, as described in Patent Document 1. This label comprises a first thermal substrate, a resin layer serving as a pseudo-adhesive layer made of a hot melt adhesive containing a thermoplastic resin and having pseudo-adhesion, a second thermal substrate, an adhesive layer, and a release sheet, laminated in this order to provide pseudo-adhesion between the resin layer and the second thermal substrate. A receipt stamp field along with information about the delivery destination is written on the surface of the first thermal substrate. After the recipient confirms receipt in the receipt stamp field, the resin layer and the second thermal substrate are peeled off at their interface, and the peeled laminate of the first thermal substrate and resin layer is collected and managed as proof of delivery completion.

Shipping labels have traditionally been attached to packaging materials such as cardboard boxes and paper boxes, but recently, soft packaging materials such as plastic bags and paper bags have also been used to eliminate dead space during transport. In the case of soft bags, if the bag is bent during delivery, the shipping label affixed to the bag will also be bent.

In addition, the use of irregularly shaped boxes that correspond to the shape of the contents, such as boxes with one side that is polygonal (triangle, trapezoid, etc.), or boxes with uneven or curved surfaces, is also increasing. Depending on the shape and size of the box, the shipping label may be affixed in a bent state across two adjacent sides, straddling a corner, rather than just on the flat part of the box.

When a shipping label is bent in this way, stress is applied to the bent portion, which can cause the surface of the pseudo-adhesive layer to peel off during shipping.

JP 2015-179193 A

The object of the present invention is to provide a pseudo-adhesive label that effectively prevents unintentional peeling from the surface of the pseudo-adhesive layer, even when attached to a curved or bent surface of an adherend.

These objects can be achieved by the present invention as set forth in (1) to ( 6 ) below.
(1) a substrate;
A pseudo-adhesive layer provided on one surface of the substrate;
a pressure-sensitive adhesive layer for adhering to an adherend, the pressure-sensitive adhesive layer being provided adjacent to the pseudo-adhesive layer on the opposite side from the substrate;
The pseudo-adhesive layer contains an ethylene-vinyl acetate copolymer in which the copolymerization ratio of vinyl acetate is 3% by mass or more and 9% by mass or less , does not contain a tackifier, and has a thickness of 5.0 μm or more and 15.0 μm or less,
A pseudo-adhesive label characterized in that, when attached to the substrate, it is peeled off at the interface between the substrate and the pseudo-adhesive layer, thereby removing the substrate from the substrate and leaving a laminate having the pseudo-adhesive layer and the pressure-sensitive adhesive layer on the substrate.

( 2 ) The pseudo-adhesive label according to (1) above, wherein the Young's modulus of the pseudo-adhesive layer measured by a method conforming to JIS K7161-1:2014 and JIS K 7127:1999 is 20 MPa or more and 80 MPa or less.

( 3 ) The pseudo-adhesive layer is formed into a rectangular sample piece having a width of 15 mm and a length of 200 mm. A tensile test is performed on the sample piece, with the measurement range set to a length of 100 mm, in an environment of 23°C and 50% RH, in which the sample piece is elongated by 5% in the length direction at a speed of 0.2 m/min. When the initial stress value measured is S1 [MPa] and the residual stress value 5 minutes after the start of the measurement is S2 [MPa], the following formula is obtained:
Stress relaxation rate (%) = {(S1 - S2) / S1} × 100
The pseudo-adhesive label according to (1) or (2) above, wherein the stress relaxation rate represented by the following formula is 12% or more.

( 4 ) A pseudo-adhesive label according to any one of (1) to (3) above, wherein the pseudo-adhesion strength between the substrate and the pseudo-adhesive layer measured at a peel speed of 10 m/min in a 180 ° peel test specified in JIS Z 0237:2009 is 4000 mN/50 mm or more and 7000 mN/50 mm or less.

( 5 ) A pseudo-adhesive label according to any one of (1) to ( 4 ) above, wherein the pseudo-adhesive layer and the pressure-sensitive adhesive layer are substantially transparent.

( 6 ) A pseudo-adhesive label according to any one of (1) to ( 5 ) above, which is used as a shipping label.

The present invention provides a pseudo-adhesive label that effectively prevents unintentional peeling from the surface of the pseudo-adhesive layer, even when attached to a curved or bent surface of an adherend.

1 is a cross-sectional view showing a preferred embodiment of the pseudo-adhesive label of the present invention. 1 is a perspective view showing a state in which the pseudo-adhesive label of the present invention is attached to a cardboard box, which is an adherend. 1 is a cross-sectional view showing a state in which the pseudo-adhesive label of the present invention is attached to a cardboard box, which is an adherend. FIG. 2 is a cross-sectional view showing the state in which the substrate has been peeled off from the pseudo-adhesive label of the present invention. 1 is a cross-sectional view showing a state in which a pseudo-adhesive label of a comparative example is attached to an adherend, which is a cardboard box.

Preferred embodiments of the present invention will be described in detail below.
[1] Pseudo-adhesive label FIG. 1 is a cross-sectional view showing a preferred embodiment of the pseudo-adhesive label of the present invention.

The pseudo-adhesive label 1 of this embodiment comprises a substrate 10, a pseudo-adhesive layer 20 provided on one side of the substrate 10, and a pressure-sensitive adhesive layer 30 provided adjacent to the pseudo-adhesive layer 20 on the side opposite the substrate 10. The pseudo-adhesive layer 20 contains a copolymer of ethylene and another monomer, and is configured to peel at interface A between the substrate 10 and the pseudo-adhesive layer 20.

In this specification, "pseudo-adhesion" refers to an adhesion in which separation by interlayer peeling is possible at the interface between one layer and another layer that have been bonded together under specific conditions (for example, a combination of materials and a temperature range), but which does not exhibit re-adhesion or re-stickiness after separation.

