Labeled adherend and method for peeling label

Abstract

To provide a label which can be easily peeled off from an adherend without immersing the adherend in a liquid.SOLUTION: The labeled adherend (1) has at least a portion where the light transmittance defined by the following formula is less than 20%. Light transmittance (%)=(A / B)*100(%) A: intensity of ultraviolet light (6) obtained after the ultraviolet light (6) having an arbitrary wavelength in a wavelength range of 320 nm to 400 nm is irradiated on the label (2) and transmitted through the adherend (3); B: intensity of the ultraviolet light (6) irradiated on the label (2) before being irradiated on the label (2).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a labeled object and a method for removing the label. [Background technology]

[0002] There are known technologies for separating labels from containers for the purpose of recycling. For example, Patent Document 1 discloses a label adapted to be adhered to a beverage bottle, which shrinks at a designated washing temperature ranging from about 50°C to about 95°C. The invention described in Patent Document 1 specifies the degree of shrinkage and shrinkage stress of the laminate when shrinking at the designated washing temperature, thereby separating the label from the container even when the adhesive strength of the label to the container is high. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2012-502305 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when recycling or reusing (including remanufacturing and refurbishing) labeled objects, it may be necessary to remove the label from the container by washing and then dry the object. Also, when the label is affixed to a container that should not be immersed in liquid, such as an electronic device, ink cartridge, or wrapping paper, it may not be possible to remove the label from the object by washing.

[0005] Furthermore, while an alkaline solution can be used as a technology for separating labels from containers, this requires a post-treatment process for treating the waste liquid. Furthermore, in this case, the container and label are usually crushed before separation, making the container unreusable.

[0006] An object of one aspect of the present invention is to easily peel a label from an object to be adhered to without immersing the object in a liquid. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one embodiment of the present invention provides a labeled object comprising a label including at least a substrate and an adhesive layer, and an object to which the label is attached and which can be recycled or reused, and which has at least a portion in which the light transmittance defined by the following formula is less than 20%. Light transmittance (%)=(A / B)×100(%) A: The intensity of ultraviolet light obtained after the label is irradiated with ultraviolet light of a wavelength in the wavelength range of 320 nm to 400 nm and the ultraviolet light passes through the adhesive substrate; B: Intensity of the ultraviolet light irradiated onto the label before it is irradiated onto the label.

[0008] Furthermore, a label removal method according to one embodiment of the present invention is a label removal method for removing a label from a labeled object, and includes an irradiation step of irradiating the labeled object with ultraviolet light of any wavelength in the wavelength range of 320 nm or more and 400 nm or less. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to provide a labeled object and a method for removing a label, which allows the label to be easily removed from the object without immersing the object in a liquid. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a labeled adhesive-receiving object according to a first embodiment of the present invention. [Figure 2] FIG. 3 is a plan view showing an example of the configuration of the label. [Figure 3]FIG. 4 is a front view showing the label after ultraviolet light has been irradiated onto it. [Figure 4] FIG. 10 is a plan view showing a modified example of the label configuration. [Figure 5] 10A to 10C are diagrams illustrating a method for peeling a label from an adhesive substrate. [Figure 6] FIG. 1 is a diagram showing an example of a peel test device in a test example of the present invention. [Figure 7] 1 is a table showing the results of the test examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment] An embodiment of the present invention will be described in detail below. However, the following description is an example of a labeled object 1 according to the present invention, and the technical scope of the present invention is not limited to the illustrated example.

[0012] (Overview of labeled objects) 1 is a cross-sectional view of a labeled object 1 according to embodiment 1 of the present invention. As shown in FIG. 1, the labeled object 1 includes a label 2 and an object 3 to be labeled.

[0013] (Basic label configuration) The label 2 is a label that is affixed to an adhesive substrate 3 that can be reused or recycled. The label 2 comprises an adhesive layer 4 and a label body 5. Here, reuse refers to reusing the adhesive substrate 3. Recycling refers to using the adhesive substrate 3 as a material to create a new product.

[0014] (UV light exposure on label) This labeled object 1 is characterized in that it has at least a portion where the light transmittance, as described below, becomes less than 20% when the label 2 is irradiated with ultraviolet light 6 of a wavelength in the wavelength range of 320 nm to 400 nm. With this configuration, the label 2 heats up and distorts upon irradiation with ultraviolet light 6, resulting in portions of the label 2 that float away from the object 3. The inventors have found, through extensive research, that this makes it possible to peel the label 2 from the object 3 or to create a clue for peeling the label 2 from the object 3. As a result, with respect to the labeled object 1, it is possible to easily peel the label 2 from the object 3 without immersing the object 3 in a liquid. The ultraviolet light 6 is UVA of a wavelength in the wavelength range of 320 nm to 400 nm, and is irradiated, for example, from an irradiation source 7 (see FIG. 5 ). The irradiation source 7 is preferably an LED (light-emitting diode) light source, and the wavelength of the ultraviolet light 6 can be selected arbitrarily, such as 320 nm, 365 nm, or 385 nm. The following describes a more specific configuration of the labeled object 1, modifications, a label peeling method, and examples / comparative examples.

