Adhesive sheet, and method for removing the adhesive sheet

Abstract

To provide an adhesive sheet that effectively suppresses peeling from the adherend during use, while being easily removable after use. [Solution] An adhesive sheet comprising a base material and an adhesive layer, wherein the base material is made of a non-permeable material, and the adhesive layer is made of a water-soluble or water-swellable material, and the adhesive sheet having the following structure (a) and / or the following structure (b). Structure (a): The thickness of the adhesive layer is 1000 μm or less, and the adhesive layer forming surface of the substrate has an adhesive non-forming portion that is formed continuously along at least a part of the outer circumference of the adhesive layer forming portion, on the outer circumference side of the adhesive layer forming portion. Structure (b): The substrate has through-holes with an average pore diameter of 1000 μm or less.

Description

[Technical Field]

[0001] The present invention relates to an adhesive sheet that effectively suppresses peeling from the adherend during use and can be easily peeled off the adherend after use, and to a method for peeling off such an adhesive sheet. [Background technology]

[0002] Many industrial products utilize adhesives and sealants. While these adhesives and sealants must provide a secure bond during use, they are difficult to remove during dismantling after use, requiring significant effort for removal and hindering material recycling. In recent years, with growing environmental awareness, there has been a demand for adhesive materials that can be easily removed during dismantling.

[0003] In response to this, for example, Patent Documents 1 to 3 propose adhesive materials that can be peeled off or have their adhesive strength reduced by water. However, the technology in Patent Document 1 has the problem that it peels off if water is accidentally applied during use, and the technologies in Patent Documents 2 and 3 have the problem that strict conditions are required for peeling with water, and the peeling operation is complicated. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 5408956 [Patent Document 2] Japanese Patent Application Publication No. 9-114382 [Patent Document 3] Japanese Patent Application Publication No. 5-163470 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present invention aims to provide an adhesive sheet that effectively suppresses peeling from the adherend during use, while being easily removable from the adherend after use. [Means for solving the problem]

[0006] In order to achieve the above objective, the inventors of the present invention conducted studies and found that, in an adhesive sheet comprising a base material and an adhesive layer, by using a base material made of a non-permeable material as the base material, and an adhesive layer made of a water-soluble or water-swellable material, and by having an adhesive layer with a thickness of a predetermined value or less, and having a non-adhesive layer portion continuously formed on the adhesive layer forming surface of the base material, on the outer periphery of the adhesive layer forming portion, along at least a part of the outer periphery of the adhesive layer forming portion, or by having through holes in the base material with an average pore diameter of a predetermined value or less, it is possible to effectively suppress peeling from the adherend during use, while being able to easily peel off the adherend after use, and thus completed the present invention.

[0007] In other words, the present invention provides the following adhesive sheet and method for peeling off the adhesive sheet. [1] An adhesive sheet comprising a base material and an adhesive layer, The aforementioned substrate is made of a non-permeable material. The adhesive layer is composed of a water-soluble or water-swellable material. An adhesive sheet having the following structure (a) and / or the following structure (b). Structure (a): The thickness of the adhesive layer is 1000 μm or less, and the adhesive layer forming surface of the substrate has an adhesive non-forming portion that is formed continuously along at least a part of the outer circumference of the adhesive layer forming portion, on the outer circumference side of the adhesive layer forming portion. Structure (b): The substrate has through-holes with an average pore diameter of 1000 μm or less. [2] The adhesive sheet according to [1], wherein the width of the portion where the adhesive layer is not formed is 0.5 mm or more. [3] The adhesive sheet according to [1] or [2], wherein the portion without an adhesive layer is formed to cover the periphery of the portion with an adhesive layer. [4] The substrate is an adhesive sheet according to any one of [1] to [3] which is permeable to surfactant water. [5] The substrate is an adhesive sheet according to any one of [1] to [4] which is permeable to water-soluble organic solvents. [6] An adhesive sheet as described in any of [1] to [5], which is a label, craft tape, medical tape, or dressing material. [7] An adhesive sheet according to any one of [1] to [6], wherein a water-impermeable film is disposed on the surface of the substrate opposite to the surface on which the adhesive layer is formed. [8] The adhesive sheet according to [7], wherein the non-permeable film is integrated with the substrate. [9] The adhesive sheet according to [7] or [8], wherein the non-permeable film has a larger area than the substrate and is arranged to cover the substrate.

[10] An adhesive sheet as described in any of [1] to [9], used for bonding to an adherend having a contact angle of 60° or more. A method for peeling off an adhesive sheet from an object, as described in any of

[11] [1] to

[10] , A method for peeling off an adhesive sheet, comprising the step of peeling the adhesive sheet from an object by bringing the adhesive sheet into contact with a peeling fluid.

[12] The method for peeling an adhesive sheet according to

[11] , wherein the peeling fluid is surfactant water.

[13] The method for peeling an adhesive sheet according to

[11] or

[12] , wherein the peeling fluid is a water-soluble organic solvent. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an adhesive sheet that effectively suppresses peeling from the adherend during use, while being easily peelable from the adherend after use. Furthermore, according to the present invention, it is also possible to provide a method for easily peeling off an adhesive sheet from an adherend. [Brief explanation of the drawing]

[0009] [Figure 1] Figures 1(A) and 1(B) show an adhesive sheet according to one embodiment of the first aspect of the present invention, and Figure 1(C) shows the adhesive sheet according to one embodiment of the first aspect of the present invention attached to an object. [Figure 2] Figures 2(A) to 2(C) show an adhesive sheet according to another embodiment of the first aspect of the present invention. [Figure 3] Figure 3(A) shows an adhesive sheet according to one embodiment of the second aspect of the present invention; Figure 3(B) shows the adhesive sheet according to one embodiment of the second aspect of the present invention attached to an object; and Figures 3(C) and 3(D) show an adhesive sheet according to another embodiment of the second aspect of the present invention. [Modes for carrying out the invention]

[0010] The adhesive sheet of the present invention An adhesive sheet comprising a base material and an adhesive layer, The aforementioned substrate is made of a non-permeable material. The adhesive layer is composed of a water-soluble or water-swellable material. It has the following structure (a) and / or the following structure (b). Structure (a): The thickness of the adhesive layer is 1000 μm or less, and the adhesive layer forming surface of the substrate has an adhesive non-forming portion that is formed continuously along at least a part of the outer circumference of the adhesive layer forming portion, on the outer circumference side of the adhesive layer forming portion. Structure (b): The substrate has through-holes with an average pore diameter of 1000 μm or less.

[0011] <Adhesive sheet for the first side> First, the embodiment of the adhesive sheet of the present invention having structure (a) is defined as an adhesive sheet relating to the first side surface, and such an adhesive sheet relating to the first side surface will be described below.

[0012] An adhesive sheet according to the first aspect of the present invention is an adhesive sheet comprising a base material and an adhesive layer, The aforementioned substrate is made of a non-permeable material. The adhesive layer is composed of a water-soluble or water-swellable material. It has the following structure (a). Structure (a): The thickness of the adhesive layer is 1000 μm or less, and the adhesive layer forming surface of the substrate has an adhesive non-forming portion that is formed continuously along at least a part of the outer circumference of the adhesive layer forming portion, on the outer circumference side of the adhesive layer forming portion.

[0013] Figure 1(A) is a side view of an adhesive sheet according to one embodiment of the first side of the present invention, and Figure 1(B) is a plan view of the adhesive sheet according to one embodiment of the first side of the present invention as seen from the adhesive layer forming surface side. In the following description, the embodiments shown in Figures 1(A) and 1(B) will be used as examples, but the present invention is not limited in any way to these embodiments.

[0014] As shown in Figures 1(A) and 1(B), an adhesive sheet according to one embodiment is constructed by forming an adhesive layer 20 on a base material 10, and has an adhesive non-formed portion 30 that is continuously formed along at least a part of the outer circumference of the portion where the adhesive layer 20 is formed, on the adhesive layer 20 forming surface of the base material 10, on the outer circumference side of the portion where the adhesive layer 20 is formed. As shown in Figure 1(B), in the adhesive sheet according to one embodiment, the adhesive layer 20 is formed in the central part, and the adhesive non-formed portion 30 is formed so as to cover the periphery of the adhesive layer 20.

[0015] In the present invention, an adhesive sheet refers to a material that is adhesive, and being adhesive means that adhesion can be achieved by light pressure, and that even after being peeled off, it can be re-adhered by the same light pressure. Furthermore, an adhesive sheet according to one embodiment is water-peelable, and when attached to a smooth glass plate as an adherend and completely submerged in water at 25°C, more than half of the initial adhesive area will be peeled off between the substrate and the adhesive layer and / or between the adhesive layer and the adherend within one hour under stirring.

[0016] In one embodiment of the adhesive sheet, the base material 10 is made of a non-permeable material, and the adhesive layer 20 is made of a water-soluble or water-swellable material.

[0017] Many industrial products utilize adhesives and sealants. While these adhesives and sealants must provide a secure bond during use, they are difficult to remove during dismantling after use, requiring significant effort for dismantling and hindering material recycling. In recent years, with growing environmental awareness, there has been a demand for adhesives and sealants that can be easily removed during dismantling, and adhesive sheets like the one in this invention are also required to be easily removable during dismantling.

[0018] In contrast, according to one embodiment of the adhesive sheet, the adhesive layer 20 is composed of a water-soluble or water-swellable material, so that it achieves excellent bonding properties while being easily peelable after use. More specifically, it can be peeled off by reducing the bonding strength, for example, by immersion in an aqueous medium such as water, thereby facilitating peeling.

[0019] On the other hand, the fact that the adhesive can be peeled off with water or other aqueous media raises concerns that unintended peeling may occur if the adhesive is unintentionally exposed to water during use. In response to this, for example, the aforementioned Patent Documents 2 and 3 propose technologies in which the adhesive layer is made of a material that can be peeled off using special peeling liquids or peeling conditions. Specifically, technologies have been proposed that enable peeling using hot water, alkaline water, hydrophobic organic solvents, high temperatures, oxidizing agents, microwaves, or voltage application. However, these methods have problems such as requiring extra energy, placing a burden on the environment, and requiring extra effort. Therefore, it is desirable to enable peeling using water or aqueous media at room temperature or below, but in such cases, it is necessary to prevent peeling due to unintended exposure to water during use.

