Water-containing bonding material, raw material solution for forming water-containing bonding material, bonding member, and bonding structure

Abstract

Provided is a water-containing bonding material for constituting a bonding structure with two or more members bonded, comprising a water-soluble or water-swellable polymer (P) and water in an amount of 60 g or more per 1 L.

Description

Hydrated bonding material, raw material solution for forming a hydrated bonding material, bonding member, and bonding structure

[0001] The present invention relates to a water-containing bonding material that has excellent bonding properties and can be easily peeled off after use. The present invention also relates to a raw material solution for forming such a water-containing bonding material, as well as a bonding member and bonding structure using such a water-containing bonding material.

[0002] Many industrial products utilize bonding materials such as 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 bonding materials that can be easily removed during dismantling.

[0003] In response to this, a technique has been proposed in which microwave-absorbing substances, such as bound water or ionic liquids, are included in the bonding material, and microwaves are irradiated during dismantling to accelerate the dismantling process (Patent Document 1, Patent Document 2).

[0004] Japanese Patent Publication No. 2001-89717 Japanese Patent Publication No. 2017-214558

[0005] The present invention aims to provide a water-containing bonding material that exhibits excellent bonding properties and can be easily peeled off after use.

[0006] The inventors of the present invention conducted studies to achieve the above objectives and discovered that by using a bonding material containing a water-soluble or water-swellable polymer and a predetermined amount of water, excellent bonding properties can be achieved, and the material can be easily peeled off after use (for example, by simple heating, heating with electromagnetic waves, or immersion in water), thus completing the present invention.

[0007] In other words, the present invention provides the following water-containing bonding material, raw material solution for forming a water-containing bonding material, bonding member, and bonding structure: [1] A water-containing bonding material comprising a bonding structure formed by bonding two or more members, comprising a water-soluble or water-swellable polymer (P) and 60 g or more of water per liter. [2] The water-containing bonding material according to [1], comprising 60 g or more of water per liter at 25°C and 50% RH. [3] The water-soluble or water-swellable polymer (P) according to [1] or [2], wherein the water-soluble or water-swellable polymer (P) is a polymer capable of holding 6% or more of its own weight in water at 25°C and 50% RH. [4] The water-containing bonding material according to any one of [1] to [3], further comprising a deliquescent substance. [5] The water-soluble or water-swellable polymer (P) according to any one of [1] to [4], wherein the water-soluble or water-swellable polymer (P) is a water-swellable polymer. [6] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to [5]. [7] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to [6]. [8] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to [6]. [9] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to [6].

[10] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to [6].

[11] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to

[102] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to

[10] .

[13] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to

[10] .

[14] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to

[10] .

[15] The water-soluble or water-swellable polymer (P) is a synthetic polymer, as described in any of [1] to

[10] .

[12] A water-containing bonding material according to any one of [1] to

[11] , which is stored in a package for use.

[13] A bonding member comprising a water-containing bonding material according to any one of [1] to

[12] and at least one conductive material bonded together.

[14] A bonding member according to

[13] , which is stored in a package for use.

[15] A raw material solution for forming a water-containing bonding material, comprising a polymer capable of holding 6% or more by weight of water at 25°C and 50% RH, and water, wherein the viscosity at 25°C is 100 cP or more.

[16] The raw material solution for forming a water-containing bonding material according to

[15] , further comprising a polyhydric alcohol compound.

[17] A bonding member comprising a water-containing bonding material according to any one of [1] to

[12] , stored in a package, wherein the water-containing bonding material forms a bonding structure by bonding the inner surface of the package.

[18] The bonding member according to

[17] , wherein the package is a non-water-permeable package.

[19] The water permeability of the package is 10 g / (m). ２ - A joining member according to

[18] , wherein the number of days is less than or equal to

[20] . A joining member according to any one of

[17] to

[19] , wherein the package is an electromagnetic wave impermeable package.

[21] A joining member according to any one of

[17] to

[20] , wherein the package is an electromagnetic wave permeable package.

[22] A joining member according to any one of

[17] to

[21] , wherein the package comprises an extension portion that extends from the joining position by the water-containing joining material, and the joining portion does not have a joining formed by the water-containing joining material.

[23] A joining structure comprising two or more members joined together, wherein at least a part of the joining structure comprises a joining portion made of a water-containing joining material that contains a water-soluble or water-swellable polymer (P) and 60 g or more of water per liter.

[0008] According to the present invention, it is possible to provide a water-containing bonding material that has excellent bonding properties and can be easily peeled off after use. Furthermore, according to the present invention, it is also possible to provide a raw material solution for forming such a water-containing bonding material, as well as a bonding member and a bonding structure using such a water-containing bonding material.

[0009] Figure 1(A) is a top view of the joining member obtained in Example 6, Figure 1(B) is a cross-sectional view of the joining member obtained in Example 6, and Figure 1(C) is a cross-sectional view of the joining test piece obtained in Example 6. Figure 2 is a top view of the joining member obtained in Example 7.

[0010] <Hydrostatic bonding material> The hydrostatic bonding material of the present invention is a bonding material that constitutes a bonding structure in which two or more members are joined together, and contains a water-soluble or water-swellable polymer (P) and 60 g or more of water per liter.

[0011] The water-containing bonding material of the present invention is a material that constitutes a bonding structure formed by bonding two or more members. Specifically, it is interposed between two or more members to bond them together, and the water-containing bonding material of the present invention refers to a material that maintains a structure in which two or more members are bonded together. In other words, in the present invention, a raw material solution that serves as the raw material for the water-containing bonding material is applied between two or more members, and then polymerization, crosslinking, etc. are performed as necessary, thereby realizing a state in which two or more members are bonded together, and this material is defined as the water-containing bonding material.

[0012] In this invention, "joining material" refers to all materials having adhesive and / or tackiness, and "water-containing joining material" refers to composite materials containing water.

[0013] The water-containing bonding material of the present invention comprises a water-soluble or water-swellable polymer (P) and water, wherein the water content in the water-containing bonding material is 60 g or more per liter of volume of the water-containing bonding material. This enables excellent bonding properties and allows for easy peeling after use.

[0014] Many industrial products utilize adhesives and bonding materials. While these materials must provide a secure bond during use, they are difficult to remove during dismantling, requiring significant effort and hindering material recycling. In recent years, with growing environmental awareness, there has been a demand for bonding materials that can be easily removed during dismantling.

[0015] In contrast, the water-containing bonding material of the present invention achieves excellent bonding properties while being easily peelable after use. More specifically, by reducing the bonding strength through methods such as simple heating, electromagnetic wave heating, or immersion in water, it can be peeled off with minimal force. Furthermore, because it can be peeled off with minimal force, damage to the adherend can be reduced, thereby effectively promoting the recycling of the adherend.

[0016] On the other hand, while Patent Documents 1 and 2 propose a technique in which microwave-absorbing substances such as bound water or ionic liquids are included in the bonding material and microwaves are irradiated during decomposition to promote decomposition, this requires microwave irradiation during peeling, which presents a problem as microwave irradiation may be difficult depending on the shape near the bonding structure. Furthermore, ionic liquids are expensive. In contrast, the present invention can effectively solve these problems because decomposition is possible by various methods such as simple heating, heating by electromagnetic waves, and immersion in water. In particular, since it is impossible to predict which decomposition method will be used during decomposition, a bonding material that can be peeled by multiple decomposition methods is useful.

[0017] The members to be joined by the water-containing joining material of the present invention (hereinafter, as appropriate, referred to as "members to be joined") are not particularly limited and include metals, glass, ceramics, plastics, rubber, paper, wood, and composite materials thereof. Furthermore, the members to be joined may be joined using joining materials other than the water-containing joining material of the present invention. On the other hand, materials that do not retain shape, such as liquids and gases, are not suitable as members to be joined. The members to be joined may have a three-dimensional shape such as a film, flat plate, block, or uneven surface, or a perforated structure such as a mesh. The surface of the members to be joined may be smooth, curved, or uneven. Moreover, the water-containing joining material of the present invention and the members to be joined may be joined via another joining material. Technical fields to which the water-containing joining material of the present invention can be applied include, but are not limited to, the manufacture of electrical appliances and electronic equipment, display manufacturing, automobile manufacturing, glass processing, papermaking, wood processing, construction, art manufacturing and restoration, medical care, and personal crafts.

[0018] The water-containing bonding material of the present invention comprises a water-soluble or water-swellable polymer (P) and water, wherein the water content in the water-containing bonding material is 60 g or more per liter of volume of the water-containing bonding material, preferably 80 g or more, more preferably 100 g or more, even more preferably 150 g or more per liter of volume of the water-containing bonding material, preferably 600 g / L or less, more preferably 500 g / L or less, even more preferably 400 g / L or less, and even more preferably 350 g / L or less. By setting the water content within the above range, sufficient bonding strength can be achieved, and when peeling by heating after use, a sufficient amount of high-temperature steam can be generated by heating, thereby appropriately promoting the reduction of bonding strength during peeling and further improving peelability. Furthermore, if the water content is within the above range, when peeling is performed using electromagnetic waves, the efficiency of conversion of electromagnetic waves into heat can be appropriately increased, and peelability by electromagnetic waves can be appropriately improved. If the water content is too low, the material will have poor delamination properties, and the strength of the water-containing bonding material itself will decrease due to a relatively large amount of components that do not contribute to bonding.