In the case of the pseudo-adhesive label 1 according to this embodiment, peeling can be achieved at interface A between the substrate 10 as one layer and the pseudo-adhesive layer 20 as the other layer, and after peeling, the surface of the substrate 10 on the interface A side and the surface of the pseudo-adhesive layer 20 on the interface A side do not exhibit re-adhesion or re-stickiness.

In the pseudo-adhesive label 1 of this embodiment, the pseudo-adhesive layer 20 contains a copolymer of ethylene and another monomer, which allows the pseudo-adhesive layer 20 to maintain sufficient pseudo-adhesive strength while imparting a low Young's modulus and high stress relaxation properties. This prevents the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20 even when the pseudo-adhesive label 1 is attached to the corner of a box, an uneven surface, a curved surface, or the like in a bent state as an adherend 100, or even when the pseudo-adhesive label 1 is attached to a soft bag and bent. This makes it possible to provide a pseudo-adhesive label 1 that is effectively prevented from unintentionally peeling off the surface of the pseudo-adhesive layer 20, i.e., at the interface between the substrate 10 and the pseudo-adhesive layer 20, during use (for example, during delivery when the pseudo-adhesive label 1 is used as a shipping label).

Furthermore, with the pseudo-adhesive label 1, the substrate 10 can be conveniently peeled off from the pseudo-adhesive layer 20 when necessary, for example, after delivery.

It is believed that such excellent effects are achieved because the pseudo-adhesive layer 20 contains a copolymer of ethylene and other monomers.

On the other hand, if the above conditions are not met, satisfactory results will not be obtained.
For example, if the pseudo adhesive layer 20 of the pseudo adhesive label 1 does not contain a copolymer of ethylene and another monomer, it is not possible to impart a low Young's modulus and high stress relaxation properties to the pseudo adhesive layer 20. As a result, it is not possible to sufficiently prevent the substrate 10 from unintentionally peeling off from the pseudo adhesive layer 20.

Note that the following explanation will focus on the case where the pseudo-adhesive label 1 of this embodiment is used as a shipping label, but the use of the pseudo-adhesive label 1 of this embodiment is not limited to this.

[1-1] Substrate The substrate 10 is not particularly limited, and may be appropriately selected from substrates used in conventional pseudo-adhesive labels depending on the intended use of the pseudo-adhesive label 1.

Examples of the substrate 10 include paper, resin film, synthetic paper, etc. The substrate 10 may also be a laminated sheet made of two or more layers of these.

Examples of papers that can be used as the substrate 10 include thermal paper, kraft paper, fine paper, glassine paper, parchment paper, rayon paper, and coated paper.

Examples of resin films that can be used as the substrate 10 include films made of polyester resin, polyvinyl chloride resin, polyvinylidene chloride resin, and polyolefin resin.

The substrate 10 is preferably made of paper, and more preferably thermal paper, kraft paper, fine paper, or glassine paper.

It is preferable that the surface of the substrate 10 that forms the surface of the pseudo-adhesive label 1, in other words, the surface opposite to the side on which the pseudo-adhesive layer 20 is provided, be capable of being labeled with various pieces of identification information.

In the pseudo adhesive label 1, the substrate 10 is, for example, an information display substrate that displays information about the adherend 100. For example, if the adherend 100 is a delivery item and the pseudo adhesive label 1 is used as a delivery label, the information about the adherend 100 may include the sender, destination, and delivery company's name or title, address, telephone number, and the contents of the delivery item.

The information may be displayed using, for example, characters, symbols, graphics, or any combination thereof, or may be displayed using two-dimensional codes such as barcodes and QR codes (registered trademark).
This information is printed, for example, by a thermal printer.

When the substrate 10 is thermal paper, the substrate 10 has a thermal coloring layer (not shown) on the side opposite the side on which the pseudo-adhesive layer 20 is provided. This makes it possible to print or imprint characters on the surface of the substrate 10 using a thermal printer or the like.

Examples of thermosensitive coloring layers include those containing a leuco dye and a color developer that reacts with the leuco dye.

The thermosensitive coloring layer can be suitably formed, for example, by applying a coating liquid containing the above-mentioned leuco dye and color developer, as well as appropriate binders, waxes, solvents, etc., to the surface of the substrate 10 opposite the side on which the pseudo-adhesive layer 20 is disposed.

The thickness of the substrate 10 is not particularly limited, but is preferably 10.0 μm or more and 200.0 μm or less, more preferably 20.0 μm or more and 150.0 μm or less, and even more preferably 30.0 μm or more and 100.0 μm or less.

This improves ease of handling when attaching the pseudo-adhesive label 1 to the adherend 100, when peeling the substrate 10 from the pseudo-adhesive layer 20, and when handling the peeled substrate 10.

In the following description, the composition for forming the pseudo-adhesive layer 20 will also be referred to as the "pseudo-adhesive layer-forming composition."

The pseudo-adhesive label 1 of this embodiment has only one substrate 10, which allows for reduced material costs compared to pseudo-adhesive labels that have multiple substrates.

Furthermore, since there is only one substrate 10, for example, the process of applying the pseudo-adhesive layer-forming composition onto the substrate 10 only needs to be done once, thereby reducing the number of manufacturing steps and manufacturing costs.

Furthermore, since there is only one substrate 10, the overall thickness of the label can be reduced, allowing for space savings when storing multiple pseudo-adhesive labels 1 in a stacked state.

[1-2] Pseudo-adhesive layer The pseudo-adhesive layer 20 is laminated to the substrate 10 so as to be pseudo-adhered to the substrate 10, and the interface A between the pseudo-adhesive layer 20 and the substrate 10 is in close contact with the substrate 10 with a peeling force sufficient to allow easy peeling when necessary.

The pseudo-adhesive layer 20 contains a copolymer of ethylene and other monomers as a thermoplastic resin that does not have tackiness at room temperature.

Traditionally, polyethylene resin has often been chosen as the thermoplastic resin that makes up the pseudo-adhesive layer due to its ease of processing and availability.

