Easy-to-disassemble adhesive material

Abstract

To provide an easily dismantlable adhesive material having both excellent adhesive strength and easy dismantling properties. [Solution] The easily dismantlable adhesive material of the present invention comprises a thermosetting hyperbranched polymer (P) and a dismantlability-imparting agent (Q), wherein the thermosetting hyperbranched polymer (P) is a dual-cure thermosetting hyperbranched polymer that contains an ethylenically unsaturated double bond group located at the end of the side chain as a first thermosetting group, and also has a second thermosetting group different from the first thermosetting group, and the dismantlability-imparting agent (Q) comprises either or both of a compound (q1) having two or more reactive groups in the molecule that are reactive with the second thermosetting group, and a catalyst compound (q2) that promotes the reaction between the second thermosetting groups.

Description

[Technical Field]

[0001] The present invention relates to an easily dismantlable adhesive technology. [Background technology]

[0002] Easily dismantlable adhesive materials possess sufficient adhesive strength for their intended use and the ability to reduce adhesive strength at any time for easy peeling (dismantling). Demand for these materials is growing for applications such as the separate collection of different materials, repair and replacement of defective parts, and temporary adhesion during manufacturing processes to improve productivity. Various mechanisms for dismantling have been investigated, including a decrease in mechanical strength due to decomposition of the polymer used as the adhesive, changes in physical properties due to polymer reactions, solid-liquid conversion due to photoisomerization, and expansion and deformation of the adhesive layer due to the thermal expansion of thermally expandable microcapsules. Patent Document 1, for example, is a prior art document relating to an adhesive containing thermally expandable microcapsules. Patent Document 2 also describes an adhesive composition containing a copolymer (X) having an alkoxycarbonyloxystyrene structural unit (a) and a glycidyl group-containing (meth)acrylate structural unit (b), and an acid generator (Y).

[0003] From a different perspective from the prior art, the present inventors have been designing and developing easily dismantlable adhesive materials that utilize changes in physical properties that accompany polymer reactions (Non-Patent Document 1). Non-Patent Document 1 describes an easily dismantlable adhesive material that uses a polymer with a tertiary butoxycarbonyl group in the side chain, and operates on a mechanism in which the adhesive strength decreases due to the decomposition of this functional group. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-225544 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-7189 [Non-patent literature]

[0005] [Non-Patent Document 1] Fumiya Suzuki, Eriko Sato, Shoichi Matsumoto "Journal of the Adhesion Society of Japan", Vol. 53, No. 1, pp. 4-10 (2017) Summary of the Invention [Problem to be solved by the invention]

[0006] To design an easily dismantlable adhesive material, it is necessary to reduce the adhesive strength once it has been developed. Furthermore, unlike aging, the material must be able to dismantle on demand and in a short time. Therefore, it is necessary to incorporate a mechanism that quickly reduces interfacial interactions and changes elastic modulus in response to external stimuli.

[0007] The most important point in designing an easily dismantlable adhesive material is how to achieve both high adhesive strength and long-term stability during use, and the ability to easily peel off with little force. In other words, the key design points are that the dismantling mechanism does not impede adhesiveness, and that the adhesive strength decreases at any time. Achieving both of these contradictory properties is often not easy.

[0008] Furthermore, considering that the main purpose of using easily dismantlable adhesive materials is to reuse or separate and recover adherends, or to temporarily bond them during the manufacturing process, it is desirable for them to dismantle at the interface between the adherend and the adhesive material, rather than by cohesive failure that leaves glue behind on the adherend. Furthermore, it is desirable that no volatile organic compounds be emitted during dismantling. Conventional technologies that utilize the decomposition of adhesive materials inevitably result in VOC emissions.

[0009] In light of the above, the present invention provides an easily dismantlable adhesive material that combines excellent adhesive strength with ease of dismantling. The present invention also provides an easily dismantlable adhesive material that dismantles easily at the interface between the adherend and the adhesive material, with reduced adhesive residue at the interface. [Means for solving the problem]

[0010] To solve the above problems, the adhesive of the present invention uses a novel dual-cure thermosetting hyperbranched polymer with specific functional groups, thereby achieving a high level of balance between excellent practical strength and easy dismantling.

[0011] According to the present invention, Contains a thermosetting hyperbranched polymer (P) and a dismantling agent (Q), The thermosetting hyperbranched polymer (P) is a dual-cure thermosetting hyperbranched polymer that includes an ethylenically unsaturated double bond group located at a side chain terminal as a first thermosetting group and has a second thermosetting group different from the first thermosetting group, The dismantling property imparting agent (Q) includes either or both of a compound (q1) having two or more reactive groups in the molecule that are reactive with the second thermosetting group, and a catalyst compound (q2) that promotes the reaction between the second thermosetting groups. Easily removable adhesive material. is provided.

[0012] The present invention also provides an article comprising an adherend and the cured product of the easily dismantlable adhesive material bonded to the adherend.

[0013] Furthermore, according to the present invention, there is provided a dismantling method including the step of heating the article to dismantle the adherend and the cured body of the easily dismantlable adhesive material.

[0014] Furthermore, according to the present invention, there is provided a dual-cure thermosetting hyperbranched polymer obtained by polymerizing a polymerization material containing a polyfunctional monomer (a) having two or more ethylenically unsaturated double bond groups and a monomer (b) having an epoxy group and an ethylenically unsaturated double bond group.

[0015] Furthermore, according to the present invention, there is provided a cured product obtained by curing the above-mentioned thermosetting hyperbranched polymer. [Effects of the Invention]

[0016] According to the present invention, an easily dismantlable adhesive material is provided that combines excellent adhesive strength with easy dismantling. According to the present invention, the material can be easily dismantled at the interface between the adherend and the adhesive material. Furthermore, since the adhesive does not decompose during dismantling, emissions of volatile organic compounds can be suppressed. [Brief explanation of the drawings]

[0017] [Figure 1] 1A and 1B are diagrams illustrating the reaction mechanism and molecular structure of a conventional multifunctional hyperbranched polymer. [Figure 2] FIG. 1 is a diagram schematically illustrating the molecular structure of a conventional multifunctional hyperbranched polymer. [Figure 3] FIG. 1 is a diagram showing a reaction for obtaining a thermosetting hyperbranched polymer of an example. [Figure 4] FIG. 1 shows the 1H-NMR spectrum and assignments of the thermosetting hyperbranched polymer obtained in the examples. [Figure 5] FIG. 1 is a diagram showing the TG-DTA curve of the thermosetting hyperbranched polymer obtained in the example. [Figure 6] FIG. 1 is a diagram showing the TG-DTA curve of the thermosetting hyperbranched polymer obtained in the example. [Figure 7] FIG. 1 is a diagram showing the TG-DTA curve of the thermosetting hyperbranched polymer obtained in the example. [Figure 8] 1 is a stress-displacement curve of the thermosetting hyperbranched polymer P1+DETA (Example B3). [Figure 9] FIG. 1 shows the results of TG-DTA measurement of the easily dismantlable adhesive material and hyperbranched polymer of the example. [Figure 10] FIG. 1 shows the results of TG-DTA measurement of the easily dismantlable adhesive material and hyperbranched polymer of the example. [Figure 11] FIG. 1 shows the results of TG-DTA measurement of the easily dismantlable adhesive material and hyperbranched polymer of the example. [Figure 12] FIG. 2 is a diagram showing the thermal properties of the easily dismantlable adhesive materials of the examples. [Figure 13] FIG. 2 is a diagram showing the results of measuring the infrared absorption spectrum of the easily dismantlable adhesive material of the example. [Figure 14] FIG. 2 is a diagram showing the reaction progress of vinyl groups and epoxy groups in the easily dismantlable adhesive material of the example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Preferred embodiments of the present invention will be described below. In the following description, the notation "to" in a numerical range means "at least, at most," unless otherwise specified. For example, the notation 1 to 5% by mass means at least 1% by mass and at most 5% by mass.

[0019] [Basic composition of easily dismantled adhesive material] The easily dismantlable adhesive material of this embodiment contains a thermosetting hyperbranched polymer (P) and a dismantlability imparting agent (Q).

[0020] As will be described later, thermosetting hyperbranched polymers (P) are multi-branched polymers with irregularly branched structures, consisting of numerous branched chains. Note that the term "branched chains" here refers to both the so-called "trunk" and "branches." The thermosetting hyperbranched polymer (P) is a dual-cure thermosetting hyperbranched polymer that contains an ethylenically unsaturated double bond group located at the end of a side chain as a first thermosetting group, and also has a second thermosetting group that is different from the first thermosetting group. The term "dual-cure" refers to the presence of thermosetting groups that undergo two different types of thermosetting reactions. Furthermore, the term "the first thermosetting group located at the end of a side chain" encompasses both cases where the first thermosetting group is located at the end of a branched chain and (ii) at the end of a pendant group extending from a portion other than the end of a branched chain. A plurality of first thermosetting groups and a plurality of second thermosetting groups may be present in a molecule. The second thermosetting group may be located at the end of a side chain. The dismantling agent (Q) contains either or both of a compound (q1) having two or more reactive groups in the molecule that are reactive with the second thermosetting group, and a catalyst compound (q2) that promotes the reaction between the second thermosetting groups.

[0021] The present inventors have already succeeded in synthesizing multifunctional hyperbranched polymers, and have reported this in the following documents. Literature: (i) Patent No. 6516319 (ii) "Analysis of the thermosetting initiation mechanism of multifunctional hyperbranched polymers by radical trapping," Network Polymer, Vol. 36, No. 4 (2015)

[0022] The multifunctional hyperbranched polymers described in these documents are polymers obtained by the reaction mechanism shown in Figure 1, using ethylene glycol dimethacrylate (EGDMA) as the divinyl monomer and 2-(bromomethyl)methyl acrylate (MBMA) as the AFCT agent. As shown in Figure 2, this multifunctional monomer has only terminal ethylenically unsaturated double bonds as thermosetting reactive groups.

[0023] In contrast, the thermosetting hyperbranched polymer (P) of this embodiment is characterized by being a "dual-cure" hyperbranched polymer having two types of thermosetting reactive groups. Representative reactive groups in the thermosetting hyperbranched polymer (P) of this embodiment include a first thermosetting group being a terminal ethylenically unsaturated double bond and a second thermosetting group being an epoxy group or an oxetanyl group. By combining this type of "dual-cure" hyperbranched polymer (P) with a dismantling agent (Q), it is possible to achieve a high level of both high adhesive strength during use and dismantling ability that allows for easy peeling with little force.