[0019] Furthermore, the water-containing bonding material of the present invention is preferably capable of maintaining a water content of 60 g or more per liter of volume of the water-containing bonding material for one month or more under conditions of 25°C and 50% RH, more preferably for three months or more, even more preferably for six months or more, and particularly preferably for one year or more.

[0020] The water-containing bonding material of the present invention must at least have shape retention properties in order to maintain bonding strength. Whether or not it has shape retention properties can be determined by whether or not a tensile test can be performed on it. For example, if a rod-shaped solid with a uniform cross-sectional area can be obtained and fixed to a tensile testing machine, it can be determined that it has shape retention properties.

[0021] The water-soluble or water-swellable polymer P (hereinafter referred to as "polymer (P)") is not particularly limited, as long as it is water-soluble or water-swellable and has a molecular weight (weight-average molecular weight (Mw)) of 1000 or more. A water-soluble polymer is one in which, when 1 g of the polymer is added to 100 ml of water and mixed at 25°C, the viscosity of the resulting mixed solution at 25°C is 2 cP or more. A water-swellable polymer is one that can form a hydrogel without phase separation, or one that does not exhibit water solubility and whose volume increases by 20% or more when immersed in water at 25°C for 24 hours. When the volume increase is 20%, the swelling rate is 120%.

[0022] In the water-containing bonding material of the present invention, the content ratio of polymer (P) per 100 parts by volume of water is preferably 0.1 to 2000 parts by volume, more preferably 0.5 to 1600 parts by volume, and even more preferably 1 to 1400 parts by volume.

[0023] In the water-containing bonding material of the present invention, the total volume ratio of water and polymer (P) is preferably 500 g / L or more, more preferably 600 g / L or more, and even more preferably 700 g / L or more, with an upper limit of 1500 g / L or less. By setting the total volume ratio of water and polymer (P) within the above range, it becomes possible to peel off the water-containing bonded portion with water and to clean off any adhesive residue with water.

[0024] The polymer (P) used in the present invention may be any polymer that is water-soluble or water-swellable, and is not particularly limited. It may be a synthetic polymer or a natural polymer. However, from the viewpoint of further suppressing spoilage, synthetic polymers and polymers obtained by modifying natural polymers are preferred, and synthetic polymers are more preferred. Suitable synthetic polymers include neutral polymers that do not contain salt structures in their structure, cation group-containing polymers, and anion group-containing polymers. Furthermore, cation group-containing polymers are preferably those that have an ammonium structure. The ammonium structure has an antibacterial effect and can suppress the spoilage of water-containing bonding materials. In particular, when spoilage is likely to progress when polyhydric alcohols or substances containing sugars in their structural units are included, this can effectively suppress such spoilage.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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; tetrafluoroboric acid, hexafluorophosphate, dicyanoamide, tetracyanoborate, carbonate, alkyl carbonate, triflate, perchloric acid, nitric acid, sulfuric acid, alkyl sulfuric acid, sulfonic acid, phosphoric acid, and alkyl phosphoric acid; and are not particularly limited.

[0030] The cation group-containing polymer is not particularly limited, but as a polymer having cation groups in its side chains, for example, a cation group-containing polyether (A) containing repeating units represented by the following general formula (1) can be mentioned.

[0031] (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.)

[0032] 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.

[0033] 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.

[0034] 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.

[0035] A ＋ The nitrogen-containing cationic aliphatic group may be linear or branched, and may also have a non-aromatic ring structure.

[0036] A＋ Specific examples of the nitrogen-containing cationic group represented by [are as follows: ammonium group; monosubstituted ammonium groups containing a cationic nitrogen atom such as methylammonium group, butylammonium group, cyclohexylammonium group, anilinium group, benzylammonium group, ethanolammonium group; disubstituted ammonium groups containing a cationic nitrogen atom such as dimethylammonium group, diethylammonium group, dibutylammonium group, nonylphenylammonium group; trisubstituted ammonium groups containing a cationic nitrogen atom such as trimethylammonium group, triethylammonium group, n-butyldimethylammonium group, stearyldimethylammonium group, tributylammonium group, trivinylammonium group, triethanolammonium group, N,N-dimethylethanolammonium group, tri(2-ethoxyethyl)ammonium group; heterocyclic groups containing a cationic nitrogen atom such as piperidinium group, 1-methylpyrrolidinium group, 1-butylpyrrolidinium group, imidazolium group, 1-methylimidazolium group, 1-ethylimidazolium group, 1-butyl-imidazolium group, benzimidazolium group, pyrrolium group, 1-methylpyrrolium group, oxazolium group, benzoxazolium group, pyrazolium group, isoxazolium group, pyridinium group, 2,6-dimethylpyridinium group, pyrazinium group, pyrimidinium group, pyridazinium group, triazinium group, N,N-dimethylanilinium group, quinolinium group, isoquinolinium group, indolinium group, quinoxalinium group, isoquinoxalinium group, etc. Among these, trisubstituted ammonium groups containing a cationic nitrogen atom and heterocyclic groups containing a cationic nitrogen atom are preferred.

[0037] 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 － Examples of [include, for example, as monovalent anions, fluoride ions such as F － , Cl － , Br － , I － ; (FSO ２ )２ N － (CF ３ SO ２ ) ２ N － (CF ３ CF ２ SO ２ ) ２ N － Sulfonylimidide ions such as CH ３ COO － C3H7COO － CF ３ COO － PhCOO － (Ph indicates the phenyl group.) Carboxylate ions such as CH ３ SO ３ － CF ３ SO ３ － Sulfonoxide ions such as OH － BF ４ － , PF ６ － , ClO ４ － , B(CN) ４ － SCN － (NC) ２ N － 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). ４ ２－ ) and carbonate ions (CO2) ３ ２－ Examples include: － O ３ SCF2CF2CF2SO ３ － , － O ３ SCF2CF2SO ３ － CF ３ SO ２ N － SO ２CF2CF2OCF2CF2OCF2CF2SO ２ N － SO ２ CF ３ These include, among others, chloride ions, bromide ions, sulfonylimide ions, carboxylate ions, and BF ４ － Preferably, sulfonylimidide ions, chloride ions, CH ３ COO － BF ４ － This is preferable.

[0038] In the cation group-containing polyether (A), the units represented by the general formula (1) are independent of each other, and two or more units represented by the general formula (1) may be present 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.

[0039] 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. (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.)

[0040] In the above general formula (2), R １ ~R ４each independently represents a hydrogen atom or a substituent. Examples of the substituent include the same ones as those described above as the substituent of the nitrogen-containing aromatic heterocyclic ring. R １ ~R ４ as a substituent may be linear or branched, and may also have a ring structure. R １ ~R ４ as a substituent is preferably linear.

[0041] In the above general formula (2), R １ 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, still more preferably an alkyl group or an alkenyl group, particularly preferably an alkyl group or a vinyl group, and most preferably an alkyl group. The number of carbon atoms of R １ is preferably 0 to 12, more preferably 0 to 8, still more preferably 1 to 6, even more preferably 1 to 4, particularly preferably 1 to 3, and most preferably 1 to 2.

[0042] In the above general formula (2), R ２ ~R ４ each independently may be a hydrogen atom or a substituent, and is not particularly limited, but each independently is preferably a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group or a vinyl group, still more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom. The number of carbon atoms of R ２ ~R ４ is each independently preferably 0 to 8, more preferably 0 to 6, still more preferably 0 to 4, even more preferably 0 to 3, particularly preferably 0 to 2, and most preferably 0 to 1.

[0043] In the above general formula (2), 1 to 3 of R ２ ~R ４ preferably represent hydrogen atoms, and 2 to 3 more preferably represent hydrogen atoms. Also, R ２ ~R ４It 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.

[0044] X in the general formula (2) above － 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.

[0045] The repeating unit represented by the above general formula (2) preferably contains an imidazolium group, a 1-methylimidazolium group, a 1-butylimidazolium group, a 1-hexylimidazolium group, or a 1-vinylimidazolium group, and more preferably contains a 1-methylimidazolium group.

[0046] 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.

[0047] 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.

[0048] The chain structure of the cation group-containing polyether (A) is not particularly limited and may be linear, or it may be a chain structure having branching such as graft or radial.

[0049] 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 following.

[0050] 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.

[0051] The weight-average molecular weight (Mw) of the cationic 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.

