Degradable crosslinking agent

Abstract

The purpose of the present invention is to provide a decomposable cross-linking agent which has high solubility in a solvent and is not susceptible to poor curing. The present invention relates to a degradable cross-linking agent which is represented by formula (1) (in formula (1), n > = 0, k > = 0, and m > = 0. R1, R2 and R3 independently comprise a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isopentenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an anhydride group, a vinyl group, an allyl group, an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, a hydroxysilyl group, an epoxy group, an oxetanyl group, an oxazolinyl group and an isocyanate group at a terminal; and one or more reactive functional groups selected from the group consisting of a carbodiimide group, a hydroxymethyl group, a silanol group, and an alkoxysilyl group, and contains a single bond, a group containing a siloxane structure, or a hydrocarbon group optionally having a substituent or a heteroatom. (In the formula, A1 to A8 are each independently a carbonyl group or a single bond, at least one of A1 and A2 is a carbonyl group, at least one of A3 and A4 is a carbonyl group, at least one of A5 and A6 is a carbonyl group, and at least one of A7 and A8 is a carbonyl group. Each Z independently represents a group containing a siloxane structure, or a hydrocarbon group optionally having a heteroatom. ) (In the formula, (a) when n = 0, R1 and R2 are different from each other; (b) when n > = 1 and k = 0, (b-1) R1 is different from R2, and / or (b-2) Z comprising at least one asymmetric structure; (c) when n > = 1 and k > = 1, (c-1) at least one of R1, R2, and R3 is different, and / or (c-2) comprises at least one Z having an asymmetric structure.

Description

Technical Field

[0001] This invention relates to decomposable crosslinking agents. Background Technology

[0002] Plastic products are used in various fields such as daily necessities, automobiles, and electronic devices due to their moldability, durability, and lightweight properties. However, they have the problem of being difficult to decompose after disposal. In recent years, in order to protect the Earth's environment, the development of easily degradable polymers has been underway.

[0003] Patent documents 1-3 disclose polymers having a diacylhydrazine structure as decomposable polymers. These polymers, by having a diacylhydrazine structure, are stable in air and are rapidly decomposed by reaction with oxidizing agents such as sodium hypochlorite. Patent documents 4-5 disclose compounds containing a hydrazine structure that can be used as pharmaceuticals.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-236381

[0007] Patent Document 2: International Publication No. 2021 / 131003

[0008] Patent Document 3: Japanese Patent Application Publication No. 2011-052075

[0009] Patent Document 4: International Publication No. 00 / 35917

[0010] Patent Document 5: International Publication No. 2014 / 071247 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The diacylhydrazine compounds described in Patent Documents 1 and 2 as polymer raw materials, and the polymers containing diacylhydrazine described in Patent Document 3, have low solubility in solvents. Therefore, they are prone to crystallization and precipitation before curing, sometimes causing poor curing. Furthermore, even when solubility in solvents is relatively high, they only dissolve in high-boiling-point aprotic polar solvents or strong acids. The process of removing the solvent to obtain the molded article requires a large amount of energy, leading to increased environmental impact. Patent Documents 4 and 5 do not disclose the use of compounds containing hydrazine structures as crosslinking agents, their decomposition due to reaction with oxidants, or their solubility in organic solvents.

[0013] The purpose of this invention is to provide a decomposable crosslinking agent that has high solubility in solvents and is not prone to causing poor curing.

[0014] Methods for solving problems

[0015] The inventors discovered that crosslinking agents containing hydrazine derivatives with specific structures exhibit high solubility in solvents and can suppress poor curing, thus completing this invention.

[0016] That is, the present invention relates to a decomposable crosslinking agent, which comprises the following formula (1) (in formula (1), • n≥0, k≥0, m≥0.

[0017] R1, R2, and R3 independently contain at their ends one or more reactive functional groups selected from the group consisting of hydroxyl, amino, hydrazide, thiol, isoprenyl, crotonamide, crotonate, carboxylic acid, anhydride, vinyl, allyl, acrylate, methacrylate, acrylamide, methacrylamide, hydroxysilyl, epoxy, oxacyclobutyl, oxazoline, isocyanate, carbodiimide, hydroxymethyl, silanol, and alkoxysilyl, and contain single bonds, groups containing siloxane structures, or optionally hydrocarbon groups having substituents or heteroatoms.

[0018] • A1 to A8 are carbonyl groups or single bonds independently of each other, at least one of A1 and A2 is a carbonyl group, at least one of A3 and A4 is a carbonyl group, at least one of A5 and A6 is a carbonyl group, and at least one of A7 and A8 is a carbonyl group.

