Laminating material, adhesive label-laminating material set, adhesive body and recovery method

Abstract

To provide a laminate material that allows for accurate determination of the material of an object even when an adhesive label is attached to its surface; to provide an adhesive label-laminated material set that allows for accurate determination of the material of an object even when attached to its surface; to provide an adhesive that allows for accurate determination of the material of an object with an adhesive label attached to its surface; and to provide a recovery method that allows for suitable separation and recovery of an adhesive with an adhesive label attached to its surface. [Solution] The laminate material of the present invention is a laminate material that is attached to an adhesive label attached to an adherend, and comprises a base material and a wash-off type adhesive layer, wherein the base material is made of the same type of resin material as the resin material that constitutes the adherend.

Description

Technical Field

[0001] The present invention relates to a laminate material, an adhesive label - laminate material set, an adherend, and a recovery method.

Background Art

[0002] As containers for storing daily - used disinfectants, shampoos, hand soaps, body soaps, etc., plastic molded containers (plastic molded containers) are widely used. Against the background of environmental problems and reduction of plastic resource usage, material recycling is practiced to obtain a resin material (recycled resin material) from used plastic molded containers. Furthermore, horizontal recycling for forming similar plastic molded containers using this resin material is also practiced (for example, Patent Document 1).

[0003] Usually, such plastic molded containers have an adhesive label (hereinafter, also simply referred to as "label") with various information recorded on its surface.

[0004] When the adhesive label attached to the container body of a plastic molded container contains a material different from the material of the container body, in order to recover and recycle the used plastic molded container, it is necessary to select and separate the resin material of the container body and other materials, for example, the material constituting the adhesive label.

[0005] Examples of the material selection process include a method of separating based on the spectrum of substances obtained by spectroscopic analysis. Examples of the above - mentioned spectroscopic analysis include Raman spectroscopy, near - infrared spectroscopy, infrared spectroscopy, etc. Among them, Raman spectroscopy is preferably used in terms of being able to select various resin materials with higher accuracy. On the other hand, near - infrared spectroscopy is also preferably used from the viewpoint of being more convenient.

[0006] Specifically, as shown in Figure 9, after use, the plastic molded containers are irradiated with inspection light such as infrared light, and the reflected light (scattered light) is analyzed to identify the constituent materials. The materials are then sorted according to their type, for example, polypropylene (PP), polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), etc., and sent to the next process.

[0007] However, for example, as shown in Figure 10, if a label is attached to the container body, and the inspection light reflects off the label surface instead of the container body surface, the label's constituent materials will be mistakenly identified as the container body's constituent materials, resulting in an incorrect determination.

[0008] This could lead to a decrease in sorting accuracy, and consequently, a decline in the quality of recycled materials. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2024-045969 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The object of the present invention is to provide a laminate material that can accurately determine the material of an object even when an adhesive label is attached to its surface; to provide an adhesive label-laminated material set that can accurately determine the material of an object even when attached to its surface; to provide an adhesive that can accurately determine the material of an object in which an adhesive label is attached to its surface; and to provide a recovery method that can suitably separate and recover an adhesive that has an adhesive label attached to its surface. [Means for solving the problem]

[0011] These objectives are achieved by the present invention as described in (1) to (13) below. (1) A laminating material that is attached to an adhesive label attached to a substrate, It comprises a base material and a wash-off type adhesive layer. A laminate material characterized in that the base material is made of the same type of resin material as the resin material constituting the adherend.

[0012] (2) The laminate material according to (1) above, wherein the adherend and the substrate are made of a polyolefin-based resin material.

[0013] (3) The laminate material according to (1) or (2) above, wherein the thickness of the substrate is 10 μm or more and 150 μm or less.

[0014] (4) The laminate material according to any one of (1) to (3) above, wherein the thickness of the wash-off adhesive layer is 5 μm or more and 100 μm or less.

[0015] (5) The laminate material according to any one of (1) to (4) above, wherein the wash-off adhesive layer is made of a material containing an acrylic adhesive.

[0016] (6) A label adhesive sheet used in the manufacture of an adhesive label to be attached to an object, and a laminate material to be attached to the adhesive label, The adhesive sheet for labels comprises a label substrate and an adhesive layer for labels disposed on one side of the label substrate. The laminate material comprises a base material and a wash-off adhesive layer. An adhesive label-laminating material set characterized in that the base material is made of the same type of resin material as the resin material constituting the adherend.

[0017] (7) The adhesive label-laminating material set according to (6) above, wherein the adhesive layer for the label is a wash-off type adhesive layer.

[0018] (8) The adhesive sheet for labels further has a release coat layer for labels on the side opposite to the surface of the base material for labels facing the adhesive layer for labels. The adhesive label - laminate material set according to the above (6), wherein the base material for labels and the adhesive layer for labels are made of the same resin material as the resin material constituting the adherend.

[0019] (9) An adherend having an adherend, an adhesive label attached to the adherend, and a laminate material attached to the adhesive label. The adhesive label has a base material for labels, an adhesive layer for labels disposed on one surface side of the base material for labels, and a printing layer disposed on the other surface side of the base material for labels. The adhesive layer for labels is in contact with the adherend. The laminate material has a base material and a wash - off type adhesive layer. The wash - off type adhesive layer is in contact with the printing layer. An adherend, characterized in that the base material is made of the same resin material as the resin material constituting the adherend.

[0020] (10) A recovery method, characterized in that by applying a liquid to the adherend described in the above (9), at least the adherend and the base material are separated and recovered from the portion including the printing layer.

[0021] (11) The recovery method according to the above (10), wherein the liquid is an alkaline liquid.

[0022] (12) The adhesive layer for labels is a wash - off type adhesive layer, and the adherend and the base material are separated and recovered from the portion including the printing layer and the base material for labels, according to the above (10) or (11). The recovery method according to the above (10) or (11), wherein the adherend and the base material are separated and recovered from the portion including the printing layer and the base material for labels.

[0023] (13) The adhesive label further has a release coat layer for labels on the side opposite to the surface of the base material for labels facing the adhesive layer for labels. The label substrate and the label adhesive layer are made of the same type of resin material as the resin material constituting the adherend. A recovery method according to any one of (10) to (12) above, wherein the substrate and the adherend to which the label substrate is joined via the label adhesive layer are separated from the portion including the printing layer and recovered. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a laminate material that can accurately determine the material of an object even when an adhesive label is attached to the surface of the object, an adhesive label-laminated material set that can accurately determine the material of an object even when attached to the surface of the object, an adhesive that can accurately determine the material of an object with an adhesive label attached to its surface, and a recovery method that can suitably separate and recover an adhesive with an adhesive label attached to its surface. [Brief explanation of the drawing]

[0025] [Figure 1] This is a cross-sectional view showing one example of the composition of a laminate material. [Figure 2] This is a cross-sectional view showing one example configuration of an adhesive label-laminated material set. [Figure 3] This is a cross-sectional view showing another configuration example of an adhesive label-laminating material set. [Figure 4] This is a cross-sectional view showing one example of the structure of an adhesive body. [Figure 5] This is a cross-sectional view showing another example of the adhesive body's configuration. [Figure 6] This is a cross-sectional view showing an example of the state in which an alkaline liquid has been applied to the adhesive shown in Figure 4. [Figure 7] Figure 5 is a cross-sectional view showing an example of the state in which an alkaline liquid has been applied to the adhesive. [Figure 8] This is a cross-sectional view showing another example of the adhesive material described in Figure 5 after an alkaline liquid has been applied to it. [Figure 9]This diagram shows a method for identifying materials using spectroscopic analysis. [Figure 10] This diagram shows a method for identifying materials using spectroscopic analysis. [Modes for carrying out the invention]

[0026] Preferred embodiments of the present invention will be described in detail below.