[0020] In contrast, according to one embodiment of the adhesive sheet, the base material 10 is made of a non-permeable material, the adhesive layer 20 is made of a water-soluble or water-swellable material with a thickness of a predetermined thickness or less, and the surface of the adhesive layer 20 of the base material 10 has an adhesive-free portion 30 that is continuously formed along at least a part of the outer circumference of the portion where the adhesive layer 20 is formed, on the outer circumference of the portion where the adhesive layer 20 is formed, thereby suppressing peeling due to unintended exposure to water during use.

[0021] Here, Figure 1(C) shows an adhesive sheet according to one embodiment attached to an adherend 50. According to the adhesive sheet according to one embodiment, the adhesive force of the adhesive layer 20 allows the base material 10 to be attached to the adherend 50 via the adhesive layer 20. As shown in Figure 1(C), according to the adhesive sheet according to one embodiment, even if water penetrates from the side, the penetration of the water is suppressed in the gap between the base material 10 and the adherend 50 due to the surface tension of the water, thereby making it difficult for the water to penetrate into the adhesive layer 20. As a result, penetration into the interior of the adhesive layer 20 is suppressed, thereby preventing peeling due to unintended water exposure during use. Furthermore, since the base material 10 of the adhesive sheet according to one embodiment is made of a non-permeable material, the penetration of water from the surface of the base material 10 is also effectively suppressed.

[0022] Furthermore, when peeling the adhesive sheet according to one embodiment from the adherend 50, the water-soluble or water-swellable material constituting the adhesive layer 20 can be dissolved and / or swollen by bringing the adhesive sheet into contact with a peeling fluid, thereby allowing for easy peeling. As the peeling fluid, a fluid that does not exhibit surface tension or a fluid with reduced surface tension can be used, and specific examples of peeling fluids include surfactant water and water-soluble organic solvents.

[0023] As the surfactant water, a solution or dispersion obtained by dissolving or dispersing a surfactant in water can be used. The surfactant can be anionic, cationic, or neutral, as long as it can reduce the surface tension of water. For example, known surfactants such as polyoxyethylene alkyl ethers such as hexaethylene glycol monododecyl ether can be used. Furthermore, if the adhesive layer 20 contains an ionic material, a nonionic surfactant is preferably used as the surfactant. The surfactant content in the surfactant water is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, even more preferably 0.5% by weight or more, and particularly preferably 1% by weight or more. The upper limit is not particularly limited, but is preferably 10% by weight or less.

[0024] As the water-soluble organic solvent, solvents with low toxicity to living organisms, low boiling points, and no unpleasant odors are preferred. Preferred water-soluble organic solvents include methanol, ethanol, propanol, ethylene glycol, propylene glycol, glycerin, acetone, methyl ethyl ketone, methyl acetate, and ethyl acetate. Among these, ethanol, propylene glycol, glycerin, and acetone are preferred from the viewpoint of low toxicity to living organisms and low odor, with ethanol being particularly preferred.

[0025] Water-soluble organic solvents may be used as a stripping fluid as is, mixed with several other types, or mixed with water to form an aqueous solution. From a safety standpoint, it is preferable to use an aqueous solution. Furthermore, from the standpoint of mixing with water, it is preferable to use a water-soluble organic solvent that is miscible with water. If the miscibility with water is insufficient, a surfactant may be used to improve the miscibility. When a water-soluble organic solvent is used as an aqueous solution, the content of the water-soluble organic solvent in the aqueous solution is preferably 35% by weight or more, more preferably 45% by weight or more, even more preferably 60% by weight or more, and particularly preferably 75% by weight or more. The upper limit is not particularly limited, but is preferably 90% by weight or less.

[0026] The method for bringing the adhesive sheet into contact with the release fluid is not particularly limited. For example, the adhesive sheet attached to the adherend 50 may be immersed in the release fluid; the release fluid may be applied to the adhesive sheet using a shower or other flowing liquid, or by spraying; or a small amount of release fluid may be soaked into the adhesive sheet. Alternatively, steam or highly humid air may be used. The relative humidity of the highly humid air is preferably 95% RH or higher, and more preferably 98% RH or higher. Furthermore, since release using the release fluid can be performed well even at room temperature, the temperature of the release fluid should be room temperature or 10-30°C when bringing the adhesive sheet into contact with the release fluid.

[0027] In the present invention, an adhesive sheet refers to a material that is adhesive, and being adhesive means that adhesion can be achieved by light pressure, and that even after being peeled off, it can be re-adhered by the same light pressure. Furthermore, an adhesive sheet according to one embodiment is water-peelable, and when attached to a smooth glass plate as an adherend and completely submerged in water at 25°C, more than half of the initial adhesive area will be peeled off between the substrate and the adhesive layer and / or between the adhesive layer and the adherend within one hour under stirring.

[0028] In an adhesive sheet according to one embodiment, the thickness t of the adhesive layer 20 is not particularly limited, and may be 1000 μm or less. However, from the viewpoint of further enhancing the water penetration suppression effect while maintaining sufficient adhesive strength, it is preferably 1 to 1000 μm, more preferably 8 to 800 μm, and even more preferably 12 to 600 μm. If the adhesive layer does not have a uniform thickness, it refers to the thickness at the outermost edge of the adhesive layer.

[0029] Furthermore, in the adhesive sheet according to one embodiment, the width w1 of the non-adhesive layer portion 30 is not particularly limited, but from the viewpoint of further enhancing the water penetration suppression effect while maintaining sufficient adhesive strength, it is preferably 0.5 to 10 mm, more preferably 1 to 5 mm, and even more preferably 1.5 to 4 mm.

[0030] Furthermore, according to the embodiments shown in Figures 1(A) and 1(B), since the non-adhesive layer portion 30 is formed to cover the periphery of the adhesive layer 20, the water penetration suppression effect can be more appropriately enhanced.

[0031] Furthermore, in the present invention, as shown in Figure 2(A), the inner adhesive layer 20a is located in the center, an adhesive-free portion 30 is formed around it, and an outer adhesive layer 20b is formed around that portion. In the embodiment shown in Figure 2(A), water can penetrate the outer adhesive layer 20b, while the outer adhesive layer 20b and the adhesive-free portion 30 are formed, which effectively suppresses the penetration of water into the inner adhesive layer 20a. Therefore, even if the product is unintentionally exposed to water during use, the inner adhesive layer 20a can maintain sufficient adhesive strength.

[0032] In the embodiment shown in Figure 2(A), the width w2 of the outer peripheral adhesive layer 20b is not particularly limited, but from the viewpoint of achieving sufficient adhesive strength while further enhancing the water penetration suppression effect, it is preferably 0.2 to 5 mm, more preferably 0.3 to 3 mm, and even more preferably 0.4 to 1.5 mm.

[0033] Furthermore, in the embodiment shown in Figure 2(A), the width w1 of the non-adhesive layer portion 30 is not particularly limited, but from the viewpoint of further enhancing the water penetration suppression effect while maintaining sufficient adhesive strength, it is preferably 0.2 to 3 mm, more preferably 0.3 to 2 mm, and even more preferably 0.4 to 1.5 mm.

[0034] Furthermore, as shown in Figure 2(B), multiple adhesive layers 20 may be arranged in a dot pattern, and the multiple adhesive layers 20 may be surrounded by non-adhesive layer portions 30. Also, as shown in Figure 2(C), if the adhesive sheet is a long tape or sheet, the non-adhesive layer portions 30 may be formed only at the ends along the longitudinal direction. That is, if the adhesive sheet is a long tape or sheet, the impact of water intrusion at the ends in the short direction is considered to be small, so the configuration shown in Figure 2(C) can be used. Of course, in the configuration shown in Figure 2(C), non-adhesive layer portions 30 may also be formed at the ends in the short direction, and the non-adhesive layer portions 30 may be formed in a way that surrounds the adhesive layers 20.

[0035] The base material 10 is not particularly limited and can be made of an impermeable material, but in consideration of the surface tension of water, it is preferable that the surface tension be 40 dyne / cm or less, more preferably 35 dyne / cm or less, and even more preferably 30 dyne / cm or less. Suitable materials for such a base material include, for example, polyvinyl chloride (39 dyne / cm), polystyrene (36 dyne / cm), polyethylene (31 dyne / cm), polypropylene (29 dyne / cm), and PTFE (18 dyne / cm). Furthermore, in consideration of the surface tension of water, the base material 10 is preferable that the water contact angle at 25°C be 60° or more, more preferably 85° or more, and even more preferably 90° or more. Suitable materials for such a base material include, for example, PET (65°), polyethylene (88°), polypropylene (94°), and PTFE (108°). The base material may be made of a single material or may consist of multiple layers. In that case, it is preferable that the surface tension or water contact angle of at least one layer is within the above range. To determine whether a material is impermeable to water, for example, after placing filter paper at the bottom of the base material 10, drop one drop of water (approximately 25 mg) onto the base material 10, and after 1 minute, measure the weight of the filter paper. If the weight increase is less than 0.1 mg, it can be determined that the material is impermeable to water. On the other hand, if the weight increase is 5 mg or more in this case, it is determined that the material is permeable to water.

[0036] Suitable materials for the base material 10 include, for example, polyolefins such as polyethylene, polypropylene, and cycloolefin polymers, fluororesins, and silicone resins, as these materials have a surface tension within the above range, and various other additives may be blended with them. The base material 10 may also be metal, glass, ceramics, paper, wood, polystyrene, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, urethane, rubber, and composite materials thereof, and various other additives may be blended with them. These materials may have their water contact angle within the above range through surface treatment. Examples of such surface treatments include water-repellent treatments and treatments that produce a lotus effect.

[0037] The base material 10 may be in the form of a film, sheet, or plate, or it may have a three-dimensional shape such as an uneven surface, or it may be a woven fabric, nonwoven fabric, mesh, sponge, etc. When the base material 10 is in the form of a film, sheet, or plate, its thickness is not particularly limited, but is preferably 0.001 to 10 mm, more preferably 0.005 to 5 mm, and more preferably 0.01 to 1 mm.