[0019] • Z is a group containing a siloxane structure or optionally a hydrocarbon group having heteroatoms. ) represents a decomposable crosslinking agent for a compound, wherein (a) when n=0, R1 and R2 are different; (b) when n≥1 and k=0, (b-1) R1 and R2 are different, and / or (b-2) Z contains at least one asymmetric structure. (c) When n≥1 and k≥1, (c-1) at least one of R1, R2 and R3 is different, and / or (c-2) contains at least one asymmetric structure Z.

[0020] [Chemical Formula 1]

[0021] Among the above-mentioned decomposable crosslinking agents, R1, R2, and R3 are preferably different from each other.

[0022] In the above-mentioned decomposable crosslinking agents, it is preferable that R1, R2 and R3 contain the same reactive functional groups.

[0023] In the above-mentioned decomposable crosslinking agents, n≥1 is preferred, Z contains at least one asymmetric structure, and R1, R2 and R3 are the same.

[0024] Among the above-mentioned decomposable crosslinking agents, n≥1 is preferred, and all Z are asymmetric structures.

[0025] In the above-mentioned decomposable crosslinking agents, n≥1 is preferred, Z is all symmetrical structure, and R1, R2 and R3 contain the same reactive functional groups.

[0026] In the above-mentioned decomposable crosslinking agents, it is preferable that the reactive functional groups contained in R1, R2 and R3 are classified into different groups as shown in (A) to (O) below.

[0027] (A) Hydroxyl

[0028] (B) Amino, acylhydrazide

[0029] (C) Thiol group

[0030] (D) Isoprenyl, crotonamide, crotonate group

[0031] (E) carboxylic acid

[0032] (F) acid anhydride group

[0033] (G) Vinyl, Allyl

[0034] (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group

[0035] (I) Hydroxysilyl

[0036] (J) Epoxy groups, oxetane-butyl groups

[0037] (K)oxazolinyl

[0038] (L) Isocyanate group

[0039] (M) carbodiimine group

[0040] (N)hydroxymethyl

[0041] (O)silanol group, alkoxysilyl group

[0042] In the above-mentioned decomposable crosslinking agents, it is preferable that the reactive functional groups contained in R1, R2 and R3 are classified into any one of the groups (A) to (O) below, and two or more of the reactive functional groups contained in R1, R2 and R3 are classified into the same group.

[0043] (A) Hydroxyl

[0044] (B) Amino, acylhydrazide

[0045] (C) Thiol group

[0046] (D) Isoprenyl, crotonamide, crotonate group

[0047] (E) carboxylic acid

[0048] (F) acid anhydride group

[0049] (G) Vinyl, Allyl

[0050] (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group

[0051] (I) Hydroxysilyl

[0052] (J) Epoxy groups, oxetane-butyl groups

[0053] (K)oxazolinyl

[0054] (L) Isocyanate group

[0055] (M) carbodiimine group

[0056] (N)hydroxymethyl

[0057] (O)silanol group, alkoxysilyl group

[0058] The aforementioned decomposable crosslinking agent is preferably in liquid form at 30°C to 60°C.

[0059] In addition, the present invention relates to a composition comprising the above-mentioned decomposable crosslinking agent and one or more selected from the group consisting of a curable resin, a polymerization initiator and a solvent.

[0060] In addition, the present invention relates to decomposable crosslinked products formed from the above-described compositions.

[0061] The aforementioned decomposable crosslinked compounds are preferably decomposed by an oxidizing agent.

[0062] In addition, the present invention relates to a method for decomposing a decomposable crosslinked compound, which includes a step of contacting the decomposable crosslinked compound with an aqueous solution containing an oxidant at a temperature below 100°C.

[0063] The effects of the invention

[0064] The decomposable crosslinking agent of the present invention has high solubility in solvents and is less prone to poor curing. Detailed Implementation

[0065] <<Decomposing Crosslinking Agents>>

[0066] The decomposable crosslinking agent of the present invention comprises a compound represented by the following formula (1).

[0067] [Chemical Formula 2]

[0068] In equation (1), n, m, k, R1, R2, R3, and Z are as follows.

[0069] • n≥0, k≥0, m≥0.

[0070] R1, R2, and R3 independently contain at their ends one or more reactive functional groups selected from the group consisting of hydroxyl, amino, hydrazide, thiol, isopentenyl, crotonamide, crotonate, carboxylic acid, acid anhydride, vinyl, allyl, acrylate, methacrylate, acrylamide, methacrylamide, hydroxysilyl, epoxy, oxacyclobutyl, oxazoline, isocyanate, carbodiimide, hydroxymethyl, silanol, and alkoxysilyl, and contain single bonds, groups containing siloxane structures, or optionally hydrocarbon groups having substituents or heteroatoms.