[0027] [1] Laminate material First, the laminate material of the present invention will be described.

[0028] Figure 1 is a cross-sectional view showing an example of the composition of a laminate material. The laminate material 1 shown in Figure 1 is attached to an adhesive label 10 that is attached to an adherend 50, and has a base material 2 and a wash-off type adhesive layer 4, the base material 2 is made of the same type of resin material as the resin material that makes up the adherend 50.

[0029] This configuration makes it possible to provide a laminate material 1 that can accurately determine the material of the adherend 50 even when an adhesive label 10 is attached to the surface of the adherend 50.

[0030] More specifically, when the laminate material 1 is attached to an adhesive label 10 that is attached to an object 50, the base material 2 of the laminate material 1 is positioned as the outermost layer in the label portion. Furthermore, in the material identification method using spectroscopic analysis, even if the inspection light, such as infrared light, is reflected not from the surface of the object 50 but from the surface of the laminate material 1 attached to the adhesive label 10, the base material 2 of the laminate material 1 is made of the same type of resin material as the resin material that makes up the object 50. Therefore, by identifying the constituent material of the base material 2 of the laminate material 1, it becomes possible to accurately determine the constituent material of the object 50.

[0031] Furthermore, because the laminate material 1 has a wash-off adhesive layer 4, when the adhesive body 100 obtained using this laminate material 1 is recycled after use, applying liquid to the adhesive body 100 allows it to peel off at the interface between the wash-off adhesive layer 4 and the substrate 2, making it easy to separate the substrate 2 from the adhesive label 10.

[0032] In this specification, a wash-off adhesive layer refers to an adhesive layer that is soluble in liquid. The liquid may be, for example, an alkaline liquid.

[0033] Furthermore, in this specification, the wash-off adhesive layer comprises at least one of a wash-off adhesive and a wash-off adhesive.

[0034] The following description will primarily focus on the case where the wash-off adhesive layer 4 includes a wash-off adhesive, but the present invention is not limited to this, and may also include a wash-off adhesive.

[0035] Furthermore, in this specification, "same type of resin material" means any material having a common repeating chemical structure (unit structure). For example, if both the base material 2 and the adherend 50 are made of polypropylene, even if their weight-average molecular weight, glass transition temperature, softening point, and other conditions differ, they shall be considered to be made of the same type of resin material. Also, even if the constituent materials of the base material 2 and the constituent materials of the adherend 50 differ in the presence or absence of plasticizers, their content, etc., as long as the main resin component has a common repeating chemical structure (unit structure), they shall be considered to be made of the same type of resin material.

[0036] Furthermore, in this specification, the concept of "label" includes things such as films, sheets, and tapes.

[0037] [1-1] Base material The base material 2 is a sheet-like component that has the function of supporting the wash-off type adhesive layer 4. The base material 2 is made of the same type of resin material as the resin material that makes up the adherend 50.

[0038] The resin material constituting the base material 2 is not particularly limited as long as it is the same type of resin material as the resin material constituting the adherend 50. Examples include polyester resins, acrylic resins, polyvinyl chloride resins, and polyolefin resins, among which polyolefin resins (polyolefin resins) are preferred.

[0039] This allows for the efficient recycling of the base material 2 and the adherend 50. Furthermore, it offers cost advantages.

[0040] Polyolefin resins are polymer compounds having a chemical structure obtained by polymerizing olefins containing carbon-carbon double bonds as monomers.

[0041] Such polyolefin resins generally possess excellent flexibility and transparency. Therefore, by having the base material 2 composed of a material containing a polyolefin resin, a laminate material 1 can be obtained that conforms well to curved surfaces and has high visibility of the adhesive label 10 placed on the underside.

[0042] Examples of polyolefin resins constituting the base material 2 include polyethylene (PE), polypropylene (PP), polybutene (PB), ethylene-propylene copolymer, olefin elastomer (TPO), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), and olefin ternary copolymers such as ethylene-propylene-(5-ethylidene-2-norbornene). One or more of these can be selected and used in combination, but it is preferable that at least one of polypropylene and polyethylene be used, and more preferably polypropylene. Polypropylene may be, for example, stretched polypropylene (OPP).

[0043] When the base material 2 is composed of a polyolefin-based resin material, the base material 2 may also contain other resin materials in addition to the polyolefin-based resin.

[0044] Examples of resin materials other than polyolefin resins included in base material 2 include polyester resins such as polyethylene terephthalate (PET), polybutylene succinate, and polylactic acid; acetate resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, polystyrene, polyvinyl chloride (PVC), polyamide, polyimide, polycarbonate, and cellulose acetate. One or more of these can be selected and used in combination.

[0045] Furthermore, the base material 2 may contain various additives as needed. Examples of additives include plasticizers, stabilizers, colorants, fillers, and flame retardants.

[0046] The thickness of the substrate 2 is not particularly limited, but is preferably 10 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0047] This improves the mechanical strength of the laminate material 1, the handling of the laminate material 1 when it is attached to the adhesive label 10, and the handling of the base material 2 that is separated when the attached body 100 is recycled.

[0048] Such a substrate 2 can be manufactured by known methods, such as film formation methods including extrusion, calendering, solution coating, and casting.

[0049] [1-2] Wash-off adhesive layer The wash-off adhesive layer 4 has the function of adhering the laminate material 1 to the adhesive label 10.

[0050] The wash-off type adhesive layer 4 can be any adhesive layer that is soluble in liquid, but it is preferable that the gel fraction when the wash-off type adhesive layer 4 is immersed in a 1.5% by mass aqueous sodium hydroxide solution at 70°C for 30 minutes is 0% or more and 10% or less.

[0051] This allows for more favorable separation of the substrate 2 at the interface with the wash-off adhesive layer 4 when recycling the adhesive body 100 after use.

[0052] The wash-off adhesive layer 4 is preferably composed of a material containing an acrylic adhesive, and more preferably contains an acrylic polymer as the adhesive, which contains a "specific hydrophilic monomer" as described later as a constituent monomer in a predetermined proportion.

[0053] This results in more favorable alkali solubility of the adhesive layer during the recycling process.