[0024] The easily dismantlable adhesive material of this embodiment contains a dual-cure thermosetting hyperbranched polymer (P) having first and second thermosetting groups and a dismantling property imparting agent (Q), and therefore combines excellent practical strength with ease of dismantling. When the easily dismantlable adhesive material of this embodiment is attached to an adherend and then subjected to a first heat treatment, some of the first and second thermosetting groups react to produce a cured product with a three-dimensional crosslinked structure. When the material is then subjected to a second heat treatment, the remaining thermosetting groups react with the action of the dismantling property imparting agent (Q), further promoting curing, and the cured product can be peeled from the adherend and dismantled. The polymer itself, which has two types of reactive groups with different reactivities, is common. Simply using a polymer with two types of thermosetting groups makes it difficult to achieve easy dismantling. The easily dismantlable adhesive material of this embodiment is characterized by introducing two types of thermosetting groups with different reactivities into a thermosetting hyperbranched polymer and combining this polymer with a dismantling agent (Q). By adopting this configuration, the first heat treatment allows the mechanical strength, such as adhesive strength and elastic modulus, to reach a practical level, and the second heat treatment makes it easy to peel with a weak force. The reason why sufficient mechanical strength and easy disassembly can be achieved by using a thermosetting hyperbranched polymer (P) with two types of thermosetting groups is not entirely clear, but it is speculated as follows. As will be described later, a thermosetting hyperbranched polymer (P) is a multi-branched polymer with an irregularly branched structure, with molecular chains that extend three-dimensionally. This is thought to be because, at the stage where it is hardened by the first heat treatment, it is possible to leave sufficient thermosetting groups that will react in the subsequent heat treatment for disassembly.

[0025] The easily dismantlable adhesive material of this embodiment has two types of thermosetting groups (reactive groups) with different reactivities. Therefore, it is possible to ensure that sufficient residual thermosetting groups are present at the stage at which a cured body is obtained by the first heat treatment. This allows the curing reaction to proceed further by interaction with the dismantlability imparting agent (Q) during the second heat treatment. Therefore, when the temperature is returned to room temperature after the second heat treatment, a large residual thermal stress is generated at the adhesive interface between the cured body and the adherend, allowing the material to be peeled and dismantled.

[0026] The reactions that occur during the first and second heat treatments include various modes. Representative modes include a mode in which at least the first thermosetting groups react with each other during the first heat treatment, and a mode in which at least the second thermosetting groups react due to the action of the dismantling agent (Q) during the second heat treatment. Modes in which the second thermosetting groups react due to the action of the dismantling agent (Q) include a mode in which the second thermosetting groups react with the compound (q1) to bond the thermosetting hyperbranched polymers (P) together, and a mode in which the second thermosetting groups react with each other due to the action of the catalyst compound (q2) to bond the thermosetting hyperbranched polymers (P) together (details of the compound (q1) and the catalyst compound (q2) will be described later).

[0027] The easily dismantlable adhesive material of this embodiment includes a dual-cure thermosetting hyperbranched polymer (P) having first and second thermosetting groups, and a dismantlability-imparting agent (Q). When a compound (q1) having two or more reactive groups in the molecule is used as the dismantlability-imparting agent (Q), the following examples of combinations of the second thermosetting group and the reactive group can be given: Example 1 Second thermosetting group: epoxy group or oxetanyl group Reactive groups: amino, carboxyl, hydroxyl or thiol groups Example 2 Second thermosetting group: an amino group, a carboxyl group, a hydroxyl group, or a thiol group Reactive group: epoxy group or oxetanyl group

[0028] A typical use of the dismantlable adhesive material of this embodiment is to apply the adhesive material to the surface of an adherend, perform a first heat treatment to obtain a hardened body that bonds to the adherend, and then perform a second heat treatment on the hardened body to dismantle the adherend and the hardened body.

[0029] The easily dismantlable adhesive material of this embodiment may be a two-component adhesive material containing a dual-cure thermosetting hyperbranched polymer (P) and a dismantlability imparting agent (Q) (the thermosetting hyperbranched polymer (P) and the dismantlability imparting agent (Q) are filled in separate containers and mixed immediately before use), or may be a one-component adhesive material containing these.

[0030] [Cure properties of easily dismantled adhesive materials] In the easily dismantlable adhesive material of this embodiment, the ratio of F2 to F1 (F2 / F1), measured under the following conditions, is preferably 0.9 or less, more preferably 0.8 or less. There is no particular restriction on the lower limit, and it may be 0, but a ratio of, for example, 0.01 or more or 0.1 or more is sufficient. This makes it possible to achieve a high level of both high adhesive strength during use and dismantlability that allows easy peeling with little force.

[0031] (conditions) (i) Using SUS304 as the adherend, two adherends are bonded together with the easily dismantlable adhesive material, and the shear adhesive strength of the sample is measured in accordance with JIS K 6850:1999. (ii) The shear adhesive strength of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition of 80°C for 7 hours is designated as F1, and the shear adhesive strength of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition and then heat-treating it under the second heat treatment condition of 180°C for 2 hours is designated as F2.

[0032] The technical significance of the F2 / F1 value is as follows: The F2 / F1 value indicates the ease of disassembly by heating. An F2 / F1 ratio less than 1 means that the shear adhesive strength decreases upon heat treatment under the second heat treatment conditions. In adhesive materials using thermosetting resins, heat treatment at high temperatures generally promotes crosslinking of the thermosetting resin, improving the shear adhesive strength of the cured product. In contrast, the shear adhesive strength of the easily dismantled adhesive material of this embodiment decreases upon heat treatment under the second heat treatment conditions. The F2 / F1 value indicates the degree of this decrease, and the inventors have found that this value serves as an index of the ease of disassembly by heating. Considering a structure in which two adherends are bonded using the easily dismantled adhesive material of this embodiment, thermal stress remains in the adhesive material layer due to the difference in linear expansion coefficient between the adhesive material and the adherends. Therefore, a certain degree of peeling action is inherently present at the interface between the adhesive material layer and the adherends. In this state, if an adhesive material is used that reduces F2 compared to F1, particularly if (F2 / F1) is preferably 0.9 or less, more preferably 0.8 or less, it is possible to achieve sufficient ease of dismantling for practical use.

[0033] In the easily dismantlable adhesive material of this embodiment, the ratio of E2 to E1 (E2 / E1), measured under the following conditions, is 0.8 or more, more preferably 0.9 or more, and preferably 1.2 or less, more preferably 1.1 or less. This allows the adherend and the adhesive material to be easily dismantled at their interface, and prevents the adhesive material from remaining on the adherend.

[0034] (conditions) (i) Using SUS304 as the adherend, two adherends are bonded together with the easily dismantlable adhesive material, and the elastic modulus of the sample is measured by a shear test in accordance with JIS K 6850:1999. (ii) The modulus of elasticity in a shear test of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition of 80°C for 7 hours is defined as E1, and the modulus of elasticity in a shear test of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition and then heat-treating it under the second heat treatment condition of 180°C for 2 hours is defined as E2.

[0035] The present inventors have found that the value of (E2 / E1) measured as described above is a good indicator of the likelihood of interfacial peeling occurring. Considering that the main purpose of easily dismantlable adhesive materials is to reuse or separate and recover adherends, or to temporarily bond them in the manufacturing process, it is ideal for them to dismantle at the interface between the adherend and the adhesive material, rather than by cohesive failure that leaves adhesive residue on the adherend. When (E2 / E1) is within the specified range, dismantling occurs easily at the interface between the adherend and the adhesive material, effectively suppressing the amount of adhesive remaining at the interface. E1 and E2 are values ​​calculated by performing a tensile shear bond strength test using the tensile shear bond strength test method for rigid adherends in accordance with JIS K 6850:1999, and calculating the (breaking stress) / (breaking strain) ratio in the resulting stress-strain curve. The flexural modulus and the elastic modulus obtained by viscoelasticity measurement represent the physical properties of the cured body itself. In contrast, the elastic modulus obtained by the shear test calculated as described above represents the physical properties of the interface between the cured body and the adherend.

[0036] As mentioned above, the reason why the (E2 / E1) value is a good indicator of the likelihood of interfacial delamination is not entirely clear. However, it is speculated as follows. The physical properties of the cured material after heat treatment under the second heat treatment conditions of 180°C for 2 hours differ from those after heat treatment under the first heat treatment conditions. Generally, high-temperature heat treatment promotes crosslinking of the thermosetting resin, improving the elastic modulus of the cured material. If the failure mode in the shear adhesion test of Sample 2 was cohesive failure (a mode in which the cured resin itself, rather than the interface, fails), E2 should increase, reflecting the improved elastic modulus. A value of (E2 / E1) close to 1 indicates that the failure in the adhesion test occurs in a failure mode that does not reflect the elastic modulus of the cured resin itself. Specifically, it indicates that the failure is occurring in an interfacial failure mode rather than a cohesive failure mode, meaning that the interface fails before the cured resin fails. The fact that (F2 / F1) is smaller than 1 and the value of E2 / E1 is close to 1 indicates that Sample 2 after the second heat treatment has failed in an interfacial failure mode, and that the interfacial adhesive strength has decreased due to heating under the second heat treatment conditions.

[0037] The 5% weight loss temperature of the cured body obtained by curing the easily dismantlable adhesive material of this embodiment through heat treatment at 80°C for 7 hours is preferably 180°C or higher, more preferably 200°C or higher. There is no particular upper limit, but it can be set to, for example, 350°C or lower. In this way, it is possible to obtain a cured body with sufficient heat resistance through heat treatment at a relatively low temperature.

[0038] In the easily dismantlable adhesive material of this embodiment, the difference (T2 - T1) between the 5% weight loss temperatures T2 and T1 measured under the following conditions is preferably -20°C or higher, more preferably -10°C or higher, and preferably 10°C or lower, more preferably 5°C or lower. This makes it possible to achieve both high adhesive strength during use and dismantlability that allows easy peeling with little force at a high level. (conditions) The 5% weight loss temperature of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions of 80°C for 7 hours is defined as T1, and the 5% weight loss temperature of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions and then heat-treating it under the second heat treatment conditions of 180°C for 2 hours is defined as T2.

[0039] The 5% weight loss temperature of the cured body obtained by curing the easily dismantlable adhesive material of this embodiment through heat treatment at 180°C for 1 hour is preferably 200°C or higher, more preferably 240°C or higher. There is no particular upper limit, but it can be set to 400°C or lower. This improves the heat resistance of the easily dismantlable adhesive material cured body. The constituent components of the easily dismantlable adhesive material of this embodiment will be described below.