[0071] • A1 to A8 are carbonyl groups or single bonds independently of each other, at least one of A1 and A2 is a carbonyl group, at least one of A3 and A4 is a carbonyl group, at least one of A5 and A6 is a carbonyl group, and at least one of A7 and A8 is a carbonyl group.

[0072] ·Z can be a group containing a siloxane structure or optionally a hydrocarbon group with heteroatoms.

[0073] It should be noted that, in a narrow sense, "crosslinking agent" sometimes refers to a chemical substance that forms chemical bonds between or within polymers. However, in this specification, in addition to chemical substances that form chemical bonds between or within polymers, it also refers to chemical substances whose molecules can form chemical bonds with each other.

[0074] <n, m, k in equation (1)>

[0075] In formula (1), n ​​and m are both 0 or more, and are preferably 1 or more, more preferably 2 or more. When n is 1 or more, it has two or more structures derived from hydrazine (-A-NH-NH-A-), thus improving the decomposability of the decomposable crosslinking agent. There is no particular upper limit for n and m, and they can be 50 or less respectively.

[0076] In formula (1), k is 0 or more, preferably 1 or more, and more preferably 2 or more. When k is 1 or more, three-dimensional crosslinking can be performed using the decomposable crosslinking agent of the present invention. There is no particular upper limit to k, and it can be 50 or less.

[0077] <R1, R2 and R3 in equation (1)>

[0078] R1, R2, and R3 independently contain reactive functional groups at their ends and contain single bonds, groups with siloxane structures, or optionally hydrocarbon groups with substituents or heteroatoms.

[0079] R 1～3 It can be represented by the following formula (2).

[0080] P j -Q j (2)

[0081] In R1, j=1; in R2, j=2; and in R3, j=3. P j For R 1～3 It contains reactive functional groups, Q j For R 1～3 It contains single bonds, groups with siloxane structures, or hydrocarbon groups. Reactive functional group P j via Q j That is, a single bond, a group containing a siloxane structure or a hydrocarbon group is bonded to a structure (-A-NH-NH-A-) derived from hydrazine.

[0082] Reactive functional group P j The reactive functional group is selected from one or more of the following groups: hydroxyl, amino, hydrazide, thiol, isopentenyl, crotonamide, crotonate, carboxylic acid, acid anhydride, vinyl, allyl, acrylate, methacrylate, acrylamide, methacrylamide, hydroxysilyl, epoxy, oxacyclobutyl, oxazoline, isocyanate, carbodiimide, hydroxymethyl, silanol, and alkoxysilyl. The optimal reactive functional group can be selected according to the application and process.

[0083] In R1, R2, and R3, the reactive functional group P j The quantities are 1 or more, and each is preferably 1 to 4, more preferably 1 to 2. P j When the value is 2 or higher, three-dimensional cross-linking becomes easier, and the strength and reliability of the cross-linked material are improved.

[0084] R1, R2, and R3 can each independently possess two or more reactive functional groups P. j In P with two or more reactive functional groups j In this case, various curable resins and crosslinking processes can be selected for the crosslinking agent. Furthermore, specific reactive functional groups can be used only in the crosslinking reaction; reactive functional groups not used in the crosslinking reaction can contribute to improvements in other physical properties such as adhesion and solubility. Reactive functional group P j When the quantity is 1, there is a tendency for the decomposition rate to increase.

[0085] From the perspective of the strength of crosslinked materials, hydrocarbon group Q j The number of carbon atoms is preferably 1 to 600, more preferably 1 to 100, and even more preferably 1 to 20. Hydrocarbon group Q j It can be a saturated or unsaturated hydrocarbon group, and can be any of the following structures: straight chain, branched chain, or cyclic structure.

[0086] Hydrocarbon Qj It may have substituents. Specific examples of substituents include alkoxy, phenoxy, halogen atoms, amino, sulfonyl, cyano, nitro, etc.

[0087] Hydrocarbon Q j It may contain heteroatoms. When heteroatoms are included, the number is preferably 1 to 300, more preferably 1 to 100, and even more preferably 1 to 10. Heteroatoms may be present in the hydrocarbon group Q. j The main chain can also exist in the side chain. Examples of heteroatoms include N, S, O, and P. As a hydrocarbon group, Q... j Examples of structures containing heteroatoms can be found in [the text].

[0088] [Chemical Formula 3] wait.

[0089] As a hydrocarbon group Q j Specific examples include straight-chain hydrocarbons such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, ethers, carbamates, ureas, esters, thioethers, carbonates, and amides; branched-chain hydrocarbons such as isopropylene, isobutylene, 2,2-dimethylpropylene, and 2-ethyl-2-methylpropylene; cyclic hydrocarbons such as cyclohexylene, cyclopentylene, norbornylene, phenylene, and naphthylene; PEG chains; and groups obtained by making these groups trivalent or tetravalent. The hydrogen atoms of these hydrocarbon groups can be replaced by the substituents mentioned above.

