How to treat the release liner

Abstract

To provide a release liner which can be efficiently processed after being released from an adhesive sheet, to provide an adhesive sheet with a release liner having the release liner and in addition, to provide a processing method capable of increasing the processing efficiency of the release liner released from an adhesive sheet.SOLUTION: There is provided a release liner which is used for covering the surface of an adhesive layer constituting an adhesive sheet and is shrunk when heated. A release liner has a liner base material and a release agent layer and the liner base material preferably is a heat shrinkage material. The liner base material is preferably composed of a laminate having a first layer and a second layer having a greater shrinkage rate when heated than the first layer.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention provides How to treat the release liner Regarding. [Background technology]

[0002] BACKGROUND ART Pressure-sensitive adhesive sheets having a pressure-sensitive adhesive layer are widely used for a variety of purposes. In such adhesive sheets, the surface of the adhesive layer is usually covered and protected by a release liner before being attached to an adherend, and the release liner is peeled off and removed from the adhesive sheet when it is attached to an adherend (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-220424 Summary of the Invention [Problem to be solved by the invention]

[0004] The release liner that has been peeled and removed from the pressure-sensitive adhesive sheet tends to be bulky, and subsequent transportation and disposal, etc., tend to be time-consuming.

[0005] The object of the present invention is to 、 To provide a treatment method capable of increasing the efficiency of treating a release liner peeled from a pressure-sensitive adhesive sheet. [Means for solving the problem]

[0006] Such objectives are as follows: (1) 5 This is achieved by the present invention described in (1) a peeling step of peeling the pressure-sensitive adhesive sheet from a release-liner-attached pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a release liner that covers the surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet and that shrinks when heated; a heating step of heating and shrinking the release liner from which the pressure-sensitive adhesive sheet has been peeled off; Equipped with The heating temperature in the heating step is 70°C or higher and 600°C or lower. A method for treating a release liner, comprising:

[0007] (2) The aforementioned The release liner has a liner substrate and a release agent layer, The release liner according to (1) above, wherein the liner substrate is heat-shrinkable. How to handle .

[0008] (3) The release liner according to (2) above, wherein the liner substrate is a laminate having a first layer and a second layer having a larger shrinkage rate when heated than the first layer. How to handle .

[0009] (4) The release liner according to (2) or (3), wherein the liner substrate has a region made of a stretched film. How to handle .

[0012] ( 5 The method further comprises a heating preparation step of bending or rolling the peeled release liner before the heating step. Either (1) or (4) 10. A method for treating a release liner according to claim 1. [Effects of the Invention]

[0014] According to the present invention 、 It is possible to provide a processing method that can increase the processing efficiency of a release liner that has been peeled off from a pressure-sensitive adhesive sheet. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic longitudinal cross-sectional view of a release liner of a first embodiment. [Figure 2] 1 is a schematic longitudinal cross-sectional view of a pressure-sensitive adhesive sheet with a release liner according to a first embodiment. [Figure 3] FIG. 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet with a release liner according to a first embodiment in a rolled state. [Figure 4] 1 is a flowchart illustrating a method for treating a release liner. [Figure 5] FIG. 10 is a schematic diagram showing the processing content of a heating preparation step. [Figure 6] FIG. 4 is a schematic longitudinal cross-sectional view of a release liner of a second embodiment. [Figure 7] FIG. 3 is a schematic longitudinal cross-sectional view of a pressure-sensitive adhesive sheet with a release liner according to a second embodiment. [Figure 8] FIG. 10 is a schematic diagram showing how the release liner of the second embodiment bends when heated. 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] Figure 1 is a schematic longitudinal cross-sectional view of a release liner of the first embodiment, Figure 2 is a schematic longitudinal cross-sectional view of a pressure-sensitive adhesive sheet with a release liner of the first embodiment, and Figure 3 is a schematic cross-sectional view of a rolled pressure-sensitive adhesive sheet with a release liner of the first embodiment.