[0038] Furthermore, from the viewpoint of more appropriately enjoying the water penetration suppression effect, it is preferable that the adherend 50 to which the adhesive sheet according to one embodiment is applied is made of the same material as the material constituting the base material 10. In particular, the adherend 50 is preferably one to which the water contact angle is 60° or more, more preferably 85° or more, and even more preferably 90° or more, considering the balance with the surface tension of water.

[0039] The adherend 50 is not particularly limited and includes metals, glass, ceramics, polymer materials, paper, wood, and composite materials thereof. Examples of polymer materials include polyethylene, polypropylene, polyolefins such as cycloolefin polymers, fluororesins, silicone resins, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, urethane, and rubber. The adherend 50 may be in the form of a film, sheet, or plate, or it may have a three-dimensional shape such as an uneven surface, or it may be a woven fabric, nonwoven fabric, mesh, or sponge.

[0040] The adhesive layer 20 is composed of a water-soluble or water-swellable material. Here, water-soluble means that when the adhesive material constituting the adhesive layer 20 is completely immersed in water (25°C) at a volume of 1000 times or more the volume of the adhesive material and stirred for 1 hour, the portion that retains its original shape is 80% or less of the initial volume even for the largest piece, or at least 20% of the initial weight is lost even for the largest piece that retains its original shape. Water-swellable means that when the adhesive material constituting the adhesive layer 20 is completely immersed in water (25°C) at a volume of 1000 times or more the volume of the adhesive material and left to stand for 1 hour, its volume is 1.5 times or more of the original volume.

[0041] The material constituting the adhesive layer 20 may be any water-soluble or water-swellable material, and is not particularly limited, but a water-soluble or water-swellable polymer is preferred. Furthermore, from the viewpoint of further enhancing the adhesiveness, it is preferable that the water-soluble or water-swellable polymer in the adhesive layer 20 retains moisture (i.e., it is preferable that the adhesive layer 20 contains a water-soluble or water-swellable polymer and water), and preferably contains a water-soluble or water-swellable polymer in a proportion of 55% to 95% by weight and water in a proportion of 5% to 45% by weight.

[0042] The content of water-soluble or water-swellable polymers in the adhesive layer 20 is preferably 55% by weight or more and 95% by weight or less, more preferably 60% by weight or more and 90% by weight or less, and even more preferably 65% ​​by weight or more and 85% by weight or less. The content of water in the adhesive layer 20 is preferably 5% by weight or more and 45% by weight or less, more preferably 10% by weight or more and 40% by weight or less, and even more preferably 15% by weight or more and 35% by weight or less. The content of water-soluble or water-swellable polymers and water may be within the above ranges in the usage environment, but it is desirable that they be within the above ranges at least in an environment of 25°C and 50%RH. It is desirable to measure the content of water-soluble or water-swellable polymers and water after leaving them for a long period of time (for example, about one week) to allow the condition to stabilize, taking into account their hygroscopic properties.

[0043] The water-soluble or water-swellable polymer may be either a synthetic polymer or a natural polymer, but from the viewpoint of further suppressing spoilage, synthetic polymers and polymers obtained by modifying natural polymers are preferred, and synthetic polymers are more preferred. As synthetic polymers, neutral polymers that do not contain salt structures in their structure, cation group-containing polymers, and anion group-containing polymers can be suitably used. Furthermore, as a cation group-containing polymer, it is preferable that it has an ammonium structure, as the ammonium structure has an antibacterial effect and can suppress the spoilage of the adhesive layer 20. In particular, when spoilage is likely to progress when polyhydric alcohols or substances containing sugars in their structural units are included, such spoilage can be effectively suppressed.

[0044] The cation group-containing polymer can be any polymer having a cation group in its polymer chain, and is not particularly limited. It may be a polymer having a cation group in its main chain, or a polymer having a cation group in its side chain, or even a polymer having cation groups in both its main chain and side chain.

[0045] The cationic groups contained in the cationic group-containing polymer are not particularly limited, but include cationic groups containing a nitrogen atom, phosphorus atom, sulfur atom, or oxygen atom as the central atom. Among these, cationic groups containing a nitrogen atom as the central atom are preferred from the viewpoint of being able to further enhance antibacterial properties. Preferred cationic structures are the following structures (I) or (II), specifically including ammonium, iminium, imidazolium, pyridinium, etc. Furthermore, it is preferable that the substituents of the cationic group consist of two or more groups with two or more atoms bonded to them. In addition, the cationic group-containing polymer may also have anionic groups in the polymer chain in addition to the cationic group, for example, it may have a betaine structure. [ka]

[0046] A cation-containing polymer preferably has polar atoms other than cations in addition to the cation group. The presence of such polar atoms neutralizes the positive charge of the cation, improving the anion's dissociability, thereby enhancing bonding properties, transparency, and flexibility. Examples of such polar atoms include oxygen atoms and nitrogen atoms. Examples of groups having such polar atoms include, but are not limited to, ether bonds, ketone groups, carboxyl groups, hydroxyl groups, amine groups, amide bonds, urethane bonds, and urea bonds. In addition, the imidazolium structure has another nitrogen atom in the imidazolium ring in addition to the cationic nitrogen atom, and such another nitrogen atom can also be considered a polar atom other than a cation.

[0047] Examples of cationic group-containing polymers include addition polymers of vinyl compounds, polyethers, polyethyleneimines, and polyoxazolines, which have cationic groups in their side chains, and ionenes, epichlorohydrin-amine condensates, and polyamide polyamine epichlorohydrins, which have cationic groups in their main chains. These may have any other substituents, or some hydrogen atoms may be substituted with halogen atoms such as fluorine. Furthermore, cationic group-containing polymers may be copolymerized with structural units derived from monomers that do not have cationic groups, in addition to structural units that have cationic groups, and the pH may be adjusted by introducing structural units derived from acidic monomers or structural units derived from basic monomers.

[0048] A cation group-containing polymer has a cation group in its polymer chain. The counter anions for such cation groups are not particularly limited, but include, for example, imides such as fluorosulfonylimide, bistrifluoromethylsulfonylimide, and bispentafluoroethylsulfonylimide; halogens such as chlorides and bromides; and, but are not particularly limited, tetrafluoroboric acid, hexafluorophosphate, dicyanoamide, tetracyanoborate, carbonic acid, alkyl carbonate, triflate, perchloric acid, nitric acid, sulfuric acid, alkyl sulfuric acid, sulfonic acid, phosphoric acid, and alkyl phosphoric acid.

[0049] The cation group-containing polymer is not particularly limited, but an example of a polymer having cation groups in its side chains is a cation group-containing polyether (A) containing repeating units represented by the following general formula (1).

[0050] [ka] (In the above general formula (1), A + represents a nitrogen-containing cation group. Also, in the above general formula (1), X - (This represents an anion.)

[0051] A + Examples of nitrogen-containing cationic groups represented by this formula include amino groups, nitrogen-containing cationic aromatic groups, and nitrogen-containing cationic aliphatic groups.

[0052] A + As a nitrogen-containing cationic aromatic group, a group containing a cationic nitrogen-containing aromatic heterocycle is preferred. The nitrogen-containing aromatic heterocycle in the cationic nitrogen-containing aromatic heterocycle in the group only needs to have a nitrogen atom in the ring and be aromatic, and may also have heteroatoms other than nitrogen, such as oxygen atoms and sulfur atoms, and some of the atoms constituting the heterocycle may be substituted by substituents. It may also take the form of a polycyclic structure in which two or more rings are fused. Examples of nitrogen-containing aromatic heterocycle structures include five-membered heterocycles such as imidazole rings, pyrrole rings, thiazole rings, oxazole rings, pyrazole rings, and isoxazole rings; six-membered heterocycles such as pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, and triazine rings; and condensed heterocycles such as quinoline rings, isoquinoline rings, quinoxaline rings, quinazoline rings, sinnoline rings, purine rings, indole rings, isoindole rings, benzimidazole rings, benzoxazole rings, and benzoisoxazole rings. Among these, five-membered and six-membered heterocycles are preferred, and imidazole rings are more preferred.

[0053] The substituents on the nitrogen-containing aromatic heterocycle are not particularly limited, but examples include alkyl groups; cycloalkyl groups; alkenyl groups such as vinyl groups; aryl groups such as phenyl groups; arylalkyl groups; alkylaryl groups; alkoxyl groups; alkoxyalkyl groups; aryloxy groups; alkanol groups; hydroxyl groups; carbonyl groups; alkoxycarbonyl groups; amino groups; imino groups; nitrile groups; alkylsilyl groups; halogen atoms; and the like. The number of carbon atoms in these substituents is preferably 0 to 12, more preferably 1 to 8, and even more preferably 1 to 6.

[0054] A +The nitrogen-containing cationic aliphatic group as such may be linear or branched and may also have a non-aromatic ring structure.

[0055] A + Specific examples of the nitrogen-containing cationic group represented by include an ammonium group; a monosubstituted ammonium group containing a cationic nitrogen atom such as a methylammonium group, a butylammonium group, a cyclohexylammonium group, anilinium group, a benzylammonium group, an ethanolammonium group; a disubstituted ammonium group containing a cationic nitrogen atom such as a dimethylammonium group, a diethylammonium group, a dibutylammonium group, a nonylphenylammonium group; a trisubstituted ammonium group containing a cationic nitrogen atom such as a trimethylammonium group, a triethylammonium group, an n-butyldimethylammonium group, a stearyldimethylammonium group, a tributylammonium group, a trivinylammonium group, a triethanolammonium group, an N,N-dimethylethanolammonium group, a tri(2-ethoxyethyl)ammonium group; a heterocyclic group containing a cationic nitrogen atom such as a piperidinium group, a 1-methylpyrrolidinium group, a 1-butylpyrrolidinium group, an imidazolium group, a 1-methylimidazolium group, a 1-ethylimidazolium group, a 1-butyl-imidazolium group, a benzimidazolium group, a pyrrolium group, a 1-methylpyrrolium group, an oxazolium group, a benzoxazolium group, a pyrazolium group, an isoxazolium group, a pyridinium group, a 2,6-dimethylpyridinium group, a pyrazinium group, a pyrimidinium group, a pyridazinium group, a triazinium group, an N,N-dimethylanilinium group, a quinolinium group, an isoquinolinium group, an indolinium group, a quinoxalinium group, an isoquinoxalinium group. Among these, a trisubstituted ammonium group containing a cationic nitrogen atom and a heterocyclic group containing a cationic nitrogen atom are preferred.