[0015] (Label body) As shown in Figure 1, the label body 5 includes at least a base material layer (base material) 51, and is constructed by laminating the base material layer 51, a printing layer 52, and a shrink layer 53 in this order from the adhesive layer 4 side.

[0016] (base material layer) The base layer 51 shown in Fig. 1 is a support for the label 2, and is laminated on the back side (adhesive layer 4 side) of the printed layer 52. There are no particular restrictions on the material of the base layer 51, but it is preferable that it undergoes thermal deformation at 80 to 90°C in relation to the substrate 3. For example, transparent OPP (biaxially oriented polypropylene), white PP (polypropylene), YUPO (registered trademark), or PE (polyethylene) are preferable.

[0017] The base layer 51 may be transparent. However, if it is transparent, when the labeled object 1 is irradiated with ultraviolet light 6 as described above, the heat generated by the object 3 indirectly heats the base layer 51. This can make it difficult to remove the label 2 from the labeled object 1. Furthermore, the heat generated by the object 3 can easily cause surface roughness of the object 3, which can affect quality when reused. From these perspectives, white PP (Yupo) and other materials are preferred for the base layer 51 because they peel more easily than transparent substrates and prevent surface roughness of the object 3. When white PP is used as the base layer 51, the label body 5 may be composed of the base layer 51 alone.

[0018] The base material layer 51 is preferably stretched by application of heat so that it is more likely to shrink when heated by irradiation with ultraviolet rays 6. Here, stretching in this specification means that the base material layer 51 is stretched in the direction in which it is extruded, for example, by a pressure roller, and in a direction approximately perpendicular to the extrusion direction.

[0019] Furthermore, it is preferable that the base layer 51 has voids. The presence of voids weakens the stiffness of the base layer 51, making it more likely to peel off. Here, in this specification, the term "voids" refers to holes formed during the production process of the base layer 51 due to the addition of a white pigment such as titanium oxide.

[0020] (Printing layer) The printed layer 52 is laminated on the base layer 51. As described above, if the base layer 51 is made of an opaque material such as white PP, the printed layer 52 may be omitted. The thickness of the printed layer 52 is, for example, 1 μm or more and 5 μm or less. Furthermore, for example, product-related information can be printed on the printed layer 52. The product-related information may be, for example, the product name, a design, the manufacturer's name, a logo, a product description, etc.

[0021] The printed layer 52 may contain a varnish mixed with an ultraviolet absorber, or may contain black ink. When the printed layer 52 contains varnish or black ink, even if a transparent substrate layer 51 is used, the printed layer 52 generates heat when exposed to ultraviolet light 6, and the heat causes the label 2D to heat up and distort. This allows the label 2D to be easily peeled from the substrate 3. The printed layer 52 may also be made of an anchor coating agent mixed with an ultraviolet absorber, or black or indigo ink. Even in this case, it is believed that the same effect as described above can be obtained.

[0022] (shrink layer) The shrink layer 53 is laminated on the front side of the printed layer 52 (the side opposite to the base layer 51) and protects the printed layer 52. The shrink layer 53 is heat-shrinkable. By having the shrink layer 53 in the label body 5, the label body 5 itself can be further shrunk by heat generated by the label 2 when irradiated with ultraviolet light 6, making it easier for the label 2 to separate from the substrate 3.

[0023] Furthermore, when the base layer 51 is made of an opaque material such as white PP, the shrink layer 53 can be omitted. When the shrink layer 53 is omitted, for example, a heat-shrinkable material may be used for the base layer 51. This causes the base layer 51 to thermally shrink due to heat generation in the label body 5, so that the label 2 can be suitably peeled off from the substrate 3 even if the label body 5 does not include the shrink layer 53.

[0024] Furthermore, if the printed layer 52 has a heating element such as black ink or varnish, the shrink layer 53 can be omitted. Furthermore, if the adherend 3 is made of white ABS (acrylonitrile butadiene styrene), the shrink layer 53 can be omitted.

[0025] Furthermore, a protective layer that does not have heat shrinkability may be used instead of the shrink layer 53. In that case, the label body 5 may be configured by laminating the base material layer 51, the printing layer 52, and the protective layer in this order from the adhesive layer 4 side.

[0026] Alternatively, the shrink layer 53 may be provided by laminating it on the label body 5. In this way, the shrink layer 53 used for lamination will thermally shrink when irradiated with ultraviolet light 6, so that the label 2 can be suitably peeled off from the substrate 3 while protecting the label body 5.