[0040] [Thermosetting hyperbranched polymer (P)] The thermosetting hyperbranched polymer (P) in this embodiment is a multi-branched polymer with an irregularly branched structure. It differs significantly from conventional branched polymers in that the branched chains are spread three-dimensionally. The thermosetting hyperbranched polymer (P) is a polymer with a high molecular weight, but with little three-dimensional molecular entanglement, and a lower viscosity (solution viscosity) than a linear polymer of the same molecular weight.

[0041] The thermosetting hyperbranched polymer (P) in this embodiment is a polymer having two types of thermosetting reactive groups, and the reactive groups react with each other by heat treatment, bonding the polymers together to form a three-dimensional crosslinked body.

[0042] The thermosetting hyperbranched polymer (P) of this embodiment has a thermosetting group, and therefore exhibits thermosetting properties as a polymer alone. Furthermore, the thermosetting hyperbranched polymer (P) of this embodiment has a second thermosetting group, and therefore a thermosetting reaction also occurs due to the action of the dismantling agent (Q). When a compound (q1) having two or more reactive groups reactive with the second thermosetting group in its molecule is selected as the dismantling agent (Q), the first thermosetting groups contained in different thermosetting hyperbranched polymers (P) are bonded to each other via the compound (q1). When a catalyst compound (q2) is selected as the dismantling agent (Q), the first thermosetting groups contained in different thermosetting hyperbranched polymers (P) are bonded to each other directly.

[0043] [Basic structure of thermosetting hyperbranched polymer (P)] The thermosetting hyperbranched polymer (P) of this embodiment may have, for example, an ethylenically unsaturated double bond at the end of a first side chain in the molecule and an epoxy group at the end of a second side chain in the molecule. More specifically, the thermosetting hyperbranched polymer (P) of this embodiment can include, for example, the following structural unit I and structural unit II. (Structural unit I)

[0044] [ka]

[0045] [In the formula, R 11 and R 12 each independently represents a hydrogen atom or a methyl group, and A represents a direct bond or a divalent group. (Structural Unit II)

[0046] [ka]

[0047] [In the formula, R 21represents a hydrogen atom or a methyl group, B represents a direct bond or a divalent group, and Ep represents a monovalent group containing an epoxy group. Here, the Ep group may include a glycyl group or a 3,4-epoxycyclohexyl group.

[0048] Preferred examples of (structural unit I) include the following structural units Ia and Ib. (Structural unit Ia)

[0049] [ka]

[0050] [In the formula, R 11 and R 12 each independently represents a hydrogen atom or a methyl group; A 1 represents a direct bond or a divalent group. (Structural unit Ib)

[0051] [ka]

[0052] [In the formula, R 11 and R 12 each independently represents a hydrogen atom or a methyl group; A 2 represents a direct bond or a divalent group.

[0053] In the above general formulas, A, B, A 1 and A 2 The divalent group is not particularly limited, and examples thereof include divalent organic groups having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. Specific examples of the divalent organic group include linear or branched alkylene groups, cycloalkylene groups, polycyclic aliphatic groups, arylene groups, -O-, -CO-, -COO-, -OCO-, -S-, -SO2-, -NH-, -NR- (where R is a monovalent organic group), and groups formed by combining two or more of these groups.

[0054] A preferred embodiment of (structural unit II) will be explained. Specific examples of the (-B-Ep) group include those represented by the following formula (E1): [ka]

[0055] [R 22 is a direct bond, an alkylene group having 1 to 18 carbon atoms, or an oxyalkylene group having 1 to 18 carbon atoms.] Or, the following formula (E2)

[0056] [ka]

[0057] [R 23 is a direct bond, an alkylene group having 1 to 18 carbon atoms, or an oxyalkylene group having 1 to 18 carbon atoms.] Examples of the group include any of the groups represented by the following formula:

[0058] The thermosetting hyperbranched polymer (P) can be a polymer obtained by polymerizing a polymer material containing a polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds and a monomer (b) having an epoxy group and an ethylenically unsaturated double bond (however, the polyfunctional monomer (a) does not fall under the category of monomer (b)).

[0059] The polymeric material has the general formula (I):

[0060] [ka]

[0061] [In the formula, R 1 is a halogen atom, an -SR group, an -OR group, an -OOR group, or a -C(R) group (wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The three Rs may be the same or different), and R 2is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The copolymer may further contain an addition-fragmentation chain transfer agent (c) represented by the following formula:

[0062] As mentioned above, the multifunctional hyperbranched polymers previously developed by the present inventors have only a terminal ethylenically unsaturated double bond as a thermosetting reactive group. In contrast, the thermosetting hyperbranched polymer (P) of this embodiment is characterized by being a "dual-cure" hyperbranched polymer having two types of thermosetting reactive groups. The thermosetting hyperbranched polymer (P) of this embodiment is obtained by polymerizing a polymerization material containing a multifunctional monomer (a) and a monomer (b) having an epoxy group and an ethylenically unsaturated double bond. The combined use of the multifunctional monomer (a) and the monomer (b) achieves both high adhesive strength during use and easy disassembly, allowing for weak peeling.

[0063] The polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds, the monomer (b) having an epoxy group and an ethylenically unsaturated double bond, the addition-fragmentation chain transfer agent (c), and the other monomers will be described below. The following will describe the monomer (b), the other monomers, the addition-fragmentation chain transfer agent (c), and the polyfunctional monomer (a) in that order.

[0064] [Monomer (b) having an epoxy group and an ethylenically unsaturated double bond] The monomer (b) having an epoxy group and an ethylenically unsaturated double bond may be: Glycidyl group-containing methacrylic acid esters such as glycidyl methacrylate, 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl methacrylate, and 4-hydroxybutyl methacrylate glycidyl ether (4HBAGE): vinylbenzyl glycidyl ethers such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether; Alicyclic epoxy group-containing methacrylic acid esters such as 3,4-epoxycyclohexylmethyl methacrylate, 2-propenoic acid, 2-methyl-, 7-oxabicyclo[4.1.0]hept-3-ylmethyl ester (CAS No.: 82428-30-6), 2-propenoic acid, 2-methyl-, octahydro-2,5-methano-2H-indeno[1,2-b]oxiren-4-yl ester (CAS No.: 143963-39-7), etc.; Glycidyl group-containing acrylic esters such as glycidyl acrylate, 3,4-epoxybutyl acrylate, 6,7-epoxyheptyl acrylate, α-ethyl acrylate-6,7-epoxyheptyl, and 4-hydroxybutyl acrylate glycidyl ether (4HBAGE): glycidyl group-containing α-alkyl acrylate esters such as α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, and α-n-butyl glycidyl acrylate; Examples include:

[0065] Among these, glycidyl group-containing methacrylic acid esters such as glycidyl methacrylate and 6,7-epoxyheptyl methacrylate, and vinylbenzyl group-containing glycidyl compounds such as o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether are preferably used in terms of copolymerization reactivity. These epoxy group-containing unsaturated compounds may be used singly or in combination of two or more.

[0066] [Other monomers] A preferred example of the thermosetting hyperbranched polymer (P) in this embodiment is based on three components: a polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds, a monomer (b) having an epoxy group and an ethylenically unsaturated double bond, and an addition-fragmentation chain transfer agent (c), but other monomers may be used in combination as long as they do not impair the effects of this embodiment. Examples of other monomers include monofunctional vinyl monomers.

[0067] Examples of monofunctional vinyl monomers include n-dodecyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-undecyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate, benzyl (meth)acrylate, acrylate, methoxypolyethylene glycol mono(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, 2-hydroxyhexyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, 8-hydroxyoctyl(meth)acrylate, 10-hydroxydecyl(meth)acrylate, 12-hydroxylauryl(meth)acrylate, styrene, styrene derivatives, vinyl acetate, acrylonitrile, and (meth)acrylamide.

[0068] Among these, as the monofunctional vinyl monomer, methacrylates having an alkyl group or a hydroxyalkyl group are preferred in terms of copolymerizability and adhesiveness, and n-dodecyl methacrylate (DMA: dodecyl methacrylate), 2-ethylhexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, n-nonyl methacrylate, isononyl methacrylate, n-decyl methacrylate, isodecyl methacrylate, n-undecyl methacrylate, 10-hydroxydecyl methacrylate, 12-hydroxylauryl methacrylate, 2-hydroxyhexyl methacrylate, 6-hydroxyhexyl methacrylate, 8-hydroxyoctyl methacrylate, 10-hydroxydecyl methacrylate, and 12-hydroxylauryl methacrylate are more preferred, with DMA being particularly preferred.

[0069] [Addition-fragmentation chain transfer agents] The addition-fragmentation chain transfer agent (AFCT agent) is represented, for example, by the general formula (I).

[0070] [ka]

[0071] [In the formula, R 1 is a halogen atom, a -SR group, a -OR group, a -OOR group, or a -C(R) group (wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and R 2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.] Substituent R 1 Examples of the halogen atom include fluorine, chlorine, bromine, and iodine. In terms of the chain transfer constant, chlorine and bromine are preferred, with bromine being particularly preferred.

[0072] The substituent R in the general formula (I) 1 Examples of the alkyl group having 1 to 4 carbon atoms as the substituent R in the -SR group, -OR group, -OOR group and -C(R) group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and sec-butyl, and among these, tert-butyl is particularly preferred in terms of the chain transfer constant.

[0073] Substituent R 1 In addition to the above, the alkyl group may have an aromatic ring, an oxygen atom, or a nitrogen atom, and specific examples thereof include 2-hydroxyethyl, 2-aminoethyl, 2-carboxyethyl, carboxymethyl, 3-(trimethoxysilyl)propyl, bis(methoxycarbonyl)methyl, bis(ethoxycarbonyl)methyl, tris(methoxycarbonyl)methyl, tris(ethoxycarbonyl)methyl, and (dimethylmethoxycarbonyl)methyl.

[0074] The substituent R in the general formula (I) 2Examples of the alkyl group having 1 to 10 carbon atoms include linear, branched, or cyclic alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl. Among these, alkyl groups that give primary and secondary ester groups are particularly preferred in terms of thermal stability.

