How to dispose of adhesive sheets

Abstract

To provide a processing method capable of increasing processing efficiency of a used adhesive sheet and to provide an adhesive sheet which can be suitably used for the processing method.SOLUTION: There is provided a processing method which comprises: a peeling step of peeling an adhesive sheet which has a base material and an adhesive layer and is adhered to an adherend by the adhesive force of the adhesive layer from the adherend; and a heating step of heating and shrinking the peeled and used adhesive sheet. The method preferably further comprises, before the heating step, a heating preparation step of bending or rounding the peeled adhesive sheet. In the heating preparation step, the peeled adhesive sheet is preferably bent or rounded so that the adhesive layer faces inward.SELECTED DRAWING: Figure 2

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] An object of the present invention is to provide a processing method that can improve the processing efficiency of used pressure-sensitive adhesive sheets. to be. [Means for solving the problem]

[0008] Such objectives are as follows: (1) 4 This is achieved by the present invention described in (1) a peeling step of peeling a pressure-sensitive adhesive sheet, which has a substrate and a pressure-sensitive adhesive layer and is attached to an adherend by the adhesive force of the pressure-sensitive adhesive layer, 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 structure that makes it easy to bend toward the surface on which the pressure-sensitive adhesive layer is provided when heated. A method for treating an adhesive sheet.

[0009] (2) The method further includes a heating preparation step of bending or rolling the peeled pressure-sensitive adhesive sheet before the heating step. the above( 1 ) A method for treating a pressure-sensitive adhesive sheet according to claim 1.

[0010] (3) In the heating preparation step, the peeled adhesive sheet is bent or rolled so that the adhesive layer faces inward. the above( 2 ) A method for treating a pressure-sensitive adhesive sheet according to claim 1.

[0012] ( 4 ) The heating temperature in the heating step is 70°C or higher and 600°C or lower. the above( 1 ) Or (3) 10. The method for treating a pressure-sensitive adhesive sheet according to claim 9, wherein [Effects of the Invention]

[0014] According to the present invention, there is provided a processing method capable of efficiently processing used pressure-sensitive adhesive sheets. but can. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic longitudinal sectional view of a pressure-sensitive adhesive sheet according to a first embodiment. [Figure 2]1 is a flowchart showing a first embodiment of a method for treating a pressure-sensitive adhesive sheet according to the present invention. [Figure 3] FIG. 10 is a schematic diagram showing the processing content of a heating preparation step. [Figure 4] FIG. 4 is a schematic vertical cross-sectional view of a pressure-sensitive adhesive sheet according to a second embodiment. [Figure 5] 10A and 10B are schematic diagrams showing how the pressure-sensitive adhesive sheet of the second embodiment is bent by heating. DETAILED DESCRIPTION OF THE INVENTION

[0016] Preferred embodiments of the present invention will be described in detail below. <<First Embodiment>> First, a first embodiment of the present invention will be described.

[0017] Fig. 1 is a schematic longitudinal cross-sectional view of a pressure-sensitive adhesive sheet according to a first embodiment, showing a state in which a pressure-sensitive adhesive sheet 10 is attached to an adherend 20 during use.

[0018] The pressure-sensitive adhesive sheet 10 comprises a substrate 11 and a pressure-sensitive adhesive layer 13 provided on one surface of the substrate 11. In this specification, the term "sheet" includes the concept of a film.

[0019] 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 .

[0020] In this embodiment, the adhesive sheet 10 is configured as a so-called decorative film. 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.

[0021] 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.

[0022] 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.

[0023] The base material 11 is usually made of a resin material and has heat shrinkability. 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.

[0024] The thickness of the substrate 11 is not particularly limited, but is preferably 15 μm or more and 300 μm or less, and more preferably 20 μm or more and 200 μm or less.

[0025] This makes it possible to improve, for example, the efficiency of the work of adhering the adhesive sheet 10 to the substrate 20 and the efficiency of the work of peeling it off from the substrate 20, and when the processing method of the present invention is carried out, the effects of the present invention, as described in detail below, are more pronounced, and the adhesive sheet 10 can be deformed so that it can be made smaller and more compact.

[0026] The substrate 11 preferably has a high thermal shrinkage rate because it shrinks when heated in the treatment method described below.

[0027] The substrate 11 may be made of a stretched film with enhanced heat shrinkability, for example, by heating, stretching, and cooling a non-stretched film. Such stretched films include materials known as shrink films, which can achieve stable and high heat shrinkability.

[0028] When a stretched film is used as the substrate 11, the stretched film may be, for example, a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film.

[0029] This allows substrate 11 to shrink more effectively by heat treatment in step S3, which corresponds to the heating step described below, and allows pressure-sensitive adhesive sheet 10 to be deformed so as to be more compact.

[0030] For example, 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.

[0031] This allows substrate 11 to shrink more effectively by heat treatment in step S3, which corresponds to the heating step described below, and allows pressure-sensitive adhesive sheet 10 to be deformed so as to be more compact.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] Fig. 2 is a flow chart showing a first 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 the heating preparation step.

[0041] The method for treating an adhesive sheet of the present invention comprises a peeling step of peeling an adhesive sheet, which has a substrate and an adhesive layer and is attached to an adherend by the adhesive force of the adhesive layer, from the adherend, and a heating step of heating the peeled, used adhesive sheet to cause it to shrink.

[0042] This makes it possible to provide a disposal method that can efficiently dispose of used pressure-sensitive adhesive sheets 10.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] "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.

[0051] 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.), exerting 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 subjected to the treatment method of the present invention is ultimately more likely to be compact and compact. Therefore, the effects of the present invention are more pronounced.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Furthermore, the adhesive sheet 10 of this embodiment can be easily made smaller by heat shrinkage, and therefore can be suitably used in the processing method of this embodiment.