[0027] In addition, if the material of the shrink layer 53 is, for example, PET (polyethylene terephthalate), PS (polystyrene), or PP, the heat generated by the shrink layer 53 will further shrink the label body 5, making it easier to peel off the label 2.

[0028] Fig. 2 is a plan view showing an example of the configuration of the label 2. 201 in Fig. 2 is a view of the label 2 as seen from the front side (the side on which the adhesive layer 4 is not formed), and 202 in Fig. 2 is a view of the label 2 as seen from the back side (the side on which the adhesive layer 4 is formed). As shown in 201 and 202 in Fig. 2, the label 2 has a substantially rectangular shape.

[0029] (Adhesive layer) The adhesive layer 4 is a layer that can adhere to the substrate 3 and adheres the label body 5 to the substrate 3. When the area of ​​the label 2 is larger than the LED irradiation range, the adhesive layer 4 may have a strong adhesive portion 41 and a weak adhesive portion 42 having lower adhesive strength than the strong adhesive portion 41, as shown in 202 of FIG. 2. In the adhesive layer 4 shown in 202 of FIG. 2, the strong adhesive portion 41 corresponds to the black portion, and the weak adhesive portion 42 corresponds to the white portion. Also, as shown in 202 of FIG. 2, the strong adhesive portion 41 is provided on the back surface 54 of the label body 5 at a position that corresponds to the outer periphery of the label body 5 when the label body 5 is viewed in plan, preventing the label 2 from peeling off from the periphery. Therefore, the label 2 can be maintained adhered to the substrate 3 while the consumer is using the label 2, preventing the label 2 from being unintentionally peeled off.

[0030] The low-adhesion portion 42 is formed in a region corresponding to the center of the label 2 when the label 2 is viewed in plan. The low-adhesion portion 42 may be formed, for example, by applying an adhesive suppressant to the surface of the adhesive layer 4 opposite the label body 5. Note that if the strong-adhesion portion 41 formed on the outer periphery of the adhesive layer 4 ensures sufficient adhesive strength to prevent the label 2 from being unintentionally peeled off, the low-adhesion portion 42 may not be provided.

[0031] 2, the strong adhesive portion 41 is formed continuously on the outer periphery of the label 2, but this configuration is not limited to this. For example, it is also possible to replace a part of the strong adhesive portion 41 formed on the outer periphery of the label 2 with a weak adhesive portion, as long as the strong adhesive portion 41 can have a sufficient adhesive strength to prevent the label 2 from being unintentionally peeled off. Furthermore, the strong adhesive portion 41 may be formed on the entire back surface 54 of the label body 5.

[0032] The adhesive layer 4 may be provided over the entire surface or a part of the back surface 54 of the label body 5. The positions or areas of the strong adhesive portion 41 and the weak adhesive portion 42 may be appropriately designed depending on the desired adhesive strength of the label 2.

[0033] The adhesive used in adhesive layer 4 is not particularly limited as long as it can be peeled off after adhesion, but it is desirable that the adhesive strength to a stainless steel test plate at room temperature be 5.0 N / 25 mm or more and 20.0 N / 25 mm or less, and more preferably 10.0 N / 25 mm or more and 15.0 N / 25 mm or less.

[0034] (subject to be adhered) The substrate 3 has a label 2 adhered thereto and is recyclable or reusable, and has a label adhesive surface 31 formed of glue or the like. The substrate 3 is not particularly limited and may be an ink cartridge, a pouch (bag-like container), or a beverage container. As described above, the label 2 can be easily peeled off the substrate 3 by irradiating it with ultraviolet light 6 without immersing it in liquid. Therefore, even if the substrate 3 is an electrical device that should not be immersed in liquid, or a plastic container that contains an ink cartridge or cleaning fluid, the label 2 can be peeled off the substrate 3 and the substrate 3 can be reused.

[0035] It is preferable that the surface roughness Ra of at least a portion of the label adhesive surface 31 of the substrate 3 to which the label 2 is adhered is 0.1 μm or more and 20 μm or less. The inventors have found, through extensive research, that by setting the surface roughness Ra within this range, the label 2 is less likely to peel off before irradiation with ultraviolet light 6, and can be more reliably lifted and separated from the substrate 3 upon irradiation with ultraviolet light 6. This makes it easier to peel the label 2 from the substrate 3. It is more preferable that the surface roughness Ra of the label adhesive surface 31 is 0.1 to 5.0 μm. This allows the delabeling effect (the effect of peeling the label from the substrate) to be achieved even when, for example, an ink cartridge is used as the substrate 3.