[0056] In the above general formula (1), X - The anion represented by is the counter anion of the nitrogen-containing cationic group represented by A + X -For example, as a monovalent anion, F - Cl - , Br - , I - Halide ions such as (FSO2)2N - (CF3SO2)2N - , (CF3CF2SO2)2N - Sulfonylimidide ions such as CH3COO - C3H7COO - CF3COO - PhCOO - (Ph indicates the phenyl group.) Carboxylate ions such as CH3SO3 - CF3SO3 - Sulfonoxide ions such as OH - BF4 - PF6 - ClO4 - , B(CN)4 - SCN - , (NC)2N - These are some examples. - The anion may be a polyvalent anion, or it may be a polyanion having two or more monovalent anionic groups in its molecule. For example, a polyvalent anion is the sulfate ion (SO4 2- ) and carbonate ions (CO3 2- Examples include: - O3SCF2CF2CF2SO3 - , - O3SCF2CF2SO3 - CF3SO2N - SO2CF2CF2OCF2CF2OCF2CF2SO2N - Examples include SO2CF3. Among them, chloride ions, bromide ions, sulfonylimide ions, carboxylate ions, and BF4 are particularly noteworthy. - Preferably, sulfonylimidide ions, chloride ions, CH3COO - BF4 - This is preferable.

[0057] In the cation group-containing polyether (A), the units represented by the general formula (1) are independent of each other, and there may be two or more units represented by the general formula (1) in the cation group-containing polyether (A). For example, in the entire repeating unit represented by the general formula (1) in the cation group-containing polyether (A), A + All of the nitrogen-containing cationic groups represented by may be of the same type, or they may be a mixture of different types of nitrogen-containing cationic groups. Furthermore, in the entire repeating unit represented by general formula (1) in the cationic group-containing polyether (A), X - All of the anions represented may be of the same type, or they may be a mixture of different types of anions.

[0058] Examples of repeating units represented by the above general formula (1) include the repeating unit represented by the following general formula (2). The repeating unit represented by the following general formula (2) is an oxirane unit containing an imidazolium structure. [ka] (In the above general formula (2), R 1 ~R 4 Each of these independently represents a hydrogen atom or a substituent, R 2 and R 3 They may be joined to each other. Also, in general formula (2), X - (This represents an anion.)

[0059] In the above general formula (2), R 1 ~R 4 Each of these independently represents a hydrogen atom or a substituent. Examples of substituents include those similar to those described above for nitrogen-containing aromatic heterocycles. 1 ~R 4 The substituents may be linear or branched, and may also have a ring structure. 1 ~R 4 The substituent is preferably linear in shape.

[0060] In the above general formula (2), R 1 R may be a hydrogen atom or a substituent, and is not particularly limited, but is preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrocarbon group, even more preferably an alkyl group or an alkenyl group, particularly preferably an alkyl group or a vinyl group, and most preferably an alkyl group. 1 The number of carbon atoms is preferably 0 to 12, more preferably 0 to 8, even more preferably 1 to 6, even more preferably 1 to 4, particularly preferably 1 to 3, and most preferably 1 to 2.

[0061] In the above general formula (2), R 2 ~R 4 Each of these may independently be a hydrogen atom or a substituent, and is not particularly limited, but each may independently be a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group or a vinyl group, even more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom. 2 ~R 4 The number of carbon atoms is preferably 0 to 8, more preferably 0 to 6, even more preferably 0 to 4, even more preferably 0 to 3, particularly preferably 0 to 2, and most preferably 0 to 1.

[0062] In the above general formula (2), R 2 ~R 4 It is preferable that 1 to 3 of them represent hydrogen atoms, and more preferably that 2 to 3 of them represent hydrogen atoms. Also, R 2 ~R 4 It is preferable that 0 to 2 of these represent substituents such as hydrocarbon groups, and it is more preferable that 0 to 1 of them represent substituents such as hydrocarbon groups.

[0063] X in the above general formula (2) - The anion represented by is X in general formula (1). - Examples of anions similar to those represented by can be cited, and preferred embodiments are also similar.

[0064] The repeating unit represented by the above general formula (2) preferably contains an imidazolium group, a 1-methylimidasolium group, a 1-butylimidasolium group, a 1-hexylimidasolium group, or a 1-vinylimidasolium group, and more preferably contains a 1-methylimidasolium group.

[0065] The cationic group-containing polyether (A) may contain repeating units other than the repeating unit represented by the general formula (1) above. The repeating units other than the repeating unit represented by the general formula (1) above are not particularly limited, but may be any units derived from monomers copolymerizable with the monomer that gives the repeating unit represented by the general formula (1) above. Examples include alkylene oxide monomer units such as ethylene oxide units, propylene oxide units, 1,2-butylene oxide units, and 1,2-octylene oxide units; aromatic oxirane monomer units such as styrene oxide units, epihalohydrin monomer units such as epichlorohydrin units, epibromohydrin units, and epiiodohydrin units; alkenyl group-containing oxirane monomer units such as allyl glycidyl ether units; aromatic ether group-containing oxirane monomer units such as phenyl glycidyl ether units; and (meth)acryloyl group-containing oxirane monomer units such as glycidyl acrylate units and glycidyl methacrylate units. Among these, alkylene oxide monomer units, epihalohydrin monomer units, and (meth)acryloyl group-containing oxirane monomer units are preferred, and ethylene oxide units, propylene oxide units, epichlorohydrin units, and glycidyl methacrylate units are more preferred. The cationic group-containing polyether (A) may contain one repeating unit other than the repeating unit represented by the general formula (1) above, or it may contain two or more repeating units.

[0066] The cation group-containing polyether (A) may contain two or more repeating units, in which case the distribution pattern of these multiple repeating units is not particularly limited, but it is preferable that it has a random distribution.

[0067] The chain structure of the cation group-containing polyether (A) is not particularly limited and may be linear, or it may have a branched chain structure such as grafted or radial.

[0068] The terminal group of the cationic group-containing polyether (A) is not particularly limited and can be any monovalent group. Specific examples of terminal groups include hydrogen atoms, halogen groups, alkyl groups, haloalkyl groups, hydroxyl groups, azide groups, etc. Furthermore, the terminal group may be a nitrogen-containing cationic group (A) possessed by the repeating unit represented by general formula (1). + ) and anion (X - ) may be a base consisting of the same thing.

[0069] The content of the repeating units represented by the above general formula (1) in the cationic group-containing polyether (A) is not particularly limited, but is preferably 1 to 100,000 on average per molecule, more preferably 3 to 50,000, even more preferably 10 to 30,000, and particularly preferably 30 to 10,000.

[0070] The weight-average molecular weight (Mw) of the cation group-containing polyether (A) is not particularly limited, but is preferably 1,000 to 10,000,000, more preferably 2,000 to 7,000,000, even more preferably 4,000 to 5,000,000, and particularly preferably 10,000 to 200,000.

[0071] The molecular weight distribution (Mw / Mn) of the cation group-containing polyether (A) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 2.0, and even more preferably 1.0 to 1.5.

[0072] The weight-average molecular weight and molecular weight distribution of the cation-containing polyether (A) can be measured as polystyrene equivalent values ​​by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent. The molecular weight distribution of the cation-containing polyether (A) can be treated as unchanged from the molecular weight distribution of the base polymer (polyether without cation groups) before the introduction of the cation groups.

[0073] The proportion of the repeating units represented by the above general formula (1) in the cation group-containing polyether (A) is not particularly limited, but is preferably 5 to 100 mol%, and more preferably 10 to 100 mol%, relative to the total repeating units of the cation group-containing polyether (A).

[0074] The method for synthesizing the cationic group-containing polyether (A) is not particularly limited, and any synthesis method can be used as long as it yields the desired polyether compound. For example, the method described in International Publication No. 2023 / 042748 can be used.

[0075] Furthermore, as an example of a cationic group-containing polymer, a polymer (B) containing a side-chain ammonium group that includes a repeating unit represented by the following general formula (3) is also an example of a polymer having cationic groups in its side chains. [ka] (In the above general formula (3), Z is a divalent linking group, and R 5 ~R 7 Each of these independently represents a hydrogen atom or a substituent, R 5 ~R 7 They may be joined to each other. Also, in general formula (3), X - (This represents an anion.)

[0076] Z is a divalent linking group and is preferably an alkylene group which may contain a heteroatom. Examples of heteroatoms include oxygen, nitrogen, and sulfur atoms, and examples of groups containing heteroatoms include amide groups (-CO-NH-), ester groups (-COO-), ether groups (-O-), and thioether groups (-S-). Among these, Z is preferably an alkylene group containing an amide group, such as -CO-NH-(CH2) p It is more preferable that the base be represented by -(p is an integer from 1 to 5, preferably n=3).

[0077] R 5 ~R 7 Each of these may independently be a hydrogen atom or a substituent, and is not particularly limited, but each may independently be a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group or a vinyl group, even more preferably a hydrogen atom or an alkyl group, and particularly preferably an alkyl group. 5 ~R 7 The number of carbon atoms in each group is preferably 1 to 8, more preferably 1 to 3, even more preferably 1 to 4, and particularly preferably 1. In other words, it is preferably a methyl group.

[0078] In the above general formula (3), X - The anions represented by are not particularly limited, but include those similar to those in the general formula (1) above.

[0079] Furthermore, the side-chain ammonium group-containing polymer (B) may also contain repeating units other than the repeating unit represented by general formula (3). The repeating units other than the repeating unit represented by general formula (3) are not particularly limited, but may be any units derived from monomers copolymerizable with the monomer that gives the repeating unit represented by general formula (3). Examples include unsaturated carboxylic acids and their salts such as acrylic acid and methacrylic acid, unsaturated carboxylic acid esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, and methoxyethoxyethoxyethyl acrylate, acrylamide, substituent-containing acrylamide, styrene, vinylpyridine, vinylpyrrolidone, etc.

