How to dispose of adhesive sheets

Abstract

To provide an adhesive sheet which can be efficiently processed after use and in addition, to provide a processing method capable of increasing the processing efficiency of the used adhesive sheet.SOLUTION: There is provided an adhesive sheet having a base material and an adhesive layer, wherein the base material is composed of a laminate having a first layer and a second layer having a greater shrinkage rate when heated than the first layer. The second layer is preferably provided on the adhesive layer side than the first layer. In addition, there is provided a processing method which comprises: a peeling step of peeling the adhesive sheet adhered to an adherend from the adherend; and a heating step of heating and shrinking the peeled and used adhesive sheet.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides How to dispose of adhesive sheets Regarding. [Background technology]

[0002] BACKGROUND ART Pressure-sensitive adhesive sheets having a substrate made of a resin film or the like and a pressure-sensitive adhesive layer are widely used (see, for example, Patent Document 1).

[0003] As disclosed in Patent Document 1, pressure-sensitive adhesive sheets are sometimes used as so-called decorative films on which advertisements or the like are printed.

[0004] Large decorative films are pasted on walls in large quantities for purposes such as announcing events, advertising products, services, and companies, and are then peeled off from the walls after a specified advertising period has passed and disposed of as used films. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-178321 Summary of the Invention [Problem to be solved by the invention]

[0006] Used decorative films are often large in size and applied in large quantities, so they tend to be bulky and require a lot of effort for subsequent transportation and disposal, etc. These issues are not limited to used decorative films, but are also common to other pressure-sensitive adhesive sheets that have been used for various purposes.

[0007] The object of the present invention is to 、 To provide a method for treating used pressure-sensitive adhesive sheets, which can increase the efficiency of treating the sheets. [Means for solving the problem]

[0008] Such objectives are as follows: (1) 6 This is achieved by the present invention described in (1) a peeling step of peeling the pressure-sensitive adhesive sheet attached to the adherend from the adherend; a heating step of heating and shrinking the peeled, used pressure-sensitive adhesive sheet; Equipped with The pressure-sensitive adhesive sheet is Having a substrate and an adhesive layer It is something, The adhesive sheet is characterized in that the substrate is composed of a laminate having a first layer and a second layer that has a larger shrinkage rate when heated than the first layer. How to handle .

[0009] (2) The pressure-sensitive adhesive sheet according to (1), wherein the second layer is provided closer to the pressure-sensitive adhesive layer than the first layer. How to handle .

[0010] (3) The pressure-sensitive adhesive sheet according to (1) or (2) above, wherein the second layer is made of a stretched film. How to handle .

[0012] ( 4 ) The above method further includes a heating preparation step of bending or rolling the peeled pressure-sensitive adhesive sheet before the heating step. 1 ) or (3) A method for treating a pressure-sensitive adhesive sheet according to claim 1.

[0013] ( 5 In the heating preparation step, the peeled pressure-sensitive adhesive sheet is bent or rolled so that the pressure-sensitive adhesive layer faces inward. 4 ) A method for treating a pressure-sensitive adhesive sheet according to the above.

[0014] ( 6 ) The heating temperature in the heating step is 70°C or more and 600°C or less. 1 ) or ( 5 10. A method for treating a pressure-sensitive adhesive sheet according to any one of claims 1 to 9. [Effects of the Invention]

[0015] According to the present invention 、 It is possible to provide a disposal method that can increase the efficiency of disposal of used pressure-sensitive adhesive sheets. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic longitudinal sectional view of a preferred embodiment of the pressure-sensitive adhesive sheet of the present invention. [Figure 2] 1 is a flowchart showing a preferred embodiment of a method for treating a pressure-sensitive adhesive sheet of the present invention. [Figure 3] FIG. 10 is a schematic diagram showing the processing content of a heating preparation step. [Figure 4] FIG. 2 is a schematic diagram showing how the adhesive sheet shown in FIG. 1 is bent by heating. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present invention will be described in detail below. [1] Adhesive sheet First, the pressure-sensitive adhesive sheet of the present invention will be described.

[0018] Fig. 1 is a schematic longitudinal sectional view of a preferred embodiment of the pressure-sensitive adhesive sheet of the present invention, showing a pressure-sensitive adhesive sheet 10 attached to an adherend 20 during use.

[0019] The adhesive sheet 10 includes a substrate 11 and an adhesive layer 13 provided on one surface of the substrate 11 . In this specification, the term "sheet" includes the concept of film.

[0020] When the pressure-sensitive adhesive sheet 10 is used, it is attached to the surface of the adherend 20 by the adhesive force of the pressure-sensitive adhesive layer 13 .