[0036] It is preferable that the surface roughness Ra is 0.1 μm or more because gaps are formed on the label adhesive surface 31, and the adhesive layer 4 penetrates into these gaps, ensuring an appropriate adhesive state between the label 2 and the object 3. If the surface roughness Ra exceeds 5 μm, consumers may easily peel the label off by hand, so it is preferable that the surface roughness Ra is 5 μm or less.

[0037] Furthermore, the material of the adhesive target 3 is not particularly limited, but for example, PS, PP, or ABS can be used. The heat resistance temperature of the adhesive target 3 varies depending on the resin processing method, but is 60 to 80°C for PS, 80 to 120°C for PP, and 70 to 100°C for ABS. In particular, if the adhesive target 3 is made of PP or ABS, which have a relatively high heat resistance temperature, it is considered that it is unlikely to deform due to the heat generated when the label 2 is peeled off, and is therefore suitable for reuse. Note that even if the adhesive target 3 is made of a material with a low heat resistance temperature (such as PS) and undergoes some deformation due to the heat generated when the label 2 is peeled off, it can still be recycled.

[0038] (Light transmittance details) 3 is a front view showing the labeled object 1 irradiated with ultraviolet light 6. The labeled object 1 has at least a portion where the light transmittance defined by the following formula is less than 20%.

[0039] Light transmittance (%)=(A / B)×100(%) A: Intensity of ultraviolet light 6 obtained after ultraviolet light 6 of any wavelength in the wavelength range of 320 nm to 400 nm is irradiated onto the label 2 and passes through the adhesive object 3; B: Intensity of ultraviolet light 6 irradiated onto label 2 before it was irradiated onto label 2.

[0040] The intensity of ultraviolet light 6 shown by the solid line in Fig. 3 corresponds to B, and the intensity of ultraviolet light 6 shown by the two-dot chain line in Fig. 3 corresponds to A. Furthermore, when exposed to ultraviolet light 6, heat is generated at the locations where the adhesive strength of the adhesive layer 4 of label 2 has decreased, causing label 2 to distort, and as a result, as shown in Fig. 3, label 2 shown by the dashed line that was adhered to substrate 3 separates from substrate 3 and floats, as shown by the solid line. As a result, a label can be realized that can be easily peeled from substrate 3 without immersing substrate 3 in liquid.

[0041] It is preferable to select materials for the label 2 and the substrate 3 so that the temperature at which the label 2 heats up when irradiated with ultraviolet light 6 at the minimum intensity required to peel the label 2 from the substrate 3 is equal to or lower than the heat resistance temperature of the substrate 3. This prevents deformation of the substrate 3 when the label 2 is heated for peeling, and improves the possibility that the substrate 3 can be reused after the label 2 has been peeled off. In this embodiment, the temperature at which the label 2 heats up is assumed to be 70°C to 120°C.

[0042] Furthermore, when the print layer 52 does not have a heating element, the shrink layer 53 is omitted, and synthetic paper PP is used as the base layer 51, the light transmittance is preferably 3% or less, and more preferably 2% or less.

[0043] (Label variation) FIG. 4 is a plan view showing a modified example of the configuration of the label 2. 401 to 404 in FIG. 4 are views of the labels 2A to 2D as seen from the back side (the side on which the adhesive layer 4 is formed), respectively. The label 2A shown in 401 in FIG. 4 differs from the label 2 in that the strong adhesive portion 41 is located at only one corner of the adhesive layer 4 when viewed in plan. The corner on the label 2A where the strong adhesive portion 41 is provided may be the corner that the user first accesses when trying to peel off the label. Even with this configuration, the label 2A can be prevented from being peeled off unintentionally, and the label 2A can be maintained in a state where it adheres to the object 3.

[0044] 4 differs from label 2A, which has strong adhesive portion 41 located only at one corner, in that strong adhesive portion 41 is located at four corners of adhesive layer 4. This more reliably prevents label 2B from being unintentionally peeled off from substrate 3.

[0045] 4 differs from the label 2 in that the strong adhesive portion 41 is formed only near one short side of the label 2C. The short side of the label 2C is more easily accessible to consumers than the long side of the label 2C when they attempt to peel the label off. This prevents the label 2C from being peeled off the substrate 3 by the user.

[0046] Furthermore, label 2D shown in 404 of FIG. 4 differs from label 2 in that it contains black ink 55 in the printing layer 52. Here, the black ink 55 is contained in the printing layer 52 located at the back of the adhesive layer 4 in the direction perpendicular to the paper surface, and therefore the boundary between the area containing black ink 55 and the area not containing black ink 55 is indicated by a dotted line. That is, as shown in 404 of FIG. 4, black ink 55 is arranged along the outer periphery of label 2D and has a portion that overlaps with the strong adhesive portion 41 when viewed in plan. This configuration prevents unintentional peeling of label 2D by the strong adhesive portion 41. Furthermore, upon irradiation with ultraviolet light 6, the portion of black ink 55 that overlaps with the strong adhesive portion 41 heats up and distorts. This allows label 2D to be easily peeled from the substrate 3.