[0080] In the side-chain ammonium group-containing polymer (B), the units represented by the general formula (3) are independent of each other, and two or more units represented by the general formula (3) may be present in the side-chain ammonium group-containing polymer (B). When the side-chain ammonium group-containing polymer (B) contains two or more repeating units, the distribution pattern of these multiple repeating units is not particularly limited, but it is preferable that they have a random distribution.

[0081] Specific examples of side-chain ammonium group-containing polymers (B) include poly{[3-(methacryloylamino)propyl]trimethylammonium chloride}, poly[(3-acrylamidopropyl)trimethylammonium chloride], poly{[2-(methacryloyloxy)ethyl]trimethylammonium chloride}, poly{[2-(acryloyloxy)ethyl]trimethylammonium chloride}, poly[2-(dimethylamino)ethyl acrylate-benzyl quaternary chloride], and poly[2-dimethylaminoethyl methacrylate ethyl sulfate]. Examples include poly[vinylbenzyltrimethylammonium chloride], poly[N-(2-acryloyloxyethyl)-N-benzyl-N,N-dimethylammonium chloride], poly[2-methacryloyloxyethyl phosphorylcholine], and poly[2-(N-3-sulfopropyl-N,N-dimethylammonium)ethyl methacrylate], among which poly[(3-acrylamidopropyl)trimethylammonium chloride] and poly[2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt] are preferred. These may also be copolymerized with a crosslinkable monomer such as diallyldimethylammonium chloride to have crosslinkable groups. In this case, the content of the crosslinkable monomer units is preferably 0.001 to 5% by weight.

[0082] The weight-average molecular weight (Mw) of the side-chain ammonium group-containing polymer (B) is not particularly limited, but is preferably 1,000 to 10,000,000, more preferably 2,000 to 7,000,000, even more preferably 4,000 to 5,000,000, and particularly preferably 10,000 to 200,000. The weight-average molecular weight of the side-chain ammonium group-containing polymer (B) can be determined using GPC on a standard polyethylene oxide basis.

[0083] Furthermore, as a cationic group-containing polymer, a polymer (C) containing a side-chain cyclic ammonium group that includes a repeating unit represented by the following general formula (4-1) or the following general formula (4-2) is also an example of a polymer having a cationic group in its side chain. [ka] (In the above general formulas (4-1) and (4-2), R 8 ,R 9 Each of these independently represents a hydrogen atom or a substituent, R 8 ,R 9 They may be combined with each other. Also, in general formulas (4-1) and (4-2), X - (This represents an anion.)

[0084] R 8 ,R 9 Each of these may independently be a hydrogen atom or a substituent, and is not particularly limited, but each may independently be a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group or a vinyl group, even more preferably a hydrogen atom or an alkyl group, and particularly preferably an alkyl group. 8 ,R 9 The number of carbon atoms in each group is preferably 1 to 8, more preferably 1 to 3, even more preferably 1 to 4, and particularly preferably 1. In other words, it is preferably a methyl group.

[0085] In the above general formulas (4-1) and (4-2), X - The anions represented by are not particularly limited, but include those similar to those in the general formula (1) above.

[0086] Furthermore, the side-chain cyclic ammonium group-containing polymer (C) may also contain repeating units other than those represented by general formulas (4-1) and (4-2). The repeating units other than those represented by general formula (4) above are not particularly limited, as they may be units derived from monomers copolymerizable with the monomers that give the repeating units represented by general formulas (4-1) and (4-2). Examples of such monomers, from the viewpoint of having lone pairs of electrons, include N-vinylpyrrolidone, acrylamide, (meth)acrylic acid, (meth)acrylate salts, (meth)acrylates having ethylene oxide units, and substituted products thereof.

[0087] In the side-chain cyclic ammonium group-containing polymer (C), the units represented by the general formula (4) are independent of each other, and two or more units represented by the general formula (4) may be present in the side-chain cyclic ammonium group-containing polymer (C). When the side-chain cyclic ammonium group-containing polymer (C) contains two or more repeating units, the distribution pattern of these multiple repeating units is not particularly limited, but it is preferable that they have a random distribution.

[0088] Specific examples of the side-chain cyclic ammonium group-containing polymer (C) include poly(diallyldimethylammonium chloride). Copolymers of diallyldimethylammonium chloride and crosslinkable monomers such as diallyldimethylammonium chloride can also be suitably used. In this case, the content of the crosslinkable monomer units is preferably 0.1 to 5% by weight.

[0089] The weight average molecular weight (Mw) of the polymer (C) containing a side-chain cyclic ammonium group is not particularly limited, but is preferably from 1,000 to 10,000,000, more preferably from 2,000 to 7,000,000, even more preferably from 4,000 to 5,000,000, and particularly preferably from 10,000 to 2,000,000. The weight average molecular weight of the polymer (C) containing a side-chain cyclic ammonium group can be determined in terms of standard polyethylene oxide using GPC.

[0090] Furthermore, examples of the cationic group-containing polymer include a main-chain ammonium group-containing polymer (D) containing a repeating unit represented by the following general formula (5) as a polymer having a cationic group in the main chain of the polymer. [Chemical formula] (In the above general formula (5), R 10 , R 11 each independently represents a hydrogen atom or a substituent, and R 10 , R 11 may be bonded to each other. Also, in the general formula (5), X - represents an anion.)

[0091] R 10 , R 11 each may independently be a hydrogen atom or a substituent, and is not particularly limited, but each is preferably independently a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group or a vinyl group, even more preferably a hydrogen atom or an alkyl group, and particularly preferably an alkyl group. The number of carbon atoms of R 10 , R 11 is each independently preferably 1 to 8, more preferably 1 to 3, even more preferably 1 to 4, and particularly preferably 1. That is, it is preferably a methyl group.

[0092] In the above general formula (5), the anion represented by X - is not particularly limited, and examples thereof include the same as those in the above general formula (1).

[0093] The main-chain ammonium group-containing polymer (D) can be obtained by reacting a secondary amine with an epihalohydrin to form a repeating unit represented by general formula (5).

[0094] Secondary amines are compounds in which one nitrogen atom is bonded to two hydrocarbon groups and one hydrogen atom, as well as compounds having a nitrogen atom in a heterocyclic ring, where the nitrogen atom has one hydrogen atom. Examples of such secondary amines include aliphatic secondary amines, aromatic secondary amines, alicyclic secondary amines, heterocyclic secondary amines, and two or more of these may be used in combination.

[0095] Examples of aliphatic secondary amines include dimethylamine, diethylamine, diisopropylamine, dibutylamine, methylethylamine, methylpropylamine, methylbutylamine, methyloctylamine, methyllaurylamine, and dibenzylamine.

[0096] Examples of aromatic secondary amines include N-alkylanilines such as N-methylaniline, N-ethylaniline, N-propylaniline, N-butylaniline, N-pentylaniline, N-hexylaniline, N-octylaniline, N-decylaniline, N-laurylaniline, and N-benzylaniline; and N-methyltoluidine, N-ethyltoluidine, N-propyltoluidine, N-butyltoluidine, N-pentyltoluidine, N-hexyltoluidine, and N-octyltoluidine. Examples include N-alkyltoluidines such as idine, N-decyltoluidine, N-lauryltoluidine, and N-benzyltoluidine; and N-alkylnaphthylamines such as N-methylnaphthylamine, N-ethylnaphthylamine, N-propylnaphthylamine, N-butylnaphthylamine, N-pentylnaphthylamine, N-hexylnaphthylamine, N-octylnaphthylamine, N-decylnaphthylamine, N-laurylnaphthylamine, and N-benzylnaphthylamine.

[0097] Examples of alicyclic secondary amines include N-alkylcyclohexylamines such as N-methylcyclohexylamine, N-ethylcyclohexylamine, N-propylcyclohexylamine, N-butylcyclohexylamine, N-hexylcyclohexylamine, N-octylcyclohexylamine, N-decylcyclohexylamine, and N-laurylcyclohexylamine; N-alkylcyclooctylamines such as N-methylcyclooctylamine, N-ethylcyclooctylamine, N-propylcyclooctylamine, N-butylcyclooctylamine, N-hexylcyclooctylamine, N-octylcyclooctylamine, N-decylcyclooctylamine, and N-laurylcyclooctylamine; dicyclohexylamines and dicycloalkylamines such as dicyclooctylamine; and the like.

[0098] Examples of heterocyclic secondary amines include piperidine, pyrrolidine, 2-methylpiperidine, and 4-methylpiperidine.

[0099] As the secondary amine, an aliphatic secondary amine is preferred, with dimethylamine and diethylamine being preferred, and dimethylamine being particularly preferred.

[0100] Examples of epihalohydrins include epichlorohydrin, epibromohydrin, methylepichlorohydrin, and methylepibromohydrin. Among these, epichlorohydrin is particularly preferred.

[0101] Furthermore, the main-chain ammonium group-containing polymer (D) may be obtained by reacting an amine other than a secondary amine with a secondary amine and an epihalohydrin. Examples of amines other than secondary amines include compounds having two or more amino groups, such as ethylenediamine, propylenediamine, diethylenetriamine, hexylenediamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, piperazine, diphenylmethanediamine, hydrazine, and hydrazides such as adipic acid dihydrazide. Among these, ethylenediamine is preferably used.

[0102] The main-chain ammonium group-containing polymer (D) is produced, for example, by mixing and stirring a secondary amine, an epihalohydrin, and other amines other than the secondary amine, as needed, under heating conditions, and then by addition polymerization using known and conventional methods.

[0103] The weight-average molecular weight (Mw) of the main-chain ammonium group-containing polymer (D) is not particularly limited, but is preferably 1,000 to 10,000,000, more preferably 2,000 to 7,000,000, even more preferably 4,000 to 5,000,000, and particularly preferably 10,000 to 2,000,000. The weight-average molecular weight of the main-chain ammonium group-containing polymer (D) can be determined using GPC on a standard polyethylene oxide basis.

[0104] Furthermore, a crosslinked polymer (three-dimensional crosslinked body) may be obtained by crosslinking (three-dimensional crosslinking) a cation group-containing polymer. In this case, a crosslinkable polymer capable of forming a crosslinked structure may be present separately from the cation group-containing polymer, and the crosslinked polymer (three-dimensional crosslinked body) may be crosslinked (three-dimensional crosslinked). Examples of crosslinking methods include ultraviolet irradiation, visible light irradiation, heating, electron beam irradiation, and radiation irradiation. Urethane reactions, epoxy reactions, oxazoline group reactions, dimerization reactions of cinnamic acid, and azetidinium ring reactions can also be utilized.