By copolymerizing ethylene with other monomers (monomers other than ethylene), the crystallinity is reduced and the flexibility of the resin can be increased compared to polyethylene resin, which is a polymer of ethylene alone.

In other words, by using a copolymer of ethylene and other monomers as the thermoplastic resin that constitutes the pseudo-adhesive layer 20, it is possible to achieve appropriate pseudo-adhesion while also achieving a low Young's modulus for the pseudo-adhesive layer 20 and imparting high stress relaxation properties.

Furthermore, by using a copolymer of ethylene and other monomers for the pseudo-adhesive layer 20, better pseudo-adhesion can be achieved between the substrate 10 and the paper substrate, if the substrate 10 is a paper substrate.

Examples of copolymers of ethylene and other monomers that constitute the pseudo-adhesive layer 20 include ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-butene copolymer, ethylene-octene copolymer, etc., and one or a combination of two or more selected from these can be used, but ethylene-vinyl acetate copolymer is preferred.
This makes the above-mentioned effects more pronounced.

When the pseudo-adhesive layer 20 contains ethylene-vinyl acetate copolymer as a copolymer of ethylene and other monomers, the proportion of ethylene-vinyl acetate copolymer in the entire copolymer of ethylene and other monomers that constitutes the pseudo-adhesive layer 20 is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

The following explanation will focus on the case where the copolymer of ethylene and another monomer is an ethylene-vinyl acetate copolymer (i.e., a copolymer of ethylene and vinyl acetate).

The copolymerization ratio of vinyl acetate in ethylene-vinyl acetate copolymer, i.e., the ratio of vinyl acetate as a monomer to all constituent monomers that make up ethylene-vinyl acetate copolymer, is preferably 3% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 12% by mass or less, and even more preferably 5% by mass or more and 9% by mass or less.

This allows the pseudo-adhesive layer 20 to have suitable flexibility while maintaining a suitable pseudo-adhesive strength, making the effects of the present invention as described above more pronounced, and more effectively preventing the label from tearing or curling even when the substrate 10 is peeled off at high speed.

The copolymerization form of ethylene and vinyl acetate in the ethylene-vinyl acetate copolymer is not particularly limited. Examples of ethylene-vinyl acetate copolymers include random copolymers, alternating copolymers, block copolymers, and graft copolymers, with random copolymers being preferred.

This allows the ethylene-vinyl acetate copolymer to have more suitable flexibility, making the effects of the present invention described above even more pronounced.

The softening point of the ethylene-vinyl acetate copolymer is preferably 50°C or higher and 100°C or lower, and more preferably 70°C or higher and lower than 90°C.

This prevents the pseudo-adhesive label 1 from becoming tacky at room temperature, improving its heat resistance. For example, even when temperatures rise in the summer, the pseudo-adhesive layer 20 is prevented from softening, improving adhesive stability. Furthermore, the coating temperature can be lowered when applying the pseudo-adhesive layer-forming composition to the substrate 10. For example, even when thermal paper is used as the substrate 10, this more reliably prevents the thermal paper from changing color due to the heat during application.

The softening point can be adjusted by, for example, appropriately selecting the copolymerization ratio of vinyl acetate in the ethylene-vinyl acetate copolymer, the molecular weight, molecular weight distribution, and the ratio of low molecular weight components to high molecular weight components.

As described above, the pseudo-adhesive layer 20 has pseudo-adhesion to the substrate 10, and the pseudo-adhesive layer 20 and the substrate 10 are adhered together with a peeling force that allows them to be easily peeled off.

The pseudo-adhesion strength between the substrate 10 and the pseudo-adhesive layer 20, measured at a peel speed of 0.3 m/min in the 180° peel test specified in JIS Z 0237:2009, is preferably 200 mN/50 mm or more and 900 mN/50 mm or less, more preferably 250 mN/50 mm or more and 850 mN/50 mm or less, and even more preferably 300 mN/50 mm or more and 800 mN/50 mm or less.

This more reliably prevents the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20, and, for example, when necessary, when the substrate 10 is manually peeled off from the pseudo-adhesive layer 20, the peeling can be performed more smoothly with relatively little peeling resistance while preventing the substrate 10 from tearing.

Furthermore, in the above-mentioned peel test, i.e., the 180° peel test specified in JIS Z 0237:2009, the pseudo-adhesion strength between the substrate 10 and the pseudo-adhesive layer 20 measured at a peel speed of 10 m/min is preferably 4000 mN/50 mm or more and 9500 mN/50 mm or less, more preferably 4000 mN/50 mm or more and 8000 mN/50 mm or less, and even more preferably 4000 mN/50 mm or more and 7000 mN/50 mm or less.

This achieves the same effect as above. Furthermore, when peeling the substrate 10 from the pseudo-adhesive layer 20, curling of the substrate 10 is more effectively prevented, even when peeled at high speed, and the peeled substrate 10 is easier to handle when stored.

Furthermore, by preventing curling of the peeled substrate 10, it is possible to conveniently read the information recorded on the peeled substrate 10. Furthermore, when peeled substrates 10 are stacked and stored as delivery slips or the like, bulkiness can be effectively prevented, contributing to space-saving storage.

As described above, the pseudo-adhesive layer 20 has pseudo-adhesion at interface A with the substrate 10 that allows it to be peeled off when necessary. However, at interface B between the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30, the adhesion is stronger than the peel strength at interface A between the pseudo-adhesive layer 20 and the substrate 10. Therefore, when the pseudo-adhesive label 1 from which the release liner 40 has been removed is attached to the adherend 100 by the pressure-sensitive adhesive layer 30, peeling the substrate 10 side off by hand or the like will result in the substrate 10 being peeled off from the pseudo-adhesive layer 20.

The Young's modulus of the pseudo-adhesive layer 20 is preferably 20 MPa or more and 80 MPa or less, more preferably 30 MPa or more and 70 MPa or less, and even more preferably 40 MPa or more and 60 MPa or less.