[0075] Substituent R 2 In addition to the above, the alkyl group may have an aromatic ring, an oxygen atom, or a nitrogen atom, and specific examples thereof include benzyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxybutyl, 4-hydroxybutyl, 2-hydroxyhexyl, 6-hydroxyhexyl, 8-hydroxyoctyl, 10-hydroxydecyl, and 12-hydroxylauryl.

[0076] As described above, the substituent R in the general formula (I) 1 As the substituent R, bromine is preferred in terms of not exhibiting homopolymerizability, having a large chain transfer constant, and the thermosetting properties of the thermosetting hyperbranched polymer. 2 As the alkyl group, alkyl groups that give primary and secondary ester groups are particularly preferred in terms of thermal stability.

[0077] Examples of addition-fragmentation chain transfer agents include methyl 2-(bromomethyl)acrylate (MBMA), ethyl 2-(bromomethyl)acrylate, n-propyl 2-(bromomethyl)acrylate, isopropyl 2-(bromomethyl)acrylate, n-butyl 2-(bromomethyl)acrylate, isobutyl 2-(bromomethyl)acrylate, sec-butyl 2-(bromomethyl)acrylate, tert-butyl 2-(bromomethyl)acrylate, pentyl 2-(bromomethyl)acrylate, hexyl 2-(bromomethyl)acrylate, cyclohexyl 2-(bromomethyl)acrylate, heptyl 2-(bromomethyl)acrylate, octyl 2-(bromomethyl)acrylate, 2-ethylhexyl 2-(bromomethyl)acrylate, nonyl 2-(bromomethyl)acrylate, decyl 2-(bromomethyl)acrylate, methyl 2-(tert-butylthiomethyl)acrylate, and methyl 2-( tert-butylthiomethyl)ethyl acrylate, 2-(tert-butylthiomethyl)benzyl acrylate, 2-(2-hydroxyethylthioethyl)ethyl acrylate, 2-(carboxymethylthiomethyl)ethyl acrylate, 2-(2-hydroxyethylthiomethyl)acrylic acid, 2-(carboxymethylthiomethyl)acrylic acid, 2-(bromomethyl)styrene, 2-(t-butylthiomethyl)styrene, 2-(2-hydroxyethylthiomethyl)styrene, 2-(2-aminoethylthiomethyl)styrene, 2-(carboxymethylthiomethyl)styrene, 2-(2-carboxyethylthiomethyl)styrene, 2-((3-trimethoxysilylpropyl)thiomethyl)styrene, 2-(bromomethyl)acrylonitrile, 2-(tert-butylthiomethyl)acrylonitrile, dimethyl 2,2-dimethyl-4-methyleneglutamate.

[0078] Among these, the addition-fragmentation chain transfer agent is preferably an aliphatic (meth)acrylic compound from the viewpoint of the heat resistance and adhesiveness of the resulting polymer. MBMA, which has high chain transfer ability, such as ethyl 2-(bromomethyl)acrylate, n-propyl 2-(bromomethyl)acrylate, isopropyl 2-(bromomethyl)acrylate, n-butyl 2-(bromomethyl)acrylate, isobutyl 2-(bromomethyl)acrylate, sec-butyl 2-(bromomethyl)acrylate, tert-butyl 2-(bromomethyl)acrylate, pentyl 2-(bromomethyl)acrylate, hexyl 2-(bromomethyl)acrylate, cyclohexyl 2-(bromomethyl)acrylate, heptyl 2-(bromomethyl)acrylate, octyl 2-(bromomethyl)acrylate, 2-ethylhexyl 2-(bromomethyl)acrylate, nonyl 2-(bromomethyl)acrylate, and decyl 2-(bromomethyl)acrylate are more preferred, and MBMA is particularly preferred.

[0079] [Polyfunctional Monomer (a)] The polyfunctional monomer (a) is a compound having ethylenically unsaturated double bonds at both ends of the molecule.

[0080] The polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds may be any monomer capable of forming a thermosetting hyperbranched polymer (P) by radical polymerization with an addition-fragmentation chain transfer agent. The polyfunctional monomer (a) has two or more ethylenically unsaturated double bonds in the molecule, and some of the ethylenically unsaturated double bonds can form a polymer chain as thermosetting groups. Meanwhile, some of the unreacted ethylenically unsaturated double bonds can remain as pendant groups in the side chains. Preferred examples of the polyfunctional monomer (a) include compounds having ethylenically unsaturated double bonds at both ends of the molecule.

[0081] Preferred examples of the polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds include meth(acrylic) ester compounds and aromatic vinyl compounds. In this embodiment, "(meth)acrylic" means "acrylic" or "methacrylic".

[0082] Examples of meth(acrylic) acid ester compounds include ethylene glycol dimethacrylate (EGDMA), ethylene glycol diacrylate (EGDA), diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 2,2-dimethylpropanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and dicyclopentadiene di(meth)acrylate. aliphatic di(meth)acrylic acid esters such as methanol di(meth)acrylate, glycerol di(meth)acrylate, diglycerol di(meth)acrylate, triglycerol di(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, diurethane di(meth)acrylate, bis(2-methacryloyl)oxyethyl disulfide, bis(2-acryloyl)oxyethyl disulfide, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexaacrylate; Bisphenol A di(meth)acrylate, bisphenol A ethylene glycol di(meth)acrylate, bisphenol A diethylene glycol di(meth)acrylate, bisphenol A triethylene glycol di(meth)acrylate, bisphenol A tetraethylene glycol di(meth)acrylate, bisphenol A polyethylene glycol di(meth)acrylate, bisphenol A glycerolate di(meth)acrylate, bisphenol A glycerolate tri(meth)acrylate, bisphenol A glycerolate tetra(meth)acrylate, 1,4-phenylene di(meth)acrylate Aromatic (meth)acrylic acid esters such as bisphenol F di(meth)acrylate, bisphenol F ethylene glycol di(meth)acrylate, bisphenol F diethylene glycol di(meth)acrylate, bisphenol F triethylene glycol di(meth)acrylate, bisphenol F tetraethylene glycol di(meth)acrylate, bisphenol F polyethylene glycol di(meth)acrylate, bisphenol F glycerolate di(meth)acrylate, bisphenol F glycerolate tri(meth)acrylate, bisphenol F glycerolate tetra(meth)acrylate, etc.; Examples include:

[0083] Examples of aromatic vinyl compounds include substituted or unsubstituted divinylbenzenes such as divinylbenzene, dibromodivinylbenzene, dimethoxydivinylbenzene, diethoxydivinylbenzene, dipropoxydivinylbenzene, dibutoxydivinylbenzene, dipentyloxydivinylbenzene, dihexyloxydivinylbenzene, diheptyloxydivinylbenzene, dioctyloxydivinylbenzene, dinonyloxydivinylbenzene, didecyloxydivinylbenzene, and di(2-ethylhexyl)oxydivinylbenzene.

[0084] Among these, as the polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds, from the viewpoint of achieving both adhesiveness and ease of disassembly of the resulting polymer, aliphatic (meth)acrylic monomers are preferred, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate are more preferred, and diethylene glycol dimethacrylate (EGDMA) is particularly preferred.

[0085] [Combination of ingredients] A preferred example of the components of the polymerization material is a combination in which the polyfunctional monomer (a) and the addition-fragmentation chain transfer agent (c) are both aliphatic (meth)acrylic acid ester compounds ((meth)acrylic acid ester compounds), and the monomer (b) having an epoxy group and an ethylenically unsaturated double bond is a glycidyl group-containing methacrylic acid ester or a vinylbenzyl group-containing glycidyl compound.

[0086] [Component ratio] The molar ratio of the polyfunctional monomer (a), the monomer having an epoxy group and an ethylenically unsaturated double bond (b), and the addition-fragmentation chain transfer agent (c) may be appropriately determined depending on the materials of the monomer components and the physical properties of the polymer material to be obtained.

[0087] The ratio nb / na of the number of structural units nb derived from the monomer (b) having an epoxy group and an ethylenically unsaturated double bond group to the number of structural units na derived from the polyfunctional monomer (a) is preferably 0.05 or more and 10 or less, more preferably 0.1 or more and 7 or less.

[0088] The molar ratio of the total ethylenically unsaturated double bond groups of the monomers (a) and (b) to the ethylenically unsaturated double bond groups of the addition-fragmentation chain transfer agent (c) is preferably 1 / 0.01 to 1 / 10, more preferably 1 / 0.03 to 1 / 10, even more preferably 1 / 0.05 to 1 / 10, still more preferably 1 / 0.3 to 1 / 2, and particularly preferably 1 / 0.5 to 1 / 2. If the ratio of the addition-fragmentation chain transfer agent (c) is less than 0.01 moles per mole of the total of monomers (a) and (b), gelation may occur during the polymerization reaction to obtain the thermosetting hyperbranched polymer (P). On the other hand, if the ratio of the addition-fragmentation chain transfer agent exceeds 10 moles per mole of the polyfunctional monomer, it may be difficult to obtain a product with a sufficiently high molecular weight.

[0089] (Ratio when monofunctional vinyl monomer is used in combination) When a monofunctional vinyl monomer is used in combination, the molar ratio of the polyfunctional monomer (a) to the monofunctional vinyl monomer may be appropriately determined depending on the materials of the monomer components and the physical properties of the polymer material to be obtained.

[0090] The molar ratio of the polyfunctional monomer (a) to the monofunctional vinyl monomer is preferably 1 / 0.1 to 1 / 4, more preferably 1 / 0.2 to 1 / 2, and even more preferably 1 / 0.5 to 1 / 1. This makes it possible to optimize the properties of the resulting polymer, such as the glass transition temperature, and also to optimize the branched structure and the introduction rate of reactive vinyl groups.

[0091] When the constituent monomers of the thermosetting hyperbranched polymer (P) contain a monofunctional vinyl monomer component, the total amount of the polyfunctional monomer and the monofunctional vinyl monomer is set to the polyfunctional monomer in the molar ratio of the polyfunctional monomer to the addition-fragmentation chain transfer agent. That is, the monofunctional vinyl monomer is used as a substitute for the polyfunctional monomer, and each component is set to have the ratio with the addition-fragmentation chain transfer agent. By using a monofunctional vinyl monomer and adjusting the polymerization time, the number of vinyl groups per polymer chain can be varied. The number of vinyl groups per polymer chain is usually 1 to 40, preferably 2 to 30, and more preferably 5 to 25. By having one or more vinyl groups, it is easy to obtain sufficient thermosetting properties for the thermosetting hyperbranched polymer (P), while by having 40 or fewer vinyl groups, it is easy to prevent unintended crosslinking during polymerization.