[0054] [1-2-1] Acrylic polymer containing a specific hydrophilic monomer as a constituent monomer in a predetermined proportion. The adhesive contained in the wash-off adhesive layer 4 may be an acrylic polymer containing a specific hydrophilic monomer, which is an acrylate having an ether bond, as a constituent monomer, and the proportion of the specific hydrophilic monomer to the total adhesive is 60% by mass or more and 90% by mass or less.

[0055] This configuration makes the hydrophilicity of the adhesive more suitable, resulting in the wash-off adhesive layer 4 having more suitable solubility (alkali solubility), and also resulting in more suitable adhesive strength of the wash-off adhesive layer 4 to the adhesive label 10.

[0056] In the following description, an acrylic polymer that is an adhesive containing the specified hydrophilic monomer as a constituent monomer, and in which the proportion of the specified hydrophilic monomer is 60% by mass or more and 90% by mass or less, will also be referred to as a "specified hydrophilic monomer-containing adhesive."

[0057] [1-2-1-1] Specific hydrophilic monomer The adhesive containing a specific hydrophilic monomer contains a specific hydrophilic monomer, which is an acrylate having an ether bond, as a constituent monomer.

[0058] Examples of specific hydrophilic monomers that constitute the adhesive containing specific hydrophilic monomers include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate. One or more selected from these can be used in combination, but it is preferable that at least one selected from the group consisting of 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, and 2-ethoxyethyl acrylate is used, and it is more preferable that it is 2-methoxyethyl acrylate. As a result, the wash-off adhesive layer 4 has even more suitable solubility (alkali solubility).

[0059] The proportion of the specific hydrophilic monomer in the total adhesive containing the specific hydrophilic monomer is 60% by mass or more and 90% by mass or less, but is preferably 65% ​​by mass or more and 88% by mass or less, and more preferably 70% by mass or more and 85% by mass or less. This makes the aforementioned effects even more pronounced.

[0060] In particular, when the adhesive containing a specific hydrophilic monomer contains 2-methoxyethyl acrylate as the specific hydrophilic monomer, the ratio of the content of 2-methoxyethyl acrylate to the total specific hydrophilic monomers constituting the adhesive is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 75% by mass or more. This makes the aforementioned effects even more pronounced.

[0061] [1-2-1-2] Constituent monomers other than specific hydrophilic monomers Adhesives containing specific hydrophilic monomers contain, in addition to the aforementioned specific hydrophilic monomers, other constituent monomers. Hereafter, in this section, constituent monomers other than the specific hydrophilic monomers will also be referred to as "other monomers."

[0062] Other monomers that constitute the adhesive containing a specific hydrophilic monomer include, for example, (meth)alkyl acrylates such as 2-ethylhexyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and n-butyl (meth)acrylate, (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, and (meth)acrylamide, but it is preferable to include at least one selected from the group consisting of 2-ethylhexyl acrylate, n-butyl acrylate, and acrylic acid.

[0063] This makes it possible to make the adhesive strength of the wash-off adhesive layer 4 to the adhesive label 10 more suitable, and to more reliably prevent unintended peeling of the laminate material 1 from the adhesive label 10.

[0064] In particular, the adhesive strength of the wash-off type adhesive layer 4 becomes more suitable when the adhesive containing a specific hydrophilic monomer also contains 2-ethylhexyl acrylate or n-butyl acrylate as other monomers.

[0065] When a specific hydrophilic monomer-containing adhesive contains 2-ethylhexyl acrylate in addition to the specific hydrophilic monomer, the content of 2-ethylhexyl acrylate in the entire specific hydrophilic monomer-containing adhesive is preferably 1% by mass or more and 35% by mass or less, more preferably 2% by mass or more and 30% by mass or less, and even more preferably 3% by mass or more and 20% by mass or less.

[0066] When a specific hydrophilic monomer-containing adhesive contains n-butyl acrylate in addition to the specific hydrophilic monomer, the content of n-butyl acrylate in the entire specific hydrophilic monomer-containing adhesive is preferably 2% by mass or more and 25% by mass or less, more preferably 3% by mass or more and 20% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less.

[0067] This makes it possible to achieve a more favorable balance between sufficient adhesive strength to the adhesive label 10 and excellent separation of the wash-off type adhesive layer 4 from the substrate 2 and the adhesive label 10 when treated with an alkaline liquid (alkaline solution).

[0068] Furthermore, by including acrylic acid as another monomer in the specific hydrophilic monomer-containing adhesive, the excellent separation properties of the wash-off adhesive layer 4 from the substrate 2 and adhesive label 10 when treated with an alkaline solution can be further improved. In addition, it can form crosslinks with the crosslinking agent described later, thereby improving the cohesive force of the wash-off adhesive layer 4.

[0069] When a specific hydrophilic monomer-containing adhesive contains acrylic acid in addition to the specific hydrophilic monomer, the acrylic acid content in the entire specific hydrophilic monomer-containing adhesive is preferably 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and even more preferably 3% by mass or more and 7% by mass or less.

[0070] This makes it possible to achieve a more favorable balance between sufficient adhesive strength to the adhesive label 10 and excellent separation of the wash-off type adhesive layer 4 from the adhesive label 10 when treated with an alkaline solution.

[0071] Adhesives containing specific hydrophilic monomers may be crosslinked with a crosslinking agent. This is advantageous in increasing the adhesive strength of the wash-off adhesive layer 4 to the adhesive label 10, as well as the cohesive strength of the wash-off adhesive layer 4.

[0072] The crosslinking agent is not particularly limited, and known crosslinking agents can be appropriately selected and used. Specifically, examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, metal chelate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, and carbodiimide-based crosslinking agents, and one or more selected from these can be used in combination. Among these, epoxy-based crosslinking agents are preferred.

[0073] The amount of crosslinking agent added is preferably 0.1 parts by mass or more and 10 parts by mass or less, and more preferably 0.25 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the adhesive containing the specific hydrophilic monomer. This makes the aforementioned effects even more pronounced.

[0074] If the wash-off adhesive layer 4 contains a specific hydrophilic monomer-containing adhesive, the content of the specific hydrophilic monomer-containing adhesive in the wash-off adhesive layer 4 is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. This makes the aforementioned effects even more pronounced.

[0075] [1-2-2] Other ingredients The wash-off adhesive layer 4 may contain components other than those listed above (hereinafter referred to as "other components" in this section). Examples of other components include colorants, fillers, softeners, heat and light stabilizers, antioxidants, etc., and one or more of these can be selected and used in combination.

[0076] For example, various dyes and pigments can be used as coloring agents. Examples of fillers include zinc oxide, titanium dioxide, silica, calcium carbonate, and barium sulfate.

[0077] Examples of softening agents include process oils, liquid rubber, and plasticizers. Examples of heat and light stabilizers include benzophenone-based stabilizers, benzotriazole-based stabilizers, and hindered amine-based stabilizers.