This gives the pseudo-adhesive layer 20 appropriate flexibility, and, for example, when the pseudo-adhesive label 1 is folded, it can more effectively relieve the stress applied to the folded portion, and more reliably prevent the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20.

In this specification, "Young's modulus" refers to a value measured using a method conforming to the "tensile modulus" described in JIS K7161-1:2014 and JIS K 7127:1999.

The pseudo-adhesive layer 20 is a rectangular sample piece having a width of 15 mm and a length of 200 mm. The sample piece is subjected to a tensile test in which the measurement range is 100 mm in length and the sample piece is stretched by 5% in the longitudinal direction at a speed of 0.2 m/min in an environment of 23°C and 50% RH. When the initial stress value measured is S1 [MPa] and the residual stress value 5 minutes after the start of the measurement is S2 [MPa], the stress relaxation rate shown by the following formula is preferably 12% or more, and more preferably 15% or more.
Stress relaxation rate (%) = {(S1 - S2) / S1} × 100

This allows, for example, when the pseudo-adhesive label 1 is folded, to more effectively relieve the stress applied to the folded portion, and more reliably prevent the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20.

The melt mass flow rate (MFR) of the copolymer of ethylene and other monomers is preferably 3 g/10 min or more and 35 g/10 min or less, more preferably 5 g/10 min or more and 30 g/10 min or less, and even more preferably 7 g/10 min or more and 25 g/10 min or less.

In this specification, melt mass flow rate refers to the value measured using the method specified in JIS K7210-1:2014.

This allows the pseudo-adhesive layer-forming composition to maintain its favorable fluidity when applied to the substrate 10, improving film-forming properties and film thickness accuracy, and enabling the pseudo-adhesive layer 20 to be more suitably formed on the substrate 10 by melt extrusion. Furthermore, even when the pseudo-adhesive label 1 is stored in a high-temperature, high-humidity environment, for example, the peel force of the pseudo-adhesive layer 20 is less likely to change, further improving the stability of peel performance.

The pseudo adhesive layer 20 may be made of a material containing a copolymer of ethylene and other monomers, and may contain components other than the copolymer of ethylene and other monomers, but the content of the copolymer of ethylene and other monomers in the pseudo adhesive layer 20 is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.
This makes it possible to more significantly exhibit the effects of the present invention described above.

In addition to the copolymer of ethylene and another monomer, the pseudo-adhesive layer 20 may also contain, for example, a thermoplastic resin other than the copolymer of ethylene and another monomer. Examples of such thermoplastic resins include other polyolefin-based resins, polyvinyl acetate, polyester-based resins, and polyamide-based resins.

Examples of polyolefin resins include polyethylene resin, polypropylene resin (PP), polybutene resin (PB), ethylene-propylene copolymer, olefin elastomer (TPO), ethylene-methyl methacrylate copolymer (EMMA), and olefin terpolymers such as ethylene-propylene-(5-ethylidene-2-norbornene).

If the pseudo adhesive layer 20 contains a thermoplastic resin other than the copolymer of ethylene and other monomers in addition to the copolymer of ethylene and other monomers, the content of the thermoplastic resin is preferably 0.1 to 15.0 parts by mass, more preferably 0.5 to 10.0 parts by mass, and even more preferably 1.0 to 5.0 parts by mass, per 100 parts by mass of the copolymer of ethylene and other monomers.

The pseudo-adhesive layer 20 may also contain components other than those listed above (hereinafter referred to as "other components" in this section). Examples of other components include antioxidants, UV absorbers, light stabilizers, flexibility agents, flame retardants, antistatic agents, lubricants, fillers, colorants, etc., and one or more selected from these may be used in combination.

However, the content of other components in the pseudo-adhesive layer 20 is preferably 20.0% by mass or less, more preferably 15.0% by mass or less, and even more preferably 10.0% by mass or less.

The thickness of the pseudo-adhesive layer 20 is not particularly limited, but is preferably 5.0 μm or more and 18.0 μm or less, more preferably 7.0 μm or more and 16.0 μm or less, and even more preferably 10.0 μm or more and 15.0 μm or less.

This ensures sufficient pseudo-adhesion to the substrate 10, and more reliably prevents the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20. It also prevents the substrate 10 from tearing or curling into a cylindrical shape during high-speed peeling. Furthermore, when the substrate 10 is peeled off from the pseudo-adhesive label 1 attached to the adherend 100, and the pseudo-adhesive layer 20 remains on the adherend 100 together with the pressure-sensitive adhesive layer 30, the laminate having the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30 can be made less noticeable on the adherend 100.

[1-3] Adhesive Layer The adhesive layer 30 is a layer for attaching the pseudo adhesive label 1 to the adherend 100 .

The adhesive used must have adequate adhesive strength to the adherend 100, and must be strong enough to reliably hold the pseudo adhesive layer 20 to the adherend 100 at interface B when the substrate 10 is peeled off at interface A with the pseudo adhesive layer 20, for example, with the pseudo adhesive label 1 attached to the adherend 100.

Examples of adhesives that make up the adhesive layer 30 include acrylic adhesives, natural rubber adhesives, synthetic rubber adhesives, and silicone adhesives, and one or more selected from these may be used in combination. Among these, acrylic adhesives and synthetic rubber adhesives are preferred in terms of ease of adhesive strength control and cost. Examples of acrylic adhesives include solvent-based acrylic adhesives, water-based emulsion-based acrylic adhesives, and hot-melt acrylic adhesives. Examples of synthetic rubber-based adhesives include solvent-based synthetic rubber adhesives, water-based emulsion-based synthetic rubber adhesives, and hot-melt synthetic rubber adhesives.

The adhesive layer 30 may contain components other than those listed above (hereinafter referred to as "other components" in this section). Examples of other components include fillers, softeners, heat and light stabilizers, antioxidants, crosslinking agents, etc., and one or more selected from these may be used in combination.