[0047] (How to remove the label) 5 is a diagram illustrating a method for peeling a label 2 from a labeled object 1. When peeling a label 2 from a labeled object 1 having at least a portion with a light transmittance of less than 20%, as shown in FIG. 5, first, ultraviolet light 6 is irradiated onto the labeled object 1 from an irradiation source 7 (irradiation step).

[0048] More specifically, when the irradiation intensity of the ultraviolet light 6 is a [W], the irradiation time is b [seconds], and the irradiation distance is c [cm], it is preferable to irradiate the labeled object 1 with the ultraviolet light 6 under irradiation conditions such that the parameter expressed by a×b / √c is 15 or more and 90 or less. By irradiating the ultraviolet light 6 under these irradiation conditions, the label 2 can be more reliably peeled off from the object 3.

[0049] Alternatively, air or the like may be blown toward the location where the label 2 has lifted from the substrate 3. This ensures that the label 2 can be peeled off from the substrate 3. Even if the irradiation distance is long, the parameter can be kept within the range of 15 to 90 by extending the irradiation time. However, if the irradiation distance is too long, the effect will be relatively low and work delays due to the increased irradiation time may occur, so it is preferable to keep the irradiation distance within 5 cm.

[0050] [Test example] The results of the peel test are shown in Figure 7. In this test example, a peel test was conducted in which labels 2 of Examples 1 to 13, which had different configurations, were irradiated with ultraviolet light as ultraviolet light 6 for a predetermined period of time, and each label 2 was evaluated for delabeling ability and deformation / roughness of the adhered object.

[0051] Here, the delabeling property evaluation was performed by evaluating the degree of peeling of each label 2 after irradiating each label 2 with ultraviolet light, and the evaluation was performed by visually checking the degree of peeling of each label 2 after irradiating each label 2 with ultraviolet light.

[0052] In the delabeling evaluation, delabeling evaluation AA is an evaluation when 50% or more of the area of ​​label 2 peels off from the substrate 3 after irradiation with UV-LED. Delabeling evaluation A is an evaluation when 30% or more of the area of ​​label 2 peels off from the substrate 3. Delabeling evaluation B is an evaluation when less than 30% of the area of ​​label 2 peels off from the substrate 3. Delabeling evaluation C is an evaluation when label 2 is thermally melted but not peeled off.

[0053] In the evaluation of deformation / roughness of the adhered object, the evaluation of deformation / roughness of the adhered object AA is an evaluation when no deformation / surface roughness occurs on the adhered object. The evaluation of deformation / roughness of the adhered object A is an evaluation when slight deformation / surface roughness occurs on the adhered object. The evaluation of deformation / roughness of the adhered object B is an evaluation when deformation / surface roughness occurs on the adhered object, making it unsuitable for reuse but judged to be recyclable. The evaluation of deformation / roughness of the adhered object C is an evaluation when significant deformation / surface roughness occurs on the adhered object.

[0054] (Test Procedure) 6 is a diagram showing an example of a peel test device 8 in a test example of the present invention. The peel test device 8 was composed of an irradiation source 7 and an adherend 3. As the irradiation source 7, a UV-LED (ultraviolet light-emitting diode, manufactured by Phoseon Technology) with a wavelength of 385 nm, an output of 20 W, and an irradiation area of ​​75 mm × 20 mm was used.

[0055] First, the irradiation source 7 was placed vertically on a horizontal surface so that ultraviolet light was irradiated horizontally from the irradiation source 7. Then, a label 2 was adhered to the substrate 3, and the substrate 3 was held upright on the horizontal surface using clips 9 on both ends so that the ultraviolet light was irradiated vertically onto the label 2 and the irradiation distance from the irradiation source 7 to the label 2 was a predetermined distance. In this state, UV-LED was irradiated while changing the ultraviolet light irradiation intensity a [W], irradiation distance c [cm], and irradiation time b [seconds], and the degree to which the label 2 fell off was confirmed.

[0056] The label 2 was approximately square, measuring 30 mm on each side. After the label 2 was adhered to the substrate 3, a 2 kg loaded roller was moved back and forth twice to fix the label 2 to the substrate 3. The label 2 left 24 hours later was used as the test sample.

[0057] The printed label 2 on which the printed layer 52 was formed was cut into 30 mm squares, and after being attached to the substrate 3, a 2 kg load roller was rolled back and forth twice, and the substrate with the label was left for 24 hours to be used as a test sample. Note that the uncolored PS used for the substrate 3 means that it contains almost no color pigment. PS without any color pigment may also be used.