[0078] Examples of antioxidants include anilide-based antioxidants, phenol-based antioxidants, phosphite-based antioxidants, and thioester-based antioxidants.

[0079] However, the content of other components in the wash-off adhesive layer 4 is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0080] [1-2-3] Other conditions The wash-off adhesive layer 4 preferably satisfies the condition that the gel fraction when immersed in ethyl acetate at 23°C for 72 hours is 50% or more, more preferably 50% to 95%, and even more preferably 50% to 85%.

[0081] As a result, the wash-off adhesive layer 4 achieves a balance of appropriate cohesiveness and tackiness, allowing for favorable processing of the laminate material 1. Furthermore, it can more effectively suppress unintended peeling when the label is in use.

[0082] The gel fraction value obtained by immersion in ethyl acetate at 23°C for 72 hours can be adjusted, for example, by the amount of crosslinking agent and the ratio of each monomer (especially the ratio of acrylic acid, etc.) in the components of the wash-off type adhesive layer 4.

[0083] In the measurement of the gel fraction described above, 20,000 parts by mass or more of ethyl acetate can be used per 100 parts by mass of the wash-off adhesive layer 4. Furthermore, it is preferable to use 100 mg or more of the wash-off adhesive layer 4 in the measurement of the gel fraction described above. Therefore, for example, when using 100 mg of the wash-off adhesive layer 4 in the measurement of the gel fraction described above, 20 g of ethyl acetate can be used.

[0084] The thickness of the wash-off adhesive layer 4 is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less, and even more preferably 15 μm or more and 50 μm or less.

[0085] This allows for more suitable adhesive strength to be achieved with respect to the adhesive label 10, and also improves the handling of the laminate material 1 when attaching it to the adhesive label 10. Furthermore, it improves the peelability when peeling the substrate 2 from the adhesive label 10 using an alkaline solution.

[0086] [2] Adhesive Labels - Laminating Material Set Next, the adhesive label-laminating material set of the present invention will be described. Figure 2 is a cross-sectional view showing one example configuration of an adhesive label-laminating material set. Figure 3 is a cross-sectional view showing another example configuration of an adhesive label-laminating material set.

[0087] The adhesive label-laminating material set 20 shown in Figures 2 and 3 comprises an adhesive sheet 10A for labels used in the manufacture of adhesive labels 10 to be attached to an object 50, and a laminating material 1 to be attached to the adhesive label 10.

[0088] Furthermore, the laminate material 1 included in the adhesive label-laminate material set 20 shown in Figures 2 and 3 has a base material 2 and a wash-off type adhesive layer 4, and the base material 2 is made of the same type of resin material as the resin material that constitutes the adherend 50.

[0089] Furthermore, the adhesive label sheet 10A included in the adhesive label-laminating material set 20 shown in Figures 2 and 3 has a label base material 11 and an adhesive label layer 12 disposed on one side of the label base material 11.

[0090] With this configuration, even if the adhesive label 10 is attached to the surface of the adherend 50, it is possible to provide an adhesive label-laminate material set 20 that can accurately determine the material of the adherend 50 using a material identification method based on spectroscopic analysis.

[0091] [2-1] Laminate material The laminate material 1 included in the adhesive label-laminating material set 20 comprises a base material 2 and a wash-off type adhesive layer 4, and the base material 2 is made of the same type of resin material as the resin material that constitutes the adherend 50.

[0092] The laminate material 1 included in the adhesive label-laminate material set 20 preferably satisfies the conditions described in [1] above. This results in the effects described above.

[0093] [2-2] Adhesive sheets for labels The adhesive sheet 10A for labels is an adhesive sheet used in the manufacture of adhesive labels 10 that are attached to an object 50, and has a label base material 11 and an adhesive layer 12 for labels disposed on one side of the label base material 11 (see Figures 2 and 3).

[0094] An adhesive label 10 is manufactured by forming a printing layer 15 on the other side of the label substrate 11 of the adhesive label sheet 10A.

[0095] [2-2-1] Label substrate The label substrate 11 is a sheet-like component and has the function of supporting the label adhesive layer 12 and the printing layer 15.

[0096] The label substrate 11 is not particularly limited, but it is preferable that it be made of the same type of resin material as the resin material that constitutes the adherend 50.

[0097] This allows, for example, when recycling the adhesive body 100 after use, the label substrate 11, along with the base material 2 and the adherend 50, to be recycled effectively without the need for material separation.

[0098] The thickness of the label substrate 11 is preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, and even more preferably 25 μm or more and 100 μm or less.

[0099] This improves the mechanical strength of the adhesive sheet 10A (adhesive label 10), the ease of handling when attaching the adhesive sheet 10A (adhesive label 10) to the substrate 50, and the ease of handling of the portion including the label substrate 11 that is separated when the substrate 100 is recycled.

[0100] [2-2-2] Label adhesive layer The adhesive layer 12 for labels has the function of attaching the adhesive sheet 10A (adhesive label 10) for labels to the substrate 50.

[0101] The adhesive layer 12 for the label is not particularly limited, and various adhesives such as polyester-based adhesives, urethane-based adhesives, rubber-based adhesives, olefin-based adhesives, and silicone-based adhesives can be used, but it is preferable that it be made of the same type of resin material as the resin material constituting the adherend 50.

[0102] For example, if the adherend 50 is made of a polyolefin-based resin material, the label adhesive layer 12 can be made of an olefin-based elastomer, a tackifying resin, an oil component as a plasticizer, etc.

[0103] As a result, as will be described later, when recycling the used adhesive 100, the laminate having the label substrate 11, the label adhesive layer 12, and the adherend 50 can be suitably recycled without removing the label adhesive layer 12 from the label substrate 11 (see Figure 7). However, when the label adhesive layer 12 is made of the same type of resin material as the adherend 50, and the laminate having the label substrate 11, the label adhesive layer 12, and the adherend 50 is recycled without removing the label adhesive layer 12 from the label substrate 11, it is preferable that the label adhesive sheet 10A has a label desorption coating layer 14, which will be described later.

[0104] Furthermore, the label adhesive layer 12 may be a wash-off type adhesive layer (wash-off type adhesive layer).

[0105] In the adhesive body 100 obtained using such an adhesive label-laminate set 20, as described later, when recycling after use, applying liquid to the adhesive body 100 allows for suitable peeling at the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the substrate 50, and at the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the label substrate 11 (see Figures 6 and 8).

[0106] In this specification, a wash-off adhesive layer refers to an adhesive layer that is soluble in a predetermined liquid. The liquid may be, for example, an alkaline liquid.

[0107] Furthermore, in this specification, the wash-off adhesive layer includes a wash-off adhesive.

[0108] As the wash-off adhesive that constitutes the wash-off adhesive layer 12 for the label, for example, the wash-off adhesive described above as a constituent material of the wash-off adhesive layer 4 can be suitably used.