[0018] Release liner 20 is used to cover the surface of adhesive layer 13 constituting adhesive sheet 10, and is characterized by shrinking when heated.

[0019] With this configuration, for example, the release liner 20 can be efficiently treated after being peeled off from the pressure-sensitive adhesive sheet 10. More specifically, the release liner 20 can be shrunk by a heat treatment (heating step) as described below, and the release liner 20 can be deformed so that it can be compacted. In this specification, the term "sheet" includes the concept of film.

[0020] In the illustrated configuration, the release liner 20 has a liner substrate 21 and a release agent layer 22 .

[0021] The release liner 20 as a whole may be heat-shrinkable, but it is preferable that the liner substrate 21 is heat-shrinkable.

[0022] This ensures that the above-mentioned effects are obtained without sacrificing the releasability of the PSA sheet 10 from the release liner 20, for example.

[0023] The liner substrate 21 may be made of any material, and examples of the material for the liner substrate 21 include various resin materials.

[0024] Examples of resin materials constituting the liner substrate 21 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 resin, etc. One or a combination of two or more selected from these may be used. Among these, it is preferable that the liner substrate 21 contains at least one of polyester and polypropylene.

[0025] This allows the shrinkage rate of the liner substrate 21 to be increased when the release liner 20 is heated, and the effects of the present invention as described above are more pronounced.

[0026] The liner substrate 21 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.

[0027] When a stretched film is used as the liner substrate 21, the stretched film may be, for example, a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film.

[0028] This allows the liner substrate 21 to shrink more effectively by heat treatment (heating step) as described below, and allows the release liner 20 to be deformed so as to be more compact.

[0029] For example, when the liner substrate 21 constituting the release liner 20 is heated alone at 90°C for 10 minutes, the thermal shrinkage rate in the direction along the surface of the liner substrate 21 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.

[0030] This allows the liner substrate 21 to shrink more effectively by heat treatment (heating step) as described below, and allows the release liner 20 to be deformed so as to be more compact.

[0031] When the in-plane heat shrinkage of the liner substrate 21 is anisotropic, it is preferable that the heat shrinkage in the direction in which the heat shrinkage is greatest be within the above range.

[0032] The thickness of the liner substrate 21 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.

[0033] This makes it possible to improve the work efficiency when peeling the adhesive sheet 10 from the release liner 20, for example, and when the processing method of the present invention is carried out, the effects of the present invention are more pronounced, allowing the adhesive sheet 10 to be deformed so that it can be made smaller and more compact.

[0034] The release agent layer 22 is the portion that comes into contact with the surface of the adhesive layer 13 that constitutes the adhesive sheet 10 .

[0035] The release agent layer 22 may be made of any material as long as it can exhibit releasability between the release agent layer 22 and the adhesive layer 13. Examples of materials constituting the release agent layer 22 include various types of release agents such as silicone-based, fluorine-based, and long-chain alkyl-based release agents.

[0036] The thickness of the release agent layer 22 is not particularly limited, but is preferably 0.03 μm or more and 0.5 μm or less, and more preferably 0.05 μm or more and 0.2 μm or less.

[0037] Furthermore, when the release liner 20 is heated at 90°C for 10 minutes, the thermal shrinkage rate in the direction along the surface of the release liner 20 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.

[0038] This allows the release liner 20 to be shrunk more effectively by a heat treatment (heating step) as described below, and allows the release liner 20 to be deformed so as to be more compact.

[0039] When the in-plane heat shrinkage of the release liner 20 is anisotropic, it is preferable that the heat shrinkage in the direction in which the heat shrinkage is greatest be within the above range.

[0040] The thickness of the release liner 20 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.

[0041] The pressure-sensitive adhesive sheet 100 with a release liner comprises a pressure-sensitive adhesive sheet 10 and a release liner 20 .

[0042] In the release-liner-attached pressure-sensitive adhesive sheet 100, the release liner 20 described above is in contact with the surface of the pressure-sensitive adhesive layer 13 that constitutes the pressure-sensitive adhesive sheet 10. In other words, the release liner 20 described above has the function of protecting the surface of the pressure-sensitive adhesive layer 13 that constitutes the pressure-sensitive adhesive sheet 10.