[0058] Example 1 The labeled object 1 in Example 1 includes a label 2 and an object 3. Uncolored PS (polystyrene) containing almost no coloring pigment was used as the material for the object 3. The surface roughness Ra of the object 3 is 0.1 μm.

[0059] The label 2 in Example 1 used included a label body 12 with a base layer 51 and a printing layer 52, and an adhesive layer 4. The base layer 51 was synthetic paper PP80, and the printing layer 52 was formed by curing black ink with UV irradiation. Specifically, a tack label made of synthetic paper PP (polypropylene) 80 μm thick coated with a strong adhesive was printed solidly with black UV (ultraviolet) curable flexographic ink using a flexographic coater, and the black ink was cured with UV irradiation to form the printing layer 52.

[0060] Here, synthetic paper PP80 is a film material made of polypropylene that has the properties of paper (opacity and ease of printing) and is 80 μm thick.

[0061] The adhesive of the adhesive layer 4 was a strong adhesive, and the adhesive layer 4 was formed on the entire surface of the label body 12. Here, the strong adhesive is an adhesive having an adhesive strength of 10.0 N / 25 mm or more and 15.0 N / 25 mm or less at room temperature. The light transmittance at a wavelength of 385 nm was 0%.

[0062] The UV-LED irradiation conditions were an output (irradiation intensity) of 20 W, irradiation time of 3 seconds, and irradiation distance of 3.0 cm. Therefore, the parameter expressed as a×b / √c was 34.6.

[0063] In Example 1, as shown in FIG. 7, the delabeling evaluation was AA, and the deformation / roughness evaluation of the adhered object was A, confirming that the label 2 was suitably peeled from the adhered object 3.

[0064] Example 2 In Example 2, the UV-LED irradiation conditions were different from those in Example 1, but the other configurations were the same. The UV-LED irradiation conditions were an output (irradiation intensity) of 10 W, an irradiation time of 5 seconds, and an irradiation distance of 2.0 cm. Therefore, the parameter expressed as a × b / √ c was 35.4.

[0065] In Example 2, as shown in FIG. 7, the delabeling evaluation was AA, and the deformation / roughness evaluation of the adhered body was A, confirming the same effects as in Example 1.

[0066] Example 3 In Example 3, the UV-LED irradiation conditions were different from those in Example 1, but the other configurations were the same. The UV-LED irradiation conditions were an output (irradiation intensity) of 10 W, an irradiation time of 8 seconds, and an irradiation distance of 1.0 cm. Therefore, the parameter expressed as a × b / √ c was 80.0.

[0067] In Example 3, a favorable delabeling rating of AA was obtained, as shown in Figure 7. Furthermore, the rating of deformation / roughness of the adhered object was B (adhesion object 3 was recyclable).

[0068] Example 4 In Example 4, the UV-LED irradiation conditions were different from those in Example 1, but the other configurations were the same. The UV-LED irradiation conditions were an output (irradiation intensity) of 5 W, an irradiation time of 5 seconds, and an irradiation distance of 1.0 cm. Therefore, the parameter expressed as a × b / √ c was 25.0.

[0069] As shown in FIG. 7, Example 4 had a delabeling rating of AA and an adhered body deformation / roughening rating of A, confirming the same effects as Example 1.

[0070] Example 5 Example 5 differs from Example 1 in that the label 2 does not have a printed layer 52, the light transmittance is 0.826%, and the UV-LED irradiation conditions are the same as those of Example 1. The UV-LED irradiation conditions were an output (irradiation intensity) of 20 W, an irradiation time of 3 seconds, and an irradiation distance of 3.0 cm. Therefore, the parameter expressed as a × b / √c was 34.6.

[0071] In Example 5, as shown in Fig. 7, the delabeling evaluation was AA and the deformation / roughness evaluation of the substrate was A, confirming the same effect as in Example 1. This is thought to be because the label body 5 did not have the printing layer 52, but the light transmittance was 0.826%.

[0072] Example 6 Example 6 differs from Example 1 in that the material of the base layer 51 is transparent PP 50 μm, but the other configurations are the same. In Example 6, the light transmittance was 0.228% due to the printing layer 52, and the same effect as in Example 1 was confirmed.

[0073] Example 7 Example 7 differs from Example 6 in that the printed layer 52 is formed of a varnish containing a UV absorber instead of black flexographic ink, but the other configurations are the same. Example 7 had a light transmittance of 17.025%, a delabeling rating of A, and an adhesive substrate deformation / roughening rating of A.

[0074] Example 8 Example 8 differs from Example 1 in that the material of the adherend 3 is uncolored PP50, but the other configurations are the same. In Example 8, the light transmittance was 0.002%, the delabeling rating was AA, and the adherend deformation / roughening rating was AA.