Examples of fillers include zinc oxide, titanium oxide, silica, calcium carbonate, and barium sulfate.
Examples of the softener include process oil, liquid rubber, and plasticizer.

Examples of heat and light stabilizers include benzophenone-based stabilizers, benzotriazole-based stabilizers, and hindered amine-based stabilizers.

Examples of antioxidants include anilide antioxidants, phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

The thickness of the adhesive layer 30 is not particularly limited, but is preferably 1.0 μm or more and 50.0 μm or less, more preferably 5.0 μm or more and 45.0 μm or less, and even more preferably 10.0 μm or more and 40.0 μm or less.

This ensures sufficient adhesive strength to the adherend 100 and makes the pseudo adhesive label 1 easier to handle when affixing it to the adherend 100. Furthermore, when the substrate 10 is peeled off from the pseudo adhesive label 1 affixed to the adherend 100 and the pseudo adhesive layer 20 remains on the adherend 100 together with the pressure-sensitive adhesive layer 30, the laminate having the pseudo adhesive layer 20 and the pressure-sensitive adhesive layer 30 can be made less noticeable on the adherend 100.

In the pseudo-adhesive label 1 of this embodiment, it is preferable that the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30 are substantially transparent.

This provides the following benefits. For example, when pseudo adhesive label 1 is used as a shipping label, there may be cases where an order is canceled or the shipping destination information is printed incorrectly, requiring the shipping label once affixed to the packaging material to be peeled off and a new shipping label with the correct information printed on it to be re-affixed. In such cases, if at least one of pseudo adhesive layer 20 and adhesive layer 30 is colored, the remaining pseudo adhesive label 1, i.e., the laminate having pseudo adhesive layer 20 and adhesive layer 30, will be conspicuous. Therefore, the box, bag, or other substrate to which pseudo adhesive label 1 is affixed must be discarded, and the contents must be repackaged with a new substrate. In contrast, if pseudo adhesive layer 20 and adhesive layer 30 are substantially transparent, the remaining pseudo adhesive label 1, i.e., the laminate having pseudo adhesive layer 20 and adhesive layer 30, remaining on the substrate will be less conspicuous when substrate 10, on which information is recorded, is peeled and removed from the substrate. Therefore, even if a laminate having the pseudo adhesive layer 20 and the pressure-sensitive adhesive layer 30 remains on the adherend, by attaching the pseudo adhesive label 1 bearing the correct information, the box, bag, or other adherend to which the pseudo adhesive label 1 is attached can be suitably reused without being discarded.

In this specification, the term "substantially transparent" refers to a material that transmits most of the visible light, so that when the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30 are attached to the surface of the adherend 100, the surface of the adherend 100 can be directly viewed through the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30, and this concept also includes translucency.

The visible light transmittance of the laminate of the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30 is preferably 80% or more, and more preferably 90% or more.
This makes the above-mentioned effects more pronounced.

[1-4] Release Liner In the pseudo adhesive label 1 shown in FIG. 1, a release liner 40 is disposed on the surface of the pressure-sensitive adhesive layer 30 opposite to the side on which the pseudo adhesive layer 20 is disposed.

The release liner 40 has the function of protecting the adhesive layer 30 during transportation, storage, etc. of the pseudo adhesive label 1. When the pseudo adhesive label 1 is attached to the adherend 100, the release liner 40 is peeled from the adhesive layer 30 at the interface C.
The pseudo-adhesive label of the present invention is not limited to an embodiment having a release liner.

The release liner 40 is not particularly limited, and any known release liner 40 can be appropriately selected and used. Typically, the release liner 40 is a substrate (release substrate) with a release treatment applied to one or both sides.

Release substrates that can be used for the release liner 40 include, for example, polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene, polypropylene, and polymethylpentene; paper substrates such as clay-coated paper, glassine paper, and recycled paper; and sheets of laminated paper formed by laminating these paper substrates with a thermoplastic resin such as polyethylene. Of these, paper substrates are particularly preferred.

The release agent used for the release treatment is not particularly limited, and any known release agent can be used. Specifically, silicone-based resins, olefin-based resins, isoprene-based resins, butadiene-based resins, long-chain alkyl-based resins, and alkyd-based resins are preferred, with butadiene-based resins and alkyd-based resins being more preferred.

The thickness of the release liner 40 is not particularly limited, but from the standpoint of ease of handling, etc., it is preferably 10.0 μm or more and 200.0 μm or less, more preferably 25.0 μm or more and 170.0 μm or less, and even more preferably 30.0 μm or more and 150.0 μm or less.

[2] Method for Manufacturing Pseudo-Adhesive Label Hereinafter, a method for manufacturing the pseudo-adhesive label will be described.

The pseudo adhesive label 1 of this embodiment can be manufactured, for example, by a method comprising a pseudo adhesive layer formation step of forming a pseudo adhesive layer 20 on one side of a substrate 10, an adhesive layer formation step of forming an adhesive layer 30 on one side of a release liner 40, and a lamination step of laminating the substrate 10 with the pseudo adhesive layer 20 laminated thereon and the release liner 40 with the adhesive layer 30 laminated thereon so that the pseudo adhesive layer 20 and the adhesive layer 30 come into contact with each other.

Each step will be described below.
[2-1] Pseudo-adhesive layer forming step In this step, the pseudo-adhesive layer 20 is laminated on one surface of the substrate 10 .

The method for laminating the pseudo-adhesive layer 20 onto the substrate 10 is not particularly limited. The method for manufacturing the pseudo-adhesive label 1 according to this embodiment includes a melt-extrusion step in which a pseudo-adhesive layer-forming composition containing the materials that make up the pseudo-adhesive layer 20 is melt-extruded onto the substrate 10.

One example of a method for melt-extruding the pseudo-adhesive layer-forming composition is a method using a T-die.