[0043] With this configuration, for example, the release liner 20 can be efficiently treated after being peeled off from the pressure-sensitive adhesive sheet 10. More specifically, the release liner 20 can be shrunk by a heat treatment (heating step) as described below, and the release liner 20 can be deformed so that it can be compacted.

[0044] The release-liner-attached pressure-sensitive adhesive sheet 100, the pressure-sensitive adhesive sheet 10, and the release liner 20 may be, for example, in the form of a tape.

[0045] When in use, the pressure-sensitive adhesive sheet 10 is peeled off from the release liner 20 to expose the pressure-sensitive adhesive layer 13, and then adhered to the surface of an adherend by the adhesive force of the pressure-sensitive adhesive layer 13.

[0046] The uses of the pressure-sensitive adhesive sheet 10 are not particularly limited, and it can be used, for example, as a decorative film, a decorative sheet, a solar radiation adjusting film, a paint protection film, a packaging film attached to the outer surface of a container or the like, and the like.

[0047] When the pressure-sensitive adhesive sheet 10 is used as a decorative film, the adherend may be, for example, a wall or window glass of a building, a signboard, or the back panel of a picture frame.

[0048] Furthermore, the surface of the adherend 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.

[0049] In the configuration shown in FIGS. 2 and 3, adhesive sheet 10 includes adhesive layer 13 as well as substrate 11 that supports adhesive layer 13 .

[0050] Examples of materials that can be used for the substrate 11 include various resin materials and paper. 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), 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.

[0051] 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.

[0052] This makes it possible to improve the efficiency of the process of adhering the pressure-sensitive adhesive sheet 10 to the adherend, for example.

[0053] 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.

[0054] 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.

[0055] This makes it possible to, for example, ensure sufficiently excellent adhesion when the pressure-sensitive adhesive sheet 10 is stuck to an adherend, and also to improve the efficiency of the work of sticking the pressure-sensitive adhesive sheet 10 to an adherend.

[0056] The release liner 20 may be stored, for example, as a single flat sheet, or may be stored in contact with the adhesive layer 13 and rolled up, as shown in FIG. 3.

[0057] The method for treating the release liner 20 will now be described. Fig. 4 is a flow chart showing a method for treating a release liner, and Fig. 5 is a schematic diagram showing the processing contents of the heating preparation step.

[0058] The method for treating the release liner 20 in this embodiment includes a peeling step of peeling the adhesive sheet 10 from the adhesive sheet 100 with a release liner, and a heating step of heating the release liner 20 from which the adhesive sheet 10 has been peeled to cause it to shrink.

[0059] This makes it possible to provide a processing method that can increase the processing efficiency of release liner 20 that has been peeled off from pressure-sensitive adhesive sheet 10.

[0060] In particular, as shown in FIG. 4, this embodiment includes step S1, which corresponds to a peeling step, step S2, which corresponds to a heating preparation step of bending or rolling the peeled release liner, 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 pressure-sensitive adhesive sheet 10, which is attached to release liner 20 by the adhesive force of pressure-sensitive adhesive layer 13, is peeled from release liner 20.

[0062] The PSA sheet 10 attached to the release liner 20 is peeled from the release liner 20 in this peeling step, for example, when the PSA sheet 10 is to be stuck to the intended adherend.

[0063] Step S2 corresponds to a heating preparation step for preparing for the subsequent heating step S3. In step S2, the worker bends or rolls at least a portion of the release liner 20 to reduce its size.

[0064] This allows release liner 20 to be deformed into a smaller, more compact shape by heat shrinkage in step S3, which corresponds to the heating step performed after step S2. Furthermore, if release liner 20 is compactly folded before heating, the heating range by the heating means can be narrowed, and the heating step in step S3 can be performed more efficiently.