[0075] Example 9 Example 9 differs from Example 8 in that the label 2 does not have the printed layer 52, but the other configurations are the same. In Example 9, although the label 2 does not have the printed layer 52, the light transmittance was 1.107%, and the same effect as in Example 8 was confirmed.

[0076] Example 10 Example 10 differs from Example 8 in that the material of the base layer 51 is transparent PP 50 μm, but the other configurations are the same. In Example 10, the light transmittance was 1.425%, and the same effect as in Example 8 was confirmed.

[0077] Example 11 Example 11 differs from Example 1 in that the material of the adherend 3 is white ABS and the surface roughness Ra is 0.2 μm, but the other configurations are the same. In Example 11, as shown in Figure 7, the delabeling evaluation was AA and the adherend deformation / roughness evaluation was A, confirming the same effect as Example 1.

[0078] Example 12 Example 12 differs from Example 11 in that the label 2 does not have the printed layer 52 and the material of the base layer 51 is transparent PP 50 μm, but the other configurations are the same. In Example 12, as shown in Figure 7, the delabeling evaluation was A and the deformation / roughness evaluation of the adhered object was A.

[0079] Example 13 In Example 13, the surface roughness Ra of the white ABS was 3.0 μm, and the UV-LED irradiation time was different from that of Example 11, but the other configurations were the same. The UV-LED irradiation time was 1.5 seconds, and the parameter expressed as a × b / √c was 17.3.

[0080] In Example 13, as shown in FIG. 7, the delabeling evaluation was AA, and the deformation / roughness evaluation of the adhered body was A, confirming the same effects as in Example 11.

[0081] Comparative Example 1 Comparative Example 1 differs from Example 1 in the UV-LED irradiation conditions, but the other configurations are the same. The UV-LED irradiation conditions were an output (irradiation intensity) of 20 W, an irradiation time of 5 seconds, and an irradiation distance of 1.0 cm. The parameter expressed as a×b / √c was 100.0.

[0082] In Comparative Example 1, as shown in FIG. 7, the delabeling evaluation was C, and the deformation / roughness evaluation of the adhered object was C (the label did not melt and peel off, and deformation and roughness were not good).

[0083] Comparative Example 2 Comparative Example 2 differs from Example 1 in the UV-LED irradiation conditions, but the other components are the same. The UV-LED irradiation conditions are an output (irradiation intensity) of 5 W, an irradiation time of 5 seconds, and an irradiation distance of 5.0 cm, i.e., the parameter expressed as a × b / √c is 11.2. In Comparative Example 2, as shown in Figure 7, the delabeling evaluation was B, and the deformation / roughness of the adhered object was AA.

[0084] Comparative Example 3 Comparative Example 3 differs from Example 1 in that the material of the base material layer 51 is transparent PP 50 μm thick, and the label body 5 does not have a printed layer 52, but the other configurations are the same. In Comparative Example 3, the light transmittance was 38.523%, the delabeling evaluation was B, and the deformation / roughness evaluation of the adhered object was A.

[0085] Comparative Example 4 Comparative Example 4 differs from Example 10 in that the label 2 does not have the printed layer 52, but the other configurations are the same. As shown in Figure 7, Comparative Example 4 had a light transmittance of 50.179%, a delabeling rating of B, and an adhesive object deformation / roughening rating of AA.

[0086] 〔summary〕 The labeled object (1) according to aspect 1 of the present invention comprises a label (2) including at least a substrate (51) and an adhesive layer (4), and an object (3) to which the label (2) is adhered and which can be recycled or reused, and has at least a portion having a light transmittance of less than 20% as defined by the following formula: Light transmittance (%)=(A / B)×100(%) A: The intensity of ultraviolet light (6) obtained after ultraviolet light (6) of any wavelength in the wavelength range of 320 nm to 400 nm is irradiated onto the label (2) and passes through the adhesive object (3); B: Intensity of ultraviolet light (6) irradiated onto label (2) before it is irradiated onto label (2).

[0087] According to the above configuration, when exposed to ultraviolet light (6), the label (2) heats up and distorts, causing portions of the label (2) to separate from the substrate (3). As a result of extensive research, the inventors discovered that this makes it possible to peel the label (2) from the substrate (3) or to create a clue for peeling the label (2) from the substrate (3). As a result, it is possible to realize a label (2) that can be easily peeled from the substrate (3) without immersing the substrate (3) in liquid.

[0088] The labeled object (1) according to aspect 2 of the present invention is the same as that of aspect 1, in which the surface roughness Ra of at least a portion of the label adhesive surface (31) to which the label (2) is adhered on the object (3) is 0.1 μm or more and 20 μm or less.