The melt extrusion temperature is preferably 180°C or higher and 400°C or lower, more preferably 200°C or higher and 350°C or lower, and even more preferably 230°C or higher and 300°C or lower.

The pseudo-adhesive layer forming process also includes a cooling process in which the melt-extruded pseudo-adhesive layer forming composition is cooled.

The cooling step can be carried out, for example, by bringing the heated and melted pseudo-adhesive layer-forming composition into contact with a cooling means such as a cooling roll. The cooling roll can be, for example, a cylindrical body with a metal outer periphery. The cooling roll may have a cooling function achieved by passing cooling water or the like through the interior of the cylindrical body. When a cooling roll is used as the cooling means, the pseudo-adhesive layer-forming composition melt-extruded onto the substrate 10 may be cooled by directly contacting the outer periphery of the cooling roll, or the substrate 10 may be directly contacted with the outer periphery of the cooling roll to indirectly cool the pseudo-adhesive layer-forming composition. Furthermore, in the cooling step, the melt-extruded pseudo-adhesive layer-forming composition may be cooled by air cooling.

[2-2] Pressure-sensitive adhesive layer forming step In this step, a pressure-sensitive adhesive layer forming composition containing materials that constitute the pressure-sensitive adhesive layer 30 is applied to one surface of the release liner 40, specifically, the surface that has been subjected to a release treatment, to form the pressure-sensitive adhesive layer 30.

Examples of methods for applying the adhesive layer-forming composition include roll coating, spray coating, bar coating, knife coating, roll knife coating, blade coating, die coating, and gravure coating.

[2-3] Lamination process In this process, the substrate 10 having the pseudo-adhesive layer 20 laminated thereon and the release liner 40 having the pressure-sensitive adhesive layer 30 laminated thereon are laminated so that the pseudo-adhesive layer 20 and the pressure-sensitive adhesive layer 30 are in contact with each other.
Through the above steps, the pseudo adhesive label 1 as shown in FIG. 1 is manufactured.

The method for producing the pseudo adhesive label is not limited to the above-described example.
For example, the pseudo adhesive label 1 can also be suitably manufactured by a method in which a composition for forming an adhesive layer is applied to the surface of a pseudo adhesive layer 20 laminated on a substrate 10 to laminate an adhesive layer 30, and then a release liner 40 is attached to the surface of the adhesive layer 30.

[3] How to Use the Pseudo-Adhesive Label Next, how to use the pseudo-adhesive label will be described.

Figure 2 is a perspective view showing the pseudo-adhesive label of the present invention attached to a corrugated cardboard box, which is an adherend. Figure 3 is a cross-sectional view showing the pseudo-adhesive label of the present invention attached to a corrugated cardboard box, which is an adherend. Figure 4 is a cross-sectional view showing the pseudo-adhesive label of the present invention after the substrate has been peeled off. Note that Figures 3 and 4 show an enlarged portion of the pseudo-adhesive label.

The pseudo adhesive label 1 of this embodiment is used, for example, as a shipping label.
That is, the pseudo-adhesive label 1 is adhered to a delivery via the adhesive layer 30 after the release liner 40 is peeled off and removed, and the substrate 10 is used as a receipt.

The pseudo-adhesive label 1 according to this embodiment can be peeled off at the interface C between the adhesive layer 30 and the release liner 40. As shown in Figure 2, after the release liner 40 is peeled off, the pseudo-adhesive label 1 is attached to the adherend 100 by the adhesive layer 30.

When the pseudo-adhesive label 1 is used as a shipping label, the adherend 100 can be, for example, a shipping item. A shipping item typically consists of the item to be shipped and packaging material in which the item is packaged. Examples of packaging material include packaging paper, packaging film, packaging bags, packaging boxes, and packaging containers. Packaging materials include cardboard, paper, plastic, and metal. The pseudo-adhesive label 1 is typically affixed to the packaging material of the shipping item.

The examples shown in Figures 2 to 4 show the case where the pseudo-adhesive label 1 is attached to a cardboard box as the adherend 100. Also, the examples shown in Figures 2 to 4 show the case where the pseudo-adhesive label 1 is attached so as to straddle the corner of the cardboard box.

In particular, with the pseudo-adhesive label 1 of this embodiment, even when it is applied across the corner of a cardboard box, i.e., in a bent state, or when it is applied to a soft resin bag and bent along with the bag during delivery, the pseudo-adhesive layer 20 contains a copolymer of ethylene and other monomers, so the pseudo-adhesive layer 20 is flexible and effectively relieves stress on the bent portion.

This prevents the substrate 10 from unintentionally peeling off from the pseudo-adhesive layer 20 during delivery.

Once delivery is complete, after stamping or signing, the substrate 10 is peeled from the pseudo-adhesive layer 20 at interface A, as shown in Figure 4, and used as a receipt to be taken back by the delivery company.

In the pseudo-adhesive label 1 of this embodiment, the pseudo-adhesive layer 20 does not remain on the substrate 10 after peeling, so the thickness of the peeled label piece can be thinner than with conventional pseudo-adhesive labels, in which the pseudo-adhesive layer is peeled off along with the substrate. This allows the thickness of the peeled substrate 10 to be reduced when storing multiple receipts stacked together, for example, leading to space savings.

Furthermore, after peeling, the label piece only has the base material 10 and does not have the pseudo-adhesive layer 20, so even if it is placed in a high-temperature environment, for example, the label piece after peeling is prevented from becoming sticky.

Furthermore, when the substrate 10 is discarded after peeling, its thin thickness reduces the amount of waste.

When the pseudo-adhesive label 1 is used as a shipping label, the base material 10 of the pseudo-adhesive label 1 may be divided into multiple label pieces, for example, by a cut (half-cut line). For example, if the base material 10 is divided into two pieces by a cut, one label piece can be used as a shipping slip and the other label piece can be used as a receipt. The label piece used as a receipt is usually peeled off at the interface A with the pseudo-adhesive layer 20 after being stamped or signed. The other label piece remains on the packaging material side.