[0052] The molecular weight distribution (Mw / Mn) of the cationic 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.

[0053] 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.

[0054] The proportion 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 5 to 100 mol%, and more preferably 10 to 100 mol%, relative to the total repeating units of the cationic group-containing polyether (A).

[0055] The method for synthesizing the cation 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.

[0056] Furthermore, as an example of a cationic group-containing polymer, a polymer (B) containing a repeating unit represented by the following general formula (3) is also an example of a polymer having cationic groups in its side chains, specifically a side-chain ammonium group-containing polymer. (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.)

[0057] 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-(CH ２ ) ｐ It is more preferable that the base be represented by -(where p is an integer from 1 to 5, preferably n=3).

[0058] R ５ ~R ７Each 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.

[0059] In the above general formula (3), X － The anion represented by is not particularly limited, but examples include those similar to those in the general formula (1) above.

[0060] 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.

[0061] 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.

[0062] 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 chloride quaternary salt], 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 0.0001 to 5% by weight.

[0063] 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.

[0064] Furthermore, as a cationic group-containing polymer, a side-chain cyclic ammonium group-containing polymer (C) is also included, which has a cationic group in the side chain of the polymer and contains a repeating unit represented by the following general formula (4-1) or the following general formula (4-2). (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.)

[0065] 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.

[0066] In the above general formulas (4-1) and (4-2), X － The anion represented by is not particularly limited, but examples include those similar to those in the general formula (1) above.

[0067] 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, but any units derived from monomers copolymerizable with the monomers that give the repeating units represented by general formulas (4-1) and (4-2) above can be used as such monomers. From the viewpoint of having lone pairs of electrons, examples of such monomers include N-vinylpyrrolidone, acrylamide, (meth)acrylic acid, (meth)acrylate salts, (meth)acrylates having ethylene oxide units, and substituted products thereof.

[0068] 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.

[0069] 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 ratio of the crosslinkable monomer units is preferably 0.0001 to 5% by weight.

[0070] The weight-average molecular weight (Mw) of the side-chain cyclic ammonium group-containing polymer (C) 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 side-chain cyclic ammonium group-containing polymer (C) can be determined using GPC on a standard polyethylene oxide basis.

[0071] Furthermore, as a cation group-containing polymer, an example is a main-chain ammonium group-containing polymer (D) that contains repeating units represented by the following general formula (5), as a polymer having a cation group in the main chain of the polymer. (In the above general formula (5), R １０ , R １１ Each of these independently represents a hydrogen atom or a substituent, R １０ , R １１ They may be joined to each other. Also, in general formula (5), X － (This represents an anion.)

[0072] R １０ , R １１Each 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. １０ , R １１ 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.

[0073] In the above general formula (5), X － The anion represented by is not particularly limited, but examples include those similar to those in the general formula (1) above.

[0074] 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).

[0075] 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.

[0076] Examples of aliphatic secondary amines include dimethylamine, diethylamine, diisopropylamine, dibutylamine, methylethylamine, methylpropylamine, methylbutylamine, methyloctylamine, methyllaurylamine, and dibenzylamine.

[0077] 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.

[0078] 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.

[0079] Examples of heterocyclic secondary amines include piperidine, pyrrolidine, 2-methylpiperidine, and 4-methylpiperidine.

[0080] As the secondary amine, an aliphatic secondary amine is preferred, with dimethylamine and diethylamine being preferred, and dimethylamine being particularly preferred.

[0081] Examples of epihalohydrins include epichlorohydrin, epibromohydrin, methylepichlorohydrin, and methylepibromohydrin. Among these, epichlorohydrin is particularly preferred.

[0082] 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.

[0083] 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 a known and conventional method.

[0084] 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.

[0085] 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.

[0086] 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 a -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 particularly preferred.

[0087] Polyalkylene oxide polymers can be any polymer having a polyalkylene oxide skeleton, such as polyethylene oxide, polypropylene oxide, and polybutylene oxide.

[0088] 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.

[0089] The acrylamide polymer can be any polymer obtained by polymerizing acrylamide monomers. Examples of acrylamide monomers include acrylamide; N-alkylacrylamides such as N-methylacrylamide, N-ethylacrylamide, N-n-propylacrylamide, N-isopropylacrylamide, N-n-butylacrylamide, and N-tert-butylacrylamide; N-cycloalkylacrylamides such as N-cyclohexylacrylamide; dialkylacrylamides such as N,N-dimethylacrylamide and N,N-diethylacrylamide; dialkylaminoalkylacrylamides such as dimethylaminoethylacrylamide and dimethylaminopropylacrylamide; hydroxyalkylacrylamides such as N-(hydroxymethyl)acrylamide and N-(hydroxyethyl)acrylamide; N-arylacrylamides such as N-phenylacrylamide; diacetoneacrylamide; and N,N'-methylenebisacrylic. Examples include N,N'-alkylene bisacrylamides such as amides; methacrylamides; N-alkyl methacrylamides such as N-methyl methacrylamide, N-ethyl methacrylamide, N-n-propyl methacrylamide, N-isopropyl methacrylamide, N-n-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.

[0090] 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.

[0091] Furthermore, the polymer (P) used in this invention is preferably water-adsorbing. Due to its water-adsorbing properties, it can maintain a certain level of moisture even without providing an outer casing. Also, if the peeling operation fails for any reason, the moisture content can be restored by leaving it for a while, making it possible to try the peeling operation again. Here, water-adsorbing means that it can hold 6% by weight or more of its own weight in moisture in an environment of 25°C and 50% RH. In other words, when 100g of dry polymer is placed in an environment of 25°C and 50% RH, it absorbs moisture from the air and, after a sufficiently long standing time, weighs 106g or more. Note that the moisture content of the material is defined as 0% by weight at 25°C and 0% relative humidity.

[0092] 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, it is more preferable for the polymer structure to have other polar atoms in addition to the ammonium cation structure, 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.

[0093] Furthermore, a polymer (P) that does not have water-adsorbing properties may be used, in which case it is preferable to further include a deliquescent substance in the water-containing bonding material. Examples of deliquescent substances include inorganic salts, organic salts and other salt compounds, and polyhydric alcohols, but are not particularly limited to these. By using a deliquescent substance, the same effect as when a polymer (P) with water-adsorbing properties is used can be obtained.

[0094] Here, deliquescence refers to the phenomenon in which a substance absorbs moisture from the air and spontaneously becomes an aqueous solution, and a deliquescent substance is a compound that possesses this characteristic. Specifically, a deliquescent substance is a compound that absorbs moisture from the air, undergoes ionic dissociation, and becomes an aqueous solution. A deliquescent substance can be any compound that exhibits deliquescence at 80% RH, but it is preferable that it exhibits deliquescence at 25°C and 80% RH, and more preferably that it exhibits deliquescence at 25°C and 50% RH. If the deliquescent substance is a polymer, it may not necessarily become an aqueous solution even if deliquescence occurs. In this case, deliquescence is considered to have occurred if it can hold 6% by weight or more of moisture relative to the weight of the polymer itself. Most ordinary polymers can only hold a few percent of moisture at most.

[0095] Such deliquescent substances are not particularly limited, but examples of salt compounds include LiCl, CsCl, and CaCl. ２ MgCl ２ ZnCl ２ Salts of chlorine with alkali metals, salts of chlorine with alkaline earth metals; LiBr, MgBr ２ Salts of bromine with alkali metals, salts of bromine with alkaline earth metals; salts of acetic acid with alkali metals, salts of acetic acid with alkaline earth metals; Li(CF) ３ SO ２ ) ２ N, Na(CF ３ SO ２ ) ２ (CF) ３ SO ２ ) ２ N － and alkali metal salts, (CF ３ SO ２ ) ２ N － Salts of alkaline earth metals; Li(FSO) ２ ) ２ N, Na(FSO) ２ ) ２ N, K (FSO) ２ ) ２ N etc. (FSO) ２ ) ２ N －and alkali metal salts, (FSO ２ ) ２ N － Salts of alkaline earth metals; NH ４ Examples include inorganic ammonium halides such as chlorine (Cl) and organic ammonium halides such as choline chloride.

[0096] Furthermore, examples of polyhydric alcohols include dihydric or more alcohols with a molecular weight of less than 1000, such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, 2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,4-phenylene glycol, and bisphenol A. Examples include trihydric alcohols such as 1,2,4-butanetriol, 1,2,5-pentanetriol, 2-methyl-1,2,4-butanetriol, glycerin, 2-methylpropanetriol, trimethylolethane, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene; tetrahydric alcohols such as 1,2,3,6-hexanthetrol and pentaerythritol; pentahydric alcohols such as glucose; and hexahydric alcohols such as dipentaerythritol.