[0089] According to the above configuration, by setting the surface roughness Ra within the above range, the label (2) is less likely to peel off before being irradiated with ultraviolet light (6), and when irradiated with ultraviolet light (6), the label (2) can be more reliably lifted and separated from the substrate (3), thereby making it easier to peel the label (2) off the substrate (3).

[0090] The labeled object (1) according to aspect 3 of the present invention is the same as that of aspect 1, in that the temperature at which the label (2) heats up when irradiated with ultraviolet light (6) at the minimum intensity required to peel the label (2) from the object (3) is equal to or lower than the heat resistance temperature of the object (3).

[0091] According to the above configuration, deformation of the substrate (3) when the label (2) is heated for peeling can be prevented, thereby improving the possibility of reusing the substrate (3) after peeling the label (2).

[0092] A labeled adhesive object (1) according to aspect 4 of the present invention is the same as that according to aspect 1, in which the label (2) further comprises a printed layer (52) containing at least one of a varnish mixed with an ultraviolet absorber and black ink (55).

[0093] According to the above configuration, even if a transparent substrate (51) is used, the printed layer (52) generates heat when exposed to ultraviolet light (6), and the heat causes the label (2) to heat up and distort, thereby allowing the label (2) to be easily peeled off from the substrate (3).

[0094] A method for removing a label (2) according to aspect 5 of the present invention is a method for removing a label (2) from a labeled object (1) according to aspect 1, and includes an irradiation step of irradiating the labeled object (1) with ultraviolet light (6) of any wavelength in the wavelength range of 320 nm or more and 400 nm or less.

[0095] According to the above configuration, the ultraviolet light (6) irradiated in the irradiation step heats and distorts the label (2), causing portions of the label (2) to float away from the substrate (3). As a result of extensive research, the inventors discovered that this makes it possible to peel the label (2) from the substrate (3) or to create a clue for peeling the label (2) from the substrate (3). As a result, it is possible to realize a label (2) that can be easily peeled from the substrate (3) without immersing the substrate (3) in a liquid.

[0096] A label peeling method according to a sixth aspect of the present invention is the same as that of the fifth aspect, in which ultraviolet light (6) is irradiated onto the labeled adhesive object (1) under irradiation conditions such that the parameter expressed by a×b / √c is 15 or more and 90 or less, where the irradiation intensity of the ultraviolet light (6) is a [W], the irradiation time is b [seconds], and the irradiation distance is c [cm].

[0097] According to the above configuration, by irradiating ultraviolet light (6) under the above irradiation conditions, the label (2) can be peeled off from the object (3) more reliably.

[0098] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0099] 1 Labeled adhesive object 2, 2A, 2B, 2C, 2D Label 3 Adhesive object 4 Adhesive layer 5 Label body 6. Ultraviolet rays 7 Irradiation source 31 Label adhesive surface 51 Base material layer 52 Printing layer 53 Shrink Layer A: The intensity of ultraviolet light obtained after a label is irradiated with ultraviolet light of any wavelength in the wavelength range of 320nm to 400nm and passes through the adhesive substrate. B. The intensity of the ultraviolet light irradiated onto the label before it was irradiated onto the label A / B light transmittance Ra surface roughness

Claims

1. A substrate; a label including at least an adhesive layer; A labeled object comprising an adhesive object to which the label is attached and which is used for recycling or reuse, A labeled object to be adhered to has at least a portion where the light transmittance defined by the following formula is less than 20%. Light transmittance (%) = (A / B) x 100 (%) A: The intensity of ultraviolet light obtained after ultraviolet light of a wavelength in the wavelength range of 320 nm to 400 nm is irradiated onto the label and passes through the adhesive substrate; B: Intensity of the ultraviolet light irradiated onto the label before it is irradiated onto the label

2. 2. The labeled object according to claim 1, wherein the label adhesive surface of the object to which the label is adhered has a surface roughness Ra of at least a portion of 0.1 μm or more and 20 μm or less.

3. 2. A labeled object according to claim 1, wherein the temperature at which the label heats when irradiated with ultraviolet light at the minimum intensity required to peel the label from the object is equal to or lower than the heat resistance temperature of the object.

4. The labeled object according to claim 1 , wherein the label further comprises a printed layer containing at least one of a varnish mixed with an ultraviolet absorber and a black ink.

5. A label peeling method for peeling a label from a labeled object according to claim 1, comprising: A label peeling method comprising an irradiation step of irradiating the labeled object with ultraviolet light of a wavelength in the wavelength range of 320 nm or more and 400 nm or less.

6. Regarding the ultraviolet light, when the irradiation intensity is a [W], the irradiation time is b [seconds], and the irradiation distance is c [cm], 6. The peeling method according to claim 5, wherein the ultraviolet light is irradiated onto the labeled object under irradiation conditions such that a parameter expressed by a×b / √c is 15 or more and 90 or less.

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