[0092] [Properties of thermosetting hyperbranched polymer (P)] The preferred numbers of first and second thermosetting groups contained in the thermosetting hyperbranched polymer (P) of this embodiment will be described. The number Na of ethylenically unsaturated double bond groups at the side chain terminals contained per molecule of the thermosetting hyperbranched polymer (P) is preferably 0.1 or more, more preferably 1 or more, and preferably 30 or less, more preferably 20 or less. This makes it possible to achieve higher adhesive strength during use.

[0093] Furthermore, the number Nb of epoxy groups at the side chain ends contained per molecule of the thermosetting hyperbranched polymer (P) of this embodiment is preferably 0.1 or more, more preferably 1 or more, and preferably 20 or less, more preferably 10 or less. This allows for a synergistic effect with the dismantling property imparting agent (Q) to achieve better dismantling properties. Incidentally, the term "epoxy group at the side chain end" encompasses both the case where the epoxy group is (i) at the end of a branched chain and the case where the epoxy group is at the end of a pendant group extending from a portion other than the end of a branched chain.

[0094] The lower limit of the ratio Nb / Na of the number Na of ethylenically unsaturated double bond groups at the side chain terminals to the number Nb of epoxy groups at the side chain terminals contained per molecule of the thermosetting hyperbranched polymer (P) of this embodiment is preferably 0.1 or more, more preferably 0.2 or more, and the upper limit is preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less. This makes it possible to achieve both high adhesive strength during use and dismantling ability that allows easy peeling with little force at a higher level.

[0095] The lower limit of the number average molecular weight Mn of the thermosetting hyperbranched polymer (P) of this embodiment is preferably 0.5 × 10 3 or more, more preferably 1×10 3 The upper limit is preferably 5×10 4 Less than or equal to 3×10 4 or less, more preferably 1 × 10 4 This makes it possible to achieve both high adhesive strength during use and ease of disassembly, allowing for easy peeling with little force, at a high level.

[0096] The thermosetting hyperbranched polymer (P) of this embodiment preferably has a number-average molecular weight Mn of 500 to 30,000. The weight-average molecular weight Mw / number-average molecular weight Mn is preferably 1.2 to 20, more preferably 1.2 to 15, and even more preferably 1.2 to 10. When the Mn and Mw / Mn satisfy these values, the viscosity of the thermosetting hyperbranched polymer (P) is usually about 0.01 to 0.3 dL / s. Incidentally, dismantling properties can sometimes be further improved by using a thermosetting hyperbranched polymer (P) with a deliberately large Mw / Mn ratio (for example, Mw / Mn of 8 to 20, specifically 10 to 15). Thermosetting hyperbranched polymers (P) with broad molecular weight distributions contain relatively large amounts of high molecular weight components. Although the details are unclear, this high molecular weight component may be related to better dismantling properties.

[0097] Furthermore, the number of thermosetting groups (for example, the total number of terminal ethylenically unsaturated double bonds and epoxy groups) in one polymer molecule of the thermosetting hyperbranched polymer (P) of this embodiment is approximately 1 to 50, and from the viewpoint of thermosetting property, it is preferably 5 to 50.

[0098] [Dismantling agent (Q)] The dismantling property imparting agent (Q) is a component that imparts dismantling property to the cured body of the easily dismantlable adhesive material. The dismantling property imparting agent (Q) is used by mixing it with the thermosetting hyperbranched polymer (P). The easily dismantlable adhesive material is used in a mode in which, for example, the easily dismantlable adhesive material is heated to perform a first curing step, and then further subjected to a second or subsequent curing step, thereby allowing the material to be dismantled. When used in this mode, the dismantling property imparting agent (Q) can exhibit any of the following actions:

[0099] ·Action 1 During the second or subsequent curing stage of the easily dismantlable adhesive material, the dismantlability-imparting agent (Q) reacts with the second thermosetting groups or promotes the reaction between the second thermosetting groups, thereby effectively reducing the adhesive strength at the interface between the easily dismantlable adhesive material and the adherend.

[0100] ·Action 2 In the first curing stage of the easily dismantlable adhesive material, the dismantlability-imparting agent (Q) reacts with the second thermosetting groups or promotes the reaction between the second thermosetting groups, thereby making the cured product obtained in the first curing stage easy to dismantle by subsequent heat treatment.

[0101] The dismantling agent (Q) contains either or both of a compound (q1) having two or more reactive groups in the molecule that are reactive with the second thermosetting group, and a catalyst compound (q2) that promotes the reaction between the second thermosetting groups. The compound (q1) can be selected depending on the type of the second thermosetting group. As mentioned above, the following examples are given. Example 1 When the second thermosetting group is an epoxy group, a compound having an amino group, a carboxyl group, a hydroxyl group or a thiol group as a reactive group is selected as the compound (q1). Example 2 When the second thermosetting group is an amino group, a carboxyl group, a hydroxyl group, or a thiol group, a compound having an epoxy group as a reactive group is selected as the compound (q1).

[0102] For example, when the second thermosetting group is an epoxy group, i.e., when the thermosetting hyperbranched polymer (P) is a polymer containing an epoxy group, the compound used as compound (q1) is preferably a compound having two or more amino groups. More specifically, from the viewpoint of imparting excellent dismantling properties, it is preferable that the compound be at least one polyamine compound selected from the group consisting of aliphatic polyamine compounds, aromatic polyamine compounds, and alicyclic polyamine compounds, and that the polyamine compound has two or more primary amino groups.

[0103] Examples of aliphatic polyamine compounds having two or more primary amino groups include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine.

[0104] Examples of aromatic polyamine compounds having two or more primary amino groups include m-xylylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.

[0105] Examples of alicyclic polyamine compounds having two or more primary amino groups include 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, isophoronediamine, menthanediamine, and 1,3-bisaminocyclohexane.

[0106] Examples of compounds other than those mentioned above include dicyandiamide, acid anhydrides, dibasic acid dihydrazides (oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, etc.), melamine, etc. When the easily dismantlable adhesive material is a one-component adhesive material, a so-called latent curing agent can be used as the dismantlability imparting agent (Q). The latent curing agent does not react when present in the thermosetting hyperbranched polymer (P) at room temperature, but is activated and begins to react upon heat treatment. The microcapsule-type latent curing agent is a particle having a shell and a core, and the core contains the curing agent. Upon heat treatment at a predetermined temperature or higher, part of the shell breaks, allowing the internal curing agent to leak out, activating its reactivity with epoxy groups. Examples of microcapsule-type latent curing agents include Novacure (registered trademark) HX-3722, HX-3748, HX-3088, HX-3741, and HX-3742 manufactured by Asahi Kasei Corporation.

[0107] The amount of the dismantling agent (Q) to be added is not particularly limited, but may be, for example, as follows. When a compound (q1) having two or more reactive groups reactive with the second thermosetting group in the molecule is used as the dismantlability-imparting agent (Q), it is preferably blended so that the number n2 of reactive groups reactive with the second thermosetting group in compound (q1) relative to the number n1 of second thermosetting groups satisfies n2 / n1 = 0.6 to 1.4. For example, when the second thermosetting group is an epoxy group or an oxetanyl group and the reactive group in compound (q1) is an amino group, a carboxyl group, a hydroxyl group, or a thiol group, it is preferable that the value of the active hydrogen equivalent of the reactive group relative to the epoxy equivalent or the oxetanyl equivalent is 0.6 to 1.4. When the catalyst compound (q2) is used as the dismantling property imparting agent (Q), the blending amount is appropriately determined depending on the type of the catalyst compound (q2) and other factors.

[0108] [Other ingredients] The easily dismantlable adhesive material of this embodiment may contain a polymer other than the thermosetting hyperbranched polymer (P). For example, an epoxy resin may be used in combination to increase adhesive strength.

[0109] The easily dismantlable adhesive material may contain an organic solvent in which the thermosetting hyperbranched polymer (P) is dissolved or dispersed. Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone.

[0110] Among the above, acetone, MEK, ethyl acetate, DMF, etc. are preferred because they have high solubility and tend to volatilize easily from the adhesive layer. The organic solvents may be used alone or in combination of two or more.

[0111] Examples of other optional components include inorganic particles such as silica and alumina, fiber fillers such as glass fiber and carbon fiber, thermoplastic elastomers, flame retardants, and antifoaming agents.

[0112] The easily dismantlable adhesive material according to this embodiment may contain a polymer other than the thermosetting hyperbranched polymer (P). For example, an epoxy resin may be used in combination to enhance adhesive strength. Furthermore, inorganic fillers, organic fillers, silane coupling agents, antifoaming agents, etc. may also be included.

[0113] [Manufacturing method for thermosetting hyperbranched polymer (P)] The thermosetting hyperbranched polymer (P) can be produced by polymerizing a polymerization material containing a polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds and a monomer (b) having an epoxy group and an ethylenically unsaturated double bond. The polymerization material may further contain the aforementioned addition-fragmentation chain transfer agent (c). The polymerization can be a one-stage polymerization at a polymerization temperature of 30 to 180°C. Different functional groups are introduced into the initiation terminal, termination terminal, and side chains by addition-fragmentation chain transfer of the addition-fragmentation chain transfer agent (c).

[0114] Addition-fragmentation chain transfer (AFCT) is a type of chain transfer reaction that involves the addition of a propagating radical to an AFCT agent and the β-cleavage of the resulting adduct radical, as shown in the following equation. A 2-substituted-2-propenyl group is introduced at the ω-terminus, and a functional group derived from the radical released by β-cleavage is introduced at the α-terminus.

[0115] [ka]

[0116] The single-stage polymerization is preferably carried out in the presence of a radical initiator such as a peroxide, an azo compound, or a persulfate, particularly preferably in the presence of a radical initiator such as a peroxide or an azo compound, and more preferably in the presence of an azo compound (azo-based polymerization initiator). Examples of the azo-based polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN) and azobisdimethylvaleronitrile.

[0117] The amount of radical initiator added may be appropriately determined depending on the materials of the monomer components and the physical properties of the polymer material to be obtained, but is usually about 0.0002 to 0.02 moles per mole of the total of monomer (a) and monomer (b). The single-stage polymerization may be carried out either in the presence or absence (bulk) of an organic solvent.

[0118] The solvent is not particularly limited as long as it dissolves the monomer components, does not inhibit the polymerization reaction, and does not adversely affect the resulting polymer. Examples of the solvent include polar solvents such as toluene, chloroform, acetone, and ethyl acetate. The polymerization conditions for the single-stage polymerization may be appropriately set depending on the materials of the monomer components, the physical properties of the polymer material to be obtained, etc. The polymerization temperature is usually 30 to 200°C.