[0097] Furthermore, the water-containing bonding material of the present invention may contain a salt compound, and by including a salt compound, the effect of suppressing the progression of decay can be further enhanced. The salt compound is not particularly limited, and known salt compounds can be used, but for example, the deliquescent salt compounds described above are preferred. The salt compound content is preferably 1 part by weight or more, more preferably 5 parts by weight or more, even more preferably 10 parts by weight or more, even more preferably 15 parts by weight or more, particularly preferably 20 parts by weight or more, and there is no particular upper limit, but it is preferably 250 parts by weight or less, per 100 parts by weight of water. When a salt compound is included, it is preferable that the polymer (P) contains atoms with lone pairs of electrons. While the addition of a salt compound may cause salting out of the polymer (P), the presence of lone pairs of electrons in the polymer (P) makes salting out less likely to occur. Atoms with lone pairs of electrons include unionized nitrogen and oxygen, and specific structures include ester bonds, ether bonds, amide bonds, urethane bonds, ketones, hydroxyl groups, carboxyl groups, epoxy groups, amino groups, and imino groups.

[0098] The water-containing bonding material of the present invention is used by applying a raw material solution to two or more members to be joined, and then performing polymerization, crosslinking, etc. as necessary, to position it between the two or more members, thereby making it act as a water-containing bonding material.

[0099] As the raw material solution, any solution containing the components that constitute the water-containing bonding material to be formed is acceptable, but a solution containing a polymer capable of holding 6% or more by weight of water at 25°C and 50% RH, along with water, and having a viscosity of 100 cP or more at 25°C can be preferably used.

[0100] The polymer to be included in the raw material solution may be the same polymer (P) that constitutes the water-containing bonding material of the present invention, or a precursor polymer that is a precursor of polymer (P) may be used. When a precursor polymer is used, the raw material solution can be applied between two or more members to be bonded, and then polymerization or crosslinking can be performed to obtain polymer (P). Examples of polymerization and crosslinking methods include ultraviolet irradiation, visible light irradiation, heating, electron beam irradiation, and radiation irradiation.

[0101] The raw material solution may contain deliquescent substances, salt compounds, or polyhydric alcohol compounds as needed.

[0102] Furthermore, the water-containing bonding material of the present invention may be a composite of other bonding materials, and the other bonding materials are not particularly limited, but include conventionally known adhesives. Examples of such adhesives include epoxy resins, urethane resins, natural polymers such as starch and their modified products, polyvinyl alcohol, polyvinyl acetate, acrylic polymers, silicone rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, water glass, silicate, cement, and gypsum.

[0103] In particular, when compounding with other bonding materials such as epoxy resins and starch pastes by mixing only water without using polymer (P), the high viscosity ratio makes it difficult to mix these other bonding materials and water well, and it is especially difficult if the other bonding materials are hydrophobic. Furthermore, when compounding with only water without using polymer (P), there is a risk of water seepage from the bonding material, and if water seepage occurs, the amount of water in the bonding material decreases, resulting in reduced release properties after use. In contrast, the water-containing bonding material of the present invention contains polymer (P) in addition to water, so it can be well mixed and compounded with other bonding materials such as epoxy resins and starch pastes, even if the materials are hydrophobic.

[0104] When compounded with other bonding materials, the amount of polymer (P) used is not particularly limited, but from the viewpoint of miscibility with other bonding materials and water release from water-containing bonding materials, the polymer (P) content in 100% by weight of the total of water and polymer (P) is preferably 0.5% by weight or more, more preferably 1% by weight or more, even more preferably 2% by weight or more, and even more preferably 5% by weight or more, and there is no particular upper limit, but it is preferably 90% by weight or less.

[0105] When compounding with other bonding materials, there are no particular limitations on the method for preparing the raw material solution (precursor), but it is preferable to prepare a composition containing a polymer (P), or a precursor polymer that is a precursor of polymer (P), and water, and then mix the other bonding material with the prepared composition to obtain the raw material solution (precursor). By adopting such a method, the mixing time required for preparation can be shortened. The viscosity of the composition containing polymer (P) or a precursor polymer and water at 25°C is preferably 100 cP or more, more preferably 1000 cP or more, even more preferably 5000 cP or more, and even more preferably 10000 cP or more. Furthermore, when a water-swellable polymer is used as the polymer (P) or precursor polymer, the viscosity at 25°C can be considered to be infinite.

[0106] The viscosity ratio when mixing a composition containing a polymer (P) or precursor polymer and water with other bonding materials is preferably within 1000 times, more preferably within 100 times, even more preferably within 10 times, and even more preferably within 5 times. Furthermore, when a water-swellable polymer is used as the polymer (P) or precursor polymer, the viscosity ratio does not need to be considered, and it can be well dispersed in other bonding materials. In particular, even if large lumps originating from the water-swellable polymer are present in the composition, they can be finely dispersed because they are broken down into small pieces during the mixing process.

[0107] When the water-containing bonding material of the present invention is compounded with other bonding materials, the ratio of the total amount of polymer (P) and water to the other bonding material is preferably 7:93 to 45:55, more preferably 10:90 to 40:60, and even more preferably 15:85 to 35:65, in terms of the weight ratio of "total amount of polymer (P) and water: other bonding material". By setting the ratio within this range, good bonding properties can be achieved while fully exhibiting the ease of peeling due to the inclusion of polymer (P) and water.

[0108] The water-containing bonding material of the present invention can achieve excellent bonding properties and can be easily peeled off after use. For example, peeling can be achieved by generating water vapor through heating. In this case, the heating method is not particularly limited, but can be solid heat transfer, liquid heat transfer, gas heat transfer, radiation, electromagnetic wave heating such as microwaves, or chemical reactions. In this case, examples of liquids used for liquid heat transfer include water, aqueous solutions, and oil, and examples of gases used for gas heat transfer include air and water vapor. From the viewpoint that water vapor is less likely to escape through the bonded member to be joined, thereby allowing peeling to proceed more appropriately, it is preferable to use water vapor generation through heating when the air permeability of the bonded member to be joined is low. The bonded member to be joined preferably has a Gurley value of 700 seconds or more, more preferably 1000 seconds or more, and even more preferably 1300 seconds or more. Examples of such bonded members include metal, glass, paper, plastic, and rubber.

[0109] From the viewpoint of making peeling easier by utilizing water vapor generation due to heating, the water-containing bonding material of the present invention is preferably capable of releasing 10% or more by weight of the moisture content before heating when heated to 80°C, more preferably capable of releasing 15% or more by weight, and even more preferably capable of releasing 20% ​​or more by weight. Furthermore, from the viewpoint of making peeling easier by microwave irradiation, the water-containing bonding material of the present invention is preferably capable of being heated to 60°C or higher by microwave irradiation at 2.45 GHz, 500 W for 5 minutes, and more preferably capable of being heated to 80°C or higher. It should be noted that while heating with electromagnetic waves such as microwaves has a fast heating rate, it can be difficult to control if it is too fast, and it is necessary to operate the device so as not to irradiate unintended areas.

[0110] The water-containing bonding material of the present invention can be easily peeled off by immersion in water. Acids, alkalis, surfactants, salts, oxidizing agents, reducing agents, etc., may be added to the water used for peeling as needed. When peeling with water, a high swelling rate of the water-containing bonding material is preferable. At 25°C, the swelling rate relative to water is preferably 1.5 times or more (150% or more), more preferably 3 times or more, even more preferably 5 times or more, even more preferably 7 times or more, preferably 500 times or less, more preferably 100 times or less, even more preferably 50 times or less, and even more preferably 20 times or less. If the swelling rate relative to water is 1.5 times or more, peeling can be done with little damage to the substrate. If it is 3 times or more, peeling can be done spontaneously without applying mechanical external force. If it is 5 times or more, the time until peeling is completed is further shortened. Furthermore, when peeling with water, a water-soluble polymer may be used as the polymer (P) contained in the water-containing bonding material. When peeling with water, it is preferable that the polymer (P) has an ionic group or an ethylene oxide chain in its structure, as this increases the swelling rate and thus the peeling rate. From the perspective of facilitating the flow of fluid for separation, it is also possible to foam the water-containing bonding material or to form holes or notches in the water-containing bonding material.