[0065] Here, "bending" the release liner 20 refers to processing that creates a curved portion in the release liner 20. Furthermore, "rolling" the release liner 20 refers to processing that curves at least a portion of the release liner 20, for example, by rolling it.

[0066] If the release liner 20 is to be stored in a rolled state, in step S2, it is preferable that the worker bend or roll the release liner 20 in the rolled direction in which it is stored, as shown in FIG.

[0067] This allows this step to be carried out more efficiently by utilizing the curling tendency of release liner 20. Furthermore, in this step, release liner 20 can be folded into a smaller size, and release liner 20 can be folded into an even smaller size after step S3, which corresponds to the heating step. Therefore, the effects of the present invention are more pronounced.

[0068] In step S3, an operator heats and shrinks the release liner 20 using a heating means such as a heating tool or a high-temperature substance.

[0069] 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.

[0070] The heating temperature in step S3 depends on, for example, the configuration of the release liner 20, 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.

[0071] This allows the release liner 20 to shrink more efficiently, the effects of the present invention to be more pronounced, and the time required for the treatment method of the present invention can be shortened, improving work efficiency, which is also preferable from the standpoints of worker safety and energy conservation.

[0072] In step S3, the release liner 20 can be made smaller by heat shrinking the release liner 20, and the release liner 20 can be prevented from becoming bulky in the subsequent steps.

[0073] In step S4, which corresponds to a post-treatment step, an operator performs a predetermined treatment on the release liner 20 that has shrunk and become small.

[0074] Examples of the "predetermined processing" include transporting the shrunk release liner 20, storing the shrunk release liner 20 in a predetermined location, disposing of the shrunk release liner 20 by incineration or landfilling, and processing the shrunk release liner 20 for reuse (recycling).

[0075] As described above, according to the method for treating release liner 20 of the present embodiment, release liner 20 is made smaller by heat shrinkage, and therefore the release liner 20 is prevented from becoming bulky when a predetermined treatment is performed on release liner 20. Therefore, treatment of release liner 20 that has already been peeled from PSA sheet 10 can be performed efficiently.

[0076] <<Second embodiment>> Next, a second embodiment of the present invention will be described.

[0077] 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.

[0078] Figure 6 is a schematic longitudinal cross-sectional view of a release liner of the second embodiment. Figure 7 is a schematic longitudinal cross-sectional view of a pressure-sensitive adhesive sheet with a release liner of the second embodiment. Figure 8 is a schematic view showing how the release liner of the second embodiment bends when heated.

[0079] This embodiment has a configuration similar to that of the first embodiment, except that the liner substrate 21 that constitutes the release liner 20 has a laminated structure having multiple layers.

[0080] More specifically, in this embodiment, the liner substrate 21 is composed of a laminate having a first layer 21a and a second layer 21b that has a larger shrinkage rate when heated than the first layer 21a.

[0081] With this configuration, the liner substrate 21 can be more effectively shrunk by the heat treatment (heating step) described above, and the release liner 20 can be deformed to be smaller and more compact. Furthermore, when the heat treatment is performed, the direction of deformation, such as curvature or bending, of the release liner 20 can be suitably controlled.

[0082] As the constituent materials of the first layer 21a and the second layer 21b, the materials exemplified as the constituent materials of the liner substrate 21 in the first embodiment can be used.

[0083] The liner substrate 21 may have portions made of different materials. More specifically, for example, the first layer 21a and the second layer 21b may be made of different materials.

[0084] The liner substrate 21 preferably has a region made of a stretched film. In particular, when the liner substrate 21 is a laminate having a first layer 21a and a second layer 21b as in the present embodiment, it is preferable that at least the second layer 21b is made of a stretched film.

[0085] This allows the liner substrate 21 to shrink more effectively, and the release liner 20 to be deformed so as to be compacted even more.

[0086] The first layer 21a may be made of a stretched film like the second layer 21b, or may be made of a non-stretched film, paper, or the like, as long as it has a smaller shrinkage rate when heated than the second layer 21b.