[0109] The average thickness of the adhesive layer 12 for the label is not particularly limited, but is preferably 1 μm or more and 200 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0110] This allows for more suitable adhesive strength to be achieved with respect to the substrate 50, and also improves the handling of the adhesive sheet 10A (adhesive label 10) when attaching it to the substrate 50.

[0111] In such an adhesive label-laminating material set 20, an adhesive label 10 is formed by forming a printing layer 15 on the other side of the label substrate 11 of the adhesive label sheet 10A, and the laminating material 1 is attached to the printing layer 15 of the adhesive label 10.

[0112] The laminate material 1 may be attached to the adhesive label 10 first, and then the adhesive label 10 with the laminate material 1 attached may be attached to the object 50, or the adhesive label 10 may be attached to the object 50 first, and then the laminate material 1 may be attached to the adhesive label 10.

[0113] As shown in Figure 3, the adhesive label-laminate set 20 has a label release coating layer 14 on the side of the label substrate 11 opposite to the side facing the label adhesive layer 12 in the label adhesive sheet 10A, and the label substrate 11 and the label adhesive layer 12 may be made of the same type of resin material as the resin material that constitutes the adherend 50.

[0114] In the adhesive body 100 (see Figure 5) obtained using such an adhesive label-laminate set 20, as will be described later, when recycling after use, applying liquid to the adhesive body 100 allows for suitable peeling at the interface between the label release coating layer 14 and the label substrate 11.

[0115] Furthermore, since the label substrate 11 and the label adhesive layer 12 are made of the same type of resin material as the resin material that constitutes the adherend 50, the label substrate 11 and the label adhesive layer 12, along with the substrate 2 and adherend 50, can be suitably recycled (see Figure 7).

[0116] The label desorption coating layer 14 will be described in detail below.

[0117] [2-2-3] Delamination coating layer for labeling The adhesive sheet 10A for labels may have a label-release coating layer 14.

[0118] The label desorption coating layer 14 is a part composed of a material that dissolves when immersed in alkaline hot water.

[0119] Having such a label-detaching coating layer 14 allows for the effective separation of the label substrate 11 at the interface with the label-detaching coating layer 14 when, for example, the adhesive body 100 is recycled after use.

[0120] The label desorption coating layer 14 may be composed of a material that dissolves when immersed in alkaline hot water, but it is preferable that it be composed of a material containing an aqueous polyester resin having an acid value of 10KOH mg / g or more and a glass transition temperature Tg of 0°C or more and 70°C or less.

[0121] This allows, for example, when recycling the adhesive 100, to more efficiently separate the label substrate 11 at the interface with the label desorption coating layer 14 using a relatively short processing time with a relatively low-temperature alkaline solution.

[0122] As described above, when the label desorption coating layer 14 is composed of a material containing the aqueous polyester resin described above, the acid value of the aqueous polyester resin may be 10KOHmg / g or more, but is preferably 15KOHmg / g or more, more preferably 20KOHmg / g or more, and even more preferably 30KOHmg / g or more. There is no particular upper limit set for the acid value of the aqueous polyester resin, but for example it may be 90KOHmg / g or less, or 70KOHmg / g or less. This makes the aforementioned effects even more pronounced.

[0123] As described above, when the label desorption coating layer 14 is composed of a material containing the aqueous polyester resin described above, the glass transition temperature Tg of the aqueous polyester resin may be 0°C or more and 70°C or less, but is preferably 10°C or more and 65°C or less, more preferably 15°C or more and 60°C or less, and even more preferably 20°C or more and 55°C or less.

[0124] This allows the aforementioned effects to be more pronounced, and also improves the blocking resistance of the adhesive sheet 10A for labels (adhesive label 10).

[0125] In this specification, the glass transition temperature (Tg) can be specifically measured based on the method described below.

[0126] In other words, the glass transition temperature (Tg) can be measured in accordance with JIS K 7121:2012 using a differential scanning calorimeter (for example, a "DSC Q2000" manufactured by T.A. Instruments Japan, etc.) at a heating rate of 20°C / min.

[0127] The glass transition temperature (Tg) values ​​of aqueous polyester resins shown herein are those measured by the method described above.

[0128] Furthermore, the number-average molecular weight (Mn) of the aqueous polyester resin is not particularly limited, but is preferably 1,000 to 15,000, more preferably 1,500 to 10,000, and even more preferably 2,000 to 5,000.

[0129] This makes the water resistance of the adhesive sheet 10A for labels (adhesive label 10) sufficiently excellent, while also improving the solubility of the aqueous polyester resin in alkaline solutions, resulting in a more pronounced effect than previously described.

[0130] In this specification, the number-average molecular weight (Mn) value is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC), and specifically, it is a value measured based on the method described below.

[0131] Specifically, the number-average molecular weight (Mn) is measured using a gel permeation chromatograph (Tosoh Corporation, product name "HLC-8320GPC") under the following conditions, and the value measured in terms of standard polystyrene is used.

[0132] • Columns: "TSK guard column super HH", "TSK gel super HM-H (x2)", "TSK gel super HM-H" (all manufactured by Tosoh Corporation) Column temperature: 40°C • Developing solvent: tetrahydrofuran ·Flow rate: 1.0mL / min

[0133] Examples of the aqueous polyester resin include copolymers obtained by polycondensation of an alcohol component and a carboxylic acid component, and modified products of said copolymer.

[0134] Examples of modified products of the copolymer include polyurethane-modified polyester resins obtained by reacting a hydroxyl group at the end of a copolymer obtained by polycondensation of an alcohol component and a carboxylic acid component with a polyisocyanate compound. In this specification, such modified products of aqueous polyester resins are also included in "aqueous polyester resins."

[0135] As the alcohol component, a polyhydric alcohol having two or more hydroxyl groups in one molecule can be used.

[0136] Specific alcohol components include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, and neopentyl glycol hydroxypivalate ester; these glycols Examples include polylactone diols obtained by adding lactones such as ε-caprolactone; polyester diols such as bis(hydroxyethyl) terephthalate; divalent cyclic alcohols such as 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, spiroglycol, and dihydroxymethyltricyclodecane; ethylene oxide and propylene oxide adducts of bisphenol A; and trivalent or higher polyhydric alcohols such as glycerin, trimethylolpropane, trimethylolethane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, and mannitol. One or more selected from these can be used in combination.

[0137] As the carboxylic acid component, a polybasic acid having two or more carboxyl groups in one molecule can be used.

[0138] Specific carboxylic acid components include, for example, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, hetic acid, maleic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, methylhexahydrophthalic acid, and other dicarboxylic acids and their anhydrides; trimellit Examples include tricarboxylic acids such as triacid, pyromellitic acid, trimesic acid, methylcyclohexentricarboxylic acid, hexahydrotrimellitic acid, and tetrachlorohexentricarboxylic acid, and their anhydrides; tetracarboxylic acids such as 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, and pyromellitic acid, and their anhydrides, and one or more selected from these can be used in combination.