[0119] If the polymerization temperature is lower than 30°C, the chain transfer ability may decrease. On the other hand, if the polymerization temperature exceeds 200°C, the produced polymer may be thermally decomposed. The preferred polymerization temperature is 30 to 180°C.

[0120] The polymerization time is usually 0.1 to 50 hours. If the polymerization time is less than 0.1 hour, the polymer yield may be low. On the other hand, if the polymerization time exceeds 50 hours, gelation may occur or the double bonds introduced into the polymer may be consumed. The preferred polymerization time is 0.5 to 12 hours.

[0121] [Easy disassembly method] The easily dismantlable adhesive material of this embodiment is used in a process in which, for example, an easily dismantlable adhesive is attached to the surface of an adherend, the easily dismantlable adhesive is heat-cured by a first heat treatment to obtain an article in which a cured body of the easily dismantled adhesive is bonded to the adherend, and then the cured body of the easily dismantled adhesive is peeled off from the adherend by a second heat treatment for dismantling. If the temperature conditions used for heat-curing (first heat treatment) are referred to as first temperature conditions and the temperature conditions used for dismantling (second heat treatment) are referred to as second temperature conditions, it is preferable that the second temperature conditions have a higher curing temperature than the first temperature conditions.

[0122] The type of adherend is not particularly limited, but examples include metals such as aluminum, aluminum alloys, and SUS, plastics such as polypropylene, polyethylene, and nylon, and ceramics. The adherend may or may not be surface-treated with a silane coupling agent or the like. In terms of adhesive strength and ease of disassembly, it is preferable to remove foreign matter / contamination from the surface of the adherend by cleaning the surface before adhering the easily dismantled adhesive to the surface of the adherend.

[0123] If the curing temperature under the first temperature condition is T1 and the curing temperature under the second temperature condition is T2, the value of (T2 - T1) is preferably 30° C. or higher, more preferably 50° C. or higher, and most preferably 70° C. or higher. This makes it possible to achieve sufficient strength of the cured body and ease of disassembly. The upper limit of the value of (T2-T1) is preferably set to 130°C or less, more preferably 120°C or less, from the viewpoint of saving energy in the dismantling process. Practically, the preferable temperature conditions are that T1 is 20°C or more and 100°C or less, and T2 is 100°C or more and 250°C or less.

[0124] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. The present invention also has an aspect as an easily dismantlable adhesive material, the reference embodiment of which is given below. 1. Contains a thermosetting hyperbranched polymer (P) and a dismantling agent (Q), the thermosetting hyperbranched polymer (P) is a dual-cure thermosetting hyperbranched polymer that includes an ethylenically unsaturated double bond group located at a side chain terminal as a first thermosetting group and has a second thermosetting group different from the first thermosetting group; The dismantling property imparting agent (Q) includes either or both of a compound (q1) having two or more reactive groups in the molecule that are reactive with the second thermosetting group, and a catalyst compound (q2) that promotes the reaction between the second thermosetting groups. Easily removable adhesive material. 2. 1. The easily dismantlable adhesive material according to claim 1, the dismantling property imparting agent (Q) contains the compound (q1), An easily dismantlable adhesive material, wherein one of the second thermosetting group and the reactive group is an epoxy group or an oxetanyl group, and the other is an amino group, a carboxyl group, a hydroxyl group, or a thiol group. 3. 1. The easily dismantlable adhesive material according to 1. or 2., The thermosetting hyperbranched polymer (P) comprises the structural unit I and the structural unit II, which are easily dismantled adhesive materials. (Structural Unit I: see above) [In the formula, R 11 and R 12 each independently represents a hydrogen atom or a methyl group, and A represents a direct bond or a divalent group. (Structural Unit II: see above) [In the formula, R 21 represents a hydrogen atom or a methyl group, B represents a direct bond or a divalent group, and Ep represents a monovalent group containing an epoxy group. 4. 3. The easily dismantlable adhesive material according to claim 1, An easily dismantlable adhesive material, wherein the Ep group contains a glycyl group or a 3,4-epoxycyclohexyl group. 5. 4. The easily dismantlable adhesive material according to claim 4, The (-B-Ep) group is represented by the formula (E1) shown above, [R 22 is a direct bond, an alkylene group having 1 to 18 carbon atoms, or an oxyalkylene group having 1 to 18 carbon atoms.] Or, the above formula (E2), [R 23 is a direct bond, an alkylene group having 1 to 18 carbon atoms, or an oxyalkylene group having 1 to 18 carbon atoms.] An easily dismantlable adhesive material, which is any of the groups represented by the following formula: 6. 5. An easily dismantlable adhesive material according to any one of 1. to 5., The easily dismantlable adhesive material has a number Na of the ethylenically unsaturated double bond groups at the side chain terminals contained in one molecule of the thermosetting hyperbranched polymer (P) of 0.1 or more and 30 or less. 7. An easily dismantlable adhesive material according to any one of 1. to 6., the second thermosetting group comprises an epoxy group; The easily dismantlable adhesive material has a number Nb of epoxy groups located at the side chain terminals contained in one molecule of the thermosetting hyperbranched polymer (P) of 0.1 or more and 20 or less. 8. An easily dismantlable adhesive material according to any one of 1. to 7., the second thermosetting group comprises an epoxy group; An easily dismantlable adhesive material, in which the ratio Nb / Na of the number Na of ethylenically unsaturated double bond groups at the side chain ends contained per molecule of the thermosetting hyperbranched polymer (P) to the number Nb of epoxy groups located at the side chain ends is 0.1 or more and 10 or less. 9. An easily dismantlable adhesive material according to any one of 1. to 8., The number average molecular weight Mn of the thermosetting hyperbranched polymer (P) is 0.5 × 10 3 That's it, 5 x 10 4 The following easily dismantlable adhesive material: 10. An easily dismantlable adhesive material according to any one of 1. to 9., The easily dismantlable adhesive material has a 5% weight loss temperature of 180°C or higher of the cured body obtained by curing the easily dismantlable adhesive material through heat treatment at 80°C for 7 hours. 11. An easily dismantlable adhesive material according to any one of 1. to 10., The dismantling agent (Q) is an easily dismantlable adhesive material containing a compound having two or more amino groups. 12. An easily dismantlable adhesive material according to any one of 1. to 11., An easily dismantlable adhesive material in which the ratio of F2 to F1 (F2 / F1) measured under the following conditions is 0.9 or less. (conditions) (i) Using SUS304 as the adherend, two adherends are bonded together with the easily dismantlable adhesive material, and the shear adhesive strength of the sample is measured in accordance with JIS K 6850:1999. (ii) The shear adhesive strength of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition of 80°C for 7 hours is designated as F1, and the shear adhesive strength of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition and then heat-treating it under the second heat treatment condition of 180°C for 2 hours is designated as F2. 13. An easily dismantlable adhesive material according to any one of 1. to 12., An easily dismantlable adhesive material in which the ratio of E2 to E1 (E2 / E1) measured under the following conditions is 0.8 or more and 1.2 or less. (conditions) (i) Using SUS304 as the adherend, a sample in which two adherends are bonded together using the easily dismantlable adhesive material is subjected to a shear adhesion test in accordance with JIS K 6850:1999, and the elastic modulus in the shear test is determined from the obtained stress-strain curve. (ii) The elastic modulus of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition of 80°C for 7 hours is defined as E1, and the elastic modulus of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment condition and then heat-treating it under the second heat treatment condition of 180°C for 2 hours is defined as E2. 14. An easily dismantlable adhesive material according to any one of 1. to 13., An easily dismantlable adhesive material in which the difference (T2-T1) between the 5% weight loss temperatures T2 and T1 measured under the following conditions is -20°C or more and 10°C or less. (conditions) The 5% weight loss temperature of Sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions of 80°C for 7 hours is defined as T1, and the 5% weight loss temperature of Sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions and then heat-treating it under the second heat treatment conditions of 180°C for 2 hours is defined as T2. 15. An easily dismantlable adhesive material according to any one of 1. to 14., The thermosetting hyperbranched polymer (P) a polyfunctional monomer (a) having two or more ethylenically unsaturated double bond groups; a monomer (b) having an epoxy group and an ethylenically unsaturated double bond group; An easily dismantlable adhesive material obtained by polymerizing a polymer material containing the above (however, the polyfunctional monomer (a) does not include those corresponding to the monomer (b)). 16. 15. The easily dismantlable adhesive material according to claim 15, The polymeric material has the general formula (I) shown above: [In the formula, R 1 is a halogen atom, -SR group, -OR group, -OOR group or -C(R) 3 is a group (wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). -C(R) 3 The three R in the group may be the same or different. 2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.] An easily dismantlable adhesive material further comprising an addition-fragmentation chain transfer agent (c) represented by the formula: 17. 15. or 16. The easily dismantlable adhesive material according to The easily dismantlable adhesive material, wherein the polyfunctional monomer (a) is a compound having ethylenically unsaturated double bond groups at both ends of the molecule. 18. 15. An easily dismantlable adhesive material according to any one of 15. to 17., An easily dismantlable adhesive material, wherein the monomer (b) having an epoxy group and an ethylenically unsaturated double bond group contains one or more epoxy compounds selected from the group consisting of a glycidyl group-containing methacrylic acid ester, vinylbenzyl glycidyl ether, and an alicyclic epoxy group-containing methacrylic acid ester. 19. 18. An easily dismantlable adhesive material according to any one of 1. to 18., The easily dismantlable adhesive material is attached to the surface of an adherend, and a first heat treatment is performed to obtain a hardened body that bonds to the adherend, and then a second heat treatment is performed to the hardened body to dismantle the adherend and the hardened body. 20. An article comprising an adherend and a cured product of the easily dismantlable adhesive material according to any one of 1. to 19. bonded to the adherend. 21. 20. A dismantling method comprising the step of heating the article described in 20. to dismantle the adherend and the cured body of the easily dismantlable adhesive material. [Example]

[0125] 1. Evaluation Method The evaluation methods used in the examples will be explained below.