The above describes preferred embodiments of the present invention, but the present invention is not limited to these.

For example, the pseudo-adhesive label of the present invention may have layers other than those described above, such as an undercoat layer, an intermediate layer, or a surface protection layer.

Furthermore, in the above-described embodiment, the pseudo-adhesive label of the present invention is used as a shipping label, but the pseudo-adhesive label of the present invention can also be used, for example, as a label other than a shipping label.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples.

In the following explanation, treatments for which no specific temperature conditions are specified were performed at room temperature (23°C) and a relative humidity of 50%. Furthermore, for various measurement conditions for which no specific temperature conditions are specified, the values are those at room temperature (23°C) and a relative humidity of 50%.

[4] Preparation of pseudo-adhesive label (Example 1)
First, thermal paper (thickness: 74 μm, basis weight: 80 g/m ² ) was prepared as a substrate.

Ethylene-vinyl acetate copolymer (EVA), the composition for forming the pseudo-adhesive layer, was heated to 250°C and extruded onto one surface of the substrate using a T-die.

Cooling water adjusted to a temperature of 23°C was passed through a water-cooled roll, and the surface of the water-cooled roll was brought into contact with the EVA on the substrate, causing the molten EVA to cool and solidify, forming a pseudo-adhesive layer 12.0 μm thick on the substrate.

The ethylene-vinyl acetate copolymer used had a copolymerization ratio of vinyl acetate of 6% by mass, a softening point of 75°C, and an MFR of 8.5 g/10 min.

In addition, the substrate conveying speed when forming the pseudo-adhesive layer, i.e., the processing speed of the pseudo-adhesive layer, was 150 m/min.

Separately, a composition for forming an adhesive layer, consisting of an acrylic adhesive, was applied to the surface of glassine paper (release liner) that had been subjected to a release treatment using a roll coater. The applied composition was then dried to form an adhesive layer on the release liner.

A pseudo-adhesive label was obtained by laminating the substrate with the pseudo-adhesive layer laminated thereon, obtained as described above, and a release liner with a pressure-sensitive adhesive layer laminated thereon, so that the pseudo-adhesive layer and the pressure-sensitive adhesive layer were in contact with each other. The resulting pseudo-adhesive label had a substrate, pseudo-adhesive layer, pressure-sensitive adhesive layer, and release liner, in that order.

(Examples 2 to 4)
Pseudo-adhesive labels were produced in the same manner as in Example 1, except that the thickness of the pseudo-adhesive layer was changed as shown in Table 1.

(Examples 5 to 8)
Pseudo-adhesive labels were produced in the same manner as in Example 1, except that the conditions for the ethylene-vinyl acetate copolymer constituting the pseudo-adhesive layer were changed as shown in Tables 1 and 2.

(Comparative Example 1)
The pseudo-adhesive label was manufactured in the same manner as in Example 1, except that polyethylene (PE) was used instead of ethylene-vinyl acetate copolymer as the material for the pseudo-adhesive layer, and the thickness of the pseudo-adhesive layer was set to 20.0 μm.

(Comparative Example 2)
A pseudo-adhesive label was produced in the same manner as in Comparative Example 1, except that the thickness of the pseudo-adhesive layer was set to 12.0 μm.

[5] Measurement and Evaluation The following measurements and evaluations were carried out for each of the above examples and comparative examples.

(Melt Mass Flow Rate)
The melt mass flow rate (MFR) of the pseudo adhesive layer-forming composition used to form the pseudo adhesive layer of the pseudo adhesive label of each of the above examples and comparative examples was measured in accordance with JIS K 7210-1:2014 at a test temperature of 190°C and a load of 2.16 kg.

(Young's modulus)
The pseudo-adhesive layer-forming composition used to form the pseudo-adhesive layer of the pseudo-adhesive label of each of the Examples and Comparative Examples was extruded onto the release-treated surface of a release liner to the same thickness as each of the Examples and Comparative Examples. After cooling, the release liner was removed to obtain a sheet consisting of the pseudo-adhesive layer-forming composition. The sheet was cut into a rectangular shape measuring 15 mm wide and 200 mm long to obtain test pieces. These test pieces were used to measure the Young's modulus at 23°C and 50% RH in accordance with JIS K7161-1:2014 and JIS K 7127:1999. Specifically, the test pieces were subjected to a tensile test at a speed of 0.2 m/min using a tensile tester with a chuck distance of 100 mm, and then subjected to a tensile test at a speed of 0.2 m/min to measure the Young's modulus (unit: MPa).

(Stress relaxation property)
Test pieces were obtained in the same manner as the test pieces for measuring Young's modulus. These test pieces were used in a tensile tester under an environment of 23°C and 50% RH, with the chuck distance set to 100 mm, and then elongated by 5% at a tensile speed of 0.2 m/min to measure the initial stress value (S1) and the residual stress value (S2) 5 minutes after the start of the measurement. From these values, the stress relaxation rate (%) was calculated using the following formula:
Stress relaxation rate (%) = {(S1 - S2) / S1} × 100

(Pseudo adhesive force)
The pseudo-adhesive labels of each of the Examples and Comparative Examples were subjected to measurement of pseudo-adhesive strength in accordance with the 180° peel adhesive strength measurement method of JIS Z 0237:2009. More specifically, the release liner was first removed from the pseudo-adhesive label, and the exposed adhesive layer was fixed by adhering it to a stainless steel plate. Then, the substrate of the pseudo-adhesive label was peeled from the pseudo-adhesive layer at a peel speed of 0.3 m/min and a peel angle of 180°. The magnitude of the force (peel force) required for this peeling was measured, and the measured peel force was taken as the pseudo-adhesive strength. The pseudo-adhesive strength is measured in mN/50 mm.