[0139] From the viewpoint of adjusting the acid value to the above range, the aqueous polyester resin preferably has constituent units derived from a polybasic acid having three or more carboxyl groups in one molecule, and more preferably has constituent units derived from a tricarboxylic acid or a tricarboxylic acid anhydride.

[0140] The aqueous polyester resin typically has hydrophilic functional groups, but it is particularly preferable that it has carboxyl groups, from the same viewpoint as described above.

[0141] Even if the label desorption coating layer 14 is composed of a material containing the aqueous polyester resin, it may also contain, in addition to the aqueous polyester resin, other components (hereinafter referred to as "other components" in this section).

[0142] However, the content of the aqueous polyester resin in the label desorption coating layer 14 is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0143] Other components include, for example, particles that have functions such as improving the slipperiness of the label delamination coating layer 14, colorants, fillers, softeners, heat and light stabilizers, antioxidants, and the like.

[0144] The aforementioned particles may be either inorganic or organic particles. Examples of inorganic particles include zirconia, silica, titanium dioxide, kaolin, alumina, titania, zeolite, calcium carbonate, barium sulfate, magnesium hydroxide, calcium phosphate, glass, mica, and talc. Examples of organic particles include acrylic resin particles such as polymethyl methacrylate, polystyrene resin particles, styrene-acrylic resin particles, and polycarbonate resin particles. One or more of these can be selected and used in combination.

[0145] The content of the aforementioned particles is not particularly limited, but it can be 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the aqueous polyester resin.

[0146] The average particle diameter of the aforementioned particles is not particularly limited, but is preferably 0.1 μm or more and 1.0 μm or less, and more preferably 0.3 μm or more and 0.6 μm or less. This allows for improved resistance to blocking.

[0147] In this specification, unless otherwise specified, the average particle diameter refers to the average particle diameter based on volume, which can be determined, for example, by measuring the particle dispersion using a Coulter counter particle size distribution analyzer (Beckman Coulter, TA-II model) with a 50 μm aperture.

[0148] The thickness of the label desorption coating layer 14 is not particularly limited, but is preferably 0.01 μm or more and 3.0 μm or less, more preferably 0.03 μm or more and 1.0 μm or less, and even more preferably 0.05 μm or more and 0.5 μm or less.

[0149] As a result, when recycling the adhesive 100, the label substrate 11 can be suitably separated at the interface with the label desorption coating layer 14 more efficiently by using a relatively low-temperature alkaline solution and a relatively short processing time.

[0150] [3] Adhesive body Next, the adhesive body of the present invention will be described. Figure 4 is a cross-sectional view showing one example of the structure of the adhesive body. Figure 5 is a cross-sectional view showing another example of the structure of the adhesive body.

[0151] The adhesive body 100 shown in Figures 4 and 5 comprises a substrate 50, an adhesive label 10 attached to the substrate 50, and a laminate material 1 attached to the adhesive label 10.

[0152] The adhesive label 10 provided by the adhesive body 100 comprises a label base material 11, a label adhesive layer 12 disposed on one side of the label base material 11, and a printing layer 15 disposed on the other side of the label base material 11, with the label adhesive layer 12 in contact with the adherend 50.

[0153] Furthermore, the laminate material 1 of the adhesive body 100 comprises a base material 2 and a wash-off adhesive layer 4, the wash-off adhesive layer 4 being in contact with the printed layer 15, and the base material 2 being made of the same type of resin material as the resin material constituting the adherend 50.

[0154] With this configuration, it is possible to provide an adhesive body 100 in which an adhesive label 10 is attached to the surface of the adherend 50, and in which the material of the adherend 50 can be accurately determined.

[0155] More specifically, in a material identification method using spectroscopic analysis, even if the inspection light, such as infrared light, is reflected not from the surface of the adherend 50 but from the surface of the laminate material 1 attached to the adhesive label 10, the base material 2 of the laminate material 1 is made of the same type of resin material as the resin material that makes up the adherend 50. Therefore, by identifying the constituent material of the base material 2 of the laminate material 1, it is possible to accurately determine the material of the adherend 50.

[0156] Furthermore, as will be described later, when recycling after use, applying liquid to the adhesive 100 allows it to peel off at the interface between the substrate 2 and the wash-off type adhesive layer 4, making it easy to separate the substrate 2.

[0157] [3-1] Laminating material The laminate material 1 of the adhesive body 100 comprises a base material 2 and a wash-off type adhesive layer 4, and the base material 2 is made of the same type of resin material as the resin material that constitutes the adherend 50.

[0158] The laminate material 1 provided by the adhesive body 100 preferably satisfies the conditions described in [1] above. This results in the effects described above.

[0159] [3-2] Adhesive Labels The adhesive label 10 of the adhesive body 100 comprises a label base material 11, a label adhesive layer 12 disposed on one side of the label base material 11, and a printing layer 15 disposed on the other side of the label base material 11, with the label adhesive layer 12 in contact with the adherend 50.

[0160] The adhesive label 10 provided on the adhesive body 100 preferably satisfies the same conditions as those for the adhesive sheet 10A for labels described in [2-2] above, except that it is provided with a printed layer 15. This results in the effects described above.

[0161] In particular, when the label adhesive layer 12 is a wash-off type adhesive layer, for example, when recycling the adhesive body 100 after use, applying liquid to the adhesive body 100 allows for peeling at the interface between the substrate 2 and the wash-off type adhesive layer 4, the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the adherend 50, and the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the label substrate 11, as described later, thereby suitably separating the substrate 2 and the adherend 50 (see Figures 6 and 8).

[0162] Furthermore, since the base material 2 is made of the same type of resin material as the adherend 50, both the adherend 50 and the base material 2 can be suitably recycled (see Figures 6 and 8).

[0163] Furthermore, as shown in Figure 5, the adhesive body 100 has a label release coating layer 14 on the side of the label substrate 11 opposite to the side facing the label adhesive layer 12 in the adhesive label 10, and the label substrate 11 and the label adhesive layer 12 may be made of the same type of resin material as the resin material constituting the adherend 50.

[0164] In such an adhesive 100, as will be described later, when recycling after use, the adhesive 100 can be peeled off at the interface between the substrate 2 and the wash-off adhesive layer 4, and at the interface between the label release coating layer 14 and the label substrate 11 by applying a liquid to the adhesive 100.

[0165] Furthermore, since the base material 2, the label base material 11, and the label adhesive layer 12 are made of the same type of resin material as the resin material that constitutes the adherend 50, the base material 2, the label base material 11, and the label adhesive layer 12 can be suitably recycled together with the adherend 50 (see Figure 7).

[0166] The printing layer 15 will be explained below. In the adhesive label 10, the printing layer 15 is formed on the other side of the label substrate 11 that constitutes the adhesive label sheet 10A described above.

[0167] The printed layer 15 can be any pattern, such as letters, symbols, figures, designs, barcodes, two-dimensional codes such as QR codes (registered trademarks), and one or more of these can be selected and used in combination. Furthermore, the printing layer 15 may be solid print.