[0126] (NMR) 1 The structure of the resulting polymer was analyzed by 1 H-NMR (manufactured by Bruker, model: Avance300) under the following conditions. Frequency: 300MHz Measurement solvent: TMS (tetramethylsilane)-containing deuterated chloroform

[0127] (GPC) The weight-average molecular weight Mw, number-average molecular weight Mn, and their ratio Mw / Mn of the obtained polymer were determined by GPC measurement using a gel permeation chromatography (GPC) apparatus (manufactured by Tosoh Corporation, model: CCPD-RE8020) and a standard polystyrene calibration curve under the following conditions. Column: TSK gel column MP (XL) Column temperature: 40℃ Eluent: tetrahydrofuran Sample injection volume: 100 μL Detector: Differential refractive index detector

[0128] (thermal analysis) Thermogravimetry / differential thermal analysis (TG / DTA) was performed using a TG / DTA6200 manufactured by Seiko Instruments Inc. under a nitrogen flow (220 mL / min) at a heating rate of 10°C / min.

[0129] (DSC) The differential scanning calorimeter (DSC) used was a DSC 6200 manufactured by Seiko Instruments Inc. Measurements were carried out under a nitrogen flow (50 mL / min) at a heating rate and cooling rate of 10°C / min.

[0130] (IR) For the IR measurement, an FT / IR-4600 manufactured by JASCO Corporation was used, and the measurement was carried out by the KBr method.

[0131] (Tensile shear adhesion test) Sample preparation As shown in the following examples, aluminum plates, SUS304, and SUS430 were used as substrates for the tensile shear adhesive test pieces. Each substrate was degreased and cleaned without surface polishing. The dimensions of the substrate were 10 mm x 100 mm x 1 mm thick for aluminum plates and SUS304, and 10 mm x 100 mm x 0.5 mm thick for SUS430. The substrate was ultrasonically cleaned in acetone for 15 minutes, then in isopropanol for 15 minutes, and then air-dried before use.

[0132] The materials to be applied to the substrate were prepared as follows: In the evaluation of the thermosetting hyperbranched polymer in Example A, a solution was prepared by dissolving the thermosetting hyperbranched polymer (30 mg) in acetone (0.1 mL), which is a good solvent. In the evaluation of the easily dismantlable adhesive material in Example B, a solution was prepared by dissolving the thermosetting hyperbranched polymer (30 mg) and a dismantling agent in acetone (0.1 mL).

[0133] The prepared solution was applied to one substrate in a coating amount of 15 μL (wet), and then dried under reduced pressure at room temperature for 1 hour to evaporate the acetone. Next, the adhesive-coated surfaces of the two substrates were bonded together, and the bonded area was fixed with clips to obtain a tensile shear adhesion test specimen. The bonded area of ​​the test specimen (the area of ​​the bonded area) was 100 mm 2 (10mm x 10mm). The test pieces were cured under the curing conditions shown in the tables below, and then subjected to a tensile shear adhesion test. The film thickness of the easily dismantlable adhesive material after curing was 30 μm.

[0134] The tensile shear adhesion test was performed using an Autograph AGS-1kNX (manufactured by SHIMAZU Corporation, maximum load 10 kN) in accordance with JIS K 6850: 1999 at a tensile speed of 1 mm / min at room temperature (25°C). Three measurements were taken and the average value was calculated.

[0135] 2. Synthesis and evaluation of thermosetting hyperbranched polymers (Example A1) The polymerization raw materials containing the following (i) to (iv) were introduced into a 20 mL Pyrex glass (registered trademark) tube and mixed. (i) a polyfunctional monomer (a) having two or more ethylenically unsaturated double bonds Ethylene glycol dimethacrylate (EGDMA), (ii) Monomer (b) having an epoxy group Glycidyl methacrylate (GMA) (iii) Addition-fragmentation chain transfer agents (c) (AFCT agents) Methyl 2-(bromomethyl)acrylate (MBMA) (In general formula (I), R 1 Let Br be R 2 (compound with methyl group) (iv) Radical initiator 2,2'-Azobisisobutyronitrile (AIBN)

[0136] The mixing ratio of the monomers was as follows: Molar ratio [EGDMA]:[GMA]:[AIBN] = 1:0.52:0.001 Molar ratio [2(EGDMA)+GMA]:[MBMA]=1:1 (The preferred molar ratio of the total ethylenically unsaturated double bond groups of the monomer (a) and the monomer (b) to the ethylenically unsaturated double bond groups of the addition-fragmentation chain transfer agent (c) was 1:1.) Molar ratio [EGDMA]:[AIBN]=1000:1

[0137] The freeze-degass-thaw cycle was repeated three times to remove dissolved oxygen, and then the tube was sealed. The reaction was carried out in a solvent-free bulk at 60°C for 12 hours, after which the polymerization was terminated by cooling with a dry ice / methanol cryogen (Figure 3). The tube was opened, and the reaction solution diluted with chloroform was added dropwise to approximately 20 times the amount of hexane. The precipitate was filtered, washed, and then dried under reduced pressure at room temperature for approximately 24 hours. The precipitate was dissolved in chloroform and purified by reprecipitation twice in hexane. The yield was 26%. The thermosetting hyperbranched polymer obtained in Example A1 is referred to as P1.

[0138] (Examples A2 to A3) Polymers were obtained in the same manner as in Example 1, except that the polymerization conditions were changed to those shown in Table 1. The thermosetting hyperbranched polymers obtained in Examples A2 and A3 are referred to as P2 and P3, respectively.

[0139] (evaluation) The polymers P1 to P3 obtained in Examples A1 to A3 were evaluated. The evaluation results are shown in Table 1 together with the polymerization conditions.

[0140] [Table 1]

[0141] (Characterization) The thermosetting hyperbranched polymer obtained in Example A2 1 The H-NMR spectrum and assignments are shown in Figure 4. The unsaturated double bond at the end of the side chain derived from EGDMA, the epoxy group derived from GMA, and the 2-carbomethoxy-2-propenyl group derived from the AFCT agent were confirmed in the polymer. From the integrated intensity ratios of peak c derived from the EGDMA unit, peaks k and m derived from the GMA unit, and peaks p, q, r, and s derived from the MBMA unit, the composition ratio of each unit was calculated to be d[EGDMA] / d[GMA] / d[MBMA] = 1 / 0.43 / 0.56. Furthermore, from the Mn (=3,170) and composition ratio determined by GPC measurement, the numbers of EGDMA, GMA, and MBMA units per polymer chain were calculated to be 8.8, 3.8, and 4.9, respectively. From the above, it was confirmed that a hyperbranched polymer with multiple unsaturated double bonds (pendant vinyl groups) and pendant epoxy groups at the end of its side chains in one molecule could be synthesized.

[0142] MBMA does not exhibit homopolymerization or copolymerization, but is introduced only to the polymer terminals by AFCT, which indicates that a hyperbranched polymer with an average of 4.9 ω-terminal groups per molecule was produced. Based on the number of EGDMA units per polymer chain (per polymer molecule) and the integrated intensity ratio of peaks c, g, and h, and on the molecular weight information obtained by GPC measurement, the number of ethylenically unsaturated double bond groups Na (pendant vinyl groups) at the end of the side chain per polymer chain was calculated to be 4.2. The number of epoxy groups at the side chain ends per polymer chain (per polymer molecule), Nb, was calculated to be 3.8, since it is equal to the number of GMA units per polymer chain.

[0143] Similar analyses were performed on hyperbranched polymers P1 and P3, and the results are shown in Table 2.

[0144] 5 to 7 are diagrams showing TG-DTA curves of the thermosetting hyperbranched polymers P1 to P3 obtained in Examples A1 to A3. The 5% weight loss temperature Td5 and the 1% weight loss temperature Td1 obtained from this data are shown in Table 1. The thermosetting hyperbranched polymer obtained in Example A1 was subjected to DSC measurement, and the glass transition temperature Tg obtained from this data is shown in Table 1. It can be seen that the thermosetting hyperbranched polymer of this embodiment has low viscosity, is capable of spontaneous thermosetting, and has high heat resistance after curing, making it a stable material. Furthermore, as shown in Table 1, it can be seen that the thermosetting hyperbranched polymer of this example exhibits high shear adhesive strength upon thermosetting.

[0145] 3. Production and evaluation of easily dismantled adhesive materials Example B1 A two-component, easily dismantled adhesive material was prepared, consisting of the following base material and an epoxy curing agent as an easily dismantled adhesive material. Main ingredient The thermosetting hyperbranched polymer (30 mg) prepared in Example A1 was dissolved in 0.1 mL of acetone to obtain a base material. Hardener (dismantling agent) Diethylenetriamine (DETA) was used. The adhesive was prepared by mixing the above-mentioned base agent and curing agent in a quantity ratio such that the molar ratio of structural units derived from glycidyl methacrylate (GMA) contained in the base thermosetting hyperbranched polymer to DETA was as follows: [GMA-derived structural units]:[DETA]=3.64:1

[0146] (Examples B2 to B6) Two-component easily dismantlable adhesive materials were prepared in the same manner as in Example B1, except that the thermosetting hyperbranched polymer used as the base agent was changed as shown in Tables 2 to 4.

[0147] (Comparative Example 1) A base agent was prepared in the same manner as in Example B1, except that the composition of the easily dismantlable adhesive material was changed as follows: The base agent was used as an adhesive as it was without blending a curing agent. Main ingredient: A mixture of 90% by mass of epoxy resin EP001N (manufactured by Cemedine) and 10% by mass of ethylene glycol dimethacrylate (EGDMA)

[0148] (evaluation) Tables 2 to 4 show the evaluation results of the tensile shear adhesive strength. The meanings of the terms in Tables 2 to 4 will be explained below.

[0149] ·1st heating, 2nd heating The adhesive-coated surfaces of two substrates are bonded together, and the bonded area is fixed with clips while curing is carried out. Example B1 is a one-stage curing process, while the other examples are two-stage curing processes. "First heating" in the table refers to the first stage curing, and the numbers in the table indicate the curing conditions. "Second heating" in the table refers to the second stage curing, and the numbers in the table indicate the curing conditions. In the "second heating," after the first stage of curing was completed, the sample was removed from the oven and allowed to cool to room temperature, and then placed in an oven pre-set to 180°C and heated for a predetermined period of time. The heating was carried out using a hot air dryer.

[0150] Elastic modulus A tensile shear bond strength test was carried out according to JIS K 6850:1999 using the tensile shear bond strength test method for rigid adherends, and the bond strength was determined by (breaking stress) / (breaking strain) in the resulting stress-strain curve.

[0151] Shear adhesive strength change index (F2 / F1) The value of the shear adhesive strength after the second heating was divided by the shear adhesive strength after the first heating, and the value was taken as the "shear adhesive strength change index."