Similarly, a peel test was carried out under the conditions of a peel speed of 10 m/min and a peel angle of 180°, and the pseudo adhesive strength was measured.
The test piece used for measuring the pseudo-adhesion strength was 50 mm wide and 150 mm long.

(Suitable for attaching to cardboard corners)
First, the release liner was removed from each of the pseudo-adhesive labels of the Examples and Comparative Examples, and the pseudo-adhesive labels were folded and attached to the cardboard boxes so that they straddled the corners of the boxes. The length of the pseudo-adhesive labels protruding from the corners, i.e., the length of the pseudo-adhesive labels folded from the edge, was 3 mm. The cardboard boxes were approximately rectangular, with corner angles of approximately 90°.

After 24 hours from application, the length of lifting of the substrate from the pseudo-adhesive layer was measured.
When no lifting of the substrate was observed, the evaluation was given as "good."

Furthermore, tests were conducted and evaluated in the same manner as above, except that the protruding length from the corner was set to 5 mm and 10 mm.

(Removability)
The substrate of the pseudo-adhesive label was manually peeled off from the pseudo-adhesive layer at a low speed (0.3 m/min), and the state of the substrate after peeling was visually observed and evaluated.

If the substrate did not curl or curled only slightly but not into a cylindrical shape, it was rated "A."
If the substrate curled into a cylindrical shape, it was rated as "B".
If the substrate was torn during peeling, it was rated as "C".

Furthermore, the test was carried out in the same manner as above except that the peeling speed was set to a high speed (10 m/min), and evaluation was carried out.
These results are summarized in Tables 1 and 2 along with the conditions of the pseudo adhesive layer.

As is clear from Tables 1 and 2, when comparing the Comparative Example, which used polyethylene as the material constituting the pseudo-adhesive layer, with the Example, which used an ethylene-vinyl acetate copolymer, it was found that even though the thickness was the same, the Example had a lower Young's modulus for the pseudo-adhesive layer than the Comparative Example. Furthermore, the Example had a lower initial stress and a higher stress relaxation rate than the Comparative Example. It was also confirmed that the Example had sufficient pseudo-adhesive strength.

Furthermore, in the corrugated cardboard corner application test, in each of the comparative examples, the substrate 10 lifted from the pseudo-adhesive layer 50, i.e., unintended peeling of the substrate 10, as shown in Figure 5. However, in each of the examples, as shown in Figure 3, the substrate did not lift from the pseudo-adhesive layer, confirming that unintended peeling of the substrate was effectively prevented.

In particular, when the thickness of the pseudo-adhesive layer was 5.0 μm or more and 18.0 μm or less, the pseudo-adhesive strength was more suitable and more favorable results were obtained.

Furthermore, when the copolymerization ratio of vinyl acetate in the ethylene-vinyl acetate copolymer was 3% by mass or more and 15% by mass or less, the pseudo-adhesion strength was more suitable, and more favorable results were obtained.

Furthermore, because the pseudo-adhesion strength at a peel speed of 10 m/min was 7000 mN/50 mm or less, the substrate could be peeled off smoothly from the pseudo-adhesive layer without curling into a cylindrical shape.

Furthermore, when the pseudo-adhesive labels of the Example and Comparative Examples were attached to a soft resin bag and then folded together with the bag, the pseudo-adhesive label was observed to lift off the pseudo-adhesive layer of the substrate in the Comparative Example, but no lifting was observed in the Example, confirming that unintended peeling of the substrate was effectively prevented.

REFERENCE SIGNS LIST 1... Pseudo adhesive label 10... Substrate 20... Pseudo adhesive layer 30... Pressure-sensitive adhesive layer 40... Release liner 50... Pseudo adhesive layer (Comparative example)
100...Adherent A...Interface B...Interface C...Interface

Claims (6)

A substrate;
A pseudo-adhesive layer provided on one surface of the substrate;
a pressure-sensitive adhesive layer for adhering to an adherend, the pressure-sensitive adhesive layer being provided adjacent to the pseudo-adhesive layer on the opposite side from the substrate;
The pseudo-adhesive layer contains an ethylene-vinyl acetate copolymer in which the copolymerization ratio of vinyl acetate is 3% by mass or more and 9% by mass or less , does not contain a tackifier, and has a thickness of 5.0 μm or more and 15.0 μm or less,
A pseudo-adhesive label characterized in that, when attached to the substrate, it is peeled off at the interface between the substrate and the pseudo-adhesive layer, thereby removing the substrate from the substrate and leaving a laminate having the pseudo-adhesive layer and the pressure-sensitive adhesive layer on the substrate. The pseudo-adhesive label according to claim 1 , wherein the Young's modulus of the pseudo-adhesive layer measured by a method conforming to JIS K7161-1:2014 and JIS K 7127:1999 is 20 MPa or more and 80 MPa or less. The pseudo-adhesive layer is formed into a rectangular sample piece having a width of 15 mm and a length of 200 mm. A tensile test is performed on the sample piece, with the measurement range set to a length of 100 mm, in an environment of 23°C and 50% RH, in which the sample piece is elongated by 5% in the length direction at a speed of 0.2 m/min. When the initial stress value measured is S1 [MPa] and the residual stress value 5 minutes after the start of the measurement is S2 [MPa], the following formula can be calculated:
Stress relaxation rate (%) = {(S1 - S2) / S1} × 100
3. The pseudo-adhesive label according to claim 1, wherein the stress relaxation rate expressed by the following formula is 12% or more. A pseudo-adhesive label according to any one of claims 1 to 3, wherein the pseudo-adhesion strength between the substrate and the pseudo-adhesive layer measured at a peel speed of 10 m/min in a 180 ° peel test specified in JIS Z 0237:2009 is 4000 mN/50 mm or more and 7000 mN/50 mm or less. 5. The pseudo-adhesive label according to claim 1, wherein the pseudo-adhesive layer and the pressure-sensitive adhesive layer are substantially transparent. The pseudo-adhesive label of any one of claims 1 to 5 , which is used as a shipping label.