[0021] In this embodiment, the adhesive sheet 10 is used as a so-called decorative film.

[0022] When the pressure-sensitive adhesive sheet 10 is used as a decorative film, the adherend 20 is, for example, a wall or window glass of a building, a signboard, or the back panel of a picture frame.

[0023] In other embodiments, the pressure-sensitive adhesive sheet 10 does not have to be used as a decorative film, but may be used, for example, as a decorative sheet or a packaging film attached to the outer surface of a container or the like.

[0024] Furthermore, the surface of the adherend 20 to which the pressure-sensitive adhesive sheet 10 is attached is not limited to a flat surface, but may be a curved surface or may have an uneven structure.

[0025] The substrate 11 constituting the adhesive sheet 10 is a laminate including a first layer 11a disposed on the outer surface side of the adhesive sheet 10 (the side on which the printed layer 15 is provided) and a second layer 11b disposed closer to the adhesive layer 13 than the first layer 11a. The second layer 11b has a larger thermal shrinkage rate than the first layer 11a.

[0026] This configuration allows the adhesive sheet 10 to be efficiently disposed of after use. More specifically, by a heat treatment (heating step) as described below, the substrate 11 can be shrunk more effectively, and the adhesive sheet 10 can be deformed to be more compact. In particular, since the substrate 11 is a laminate having multiple layers with different thermal shrinkage rates, the direction in which the adhesive sheet 10 deforms, such as by curving or bending, when subjected to heat treatment can be suitably controlled.

[0027] In particular, in this embodiment, since the second layer 11b is provided closer to the adhesive layer 13 than the first layer 11a, the adhesive sheet 10 is likely to bend toward the side on which the adhesive layer 13 is formed, i.e., so that the adhesive layer 13 faces inward, by heat treatment (heating process) as described below.

[0028] As a result, when the adhesive sheet 10 is deformed to be compact, the adhesive surface of the adhesive layer 13 is prevented from facing outward, and the adhesive layer 13 is prevented from adhering to the worker's body or objects around the work area, which would cause delays in the execution of the present treatment for the adhesive sheet 10. Furthermore, during the heat treatment, the adhesive layer 13 comes into contact with other parts of the adhesive sheet 10 (e.g., the substrate 11, the printed layer 15, other parts of the adhesive layer 13, etc.) and exerts its adhesive force, thereby effectively restricting unintended expansion of the adhesive sheet 10 once it has been heat-shrunk. Furthermore, by effectively restricting unintended expansion of the adhesive sheet 10 once it has been heat-shrunk, the adhesive layer 13 is more likely to come into contact with other parts of the adhesive sheet 10 when the adhesive sheet 10 further shrinks, and the adhesive sheet 10 is ultimately more likely to be compact. Therefore, the effects of the present invention are more significantly exhibited.

[0029] The substrate 11 is usually made of a resin material. Examples of resin materials constituting the substrate 11 include vinyl chloride resins such as polyvinyl chloride (PVC) or copolymers mainly composed of vinyl chloride, polyesters (PEs) such as polyethylene terephthalate (PET) and polylactic acid, polypropylene (PP), polyethylene (PE), polyolefin (PO), polystyrene (PS), polyurethane (PU), acrylic resins, etc., and one or more selected from these may be used in combination.

[0030] The substrate 11 may have portions made of different materials. More specifically, for example, the first layer 11a and the second layer 11b may be made of different materials.

[0031] The second layer 11b is preferably made of a stretched film. This makes it possible to achieve stable high heat shrinkability, and the effects of the present invention as described above are more stably exhibited. The stretched film includes a material called a shrink film.

[0032] The first layer 11a may be made of a stretched film like the second layer 11b, or may be made of a non-stretched film, as long as it has a smaller shrinkage rate when heated than the second layer 11b.

[0033] The stretched film may be, for example, a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film.

[0034] This allows substrate 11 to be more suitably shrunk by heat treatment (heating step) as described below, and allows adhesive sheet 10 to be deformed so as to be more compact.

[0035] When the second layer 11b constituting the base material 11 is heated alone at 90°C for 10 minutes, the thermal shrinkage rate in the direction along the surface of the second layer 11b is preferably 35% or more and 95% or less, more preferably 55% or more and 95% or less, and even more preferably 65% ​​or more and 95% or less.

[0036] This allows substrate 11 to shrink more effectively by heat treatment (heating step) as described below, and allows adhesive sheet 10 to be deformed so as to be compacted even more.