[0105] Furthermore, while the neutral polymer is not particularly limited, it is preferably a polymer that exhibits affinity for water, more preferably a polymer having a polar group, and especially preferably a polymer having an -OH, -NH, alkylene oxide chain structure. Examples of neutral polymers include acrylic acid polymers, acrylamide polymers, polyalkylene oxide polymers, polyvinyl alcohol polymers, and polymers having a sugar backbone. Among these, acrylic acid polymers, acrylamide polymers, and polyalkylene oxide polymers are preferred, with acrylic acid polymers and polyalkylene oxide polymers being preferred.

[0106] Polyalkylene oxide polymers can be any polymer having a polyalkylene oxide skeleton, such as polyethylene oxide, polypropylene oxide, and polybutylene oxide.

[0107] Furthermore, polyalkylene oxide polymers may be obtained by polymerizing polyalkylene oxide compounds having polymerizable functional groups such as acrylate groups or methacrylate groups. Examples of polyalkylene oxide compounds having polymerizable functional groups include monofunctional polyalkylene oxide compounds such as polyethylene glycol acrylate, polypropylene glycol acrylate, polyethylene glycol monomethyl ether acrylate, polypropylene glycol monomethyl acrylate, polyethylene glycol methacrylate, polypropylene glycol methacrylate, polyethylene glycol monomethyl ether methacrylate, and polypropylene glycol monomethyl methacrylate; and polyfunctional polyalkylene oxide compounds such as polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, polytetramethylene glycol dimethacrylate, polytetramethylene glycol diacrylate, polybutylene glycol dimethacrylate, and polybutylene glycol diacrylate. These can be used individually or in combination of two or more. Furthermore, by using polyfunctional polyalkylene oxide compounds, polyalkylene oxide polymers can be made crosslinkable (three-dimensional crosslinking). Examples of crosslinking methods include ultraviolet irradiation, visible light irradiation, heating, electron beam irradiation, and radiation irradiation. In addition to polyalkylene oxide compounds having polymerizable functional groups, polymerizable compounds that do not have a polyalkylene oxide structure may also be copolymerized.

[0108] The acrylamide polymer can be any polymer obtained by polymerizing acrylamide monomers, and the acrylamide monomers include acrylamide; N-alkylacrylamides such as N-methylacrylamide, N-ethylacrylamide, Nn-propylacrylamide, N-isopropylacrylamide, Nn-butylacrylamide, N-tert-butylacrylamide; N-cycloalkylacrylamides such as N-cyclohexylacrylamide; dialkylacrylamides such as N,N-dimethylacrylamide; dialkylaminoalkylacrylamides such as dimethylaminoethylacrylamide, dimethylaminopropylacrylamide; hydroxyalkylacrylamides such as N-(hydroxymethyl)acrylamide, N-(hydroxyethyl)acrylamide; N-arylacrylamides such as N-phenylacrylamide; diacetoneacrylamide; and N,N'-methylenebisacrylamide. Examples include '-alkylene bisacrylamide; methacrylamide; N-alkyl methacrylamides such as N-methyl methacrylamide, N-ethyl methacrylamide, Nn-propyl methacrylamide, N-isopropyl methacrylamide, Nn-butyl methacrylamide, and N-tert-butyl methacrylamide; N-cycloalkyl methacrylamides such as N-cyclohexyl methacrylamide; dialkyl methacrylamides such as N,N-dimethyl methacrylamide; dialkylaminoalkyl methacrylamides such as dimethylaminoethyl methacrylamide and dimethylaminopropyl methacrylamide; hydroxyalkyl methacrylamides such as N-(hydroxymethyl) methacrylamide and N-(hydroxyethyl) methacrylamide; N-aryl methacrylamides such as N-phenyl methacrylamide; diacetone methacrylamide; and N,N'-alkylene bismethacrylamides such as N,N'-methylene bismethacrylamide. These can be used individually or in combination of two or more. Furthermore, by using polyfunctional acrylamide monomers such as N,N'-alkylenebisacrylamide or N,N'-alkylenebismethacrylamide, acrylamide polymers can be made crosslinkable (three-dimensional crosslinking).In addition, polymerizable compounds other than acrylamide monomers may be copolymerized.

[0109] Examples of acrylic acid-based polymers include polyacrylic acid. Alternatively, acrylic acid-based polymers may be polymers having ionic groups, such as salts of acrylic acid-based polymers, including sodium polyacrylate and potassium polyacrylate.

[0110] Furthermore, it is preferable that the polymer constituting the adhesive layer 20 is moisture-adsorbing. By being moisture-adsorbing, a certain amount of moisture can be maintained without the need for an outer layer such as a protective film, thereby maintaining good adhesion. In addition, if the polymer constituting the adhesive layer is moisture-adsorbing, the time required for peeling using water is shortened. Here, moisture-adsorbing means that it can hold 6% or more by weight of moisture in an environment of 25°C and 50%RH. That is, if 100g of dry polymer is placed in an environment of 25°C and 50%RH, it will absorb moisture from the air and, after a sufficiently long standing time, will weigh 106g or more. Note that the moisture content of the material is defined as 0% by weight at 25°C and 0%RH relative humidity.

[0111] To exhibit high moisture adsorption properties, it is desirable for the repeating units to have an ammonium cation structure, preferably a higher ammonium compound, and quaternary ammonium is particularly preferred. Furthermore, in addition to the ammonium cation structure, it is more preferable for the polymer structure to have other polar atoms, such as oxygen, nitrogen, and halogens, which may be ionized. The more repeating units having the ammonium cation structure there are in the polymer, the stronger the moisture adsorption properties become. The content of repeating units having the ammonium cation structure is preferably 30 mol% or more, more preferably 50% or more, and even more preferably 70 mol% or more. Examples of polymers that can retain 6% by weight or more of their own weight in an environment of 25°C and 50% RH include, among the above-mentioned cation group-containing polymers, polymers having a quaternary ammonium structure, polymers having an imidazolium structure, polymers having a cation in the main chain, and cation group-containing polymers having chloride ions or bromide ions as counterions.

[0112] Furthermore, the material used to constitute the adhesive layer 20 may be the material described in Japanese Patent Publication No. 7-173445.

[0113] In addition, in the present invention, a water-impermeable film may be further provided as a water-impermeable coating on the surface of the substrate 10 opposite to the surface on which the adhesive layer 20 is formed, thereby more effectively suppressing the penetration of water into the adhesive layer 20. The water-impermeable film can be integrated with the substrate 10, and it is preferable to use a water-impermeable film that has a larger area than the substrate 10 and is arranged to cover the substrate 10.

[0114] Furthermore, additional elements may be added from the viewpoint of more effectively suppressing the intrusion of water into the adhesive layer 20. For example, a non-water-permeable coating may be superimposed (such as wrapping with a thin polyethylene film), a hydrophobic adhesive may be used in combination, or a method of forming a non-water-soluble adhesive layer on the outermost periphery of the base material 10 may be adopted, or the edges may be protected with waterproof tape, or a non-water-permeable sponge may be placed around the adhesive part of the adherend 50, or the base material 10 and adherend 50 may be subjected to water-repellent treatment (such as applying water-repellent oil).

[0115] Furthermore, although the present invention shows an adhesive sheet comprising a base material 10 and an adhesive layer 20 being attached to an adherend 50, depending on the application, the base material 10 may be the adherend 50. That is, a pair of adherends 50 may be attached to each other via the adhesive layer 20 (i.e., a "adherend 50 / adhesive layer 20 / adherend 50" configuration), in which case, by considering one of the adherends 50 as the base material 10, the adhesive sheet of the present invention (an adhesive sheet consisting of a base material 10 and an adhesive layer 20) can be considered to have a structure attached to the adherend 50. In other words, as long as the present invention has an adhesive non-adhesive layer portion 30 that is continuously formed along the outer circumference of the portion where the adhesive layer 20 is formed, on the outer circumference side of the portion where the adhesive layer 20 is formed, the adhesive sheet of the present invention can be considered to have a structure attached to the adherend 50, even if a pair of adherends 50 are attached to each other via the adhesive layer 20.

[0116] An adhesive sheet according to one embodiment can be used, for example, as a label, craft tape, medical tape, or dressing material. Examples of labels include those with various information such as letters, diagrams, patterns, pictures, or QR codes (registered trademarks) on their surface, which may be drawn with invisible ink. Examples of craft tapes include tapes for joining materials such as paper, wood, and glass together, and tapes for temporarily fixing parts in the manufacturing process. Examples of medical tapes are tapes mainly for direct application to the human body, and can take various forms, from single sheets like patches to rolls. Examples of dressing materials include adhesives mainly applied to wounds to prevent the affected area from drying out and promote healing.

[0117] <Adhesive sheet for the second side> Next, the embodiment of the adhesive sheet of the present invention having structure (b) is defined as an adhesive sheet relating to a second side surface, and such an adhesive sheet relating to a second side surface will be described below.

[0118] An adhesive sheet according to a second aspect of the present invention is an adhesive sheet comprising a base material and an adhesive layer, The aforementioned substrate is made of a non-permeable material. The adhesive layer is composed of a water-soluble or water-swellable material. It has the following structure (b). Structure (b): The substrate has through-holes with an average pore diameter of 1000 μm or less.

[0119] Figure 3(A) is a side view of an adhesive sheet according to one embodiment of the second aspect of the present invention. In the following description, the embodiment shown in Figure 3(A) will be used as an example, but the present invention is not limited in any way to this embodiment.

[0120] As shown in Figure 3(A), the adhesive sheet according to one embodiment of the second side view is composed of an adhesive layer 20 formed on a base material 10, and the base material 10 has through holes 40 formed therein. In Figure 3(A), a configuration with multiple through holes 40 is illustrated, but a configuration with only one through hole 40 is also possible.

[0121] In the adhesive sheet according to one embodiment of the second aspect, the base material 10 is made of a non-permeable material, and the adhesive layer 20 is made of a water-soluble or water-swellable material.