[0168] Methods for forming the printed layer 15 include, for example, flexographic printing, offset printing, letterpress printing, gravure printing, screen printing, inkjet printing, electrophotography (electrostatic) printing, and thermal transfer printing using a melt or sublimation method.

[0169] [3-3] Adherent

[0170] The adherend 50 is made of the same type of resin material as the resin material that constitutes the base material 2 of the laminate material 1.

[0171] The resin material constituting the adherend 50 is not particularly limited, and examples include polyester resins, acrylic resins, polyvinyl chloride resins, and polyolefin resin materials, among which polyolefin resin materials are preferred.

[0172] Examples of polyolefin-based resin materials include those described in [1-1] above, but polyethylene-based resins or polypropylene-based resins are preferred.

[0173] This makes it easier to separate and collect the adherend 50 after use, and furthermore, the plastic flakes obtained from such a adherend 50, which is composed of polyethylene resin or polypropylene resin, are easier to extrude and blow mold.

[0174] Here, "composed of polyethylene resin or polypropylene resin" means that the mass ratio of polyethylene resin or polypropylene resin to the total mass is 70% or more (the same applies hereinafter), more preferably 80% or more, even more preferably 90% or more, and most preferably 95% or more. This allows the effects mentioned above to be more pronounced.

[0175] Polyethylene resins include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ultra-low-density polyethylene (ULDPE). Bio-polyethylene (BioPE), obtained by dehydrating and polymerizing bioethanol produced from sugarcane molasses, is also included. Ethylene-vinyl alcohol copolymer (EVOH), which can impart oxygen barrier properties, is also included in this category of polyethylene resins. Furthermore, two or more of these resins may be used (composed of) a mixture. The adherend 50 may also be a mixture of such polyethylene resins and polypropylene resins.

[0176] The adherend 50 may be made of a polyester resin. Examples of polyester resins include polyethylene terephthalate (PET), amorphous polyethylene terephthalate (amorphous PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polybutylene naphthalate (PBN).

[0177] The adherend 50 is not particularly limited, but examples include various containers for holding various liquids, solids (including powders), gel-like substances, etc. More specifically, various containers for holding food and beverages, cosmetics, disinfectants, shampoos (including foam types), hand soaps (including foam types), body soaps (including foam types), conditioners, cosmetics, hair styling products, waxes, cleaning solutions, solvents, etc.

[0178] Furthermore, in the configuration shown in Figure 5, the adhesive body 100 has a label release coating layer 14 on the side of the label substrate 11 opposite to the side facing the label adhesive layer 12 in the adhesive label 10, and the label substrate 11 and the label adhesive layer 12 are made of the same type of resin material as the resin material that constitutes the adherend 50.

[0179] In such an adhesive 100, as will be described later, for example, when recycling after use, the adhesive 100 can be suitably peeled off at the interface between the label delamination coating layer 14 and the label substrate 11 by applying a liquid to the adhesive 100.

[0180] Furthermore, since the label substrate 11 and the label adhesive layer 12 are made of the same type of resin material as the resin material that constitutes the adherend 50, the label substrate 11 and the label adhesive layer 12 can be suitably recycled together with the adherend 50 (see Figure 7).

[0181] [4] Collection method Next, the recovery method of the present invention will be described.

[0182] The adhesive body 100 described above is collected after use, its constituent materials are identified, and it is sorted by material.

[0183] In the adhesive body 100 of the present invention, even if an adhesive label 10 is attached to the surface of the adherend 50, it is possible to accurately determine the material of the adherend 50 using a material identification method by spectroscopic analysis.

[0184] Subsequently, the adhesive body 100 is washed with a liquid to separate and recover it into multiple parts. Alternatively, the adhesive body 100 may be crushed into flakes before being subjected to the washing process.

[0185] The separated parts are further subjected to sorting and washing processes to produce recycled resin material.

[0186] In the recovery method of this embodiment, by applying a liquid to the adhesive body 100 as described above, at least the adherend 50 and the substrate 2 are separated and recovered from the portion including the printed layer 15.

[0187] This configuration provides a recovery method that allows for the suitable separation and recovery of the adhesive body 100, on which the adhesive label 10 is attached to the surface of the adherend 50.

[0188] Figure 6 is a cross-sectional view showing an example of the adhesive described in Figure 4 with an alkaline liquid applied. Figure 7 is a cross-sectional view showing an example of the adhesive described in Figure 5 with an alkaline liquid applied. Figure 8 is a cross-sectional view showing another example of the adhesive described in Figure 5 with an alkaline liquid applied.

[0189] In the example shown in Figure 6, the label adhesive layer 12 is a wash-off type adhesive layer (the same applies to the example shown in Figure 8). With this configuration, by applying liquid, the substrate 2 and the adherend 50 can be suitably separated from the portion including the printing layer 15 by peeling at the interface between the substrate 2 and the wash-off type adhesive layer 4, the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the adherend 50, and the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the label substrate 11.

[0190] On the other hand, the portion including the printing layer 15, in other words, the portion including the wash-off adhesive layer 4, the printing layer 15, and the label substrate 11, and the portion including the label adhesive layer 12 are not recyclable and are, for example, discarded.

[0191] Furthermore, in the example shown in Figure 7, the adhesive label 10 has an additional label release coating layer 14 on the side of the label substrate 11 opposite to the side facing the label adhesive layer 12, and the label substrate 11 and the label adhesive layer 12 are made of the same type of resin material as the resin material that constitutes the adherend 50.

[0192] In such an adhesive 100, by applying a liquid, the interface between the substrate 2 and the wash-off adhesive layer 4, and the interface between the label release coating layer 14 and the label substrate 11 can be peeled off, and the portion including the printing layer 15 can be suitably separated. In other words, the adherend 50 to which the label substrate 11 is bonded via the label adhesive layer 12 can be separated from the portion including the printing layer 15 and recovered.

[0193] Furthermore, since the base material 2, the label base material 11, and the label adhesive layer 12 are made of the same type of resin material as the resin material constituting the adherend 50, the base material 2, the label base material 11, and the label adhesive layer 12 can be suitably recycled together with the adherend 50 without the need for material separation. This ensures that pure, identical materials are selected, and high-quality recycled materials can be secured.

[0194] Similar effects can be obtained in the example shown in Figure 8. Specifically, in the example shown in Figure 8, the label adhesive layer 12 is a wash-off type adhesive layer, and by applying liquid to the adherend 100, delamination occurs not only at the interface between the substrate 2 and the wash-off type adhesive layer 4, at the interface between the label delamination coating layer 14 and the label substrate 11, but also at the interface between the label adhesive layer 12 and the adherend 50, and at the interface between the label adhesive layer 12 (wash-off type adhesive layer) and the label substrate 11. In other words, the substrate 2, the label substrate 11, the label adhesive layer 12, and the adherend 50 are separated from the portion including the printing layer 15. Of these, the substrate 2, the label substrate 11, and the adherend 50 can be suitably recycled, similar to the adherend 50 and substrate 2 obtained in the example shown in Figure 7, where the label substrate 11 is joined via the label adhesive layer 12.