[0111] The water-containing bonding material of the present invention can be easily peeled off by applying voltage. This peeling method is called electrolysis. In order to perform peeling, the water-containing bonding material only needs to be bonded to at least one conductive material, but it is preferable that it is in contact with at least two conductive materials, which serve as electrodes when voltage is applied. For example, by placing and bonding the water-containing bonding material of the present invention between two thin stainless steel sheets, an electrolysis-peelable bond can be formed. By applying a voltage of 0.1V or higher, the bonding force at the bonding interface can be weakened, and the peeling force can be reduced. The applied voltage may be DC or AC. DC is preferred from the viewpoint of simplifying the power supply device. The higher the applied voltage, the greater the effect of reducing the peeling force and the shorter the time required for peeling, but the higher the voltage, the larger the power supply device becomes and the problem of reduced safety during work. The preferred applied voltage is 0.5V or higher, more preferably 1.0V or higher, even more preferably 1.5V or higher, and even more preferably 3V or higher. The upper limit is preferably 20V or less, more preferably 10V or less, even more preferably 8V or less, and even more preferably 6V or less. In order to enable electrolysis at a lower voltage, it is preferable that the water-containing bonding material contains a salt compound. Examples of salt compounds include inorganic and organic salts such as sodium chloride, calcium chloride, sodium acetate, choline chloride, and EMI-TFSI (ethylmethylimidazolium trifluoromethanesulfonylimide). These may exist as low molecular weight compounds, or as molecules or polymers formed by the bonding of multiple such compounds. The water-soluble or water-swellable polymer (P) itself may contain a salt structure. It is more preferable that the water-soluble or water-swellable polymer (P) having a salt structure has a three-dimensional crosslinked structure. Since a three-dimensional crosslinked structure does not flow, the salt compound does not flow into the surrounding area. If the salt compound moves into the surrounding area, it may contaminate or rust the surrounding area. It is more preferable that the salt compound is a deliquescent substance.The preferred amount of salt compound to be added is 0.1% by weight or more, more preferably 1% by weight or more, even more preferably 10% by weight or more, and even more preferably 20% by weight or more, relative to the water in the water-containing bonding material. The upper limit of the amount of salt compound to be added is preferably 15 times or less the weight of water, more preferably 10 times or less, even more preferably 5 times or less, and even more preferably 2 times or less. The conductive material in contact with the water-containing bonding material only needs to be conductive, and can, but is not limited to, metals, conductive plastics, conductive rubber, conductive fibers, or articles with a conductive layer formed on the surface (e.g., PET film with an ITO film formed on it). From the viewpoint of contact with the water-containing material, it is preferable to use a material that is not easily altered by water. Specifically, examples include metals that are resistant to rust, conductive plastics, conductive rubber, conductive oxides (ITO, ATO, etc.), carbon nanotubes, and carbon nanobuds. Conductive oxides (such as ITO and ATO), carbon nanotubes, and carbon nanobuds may be readily present on the surface or as composites with other materials. Examples of rust-resistant metals include aluminum, nickel, titanium, copper, stainless steel, precious metals, and alloys thereof. Of these, conductive plastics, conductive rubber, ITO, ATO, carbon nanotubes, carbon nanobuds, and stainless steel are more preferred. Among stainless steels, those with a high chromium content are preferred (SUS304: 18-20% Cr, 316: 16-18% Cr, 430: 16-18% Cr, SUS45CP: 25% Cr, SUS836L: 25% Cr or more, SUS2507: 25% Cr or more, etc.), more preferably 15% or more, even more preferably 20% or more, and even more preferably 24% or more. Conductive plastics, conductive rubber, conductive oxides (such as ITO and ATO), carbon nanotubes, and carbon nanobuds are more preferred.

[0112] In the water-containing bonding material of the present invention, metals, glass, ceramics, plastics, rubber, paper, wood, and composite materials thereof can be used as the members to be bonded. However, it is preferable that the members to be bonded are made of different materials, as this results in different ease of delamination, allowing the delamination surface to be controlled so that the same side of the material always delaminates during delamination. Furthermore, the bonding structure may be multi-layered.

[0113] In the water-containing bonding material of the present invention, the bonding strength can be evaluated by various known tests, such as shear stress, tensile stress, peel test, and grid test.

[0114] The thickness of the water-containing bonding material of the present invention is preferably 1 μm or more, more preferably 8 μm or more, even more preferably 300 μm or more, even more preferably 1000 μm or more, preferably 10 mm or less, more preferably 8 mm or less, even more preferably 5 mm or less, and even more preferably 2 mm or less.

[0115] <Joining Member> The joining member of the present invention comprises the above-described water-containing joining material of the present invention housed in a package, and the water-containing joining material forms a joining structure by joining the inner surface of the package.

[0116] Specifically, the joining member of the present invention has a structure in which the above-described water-containing joining material of the present invention is stored in a package, and the inner surfaces of the package are joined by the water-containing joining material within the package (for example, by joining the inner surface of the lower portion of the package to the inner surface of the upper portion of the package), thereby forming a joining structure within the package. That is, the joining member of the present invention has a cross-section in which the lower portion of the package, the water-containing joining material, and the upper portion of the package are stacked in that order, and these are joined by the water-containing joining material. A package that has airtightness to prevent the entry and exit of gas can be suitably used as the package, and with such a configuration, since the water-containing joining material is stored in the package, the water content contained in the water-containing joining material can be kept constant, thereby stably achieving excellent joining performance.

[0117] Furthermore, with the joining member of the present invention, various members can be joined to the outer surface of the joining member's package (the outer surface of the lower and upper parts of the package) using conventionally known joining materials, thereby forming a joined structure in which various members are joined. In addition, after use, by opening a part of the package and subjecting the water-containing joining material of the present invention stored inside the package to simple heating, heating with electromagnetic waves, or immersion in water, the joining strength of the water-containing joining material of the present invention can be reduced and the material can be peeled off. More specifically, the joined structure formed by the water-containing joining material inside the package can be easily eliminated.

[0118] The packaging is preferably impermeable to water, and examples include metal, rubber, plastic, ceramic, glass, aluminum laminate packaging, and plastic pouch packaging with a barrier layer. If it is to be impermeable to water and also permeable to electromagnetic waves, rubber, plastic, ceramic, glass, and plastic pouch packaging with a barrier layer can be selected. By using an impermeable package, fluctuations in moisture content in the water-containing bonding material can be suppressed more effectively. The packaging should have a moisture permeability of 10 g / m ２ It is preferable that the amount is less than or equal to 1 g / (m³) or less, and more preferably 1 g / (m³). ２ - day) or less, more preferably 0.5 g / (m ２ - day) or less, more preferably 0.1 g / (m ２ - day) or less, particularly preferably 0.05 g / (m ２ - The number of days is less than or equal to the number of days. If the water impermeability of the package is not expressed in terms of moisture permeability or cannot be expressed in terms of moisture permeability, the package may be selected in accordance with the "IP Code" established by the International Electrotechnical Commission (IEC). In this case, a waterproof performance of level 4 or higher is preferable, level 5 or higher is more preferable, level 6 or higher is even more preferable, level 7 or higher is even more preferable, and level 8 or higher is particularly preferable. Examples of such packages include the exteriors of smartphones, watches, and various electronic devices.

[0119] The packaging may be electromagnetically reflective (impermeable to electromagnetic waves), in which case examples include metal, aluminum laminate packaging, and plastics or glass with conductive films such as ITO, conductive carbon, copper mesh, or aluminum mesh. If the packaging is to be both electromagnetically reflective and transparent, it is advisable to select plastics or glass with conductive films such as ITO, conductive carbon, copper mesh, or aluminum mesh. Furthermore, from the viewpoint of electromagnetic reflection, a structure with holes, such as a mesh structure, is also acceptable, and the size of the holes can be determined according to the electromagnetic waves to be used.

[0120] Furthermore, the package may contain tubular objects such as straws, or porous or mesh materials that exhibit capillary action, to facilitate the flow of a peeling fluid such as water.

[0121] Furthermore, it is preferable that the package includes an extension portion that extends from the joint position made by the water-containing bonding material, and that does not have a joint formed by the water-containing bonding material. Since the joint portion is often formed in a narrow location, peeling operations can be difficult. However, by providing such an extension portion in the package, the extension portion can be left open, and a fluid such as water, hot air or thermal fluid, or electromagnetic waves can be efficiently applied to the joint structure made by the water-containing bonding material through the open portion of the extension portion, enabling a more labor-saving peeling operation. The extension portion can be provided above the joint structure, which allows for better flow of a fluid such as water during peeling. In addition, by providing the extension portion in two directions, it can be used as an inlet and outlet for a fluid such as water, thereby making the peeling operation more efficient.

[0122] There are no particular restrictions on the length of the extension, but it is preferable that it be long enough to extend beyond the structure with the joint for easier work. It is also preferable that the extension be folded or rolled up for storage until the stripping work is performed.

[0123] Furthermore, the package may include information about the bonding process, such as "selectable peeling methods," and it is also preferable to include indicators that encourage further information acquisition, such as an internet address, barcode, or QR code (registered trademark).

[0124] 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.

[0125] <Production Example 1> A 50 wt% monomer aqueous solution was prepared by adding 1 wt% by weight of 2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt (trade name "DMAEA(R)-BQ", manufactured by KJ Chemicals) containing Omnirad 2959 (manufactured by IGM Resins, photopolymerization initiator) to a three-necked glass flask and water. After purging the system with nitrogen, photopolymerization was carried out by irradiating it with 365 nm UV light. As photopolymerization progressed, the viscosity increased, and a polymer aqueous solution of poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt (PS-1) was obtained at a concentration of 50 wt%. The viscosity of the obtained polymer aqueous solution (PS-1) at 25°C was 10,000 cP or higher. The poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt contained in the polymer aqueous solution (PS-1) exhibited both aqueous solution properties and deliquescent properties.