[0037] When the in-plane thermal shrinkage of the second layer 11b is anisotropic, it is preferable that the thermal shrinkage in the direction in which the thermal shrinkage is greatest is within the above range.

[0038] Furthermore, when the substrate 11 constituting the adhesive sheet 10 is heated alone at 90°C for 10 minutes, the thermal shrinkage rate in the direction along the surface of the substrate 11 is preferably 30% or more and 90% or less, more preferably 50% or more and 90% or less, and even more preferably 60% or more and 90% or less.

[0039] This allows substrate 11 to shrink more effectively by heat treatment (heating step) as described below, and allows adhesive sheet 10 to be deformed so as to be compacted even more.

[0040] When the in-plane thermal shrinkage of the substrate 11 is anisotropic, it is preferable that the thermal shrinkage in the direction in which the thermal shrinkage is greatest is within the above range.

[0041] Furthermore, when the thermal shrinkage rate in the direction along the surface of first layer 11a constituting substrate 11 when first layer 11a is heated alone at 90°C for 10 minutes is defined as X1 [%], and the thermal shrinkage rate in the direction along the surface of second layer 11b constituting substrate 11 when second layer 11b is heated alone at 90°C for 10 minutes is defined as X2 [%], it is preferable that the relationship 1≦X2−X1≦50 is satisfied, and it is more preferable that the relationship 5≦X2−X1≦30 is satisfied.

[0042] This allows the substrate 11 to be shrunk more effectively by a heat treatment (heating step) as described below, and the adhesive sheet 10 can be deformed to be more compact. In particular, when the heat treatment is performed, the adhesive sheet 10 can be deformed, such as curved or bent, in a desired direction more suitably.

[0043] When the in-plane thermal shrinkage rates of the first layer 11a and the second layer 11b are anisotropic, it is preferable that the direction in which the thermal shrinkage rate is maximum satisfies the above-mentioned relationship.

[0044] The thickness of the first layer 11a is not particularly limited, but is preferably 5 μm or more and 200 μm or less, and more preferably 10 μm or more and 150 μm or less.

[0045] The thickness of the second layer 11b is not particularly limited, but is preferably 5 μm or more and 200 μm or less, and more preferably 10 μm or more and 150 μm or less.

[0046] This allows the aforementioned effects of the present invention to be more pronounced, and the adhesive sheet 10 can be deformed so as to be more compact.

[0047] The overall thickness of the substrate 11 (i.e., the thickness of the substrate 11 as a laminate having the first layer 11a and the second layer 11b) is not particularly limited, but is preferably 10 μm or more and 400 μm or less, and more preferably 20 μm or more and 300 μm or less.

[0048] This makes it possible to improve the efficiency of, for example, adhering the adhesive sheet 10 to the substrate 20 and peeling it off from the substrate 20, and also to more significantly exhibit the effects of the present invention as described above, allowing the adhesive sheet 10 to be deformed so that it can be made smaller and more compact.

[0049] The adhesive layer 13 is made of a material containing various adhesives such as an acrylic adhesive, a urethane adhesive, a silicone adhesive, etc. The adhesive layer 13 may contain components other than the adhesive (other components) as needed, such as an ultraviolet absorber, a tackifier, an antioxidant, a light stabilizer, a silane coupling agent, and a filler.

[0050] The thickness of the adhesive layer 13 is not particularly limited, but is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

[0051] This makes it possible, for example, to ensure sufficiently excellent adhesion of the pressure-sensitive adhesive sheet 10 to the adherend 20, while more effectively preventing adhesive residue from being left on the adherend 20 after the pressure-sensitive adhesive sheet 10 is peeled from the adherend 20. It also makes it possible to improve the efficiency of the work of adhering the pressure-sensitive adhesive sheet 10 to the adherend 20 and the work of peeling it from the adherend 20. Furthermore, when the processing method of the present invention is carried out, the pressure-sensitive adhesive sheet 10 can be deformed so that it can be made smaller and more compact.

[0052] When the pressure-sensitive adhesive sheet 10 is in an unused state before being attached to the adherend 20, the outer surface of the pressure-sensitive adhesive layer 13 is preferably covered with a release liner (not shown).

[0053] The release liner may be, for example, a film substrate made of a resin film or a paper substrate having a release layer containing a release agent formed on the surface thereof.

[0054] In this embodiment, a printed layer 15 on which an image including figures, letters, patterns, etc. is formed with ink is provided on the surface of the substrate 11 opposite to the adhesive layer 13.

[0055] The surface of the printed layer 15 may be covered with a light-transmitting protective layer such as a laminate layer (not shown). In other embodiments, the printed layer 15 may be omitted.