[0195] In the examples shown in Figures 7 and 8, the wash-off adhesive layer 4, the printing layer 15, and the label release coating layer 14 (including the printing layer 15) are not recyclable and are, for example, discarded. In the configuration shown in Figure 8, in addition to the aforementioned parts, the label adhesive layer 12 (wash-off adhesive layer) is also not recyclable and is, for example, discarded.

[0196] The liquid used in the recovery method of the present invention is preferably an alkaline liquid.

[0197] This allows for a more favorable dissolution of the wash-off adhesive layer 4, enabling a more favorable separation of the substrate 2 from the portion containing the printed layer 15. Furthermore, if the label adhesive layer 12 is a wash-off adhesive layer, peeling and separation can also occur at the interface between the label adhesive layer 12 and the adherend 50, and at the interface between the label adhesive layer 12 (wash-off adhesive layer) and the label substrate 11. Additionally, if the adhesive label 10 has a label release coating layer 14, peeling and separation can also occur at the interface between the label substrate 11 and the label release coating layer 14.

[0198] One method for applying the alkaline solution to the adhesive body 100 is an immersion method, in which the adhesive body 100 is immersed in the alkaline solution.

[0199] By employing the immersion method, the adhesive body 100 can be easily separated into multiple parts. This allows for improved efficiency in the recycling process.

[0200] When using the immersion method, it is preferable to stir the adhesive body 100 while it is immersed in the alkaline solution. This allows for more efficient separation of the adhesive body 100.

[0201] The alkaline solution is not particularly limited, but for example, an alkaline aqueous solution can be used. Examples of alkaline aqueous solutions include sodium hydroxide solution.

[0202] When an aqueous solution of sodium hydroxide is used as the alkaline solution, the concentration of sodium hydroxide is not particularly limited, but is preferably 0.1% by mass or more and 5.0% by mass or less, more preferably 0.5% by mass or more and 3.0% by mass or less, and even more preferably 1.0% by mass or more and 2.0% by mass or less. This allows for more efficient separation of the adhesive body 100.

[0203] The temperature of the alkaline solution applied to the adhesive body 100 is not particularly limited, but is preferably 95°C or lower, more preferably 90°C or lower, and even more preferably 60°C to 85°C. This allows for more efficient separation of the adhesive body 100.

[0204] The immersion time of the adhesive body 100 in the alkaline solution is not particularly limited, but is preferably 5 minutes or more and 60 minutes or less, more preferably 10 minutes or more and 50 minutes or less, and even more preferably 15 minutes or more and 45 minutes or less. This allows for more reliable separation of the adhesive body 100 into multiple parts.

[0205] As described above, according to the present invention, since the base material of the laminate is made of the same type of resin material as the resin material constituting the adherend, the material of the adherend can be accurately selected in material sorting by spectroscopic analysis.

[0206] Furthermore, by applying a liquid to the used adhesive and separating it into multiple components, pure, identical materials can be selected, separated, and recovered, thereby improving the quality of recycled materials.

[0207] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

[0208] For example, the laminate material of the present invention may have other components besides the layers described above, such as an undercoat layer, an intermediate layer, or a surface protective layer.

[0209] Furthermore, for example, the adhesive label-laminate material set of the present invention may have other components besides the layers described above, such as an undercoat layer, an intermediate layer, or a surface protective layer.

[0210] Furthermore, for example, the adhesive of the present invention may have other components besides the layers described above, such as an undercoat layer, an intermediate layer, or a surface protective layer.

[0211] Furthermore, for example, the recovery method of the present invention may include steps other than those described above, such as a pre-treatment step, an intermediate treatment step, and a post-treatment step. [Explanation of symbols]

[0212] 1: Laminate material 2: Base material 4: Wash-off adhesive layer 10: Adhesive Labels 10A: Adhesive sheet for labels 11: Label substrate 12: Label adhesive layer 14: Delamination coating layer for labeling 15: Printing layer 20: Adhesive Labels - Laminating Material Set 50: Adherent 100: Adhesive body

Claims

1. A laminating material that is attached to an adhesive label attached to a substrate, It comprises a base material and a wash-off type adhesive layer. A laminate material characterized in that the base material is made of the same type of resin material as the resin material constituting the adherend.

2. The laminate material according to claim 1, wherein the adherend and the substrate are composed of a polyolefin-based resin material.

3. The laminate material according to claim 1 or 2, wherein the thickness of the substrate is 10 μm or more and 150 μm or less.

4. The laminate material according to claim 1 or 2, wherein the thickness of the wash-off type adhesive layer is 5 μm or more and 100 μm or less.

5. The laminate material according to claim 1 or 2, wherein the wash-off adhesive layer is made of a material containing an acrylic adhesive.

6. The invention comprises an adhesive sheet for labels used in the manufacture of adhesive labels to be attached to an object, and a laminating material to be attached to the adhesive label, The adhesive sheet for labels comprises a label substrate and an adhesive layer for labels disposed on one side of the label substrate. The laminate material comprises a base material and a wash-off adhesive layer. An adhesive label-laminating material set characterized in that the base material is made of the same type of resin material as the resin material constituting the adherend.

7. The adhesive label-laminating material set according to claim 6, wherein the adhesive layer for the label is a wash-off type adhesive layer.

8. The adhesive sheet for labels further has a label release coating layer on the side of the label substrate opposite to the side facing the adhesive layer for labels. The adhesive label-laminating material set according to claim 6, wherein the label substrate and the label adhesive layer are made of the same type of resin material as the resin material constituting the adherend.

9. It comprises a substrate, an adhesive label attached to the substrate, and a laminate material attached to the adhesive label. The adhesive label comprises a label substrate, an adhesive layer for labels disposed on one side of the label substrate, and a printing layer disposed on the other side of the label substrate. The adhesive layer for the label is in contact with the adherend. The laminate material comprises a base material and a wash-off adhesive layer. The wash-off type adhesive layer is in contact with the printed layer. The adhesive is characterized in that the base material is made of the same type of resin material as the resin material constituting the adherend.

10. A recovery method characterized by applying a liquid to the adhesive according to claim 9, thereby separating and recovering at least the adherend and the substrate from the portion including the printed layer.

11. The recovery method according to claim 10, wherein the liquid is an alkaline liquid.

12. The adhesive layer for the label is a wash-off type adhesive layer. The recovery method according to claim 10 or 11, wherein the adherend and the substrate are separated and recovered from the portion including the printing layer and the label substrate.

13. The adhesive label further has a label release coating layer on the side of the label substrate opposite to the side facing the label adhesive layer. The label substrate and the label adhesive layer are made of the same type of resin material as the resin material constituting the adherend. The recovery method according to claim 10 or 11, wherein the substrate and the adherend to which the label substrate is joined via the label adhesive layer are separated from the portion including the printing layer and recovered.

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