[0126] When the polymer aqueous solution (PS-1) of poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt obtained above was left standing in an environment of 25°C and 80% RH, although the moisture content gradually decreased, even after 365 days it still contained more than 25% by weight of water relative to the polymer's weight (the polymer's own weight), indicating that it is a polymer with high moisture adsorption properties. Similarly, when this polymer aqueous solution (PS-1) was left standing in an environment of 25°C and 30% RH, although the moisture content gradually decreased, even after 365 days it still contained more than 10% by weight of water relative to the polymer's weight (the polymer's own weight), indicating that it is a polymer with high moisture adsorption properties. Furthermore, when this polymer aqueous solution (PS-1) was applied to glass containers and stainless steel equipment, it showed good adhesion, confirming that it has excellent bonding properties and functions well as a bonding material.

[0127] <Example 1> A raw material solution for forming a water-containing bonding material was obtained by adding a predetermined amount of water to polyethylene glycol diacrylate (Sigma-Aldrich, number-average molecular weight (Mn) = 700) containing 1% by weight of Omnirad 651 (IGM Resins, photopolymerization initiator) and mixing the mixture. This raw material solution was dropped onto the center of a glass slide (76 mm × 26 mm × 1.2 mm) to be used as an adherend, and another glass slide of the same size was placed on top with a gap of 500 μm. The raw material solution was then photocured by irradiating it with 365 nm UV light from above, and a test piece having a water-containing bonding portion in the shape of a disc with a thickness of 500 μm and a diameter of 15 ± 1 mm was prepared. Furthermore, the test specimens containing the crosslinked polyethylene glycol diacrylate after photocuring and water were all colorless and transparent, with no water seepage and no phase separation observed, indicating that the photocured polyethylene glycol diacrylate was a water-swellable polymer. In this example, by adjusting the amount of water used in relation to the polyethylene glycol diacrylate, test specimens with water content in the water-containing bonding material were prepared: (1-1) with 20 g / L, (1-2) with 40 g / L, (1-3) with 60 g / L, (1-4) with 80 g / L, (1-5) with 100 g / L, and (1-6) with 150 g / L. Of these, test specimens (1-3), (1-4), (1-5), and (1-6) were examined for bonding strength. When the bonding strength was checked, it was confirmed that sufficient bonding strength was generated, as the other side of the adherend was held even when only one side of the adherend was held.

[0128] Next, we attempted to detach the test specimens prepared as described above. The detachment method involved attaching a plastic clip to the edge of the glass slide and leaving it undisturbed in each environment. The maximum test time was 1 minute, and the detachment methods included no treatment, microwave irradiation using a 500W microwave oven, and heating on a hot plate. The results are shown in Table 1.

[0129]

[0130] <Evaluation of Example 1> From the results in Table 1, when a water-swellable polymer and water are contained, and the water content is 60 g or more per liter, peeling is possible by either microwave irradiation or heating on a hot plate, and the peeling properties are excellent. Furthermore, it was confirmed that the higher the water content, the shorter the time required for peeling, and that peeling can be achieved at a lower temperature for the same amount of time. In addition, from the results in Table 1, it was confirmed that for peeling methods, microwave irradiation is suitable for peeling in a shorter time when the water content is 80 g / L or more, but for the water content is less than 80 g / L, direct heating such as on a hot plate is easier for peeling. Furthermore, in each test, if peeling was achieved under milder conditions, testing under more severe conditions was not performed and it was marked as "not measured" (indicated as "-" in the table). Furthermore, in the table, the appearance of the test specimens after the microwave irradiation test is shown as follows: either when delamination occurred (test specimens (1-4) to (1-6)), or under the conditions of 500W for 60 seconds (test specimens (1-1) to (1-3)).

[0131] <Example 2-1> To 500 mg of epoxy adhesive (product name "Araldite", manufactured by Showa Polymer Co., Ltd.), the polymer aqueous solution (PS-1) produced in Production Example 1 was added. In Example 2-1, the amount of water in the water-containing bonding material was 100 g / L, the amount of poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt as a water-soluble polymer was 100 g / L, and the remainder was epoxy adhesive. When this was kneaded with a spatula, it was easily and uniformly mixed in about 30 seconds. The resulting mixture was used as a precursor for the water-containing bonding material. This precursor was applied to the center of a glass slide (76 mm × 26 mm × 1.2 mm) as the adherend, forming a disc shape with a thickness of 500 μm and a diameter of 15 ± 1 mm. Another glass slide of the same size was placed on top as the adherend, and then it was cured in an aluminum laminate bag for 12 hours to suppress the entry and exit of moisture, thereby producing a test piece with a water-containing bond. The obtained test specimens showed no change in weight before and after curing, indicating that the moisture content remained unchanged from the initial preparation. Furthermore, no phase separation occurred in the water-containing joint, confirming that the water-containing joint material was uniform. Upon further testing of the bonding properties, it was confirmed that sufficient bonding strength was generated, as the other side of the adherend was held even when only one side was grasped. In addition, similar mixing properties were observed in Examples 2-2 to 2-6 described later, with no change in weight before and after curing, no phase separation, and sufficient bonding strength.

[0132] Next, we attempted to peel the test specimens prepared as described above. The peeling method involved either no treatment, or pretreatment such as heating on a hot plate or microwave irradiation using a 500W microwave oven, followed by slowly pressing a knife with a maximum thickness of 2 mm into the edge of the slide glass. The results are shown in Table 2. As can be seen from Table 2, peeling using a knife was easily possible after 35 seconds of microwave irradiation using a 500W microwave oven and after heating on a hot plate at 85°C for 30 seconds.

[0133] Upon examination of the delaminated water-containing bonding material, it was found to be slightly more flexible than epoxy adhesive alone, and did not break even when bent at a 90° angle. For comparison, a sample of epoxy adhesive alone hardened into the same shape was prepared and examined, and it cracked when slightly bent. From these results, it was found that combining adhesives such as epoxy adhesive with the water-containing bonding material of the present invention improves flexibility.

[0134] <Example 2-2> The same procedure as in Example 2-1 was followed to obtain test specimens, and peeling was evaluated in the same manner, except that the amount of water in the water-containing bonding material was 150 g / L and the amount of poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt as the water-soluble polymer was 150 g / L. The results are shown in Table 2.

[0135] <Example 2-3> The same procedure as in Example 2-1 was followed to obtain test specimens, and peeling was evaluated in the same manner, except that the amount of water in the water-containing bonding material was 200 g / L and the amount of poly-2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt as the water-soluble polymer was 200 g / L. The results are shown in Table 2.

[0136] <Examples 2-4 to 2-6> Test specimens were obtained in the same manner as in Examples 2-1 to 2-3, except that the thickness of the water-containing bonding material (thickness of the water-containing bonding portion) was changed from 500 μm to 8 μm, and peeling was evaluated in the same manner. The results are shown in Table 2.

[0137] <Comparative Example 2-1> A test specimen was obtained in the same manner as in Example 2-1, except that only epoxy adhesive was used without adding the polymer aqueous solution (PS-1), and peeling was evaluated in the same manner. The results are shown in Table 2.

[0138]

[0139] <Evaluation of Examples 2-1 to 2-6 and Comparative Example 2-1> As is clear from the results in Table 2, in Comparative Example 2-1, which used only epoxy adhesive, peeling was not possible by either heating with a hot plate or microwave irradiation. However, by compounding it with the water-containing bonding material of the present invention, excellent peelability was achieved. In each test, if peeling occurred under milder conditions, further testing under more severe conditions was not performed and it was marked as unmeasured (indicated as "-" in the table). In the table, the appearance of the test piece after the microwave irradiation test is either the appearance when peeling occurred (Examples 2-1 to 2-6) or the appearance under the conditions of 500W, 70 seconds (Comparative Example 2-1). All samples that peeled after heating with a microwave oven reached a temperature of 80°C or higher, and the weight loss indicated that more than 20% by weight of the initially retained moisture was lost. In all of the samples heated with a hot plate, more than 10% by weight of the initially retained moisture was lost under all conditions in which peeling occurred.

[0140] <Comparative Example 2-2> 50 mg of water was added to 500 mg of epoxy adhesive and mixing was attempted. As a result, because the viscosity of water was lower than the viscosity of the epoxy resin that makes up the epoxy adhesive, the water had very little chance of entering the epoxy resin. Therefore, although mixing was continued vigorously, the separated water could still be seen with the naked eye, so the mixing process was stopped after 10 minutes from the start of mixing, as it was determined that mixing was impossible. From this result, it was confirmed that when water is mixed directly with hydrophobic epoxy resin, it will not mix.