[0122] Figure 3(B) shows an adhesive sheet according to one embodiment of the second side view attached to an object 50. According to the adhesive sheet according to one embodiment of the second side view, the adhesive force of the adhesive layer 20 allows the base material 10 to be attached to the object 50 via the adhesive layer 20. Here, since the base material 10 is made of a non-permeable material, even if the surface of the base material 10 is unintentionally exposed to water, it is possible to prevent water from penetrating through the base material 10 to the adhesive layer 20. However, because the base material 10 is non-permeable, when it is desired to peel it off from the object 50, a peeling medium such as a peeling fluid cannot be introduced into the adhesive layer 20 from the base material 10 side.

[0123] In contrast, by providing through-holes 40 with an average pore diameter of 1000 μm or less in the substrate 10, if it is unintentionally exposed to water, the surface tension of the water prevents water from entering through the through-holes 40. At the same time, if peeling is desired, the through-holes 40 can be used as a path for the peeling fluid. This allows the peeling fluid to reach the adhesive layer 20 quickly, making it possible to peel it off quickly when desired. Specifically, the substrate 10 has through-holes 40 and is permeable to surfactant water or water-soluble organic solvents used as peeling fluids. This allows the peeling fluid to reach the adhesive layer 20 quickly, making it possible to peel it off quickly when desired. Here, whether or not it is permeable to surfactant water or water-soluble organic solvents used as peeling fluids can be determined, for example, by placing filter paper at the bottom of the substrate 10, dropping one drop (approximately 25 mg) of surfactant water or water-soluble organic solvent onto the substrate 10, and measuring the weight of the filter paper after 1 minute. If the weight increase is 5 mg or more, it is determined to be permeable.

[0124] Furthermore, since the through-holes 40 also function as inlets and outlets for water vapor under normal conditions, the amount of water retained by the water-soluble or water-swellable materials constituting the adhesive layer 20 can be stabilized. Moreover, because of the presence of the through-holes 40, even if some water penetrates into the adhesive layer 20, the water can be released through the through-holes 40, thereby increasing the rate of restoration due to drying.

[0125] Furthermore, the water-soluble or water-swellable materials constituting the adhesive layer 20 are prone to hygroscopicity and often retain a certain amount of moisture. As a result, when heat is applied or electromagnetic waves are irradiated, water vapor is generated, which can cause the interface between the adhesive layer 20 and the substrate 10, or between the adhesive layer 20 and the adherend 50, to widen, potentially leading to unintended delamination. In contrast, the substrate 10 has through holes 40, which allow water vapor to evaporate through the through holes 40, thereby suppressing such delamination.

[0126] The through-holes 40 should be of a size that prevents water from passing through, and their size is not particularly limited, but the average pore diameter (average diameter) of the through-holes 40 should be 1000 μm or less, preferably 100 μm or less, more preferably 50 μm or less, even more preferably 1 μm or less, and particularly preferably 200 nm or less. The lower limit is not particularly limited, but preferably 20 nm or more. If the pore diameter of the through-holes is 50 μm or less, the visibility of characters and images when written with a marker pen or printed is excellent, and if it is 1 μm or less, the holes are not visible to the naked eye, resulting in even more beautiful display performance. The shape of the through-holes can be circular, rectangular, triangular, star-shaped, crescent-shaped, or any other polygon. In addition, there may be one or more through-holes 40, but having multiple holes is preferable because the effect is greater.

[0127] In the adhesive sheet according to one embodiment of the second side view, the thickness t of the adhesive layer 20 may be the same as that of the first side view described above.

[0128] Furthermore, in the adhesive sheet according to one embodiment of the second side view, the base material 10 may be the same as the first side view described above, except that it has through holes 40, and the adhesive layer 20 may also be the same as the first side view described above.

[0129] Furthermore, in the adhesive sheet according to one embodiment of the second side, similar to the first side described above, when peeling it off from the adherend 50, the adhesive sheet can be easily peeled off by bringing it into contact with a peeling fluid. In particular, in the adhesive sheet according to one embodiment of the second side, the peeling fluid can penetrate the adhesive layer 20 through the through holes 40 formed in the base material 10, enabling rapid peeling.

[0130] Furthermore, in the adhesive sheet according to one embodiment of the second side surface, similar to the first side surface described above, a non-permeable film may be further provided as a non-permeable coating on the side of the base material 10 opposite to the surface on which the adhesive layer 20 is formed, or additional elements may be added from the viewpoint of more appropriately suppressing the intrusion of water into the adhesive layer 20. Also, for example, as shown in Figure 3(C), the periphery of the adhesive layer 20 may be covered with a non-permeable cover member 60 to more appropriately prevent the intrusion of water from the side. Note that the non-permeable cover member 60 is not particularly limited to the form shown in Figure 3(C), and any configuration that can more appropriately prevent the intrusion of water from the side is acceptable. In addition, in the second side surface, water-repellent oil may be added to the through-holes 40 as a water-repellent treatment for the base material 10 and the adherend 50.

[0131] The adhesive sheet according to one embodiment of the second aspect can be used, like the first aspect described above, as, for example, a label, craft tape, medical tape, or dressing material. In particular, when the adhesive sheet according to one embodiment of the second aspect is used as medical tape, the adhesive force can be removed by using a release fluid, thus enabling removal without damaging the body. In particular, commercially available medical tapes and bandages can damage the body by removing the stratum corneum when peeled off, but the adhesive sheet according to one embodiment of the second aspect can suppress the occurrence of such damage. Furthermore, since the base material 10 has through holes 40, moisture evaporating from the skin does not accumulate, thus also providing the effect of preventing the skin from becoming soggy.

[0132] Furthermore, as shown in Figure 3(D), the adhesive sheet has an adhesive layer 20 on a base material 10, and through holes 40 are formed in the base material 10. In addition, as shown in the embodiments in Figures 1(A) and 1(B), a non-adhesive layer portion 30 may be formed on the adhesive layer 20 forming surface of the base material 10, on the outer periphery of the portion where the adhesive layer 20 is formed, and continuously along at least a part of the outer periphery of the portion where the adhesive layer 20 is formed. [Examples]

[0133] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" refers to mass.

[0134] <Manufacturing Example 1> To 100 parts of a (3-acrylamidopropyl)trimethylammonium chloride solution (Sigma-Aldrich, 75% by weight aqueous solution), 1 part of methylenebisacrylamide (Sigma-Aldrich) as a crosslinkable monomer and 1 part of 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxymethylpropanone (Tokyo Chemical Industries) as a water-soluble photopolymerization initiator were added to dissolve and prepare solution (S-1C). The obtained solution (S-1C) was then sandwiched between two PET films that had been treated with a mold release agent, and the outside was further sandwiched between two 1 mm thick glass plates, maintaining a gap of 50 μm between the PET films. Next, the solution (S-1C) was cured by irradiating it with 365 nm UV light from above the glass for 2 minutes, thereby obtaining a transparent film molded body (F-1C) with a thickness of 50 μm. The resulting film molded article (F-1C) was obtained using a solution (S-1C) containing a crosslinkable monomer, and therefore did not exhibit water solubility but did swell in water.

[0135] <Manufacturing Example 2> Solution (S-1) was prepared in the same manner as in Production Example 1, except that methylenebisacrylamide was not used as the crosslinkable monomer. The obtained solution (S-1) was sandwiched between two PET films that had been treated with a release agent, and then sandwiched on the outside with two 1 mm thick glass plates, creating a gap of 500 μm between the PET films. Next, the solution (S-1) was cured by irradiating it with 365 nm UV light from above the glass for 2 minutes, thereby obtaining a transparent film molded body (F-1) with a thickness of 500 μm. Since the obtained film molded body (F-1) was obtained using solution (S-1) that did not contain a crosslinkable monomer, it was water-soluble and did not swell in water.

[0136] <Example 1-1> As a non-permeable substrate, a 60 μm thick Yupo paper (polypropylene film) was prepared. The prepared Yupo paper was cut to a size of 3 cm x 6 cm, and a sample was obtained by attaching the film molded product (F-1C) obtained in Manufacturing Example 1 to one side of it. As samples, we prepared two types of samples: Sample (EX1-1), in which a film molded body (F-1C) measuring 2.99 cm × 5.99 cm was attached to the outermost edge of the Yupo paper so as to be 0.5 mm inward (i.e., in the embodiments shown in Figures 1(A) and 1(B), the width of the non-adhesive layer portion 30 w1 = 0.5 mm); and Sample (EX1-2), in which a film molded body (F-1C) measuring 2.98 cm × 5.98 cm was attached to the outermost edge of the Yupo paper so as to be 1 mm inward (i.e., in the embodiments shown in Figures 1(A) and 1(B), the width of the non-adhesive layer portion 30 w1 = 1 mm).

[0137] Next, the samples (EX1-1) and (EX1-2) prepared above were attached to the side of a polypropylene bottle (substrate) measuring 20 cm in height and 10 cm in diameter, with the longitudinal direction of the samples aligned with the circumferential direction of the bottle. Then, the bottle with the attached samples was tilted on its side, and tap water was dripped onto the center of each attached sample at a rate of approximately 10 cc per second for 30 seconds.

[0138] The dripped water flowed sequentially along the circumferential direction of the bottle. As a result, in sample (EX1-1) where the formation width w1 = 0.5 mm of the non-adhesive layer portion 30, no swelling of the adhesive layer 20 was observed until 20 seconds after the start of water dripping. However, swelling was observed thereafter, and after 30 seconds, the edges of the adhesive layer 20 had swollen to a thickness of approximately 1 mm. At the point where the water penetrated due to swelling, it had advanced to 3.5 mm from the edge of the adhesive layer 20, but it did not peel off and maintained good adhesion. Whether or not water had penetrated was determined by the increase in thickness. In addition, in sample (EX1-2) where the formation width w1 = 1 mm of the non-adhesive layer portion 30, no swelling of the adhesive layer 20 was observed even after water was dripped for 30 seconds. Furthermore, when the post-test sample (EX1-1) was left in a room with the bottle still attached, it was confirmed that after two days, the absorbed moisture was released and it returned to its original state.