[0056] [2] How to dispose of adhesive sheets Next, the method for treating the pressure-sensitive adhesive sheet of the present invention will be described.

[0057] Fig. 2 is a flowchart showing a preferred embodiment of the method for treating a pressure-sensitive adhesive sheet of the present invention. Fig. 3 is a schematic diagram showing the processing contents of a heating preparation step. Fig. 4 is a schematic diagram showing how the pressure-sensitive adhesive sheet shown in Fig. 1 is bent by heating.

[0058] The method for treating an adhesive sheet of the present invention comprises a peeling step of peeling the adhesive sheet of the present invention, which is attached to an adherend, from the adherend, and a heating step of heating the peeled, used adhesive sheet to cause it to shrink.

[0059] This makes it possible to provide a processing method that can efficiently process used pressure-sensitive adhesive sheet 10. More specifically, by heat treatment (heating step), substrate 11 can be more effectively shrunk, and pressure-sensitive adhesive sheet 10 can be deformed to be more compact. In particular, because substrate 11 constituting pressure-sensitive adhesive sheet 10 is a laminate having first layer 11a and second layer 11b that have different thermal shrinkage rates, the direction in which pressure-sensitive adhesive sheet 10 deforms, such as by curving or bending, during the heating step can be suitably controlled.

[0060] In particular, the embodiment shown in Figure 2 includes step S1, which corresponds to a peeling step, step S2, which corresponds to a heating preparation step in which the peeled adhesive sheet is bent or rolled, step S3, which corresponds to a heating step, and step S4, which corresponds to a post-processing step.

[0061] Step S1 corresponds to a peeling step in which an operator peels off the adhesive sheet 10, which has been attached to the adherend 20 by the adhesive force of the adhesive layer 13, from the adherend 20.

[0062] The adhesive sheet 10 that has been attached to the adherend 20 and is in a used state is peeled off from the adherend 20 by this peeling step and put into a used state after a predetermined period of use, such as the period of advertisement, has elapsed.

[0063] Step S2 corresponds to a heating preparation step for preparing for the subsequent heating step S3. In step S2, in order to reduce the size of the adhesive sheet 10, the worker bends or rolls at least a portion of the adhesive sheet 10.

[0064] This allows the adhesive sheet 10 to be deformed so as to be compacted by heat shrinkage in step S3, which corresponds to the heating step performed after step S2. Furthermore, if the adhesive sheet 10 is compacted before heating, the heating range by the heating means can be narrowed, and the heating step in step S3 can be performed efficiently.

[0065] It should be noted that "bending" the adhesive sheet 10 refers to processing that creates a bent portion in the adhesive sheet 10. Furthermore, "rolling" the adhesive sheet 10 refers to processing that curves at least a portion of the adhesive sheet 10, for example, by rolling it.

[0066] In step S2, the worker preferably bends or rolls the adhesive sheet 10 so that the adhesive layer 13 faces inward, as shown in FIG.

[0067] "The adhesive layer 13 faces inward" means that the adhesive surface, which is the outer surface of the adhesive layer 13, faces toward any part of the adhesive sheet 10, as shown in FIG.

[0068] This prevents the adhesive surface of the adhesive layer 13 from facing outward, preventing the adhesive layer 13 from adhering to the worker's body or objects around the work area, which would otherwise cause delays in the execution of this treatment for the adhesive sheet 10. Furthermore, during heat shrinkage in step S3, which corresponds to the heating step, the adhesive layer 13 comes into contact with other parts of the adhesive sheet 10 (e.g., the substrate 11, the printed layer 15, other parts of the adhesive layer 13, etc.) and exerts its adhesive force, thereby effectively restricting unintended expansion of the adhesive sheet 10 once it has been heat shrunk. Furthermore, by effectively restricting unintended expansion of the adhesive sheet 10 once it has been heat shrunk, the adhesive layer 13 is more likely to come into contact with other parts of the adhesive sheet 10 when the adhesive sheet 10 further shrinks, which makes it easier for the adhesive sheet 10 to ultimately be compacted. Therefore, the effects of the present invention are more pronounced.

[0069] In particular, since the second layer 11b is provided closer to the adhesive layer 13 than the first layer 11a as shown in the figure, the effect of the adhesive sheet 10 being more likely to bend toward the side on which the adhesive layer 13 is formed, i.e., so that the adhesive layer 13 faces inward, during the heating step, as described above, and the effect of performing the heating preparation step by bending or rolling the sheet so that the adhesive layer 13 faces inward, work synergistically, and the effect of the present invention is more pronounced.