[0141] <Example 3> A commercially available sodium polyacrylate hydrogel for use as a cooling agent was prepared, and test specimens were made using the sodium polyacrylate hydrogel in the same manner as in Examples 2-1 to 2-6. The sodium polyacrylate hydrogel had a polymer content of 1% by weight and a water content of 99% by weight. It was a brittle gel that easily crumbled, formed by the swelling of sodium polyacrylate, a water-swellable polymer, in water. For the experiment, the sodium polyacrylate hydrogel was used with the same polymer content of 1% by weight and water content of 99% by weight, and the formulation was adjusted so that only the water content in the water-containing bonding material was the same as in Examples 2-1 to 2-6. For example, to correspond to the level of Example 2-1, the formulation was adjusted so that the polymer content in the water-containing bonding material was approximately 1 g / L and the water content was 100 g / L. As a result, when the sodium polyacrylate hydrogel and epoxy adhesive were mixed, the hydrogel crumbled and dispersion progressed, and a uniform water-containing bonding material was obtained by mixing for about 30 seconds.

[0142] When test specimens were prepared using the obtained water-containing bonding material in the same manner as in Examples 2-1 to 2-6, they showed similarly good bonding properties. Furthermore, when peelability was evaluated for each test specimen, it was found to be excellent, similar to Examples 2-1 to 2-6. In addition, when sodium polyacrylate hydrogel was used, as in Example 3, the amount of polymer required to introduce the same amount of water into the water-containing bonding material could be reduced, thereby reducing the impact on the epoxy adhesive.

[0143] <Example 4> A predetermined amount of the polymer aqueous solution (PS-1) produced in Production Example 1 was added to starch glue (product name "Fueki Glue", manufactured by Fueki Glue Industry Co., Ltd.) to obtain a precursor of a water-containing bonding material. 10 mg by weight of the obtained precursor was applied to the center of a piece of cardboard (76 mm x 26 mm x 0.1 mm) to be used as an adherend, and another piece of cardboard of the same size was placed on top to create a test piece with a water-containing bond. This was left to stand for 12 hours to dry completely. When the bonding properties of the obtained test piece were checked, it was confirmed that sufficient bonding force was generated, as the other adherend was held even when only one side of the adherend was held.

[0144] Furthermore, a peel test was performed by peeling the obtained test pieces by pulling them with both hands. The peel test was conducted under the following conditions: 25°C, 50% RH environment, untreated, and heated on a hot plate at 85°C for 30 seconds. In this example, since it is difficult to directly measure the moisture content in the water-containing bonding material due to the influence of the moisture content of the cardboard, the moisture content was calculated using only the water-containing bonding material dried on a glass petri dish under the same conditions. The results are shown in Table 3.

[0145] <Comparative Example 4> Test specimens were prepared in the same manner as in Example 4, except that only starch paste was used and no polymer aqueous solution (PS-1) was added, and a peel test was performed in the same manner. The results are shown in Table 3.

[0146]

[0147] <Evaluation of Example 4 and Comparative Example 4> From Table 3, it can be confirmed that similarly excellent peelability can be obtained when starch paste and the water-containing bonding material of the present invention are combined.

[0148] <Example 5> In a three-necked glass flask, 2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt (trade name "DMAEA(R)-BQ", manufactured by KJ Chemicals) containing 1% by weight of Omnirad 2959 (manufactured by IGM Resins, photopolymerization initiator) and water were added to prepare a 75% by weight monomer aqueous solution. This monomer aqueous solution was cast onto a PET film that had been treated with a mold release agent, the system was purged with nitrogen, and then photopolymerization was carried out by irradiating it with 365 nm UV light to obtain a sheet-like polymer with a thickness of 1.5 mm. The obtained polymer was adhesive and therefore could be used as a water-containing bonding material, and in fact showed good bonding properties to glass, metal, wood, plastic, rubber, paper, ceramic, human skin, etc.

[0149] <Example 6> 74 parts of 2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt (trade name "DMAEA(R)-BQ", manufactured by KJ Chemicals), 1 part of methylenebisacrylamide, and 25 parts of water were mixed to prepare a 75 wt% monomer aqueous solution. AIBN(2,2'-azobis(isobutyronitrile)) was added to the prepared monomer aqueous solution at a rate of 1 wt% relative to the monomer to obtain a raw material solution for forming a water-containing bonding material. Separately, a water vapor permeability of 0.05 g / (m) was used. ２- Day 1) Two 5cm x 5cm pieces of aluminum laminate film (a laminate of nylon / aluminum / polyethylene from the outside) were cut out to serve as the packaging material. The polyethylene layers were placed on top of each other, and three sides were heat-sealed from the edge with a seal width of 1cm each, leaving the remaining side open. Next, the monomer aqueous solution prepared above was injected through the remaining open side, and the remaining open side was heat-sealed with a seal width of 1cm, taking care to remove as much air as possible. Then, this was placed in a 60°C constant temperature bath for 24 hours while being pressed from above and below with two flat stainless steel plates (5mm thick) to ensure even thickness, and then heated further by raising the temperature to 90°C. After 12 hours, it was confirmed that the aluminum laminate film as the packaging hardly deformed when pressed with a finger, indicating that the raw material solution had hardened and lost its fluidity, and that a bonding member was obtained in which the water-containing bonding material was stored inside the aluminum laminate film package. The area in which the water-containing bonding material is bonded to the aluminum laminate film serving as the package is 3 cm square, and the total thickness of the bonding member was 400 μm. Figure 1(A) is a top view of the bonding member obtained in this way, and Figure 1(B) is a cross-sectional view of the bonding member. As shown in Figures 1(A) and 1(B), the obtained bonding member consists of a package made of a pair of aluminum laminate films heat-sealed on all four sides, in which the water-containing bonding material is housed, and the pair of aluminum laminate films are bonded by the water-containing bonding material, forming a bonded structure. Furthermore, the crosslinked body used in this embodiment, composed of 2-(dimethylamino)ethyl acrylate-benzyl chloride quaternary salt and methylenebisacrylamide, showed a volume increase of 1000% or more when immersed in water at 25°C for 24 hours, indicating that it was a water-swellable polymer. It also exhibited deliquescent properties.

[0150] An epoxy adhesive (product name "Araldite," manufactured by Showa Polymer Co., Ltd.) was applied to one side of the outer packaging of the bonding member obtained above, and the center of a glass slide (76 mm x 26 mm x 1.2 mm) was bonded to it. The bonding area was 2.6 cm square, which was within the area of ​​the water-containing bonding material. A glass slide of the same size was bonded to the opposite side of the outer packaging in the same manner. This was then left to stand for 12 hours to obtain a bonded test specimen using the bonding member. The test specimen was bonded well and did not feel loose. Figure 1(C) is a cross-sectional view of the bonded test specimen obtained in this way. As shown in Figure 1(C), the obtained bonded test specimen is made by bonding a glass slide to the upper and lower surfaces of the bonding member obtained above, with an epoxy adhesive layer in between.

[0151] Then, a peel test was performed on the obtained bonded test specimens to separate the two glass slides from the bonding material. This was done by slowly pushing a knife with a maximum thickness of 2 mm into the edge of the glass slide. When the knife was pushed in, the glass slide broke, and neither bonding surface could be separated, indicating that there was sufficient bonding strength.

[0152] Next, the heat-sealed portion of one side of the aluminum laminate film, which forms the packaging for the bonding component, was cut with scissors to expose the internal water-containing bonding material. At this point, the entire test piece was bonded and could not be opened by hand. When this was immersed in a water tank, swelling of the surface was observed after about 10 seconds, and after about 1 minute, the aluminum laminate film and the water-containing bonding material began to separate. The package made of aluminum laminate film could then be easily opened by hand, and the test piece could be separated into two without damaging the slide glass. Furthermore, by applying a peeling force to the aluminum laminate of the separated test piece and pushing a knife into the interface between the slide glass and the epoxy adhesive, it was possible to peel off the epoxy adhesive layer without breaking the glass. Since the only rigid component in the separated test piece is the glass, it can be disassembled without breaking the glass by significantly deforming the aluminum laminate and adhesive layer. This disassembly method of the present invention is useful for material recycling.

[0153] Furthermore, when a test specimen prepared in the same manner was heated on an 80°C hot plate without cutting the heat-sealed portion with scissors (maintaining airtightness and not exposing the internal moisture-containing bonding material), the aluminum laminate film bag began to swell. When the heat-sealed portion was cut along one side of the aluminum laminate film in this state, delamination was confirmed to have occurred between the aluminum laminate film and the moisture-containing bonding material. Then, by peeling off the aluminum laminate film, the test specimen could be divided into two without damaging the slide glass. This effect was observed with a 35 μm thick polyethylene film with higher moisture permeability (moisture permeability of 7 g / m²). ２ While the same can be achieved using methods such as `day`, the rate at which moisture is lost is faster than with aluminum laminate film, resulting in a shorter period during which the easy-peel performance can be maintained.