[0061] <<Second embodiment>> Next, a second embodiment of the present invention will be described.

[0062] In the following description of the second embodiment, differences from the first embodiment will be mainly described, and descriptions of similar matters will be omitted.

[0063] Fig. 4 is a schematic vertical cross-sectional view of an adhesive sheet 10A according to a second embodiment of the present invention, and Fig. 5 is a schematic view showing how the adhesive sheet of the second embodiment is bent by heating.

[0064] The configuration of the adhesive sheet 10A is almost the same as that of the adhesive sheet 10 of the first embodiment, except that instead of the substrate 11 described in the first embodiment, it has a substrate 11A with a laminated structure having multiple layers.

[0065] The adhesive sheet 10A is used in the processing method shown in Fig. 2 described in the first embodiment. The adhesive sheet 10A has a structure that makes it easy to bend toward the surface on which the adhesive layer 13 is formed when heated in step S3.

[0066] In the adhesive sheet 10A of the second embodiment, the substrate 11A comprises a first layer 11a arranged on the outer surface side of the adhesive sheet 10A (the side on which the printing layer 15 is provided), and a second layer 11b arranged on the adhesive layer 13 side of the first layer 11a.

[0067] In the adhesive sheet 10A, the first layer 11a has a smaller thermal shrinkage rate than the second layer 11b.

[0068] With the above-described configuration, when adhesive sheet 10A is heated in step S3, which corresponds to the heating step, the amount of thermal shrinkage is greater in second layer 11b than in first layer 11a.

[0069] Therefore, in step S3, which corresponds to the heating step, adhesive sheet 10A tends to bend toward the surface on which adhesive layer 13 is formed, that is, so that adhesive layer 13 faces inward, as shown in FIG.

[0070] As a result, the adhesive surface of the adhesive layer 13 is prevented from facing outward, preventing the adhesive layer 13 from adhering to the worker's body or objects around the work site, 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, and the adhesive sheet 10 subjected to the treatment method of the present invention is ultimately more likely to be compact and compact. Therefore, the effects of the present invention are more pronounced.

[0071] In particular, as described in the first embodiment, when the adhesive sheet 10 is bent or rolled in step S2 so that the adhesive layer 13 faces inward, the effect of such a process and the effect of the adhesive sheet 10A having a structure that makes it easy to bend on the side on which the adhesive layer 13 is provided when heated act synergistically, resulting in particularly excellent effects.

[0072] In the second embodiment, for example, the first layer 11a is made of an unstretched film, and the second layer 11b is made of a stretched film that is stretched while being heated, thereby making it possible to make the thermal shrinkage rate of the first layer different from that of the second layer 11b.

[0073] Furthermore, for example, when both the first layer 11a and the second layer 11b are made of stretched films, the stretch ratio of the second layer 11b may be greater than the stretch ratio of the first layer 11a.

[0074] The constituent materials of each layer constituting the base material 11A, that is, the first layer 11a and the second layer 11b, can be the same as those of the base material 11 described in the first embodiment.

[0075] As described above, the adhesive sheet 10A of the second embodiment has a structure that makes it easy to bend when heated toward the side on which the adhesive layer 13 is provided, and therefore can be shrunk so that the adhesive layer 13 faces inward in the heating step after the sheet has been used. Therefore, in the heating step of step S3, the adhesive force of the adhesive layer 13 makes it easier for the used adhesive sheet 10A to be compacted, which further prevents the used adhesive sheet 10A from becoming bulky in subsequent processing. In addition, the adhesive force of the adhesive layer 13 is further prevented from interfering with the work of the worker.

[0076] 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 steps may be made within the scope of the spirit of the present invention.

[0077] In the second embodiment described above, a pressure-sensitive adhesive sheet having a structure that easily bends on the side on which the pressure-sensitive adhesive layer is formed when heated in the heating step is typically described as having a substrate with a two-layer structure of a first layer and a second layer laminated thereon, but the same effect can be obtained even if the substrate is a laminate of three or more layers, as long as it has a structure that easily bends on the side on which the pressure-sensitive adhesive layer is formed. The same effect can also be obtained when a layer with a smaller thermal shrinkage coefficient than the substrate is disposed on the side of the substrate opposite the surface facing the pressure-sensitive adhesive layer.

[0078] 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.

[0079] Furthermore, in the above-described embodiment, a case has been described in which the substrate is heat-shrinkable, causing the entire adhesive sheet to shrink during the heating process. However, the adhesive sheet may also be configured so that the entire adhesive sheet shrinks during the heating process by having a portion other than the substrate be heat-shrinkable.

[0080] 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]

[0081] 10, 10A...Adhesive sheet 11,11A…Base material 11a...First layer 11b...Second layer 13...Adhesive layer 15...printing layer 20...Adherend S1…Process S2…Process S3…Process S4…Process

Claims

1. a peeling step of peeling a pressure-sensitive adhesive sheet, which has a substrate and a pressure-sensitive adhesive layer and is attached to an adherend by the adhesive strength of the pressure-sensitive adhesive layer, from the adherend; a heating step of heating and shrinking the peeled, used pressure-sensitive adhesive sheet; Equipped with The method for treating an adhesive sheet, wherein the adhesive sheet has a structure that makes it easy to bend toward the surface on which the adhesive layer is provided when heated.

2. 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.

3. The method for treating an adhesive sheet according to claim 2 , wherein in the heating preparation step, the peeled adhesive sheet is bent or rolled so that the adhesive layer faces inward.

4. The method for treating a pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the heating temperature in the heating step is 70°C or higher and 600°C or lower.

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