[0087] When the second layer 21b constituting the liner substrate 21 is heated alone at 90°C for 10 minutes, the thermal shrinkage rate in the direction along the surface of the second layer 21b 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.

[0088] This allows the liner substrate 21 to shrink more effectively by the heat treatment (heating step) described above, and allows the release liner 20 to be deformed so as to be more compact.

[0089] When the in-plane thermal shrinkage of the second layer 21b is anisotropic, it is preferable that the thermal shrinkage in the direction in which the thermal shrinkage is greatest is within the above range.

[0090] Furthermore, when the thermal shrinkage rate in the direction along the surface of the first layer 21a constituting the liner substrate 21 when the first layer 21a 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 the second layer 21b constituting the liner substrate 21 when the second layer 21b 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.

[0091] This allows the liner substrate 21 to shrink more effectively by the heat treatment (heating step) described above, and allows the release liner 20 to be deformed so as to be more compact. In particular, when the heat treatment is performed, the release liner 20 can be deformed, such as curved or bent, in a desired direction more suitably.

[0092] When the thermal shrinkage rates in the planes of the first layer 21a and the second layer 21b are anisotropic, it is preferable that the above relationship be satisfied in the direction in which the thermal shrinkage rate is maximum.

[0093] The thickness of the first layer 21a 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.

[0094] The thickness of the second layer 21b 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.

[0095] This allows the effects of the present invention as described above to be more pronounced, and allows the release liner 20 to be deformed into a smaller, more compact shape.

[0096] 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.

[0097] The pressure-sensitive adhesive sheet may also be provided with a printed layer on the surface of the substrate opposite to the surface on which the pressure-sensitive adhesive layer is provided, on which an image including figures, letters, patterns, etc. is formed with ink. The printed layer may also be covered with a light-transmitting protective layer such as a laminate layer.

[0098] In the above-described embodiment, the pressure-sensitive adhesive sheet has been described as having a substrate, but the pressure-sensitive adhesive sheet may be a substrateless pressure-sensitive adhesive sheet having no substrate as long as it has at least a pressure-sensitive adhesive layer. The pressure-sensitive adhesive sheet may also be a substrate in which pressure-sensitive adhesive layers are provided on both sides of the substrate.

[0099] Furthermore, in the second embodiment described above, a case was typically described in which the liner substrate constituting the release liner is a laminate consisting of a first layer and a second layer, but the liner substrate may also have one or more layers other than the first layer and the second layer.

[0100] In addition to the liner substrate and the release agent layer, the release liner may also include, for example, an intermediate layer or a base layer provided between these, and a protective layer or a printed layer provided on the surface opposite the release agent layer.

[0101] Furthermore, in the above-described embodiment, a case where the release liner has a liner substrate and a release agent layer has been described as a representative example. However, if the liner substrate itself has releasability, the release liner does not need to have a release agent layer, and may, for example, be composed of only the liner substrate. [Explanation of symbols]

[0102] 10...Adhesive sheet 11...Base material 13...Adhesive layer 20...Release liner 21...Liner base material 21a...First layer 21b...Second layer 22...Release agent layer 100...Adhesive sheet with release liner S1…Process S2…Process S3…Process S4…Process

Claims

1. a peeling step of peeling the pressure-sensitive adhesive sheet from a release-liner-attached pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a release liner that covers the surface of the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive sheet and that shrinks when heated; a heating step of heating and shrinking the release liner from which the pressure-sensitive adhesive sheet has been peeled off; Equipped with The method for treating a release liner, wherein the heating temperature in the heating step is 70°C or higher and 600°C or lower.

2. The release liner has a liner substrate and a release agent layer, 2. The method for treating a release liner according to claim 1, wherein the liner substrate is heat-shrinkable.

3. The method for treating a release liner according to claim 2, wherein the liner 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.

4. The method for treating a release liner according to claim 2 or 3, wherein the liner substrate has a region made of a stretched film.

5. 5. The method for treating a release liner according to claim 1, further comprising a heating preparation step of bending or rolling the released release liner before the heating step.

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