[0154] <Comparative Example 6> A joint test specimen was prepared in the same manner as in Example 6, except that no water-containing bonding material was included inside. The resulting joint test specimen, because no bonding structure was formed by the water-containing bonding material inside the aluminum laminate film package, felt slightly wobbly when the two slides were moved apart.

[0155] A peel test was conducted to separate two microscope slides from the bonding material by slowly pushing a knife with a maximum thickness of 2 mm into the edge of each slide. As the knife was pushed in, the laminate film deformed and the gap between the slides widened. Even when the thickest part of the knife (2 mm) entered the gap between the slides, the slides did not break. This indicates that the two aluminum laminate films constituting the package were slipping, causing the bonding area to move. Although the slides did not separate, this method is unsuitable for rigid bonding, and repeated stress could cause the aluminum laminate films to rupture due to metal fatigue.

[0156] <Example 7> Except for using an aluminum laminate film with dimensions of 5 cm x 15 cm instead of 5 cm x 5 cm, the same procedure as in Example 6 was used to form a joint structure made of a water-containing bonding material 1 cm from the edge of the aluminum laminate film, thereby obtaining a joint member with an extension. Specifically, one short side and two long sides were heat-sealed from the edge with a seal width of 1 cm each, creating a package bag with the remaining short side left open. Next, an aqueous monomer solution prepared in the same manner as in Example 6 was injected through the remaining open side, and the remaining open short side was heat-sealed with a seal width of 1 cm, taking care to remove as much air as possible. Then, by heating in the same manner as in Example 6, a joint structure made of a water-containing bonding material was formed adjacent to the previously heat-sealed short side, with a size of 3 cm square, and a joint member having a 5 cm x 11 cm extension on the side of the later heat-sealed short side was obtained. Figure 2 shows a top view of the obtained joint member. As shown in Figure 2, the obtained joining member has a joining portion and an extension portion, both joined by a water-containing joining material, within a package consisting of a pair of aluminum laminate films heat-sealed on all four sides. Then, using the obtained joining member, in the same manner as in Example 6, a slide glass as the adherend was bonded to both sides of the joining member (both sides of the portion where the joining structure with the water-containing joining material is formed) using epoxy adhesive, thereby obtaining a joining test piece using the joining member with the extension portion. The test piece was joined well and did not feel loose.

[0157] To confirm the peelability of the obtained bonded test specimen, a small portion of the extension was cut off to form a water inlet. 5 cc of water was injected into this inlet and sealed with a clip. After leaving it to stand for one hour, the water-containing bonding material absorbed water and lost its adhesive strength, causing the water-containing bonding material and the aluminum laminate film to separate. The aluminum laminate film package could then be easily opened by hand, allowing the test specimen to be separated into two without damaging the slide glass.

[0158] <Example 8> The polymer aqueous solution (PS-1) produced in Production Example 1 was applied to cellophane with a thickness of 10 μm and a width of 15 mm and dried to obtain an adhesive tape having an adhesive layer with a thickness of 10 μm. The formed adhesive layer had a water content of 280 g in a volume of 1 L. When a 30 cm x 20 cm paper poster was attached to a metal wall in a room using the obtained adhesive tape, the poster remained securely fixed for one year without peeling off. Furthermore, when the poster was removed after one year, some of the water-containing bonding material remained on the wall surface, but it could be cleanly removed by rubbing it with a tissue soaked in water.

[0159] <Comparative Example 8> Using commercially available cellophane tape (manufactured by Nichiban Co., Ltd.) with a width of 15 mm, a 30 cm x 20 cm paper poster was attached to a metal wall in a room, similar to Example 8. The poster remained fixed in place for one year without peeling off. However, when the poster was removed after one year, some of the adhesive remained on the wall surface. Although it was rubbed with a tissue soaked in water, it could not be removed at all.

[0160] <Example 9> 74 parts of (3-acrylamidopropyl)trimethylammonium chloride (trade name "DMAPAA(R)-Q", manufactured by KJ Chemicals), 1 part of methylenebisacrylamide, and 25 parts of water were mixed to prepare a 75% by weight monomer aqueous solution. To the prepared monomer aqueous solution, 1% by weight of Omnirad 2959 (manufactured by IGM Resins, photopolymerization initiator) was added relative to the monomer to obtain a raw material solution for forming a water-containing bonding material. This raw material solution was sandwiched between two releaseable PET films with a clearance of 200 μm and polymerized and cured by irradiation with 365 nm UV light to obtain an electroreleaseable, sheet-like, adhesive bonding material. The (3-acrylamidopropyl)trimethylammonium chloride polymer obtained here is water-swellable and deliquescent. This sheet was cut to 2 x 4 cm and bonded between two 2 x 4 cm SUS304 plates (thickness: 100 μm) to obtain a bonding member. At this time, the two SUS plates were in contact only through the sheet, and there was no direct electrical contact that would cause electron conduction. Similarly, a version was also made using a carbon steel (0% Cr) plate instead of the SUS304 plate. When a voltage of 3V was applied to each of these two bonding members using two dry cell batteries, the adhesive force between the sheet and the metal plate weakened, a gap gradually opened up, and after 10 seconds the two metal plates completely separated. Next, when a voltage of 4.5V was applied using three dry cell batteries, they completely separated in 6 seconds. When a voltage of 6V was applied using four dry cell batteries, they completely separated in less than 1 second. Such bonding members, for example, when used to fix the battery in a smartphone, would enable easy and quick battery replacement. When the fabricated joining components were stored for one week without electrolysis, no changes were observed in those made with SUS304, but rust formed between the water-containing joining material and the metal plate in those made with carbon steel. Rust formation is undesirable from an aesthetic standpoint and may also reduce the electrolysis properties.

Claims

1. A water-containing bonding material that constitutes a bonding structure formed by joining two or more members, comprising a water-soluble or water-swellable polymer (P) and 60 g or more of water per liter.

2. The water-containing bonding material according to claim 1, which contains 60 g or more of water per liter at 25°C and 50% RH.

3. The water-soluble or water-swellable polymer (P) is a polymer that can hold 6% by weight or more of water at 25°C and 50% RH, the water-containing bonding material according to claim 1 or 2.

4. A water-containing bonding material according to any one of claims 1 to 3, further comprising a deliquescent substance.

5. The water-soluble or water-swellable polymer (P) is a water-swellable polymer according to any one of claims 1 to 4.

6. The water-soluble or water-swellable polymer (P) is a synthetic polymer, according to any one of claims 1 to 5.

7. The water-containing bonding material according to any one of claims 1 to 6, wherein the total volume ratio of water and the water-soluble or water-swellable polymer (P) in the water-containing bonding material is 500 g / L or more.

8. A water-containing bonding material according to any one of claims 1 to 7, containing 1 part by weight or more of a salt compound per 100 parts by weight of water.

9. A water-containing bonding material according to any one of claims 1 to 8, which is capable of releasing 10% by weight or more of the moisture content before heating when heated to 80°C.

10. A water-containing bonding material according to any one of claims 1 to 9, which can be heated to 60°C or higher by irradiation with microwaves at 2.45 GHz, 500 W for 5 minutes.

11. A water-containing bonding material according to any one of claims 1 to 10, wherein the swelling rate when immersed in water at 25°C is 150% or more.

12. A water-containing bonding material according to any one of claims 1 to 11, which is stored in a package for use.

13. A bonding member comprising a water-containing bonding material according to any one of claims 1 to 12 and at least one conductive material bonded together.

14. The joining member according to claim 13, which is stored in a package for use.

15. A raw material solution for forming a water-containing bonding material, comprising a polymer capable of holding 6% or more by weight of water at 25°C and 50% RH, and water, wherein the viscosity at 25°C is 100 cP or more.

16. The raw material solution for forming a hydrated bonding material according to claim 15, further comprising a polyhydric alcohol compound.

17. A joining member comprising a water-containing joining material according to any one of claims 1 to 12, wherein the water-containing joining material forms a joining structure by joining the inner surface of the package.

18. The joining member according to claim 17, wherein the package is a non-permeable package.

19. The moisture permeability of the package is 10 g / m². ２ The joining member according to claim 18, wherein the number of days is less than or equal to the number of days.

20. The joining member according to any one of claims 17 to 19, wherein the package is an electromagnetic wave-impermeable package.

21. The joining member according to any one of claims 17 to 20, wherein the package is an electromagnetic wave-transmitting package.

22. The joining member according to any one of claims 17 to 21, wherein the package comprises an extension portion that extends from the joining position by the water-containing joining material, and the extension portion is not formed by the water-containing joining material.

23. A joint structure comprising two or more members joined together, wherein at least a part of the joint structure includes a joint portion made of a water-soluble or water-swellable polymer (P) and 60 g or more of water per liter.

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