[0070] In step S3, the worker uses a heating means such as a heating tool or a high-temperature substance to heat and shrink the adhesive sheet 10.

[0071] Examples of the heating tool that can be used include a heat gun, a hair dryer, a heater, a hot plate, etc. Examples of the high-temperature substance that can be used include hot water, etc.

[0072] In the present embodiment, when the second layer 11b is disposed closer to the adhesive layer 13 than the first layer 11a, the amount of thermal shrinkage when the adhesive sheet 10 is heated is greater for the second layer 11b than for the first layer 11a. Therefore, in step S3, which corresponds to the heating step, the adhesive sheet 10 tends to bend toward the side on which the adhesive layer 13 is formed, i.e., with the adhesive layer 13 facing inward, as shown in FIG. 4.

[0073] The heating temperature in step S3 depends on, for example, the configuration of the substrate 11, but is preferably 70°C or higher and 600°C or lower, more preferably 100°C or higher and 500°C or lower, and even more preferably 150°C or higher and 400°C or lower.

[0074] This allows the pressure-sensitive adhesive sheet 10 to shrink more efficiently, more significantly demonstrating the effects of the present invention, and also shortens the time required for the treatment method of the present invention, improving work efficiency, which is also preferable from the standpoints of worker safety and energy conservation.

[0075] In step S3, the adhesive sheet 10 is thermally shrunk, thereby making the adhesive sheet 10 smaller than before use or when in use, thereby preventing the adhesive sheet 10 from becoming bulky in subsequent operations.

[0076] In step S4, which corresponds to a post-treatment step, the worker performs a predetermined treatment on the used adhesive sheet 10 that has shrunk and become small.

[0077] Examples of "predetermined processing" include transporting used adhesive sheet 10, storing used adhesive sheet 10 in a predetermined location, disposing of used adhesive sheet 10 by incineration or landfilling, and processing to recycle used adhesive sheet 10.

[0078] As described above, according to the method for treating the adhesive sheet 10 of this embodiment, the used adhesive sheet 10 is made smaller by heat shrinkage, so that the adhesive sheet 10 is prevented from becoming bulky when a predetermined treatment is performed on the used adhesive sheet 10. Therefore, the treatment of the used adhesive sheet 10 can be performed efficiently.

[0079] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these. For example, modifications such as changing conditions or adding other configurations or steps may be made within the scope of the spirit of the present invention.

[0080] Furthermore, in the above-described embodiment, a case has been described in which the substrate constituting the adhesive sheet is a laminate consisting of a first layer and a second layer, but the substrate may have one or more layers other than the first layer and the second layer.

[0081] The pressure-sensitive adhesive sheet may also include other layers such as an intermediate layer and a base layer between the substrate and the pressure-sensitive adhesive layer.

[0082] Furthermore, in the above-described embodiment, a case has been described in which the substrate (at least the second layer) is heat-shrinkable, and thus the entire adhesive sheet is shrunk by heat treatment (heating process), but in addition to the substrate, parts other than the substrate may also be heat-shrinkable.

[0083] Furthermore, in the above-described embodiment, the case where the adhesive sheet is a decorative film has been described as a representative example, but the adhesive sheet may be something other than a decorative film. [Explanation of symbols]

[0084] 10…sticky シート 11…Substrate 11a…Level 1 11b…2nd floor 13…Adhesion layer 15…printing layers 20…being clothed S1… Project S2… Project S3… Project S4… Project

Claims

1. a peeling step of peeling the pressure-sensitive adhesive sheet attached to the adherend from the adherend; a heating step of heating and shrinking the peeled, used pressure-sensitive adhesive sheet; Equipped with The pressure-sensitive adhesive sheet has a substrate and a pressure-sensitive adhesive layer, A method for treating an adhesive sheet, characterized in that the substrate is composed of a laminate having a first layer and a second layer that has a larger shrinkage rate when heated than the first layer.

2. The method for treating a pressure-sensitive adhesive sheet according to claim 1 , wherein the second layer is provided closer to the pressure-sensitive adhesive layer than the first layer.

3. 3. The method for treating a pressure-sensitive adhesive sheet according to claim 1, wherein the second layer is made of a stretched film.

4. 4. The method for treating an adhesive sheet according to claim 1, further comprising a heating preparation step of bending or rolling the peeled adhesive sheet before the heating step.

5. The method for treating an adhesive sheet according to claim 4 , wherein in the heating preparation step, the peeled adhesive sheet is bent or rolled so that the adhesive layer faces inward.

6. The method for treating a pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the heating temperature in the heating step is 70°C or higher and 600°C or lower.

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