[0139] When a bottle to which samples (EX1-1) and (EX1-2) were attached was poured with a 5% by weight neutral detergent solution and a 40% by weight ethanol aqueous solution at a rate of approximately 10cc per second, wetting of samples (EX1-1) and (EX1-2) occurred immediately across the entire surface, and swelling of the adhesive layer began. After 5 seconds, the edges were observed to be peeling from the bottle, and after 30 seconds, samples (EX1-1) and (EX1-2) had detached from the bottle.

[0140] <Examples 1-2> Sample (EX1-3) was prepared in the same manner as in Example 1-1, except that the adhesive layers (inner adhesive layer 20a, outer adhesive layer 20b) were formed in the manner shown in Figure 2(A). In sample (EX1-3), the formation width w2 of the formed portion of the outer adhesive layer 20b was set to 2 mm, and the formation width w1 of the non-adhesive layer portion 30 was set to 2 mm. Then, as in Example 1-1, sample (EX1-3) was attached to a polypropylene bottle (adhesion object), and tap water was dropped onto it in the same manner. Immediately after the start of water dripping, swelling of the outer adhesive layer 20b began, and after 30 seconds, the outer adhesive layer 20b had swollen to a thickness of about 2 mm. On the other hand, no water penetration into the inner adhesive layer 20a was observed, and it did not peel off, maintaining good adhesiveness. Furthermore, when the post-test samples (EX1-3) were left at room temperature with the samples still attached to the bottles, it was confirmed that after one day, the absorbed moisture was released and the samples returned to their original state.

[0141] When a bottle to which sample (EX1-3) was attached was poured with 5% by weight neutral detergent solution and a 40% by weight ethanol aqueous solution at a rate of approximately 10cc per second, the sample (EX1-3) immediately became wet all over, and the adhesive layer began to swell. After 5 seconds, the edges were observed to be peeling from the bottle, and after 30 seconds, sample (EX1-3) detached from the bottle.

[0142] <Comparative Example 1> Sample (CEX1) was prepared in the same manner as in Example 1-1, except that the size of the film molded body (F-1C) to be attached to the Yupo paper was the same as the Yupo paper (i.e., 3 cm x 6 cm), and the portion 30 without adhesive layer was omitted. Then, in the same manner as in Example 1-1, sample (CEX1) was attached to a polypropylene bottle (adhesion body), and tap water was dropped onto it in the same manner. Immediately after the start of water dripping, swelling of the edges of the adhesive layer began, and after 30 seconds, the adhesive layer had swollen to a thickness of about 3 mm, resulting in partial peeling.

[0143] <Examples 1-3> Two 16mm diameter circular discs were prepared by punching out 500μm thick Teflon® sheets. Additionally, the film molded body (F-1) produced in Manufacturing Example 2 was punched out into a 12mm diameter circular disc. Next, sample (EX1-4) was manufactured by bonding the two prepared circular Teflon sheets together using the 12mm diameter circular film molded body (F-1) so that their centers coincided. Sample (EX1-4) consisted of a circular adhesive layer with a diameter of 12mm, surrounded by a non-adhesive layer with a formation width w1 = 2mm. Furthermore, in sample (EX1-4), one of the two circular Teflon sheets was used as the base material, and the other as the adherend.

[0144] Next, the sample (EX1-4) prepared as described above was placed in a beaker containing 100 ml of water and submerged. Even after submersion, the water did not penetrate the interior of the sample (EX1-4), and the bond was still sufficiently maintained when it was removed after 10 minutes. Subsequently, after removing the sample (EX1-4) from the water, it was immersed in an 80% by weight alcohol aqueous solution. Penetration of the alcohol aqueous solution into the interior of the sample (EX1-4) was observed, and after 10 minutes, the two disc-shaped Teflon sheets separated. In addition, a portion of the adhesive layer had dissolved.

[0145] <Example 2> As a substrate that is impermeable to water and has through-pores, a polyethylene microporous film (thickness 25 μm) with through-pores having an average pore diameter of 100 nm or less was prepared. The prepared polyethylene microporous film was cut into 5 cm squares, and a sample (EX2) corresponding to the configuration shown in Figure 3(A) was prepared by attaching it to one side of a 5 cm square piece of the film molded body (F-1C) obtained in Production Example 1. Next, the prepared sample (EX2) was attached to a 10 cm square glass plate with a thickness of 1 mm, and with the polyethylene microporous film side facing upwards, 1 cc of water was dropped near the center of the surface of the polyethylene microporous film. Even after 1 minute, the water did not penetrate into the polyethylene microporous film, and no particular changes were observed in the adhesive layer.

[0146] Furthermore, when 5% by weight neutral detergent solution, methanol, ethanol, propanol, acetone, tetrahydrofuran, acetonitrile, and 40% by weight ethanol aqueous solution were added dropwise to the polyethylene microporous film used in Example 2, wetting occurred in all cases. From this, it can be concluded that the adhesive layer can be easily peeled off by using these surfactant solutions and water-soluble organic solvents.

[0147] In addition, separately from the above, when 5% by weight neutral detergent solution, methanol, ethanol, propanol, acetone, tetrahydrofuran, acetonitrile, and 80% by weight ethanol aqueous solution were dropped onto a PTFE membrane with a pore size of 0.2 μm, wetting occurred in all cases. From this, it can be concluded that PTFE membranes can also be used in a similar manner.

[0148] <Comparative Example 2> A 70 μm thick sheet of paper was prepared as a water-permeable substrate. The prepared paper was cut into 5 cm squares, and a 5 cm square piece of the film molded body (F-1C) obtained in Manufacturing Example 1 was attached to one side of the cut sheet to create a sample (CEX2). Next, the prepared sample (CEX2) was attached to a 10 cm square glass plate with a thickness of 1 mm. With the paper substrate side facing upwards, 1 cc of water was dropped near the center of the paper surface. Immediately after dropping, it was confirmed that the paper was wet, and the water also penetrated into the adhesive layer below. Due to the penetration of water, the adhesive layer swelled and increased in thickness, and after 1 minute, it had spread across the entire sheet. When the glass plate with the sample (CEX2) attached was stood upright, the paper substrate, along with the adhesive layer, fell downwards.

[0149] <Example 3> As a substrate that is impermeable to water and has through-holes, a polyethylene microporous film (thickness 25 μm) with through-holes having an average pore diameter of 100 nm or less was prepared. The prepared polyethylene microporous film was cut to 3 cm × 6 cm, and a film molded body (F-1C) obtained in Production Example 1 was attached to one side to obtain sample (EX3). For sample (EX3), a film molded body (F-1C) measuring 2.98 cm × 5.98 cm was prepared by attaching it so that it was located 1 mm inward from the outermost edge of the polyethylene microporous film (i.e., a sample was prepared in which the formation width w1 = 1 mm of the non-adhesive layer portion 30 corresponds to the configuration shown in Figure 3(D)).

[0150] The prepared sample (EX3) was then attached to a person's arm and adhered well, with the adhesive layer remaining intact. It was left in place for about 3 hours, and there were no noticeable changes; it remained firmly attached. After this, cotton wool soaked in 5% by weight of neutral detergent water (nonionic surfactant water) was placed on the surface of the polyethylene microporous film substrate and pressed down. The adhesive layer gradually swelled and automatically peeled off the skin in about 30 seconds. No trace of the sample (EX3) remained on the skin, there was no itching, and no dead skin cells were attached to the sample (EX3). This sample (EX3) confirmed that it could be peeled off without stressing the skin. As for other peeling methods, the same procedure could be performed using an alcohol solution, or by applying a hot towel and peeling it off.

[0151] <Comparative Example 3> A commercially available bandage was applied to a person's arm and left for about three hours. There were no noticeable changes, and it adhered well. Afterwards, when it was slowly peeled off, several hairs fell out, and a red mark was left on the skin. Dead skin cells were attached to the bandage. After removal, there was itching, and the skin was slightly soggy, which is thought to be because moisture from the skin did not evaporate properly. [Explanation of Symbols]

[0152] 10…substrate 20,20a,20b…adhesive layer 30...Part where the adhesive layer is not formed 40…through hole 50…being covered

Claims

1. An adhesive sheet comprising a base material and an adhesive layer, The aforementioned substrate is made of a non-permeable material. The adhesive layer is composed of a water-soluble or water-swellable material. An adhesive sheet having the following structure (a) and / or the following structure (b). Structure (a): The thickness of the adhesive layer is 1000 μm or less, and the adhesive layer forming surface of the substrate has an adhesive non-forming portion that is formed continuously along at least a part of the outer circumference of the adhesive layer forming portion, on the outer circumference side of the adhesive layer forming portion. Structure (b): The substrate has through-holes with an average pore diameter of 1000 μm or less.

2. The adhesive sheet according to claim 1, wherein the width of the portion where the adhesive layer is not formed is 0.5 mm or more.

3. The adhesive sheet according to claim 1 or 2, wherein the portion without an adhesive layer is formed to cover the periphery of the portion with an adhesive layer.

4. The adhesive sheet according to claim 1 or 2, wherein the substrate exhibits permeability to surfactant water.

5. The adhesive sheet according to claim 1 or 2, wherein the substrate exhibits permeability to water-soluble organic solvents.

6. The adhesive sheet according to claim 1 or 2, which is a label, craft tape, medical tape, or dressing material.

7. The adhesive sheet according to claim 1 or 2, wherein a non-permeable film is disposed on the surface of the substrate opposite to the surface on which the adhesive layer is formed.

8. The adhesive sheet according to claim 7, wherein the non-permeable film is integrated with the substrate.

9. The adhesive sheet according to claim 7, wherein the non-permeable film has a larger area than the substrate and is arranged to cover the substrate.

10. An adhesive sheet according to claim 1 or 2, used for adhering to a substrate having a contact angle of 60° or more.

11. A method for peeling off an adhesive sheet according to claim 1 or 2 from an object, A method for peeling off an adhesive sheet, comprising the step of peeling the adhesive sheet from an object by bringing the adhesive sheet into contact with a peeling fluid.

12. The method for peeling an adhesive sheet according to claim 11, wherein the peeling fluid is surfactant water.

13. The method for peeling an adhesive sheet according to claim 11, wherein the peeling fluid is a water-soluble organic solvent.

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