[0152] Elasticity change index (E2 / E1) The value of the elastic modulus after the second heating was divided by the elastic modulus after the first heating, and the value was taken as the "shear adhesive strength change index."

[0153] Destruction Mode The term "interface" refers to interfacial failure, which means that the cured resin material peeled off at the interface between the cured resin material and the metal adherend without any remaining adhesion. "Cohesion" means cohesive failure, which means that the hardened body of the easily dismantlable adhesive material adheres to the metal adherend, and the hardened body itself is broken and peeled off. "Mixed" refers to a state of failure in which a portion where interfacial failure has occurred and a portion where cohesive failure has occurred are mixed together.

[0154] [Table 2]

[0155] [Table 3]

[0156] [Table 4]

[0157] As shown in the table above, when the easily dismantlable adhesive material of this example is used, the shear adhesive strength decreases when the cured product obtained by the first heating is subjected to the second heating. Furthermore, a comparison of the elastic modulus obtained in the shear adhesion test after the first heating and the second heating reveals little change. As described below, the Tg of the cured product itself increases, suggesting an increase in the elastic modulus of the cured product itself. On the other hand, the elastic modulus obtained in the shear adhesion test showed little change. If the failure mode in the shear adhesion test was a cohesive failure mode (a mode in which the cured resin itself, not the interface, fails), the elastic modulus in the shear test should also increase, reflecting an improvement in the elastic modulus of the cured product itself. The lack of significant change in the elastic modulus in the shear test is likely to indicate that the failure in the adhesion test occurred in an interfacial failure mode that does not reflect the elastic modulus of the cured resin itself. Visual observation also confirmed that delamination occurred at the adhesive interface without any residual cured polymer remaining.

[0158] 8 shows the stress-displacement curve of P1+DETA (compound of Example B3). The results show that the heat treatment does not significantly change the elastic modulus in the shear test.

[0159] (TG-DTA) FIG. 9 shows the thermal properties of an easily dismantlable adhesive material (Example B3) in which the thermosetting hyperbranched polymer P1 and DETA were blended in the following ratio. [GMA-derived structural units]:[DETA]=3.64:1 Figure 10 shows the thermal properties of the easily dismantlable adhesive material in which the thermosetting hyperbranched polymer P2 and DETA are blended in the above ratio. FIG. 11 shows the thermal properties of the easily dismantlable adhesive material (Example B2) in which the thermosetting hyperbranched polymer P3 and DETA were blended in the above ratio. Figures 9 to 11 show TG-DTA measurements of the thermosetting hyperbranched polymer alone without heat treatment, and TG-DTA measurements of the thermosetting hyperbranched polymer mixed with DETA and then heat-treated at 80°C for 7 hours to obtain a cured product. The Tg, 5% weight loss temperature Td5, and 1% weight loss temperature Td1 obtained from these data are shown in Figure 12. For the easily dismantlable adhesive material consisting of polymer P1 and DETA, the measurement data for the cured material was also shown (Figure 12(a)), which was heat-treated at 80°C for 7 hours, returned to room temperature, and then heat-treated at 180°C for 2 hours. Referring to the results shown in FIG. 12(a), it was confirmed that in the formulation of Example B3, the difference between the 5% weight loss temperatures T2 and T1 (T2-T1) measured under the following conditions was -8°C, and was in the range of -20°C to 10°C. (conditions) The 5% weight loss temperature of sample 1 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions of 80°C for 7 hours is defined as T1, and the 5% weight loss temperature of sample 2 obtained by heat-treating the easily dismantlable adhesive material under the first heat treatment conditions and then heat-treating it under the second heat treatment conditions of 180°C for 2 hours is defined as T2. The (T2-T1) values ​​for P2 and DETA, and P3 and DETA are also thought to be similar to those mentioned above. As such, it can be seen that the Td5 (temperature at which 5% weight loss occurs) of the hardened body obtained by heat treatment at 80°C for 7 hours does not decrease significantly with subsequent heat treatment at 180°C. The mechanism by which the body disintegrates after heat treatment at 180°C is thought to be due to a decrease in the adhesive strength at the interface, rather than a decrease in the physical properties of the hardened body. Furthermore, since Td5 is relatively large, it can be said that emissions of volatile organic compounds are suppressed.

[0160] All of the polymers P1 to P3 exhibited a high Td5 (temperature at which weight is reduced by 5%) of 230°C or higher after heat treatment at 80°C for 7 hours, confirming that this heat treatment provided sufficient thermal properties. Furthermore, referring to the results of P1+DETA (Fig. 12(a)), it can be seen that the Td5 (temperature at which 5% weight loss occurs) of the hardened body obtained by heat treatment at 80°C for 7 hours does not decrease significantly by the subsequent heat treatment at 180°C. The mechanism by which the hardened body disintegrates after heat treatment at 180°C is thought to be due to a decrease in the adhesive strength at the interface, rather than a decrease in the physical properties of the hardened body.

[0161] (IR) Figures 13 and 14 show the infrared absorption spectrum (IR) measurement results for Example B2, which used P3 as the thermosetting hyperbranched polymer and DETA as the dismantling agent. The IR spectra are shown for the thermosetting hyperbranched polymer alone, the thermosetting hyperbranched polymer and DETA mixed together, heat-treated at 80°C for 7 hours to obtain a cured product, and the product subsequently returned to room temperature and further heat-treated at 180°C for 2 hours. Referring to the results in Figure 14, after 7 hours of heat treatment at 80°C, the consumption of both vinyl (terminal ethylenically unsaturated double bond) groups and epoxy groups was within the range of 20–30%. Subsequent heat treatment at 180°C for 2 hours resulted in little consumption of vinyl groups, but increased consumption of epoxy groups. It is believed that the 2-hour heat treatment at 180°C promoted the reaction between the epoxy groups of the thermosetting hyperbranched polymer and DETA.

[0162] (Additional Example: Example A4) First, by following the method of Example A3 but doubling the reaction scale (doubling the amount of each component used), we obtained thermosetting hyperbranched polymer P4, which differs from P3 in number average molecular weight, dispersity, etc. Regarding the reaction scale, the amount of EGDMA used in synthesizing P3 was 1.00 g, and the amount of EGDMA used in synthesizing P4 was 2.00 g. The evaluation results for P4 are shown in the table below.

[0163] [Table 5]

[0164] 60 mg of the above P4 was dissolved in 0.2 mL of acetone to obtain the main compound. The adhesive was then prepared by mixing the above-mentioned main agent with diethylenetriamine (DETA), a curing agent (dismantling agent), in a quantity ratio such that the molar ratio of the structural units derived from glycidyl methacrylate (GMA) contained in P4 to DETA was as follows: [GMA-derived structural units]:[DETA]=3.40:1

[0165] The adhesive thus obtained was subjected to the same evaluation as in Example B1, with the type of adherend being varied. The results are shown in the tables below, with information about the adherends listed at the top of each table.

[0166] [Table 6]

[0167] [Table 7]

[0168] [Table 8]

[0169] [Table 9]

[0170] [Table 10]

[0171] As shown in the tables above, even when P4 was used as the thermosetting hyperbranched polymer (P), the shear adhesive strength decreased (i.e., easy disassembly was achieved) when the hardened body obtained by the first heating was subjected to the second heating. Easy disassembly was also achieved when adherends other than stainless steel plates, such as zinc plates and molybdenum plates, were used.

[0172] Interestingly, comparing Tables 4 and 8 (both adherends were SUS430, but had different adhesive formulations), the adhesive strength of Table 8 decreased even more after the second heating. This may be related to the fact that P4 has a wider molecular weight distribution than P3 and contains a relatively large amount of high molecular weight components.

[0173] What's even more interesting is that, as shown in Table 10, in an evaluation using a dissimilar bonded structure of aluminum and SUS430 plates, the second heating step resulted in interfacial delamination with 100% of the adhesive remaining on the aluminum side. The shear adhesive strength change index was also the smallest at 0.1. This result suggests that by appropriately selecting the type of adherend, it is possible to further improve the ease of recycling after disassembly.

[0174] This application claims priority based on Japanese Patent Application No. 2020-082844, filed on May 8, 2020, the disclosure of which is incorporated herein in its entirety.

Claims

1. A dual-cure thermosetting hyperbranched polymer obtained by polymerizing a polymerizable material containing a polyfunctional monomer (a) having two or more ethylenically unsaturated double bond groups and a monomer (b) having an epoxy group and an ethylenically unsaturated double bond group (however, the polyfunctional monomer (a) does not fall under the category of monomer (b)).

2. The thermosetting hyperbranched polymer according to claim 1, The polymeric material has the general formula (I): 【Chemical 1】 [In the formula, R １ is a halogen atom, a —SR group, a —OR group, a —OOR group, or a —C(R) 3 group (wherein R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). The three R's may be the same or different. ２ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Addition-fragmentation chain transfer agent (c) represented by the formula: The thermosetting hyperbranched polymer further comprises:

3. The thermosetting hyperbranched polymer according to claim 1 or 2, A thermosetting hyperbranched polymer, wherein the polyfunctional monomer (a) is a compound having ethylenically unsaturated double bond groups at both ends of the molecule.

4. The thermosetting hyperbranched polymer according to any one of claims 1 to 3, A thermosetting hyperbranched polymer, wherein the polyfunctional monomer (a) is a meth(acrylic) acid ester.

5. The thermosetting hyperbranched polymer according to any one of claims 1 to 4, A thermosetting hyperbranched polymer, wherein the monomer (b) having an epoxy group and an ethylenically unsaturated double bond group includes one or more epoxy compounds selected from the group consisting of a glycidyl group-containing methacrylic acid ester, vinylbenzyl glycidyl ether, and an alicyclic epoxy group-containing methacrylic acid ester.

6. The thermosetting hyperbranched polymer according to any one of claims 1 to 5, A thermosetting hyperbranched polymer, wherein the ratio nb / na of the number of structural units nb derived from the monomer (b) having an epoxy group and an ethylenically unsaturated double bond group to the number na of structural units derived from the polyfunctional monomer (a) is 0.05 or more and 10 or less.

7. The thermosetting hyperbranched polymer according to any one of claims 1 to 6, A thermosetting hyperbranched polymer having an ethylenically unsaturated double bond at the end of a first side chain in the molecule and an epoxy group at the end of a second side chain in the molecule.

8. A cured product obtained by curing the thermosetting hyperbranched polymer according to claim 1 .

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