[0090] Q, a group containing a siloxane structure j The silicon valence is divalent or higher. The group containing the siloxane structure includes a -Si-O- bond and can be any of a straight-chain structure, a branched structure, or a cyclic structure. The number of silicon atoms in the group containing the siloxane structure is preferably 2 to 300, more preferably 2 to 100, and even more preferably 2 to 20.

[0091] The hydrogen atoms bonded to silicon atoms can be substituted. Specific examples of substituents include alkyl, alkoxy, phenoxy, halogen atoms, amino, sulfonyl, cyano, and nitro groups.

[0092] Q is a group containing a siloxane structure. j Specific examples include polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylsilsesquioxane, and modified polysiloxanes that modify the hydrocarbon groups of their ends and / or side chains to include heteroatoms such as N, S, O, and P.

[0093] R1, R2, and R3 can be the same or different from each other. The following three examples illustrate how R1, R2, and R3 can be different from each other.

[0094] • The reactive functional group at the end is different from both single bonds, groups containing siloxane structures, and hydrocarbon groups.

[0095] • The terminal reactive functional groups are the same, but the single bonds, groups containing siloxane structures, or hydrocarbon groups are different.

[0096] • The terminal reactive functional groups differ, while the single bonds, groups containing siloxane structures, or hydrocarbon groups are the same.

[0097] When R1, R2, and R3 are different from each other, they tend to improve the solubility in the solvent.

[0098] In R 1～3 When there are two or more reactive functional groups in each of them, "the reactive functional groups of R1, R2 and R3 are different" means that the reactive functional groups are not completely consistent, and preferably there are no consistent reactive functional groups.

[0099] When n≥1 and k≥2, for example, if we define k existing R3 as R 3-1 R 3-2 ···R 3-k Therefore, in this specification, "R1, R2, and R3 are different from each other" means that R1, R2, and R3 are different from each other. 3-1 R 3-2 ···R 3-k At least one of them is different from each other, preferably R1, R2, R 3-1 R 3-2 ···R 3-k All are different from each other. "R1, R2, and R3 are the same" means that R1, R2, and R... 3-1 R 3-2 ···R 3-k At least one of them is the same, preferably R1, R2, R 3-1 R 3-2 ···R 3-k All are identical. "R1, R2, and R3 contain the same reactive functional groups" means that the reactive functional groups contained in R1 and R2 are identical to those in R... 3-1 R 3-2 ···R 3-k At least one of them contains the same reactive functional groups, preferably R1, R2, and R3. 3-1 R 3-2 ···R 3-k All of the reactive functional groups contained in the compound are the same. In the compound shown in formula (1), there is no particular limitation on the number of R1 and R2, and there can be more than two of each. When there are more than two of R1 and R2, the sameness of R1 and R2 can be judged in the same way as R3.

[0100] When R1, R2, and R3 contain the same reactive functional groups, there is a tendency to easily increase the crosslinking density through a single crosslinking process. In particular, when R1, R2, and R3 are different from each other, but contain the same reactive functional groups, there is a tendency to improve solubility in solvents and increase crosslinking density through a single crosslinking process.

[0101] <Structures used to improve solubility in solvents>

[0102] The decomposable crosslinking agent of the present invention has high solubility in solvents by having the characteristics of (a) to (c) below in formula (1).

[0103] (a) When n=0, R1 and R2 are different; (b) When n≥1 and k=0, (b-1)R1 and R2 are different, and / or (b-2) Z contains at least one asymmetric structure; (c) When n≥1 and k≥1, (c-1) at least one of R1, R2 and R3 is different, and / or (c-2) contains at least one asymmetric structure Z.

[0104] The fact that R1 is different from R2, that at least one of R1, R2 and R3 is different, and that Z contains at least one asymmetric structure respectively complicates the structure of the decomposable crosslinking agent, inhibits crystallization, and thus helps to improve its solubility in the solvent.

[0105] In addition to the features described in (a) to (c) above, R1, R2, and R3 can also be different from each other. In this case, the structure of the decomposable crosslinking agent becomes more complex, which easily improves its solubility in the solvent.

[0106] In addition to the features described in (a) to (c) above, the reactive functional groups contained in R1, R2, and R3 can also be the same. Furthermore, it can also be n≥1; containing at least one asymmetric structure Z; and R1, R2, and R3 being the same. In this case, the crosslinking density can be easily increased through a single crosslinking process.

[0107] In addition to the characteristics described in (a) to (c) above, n can also be ≥ 1; Z can be entirely asymmetric. In this case, it is easier to improve the solubility in the solvent.

[0108] In addition to the features described in (a) to (c) above, n ≥ 1; Z is entirely symmetrical; and R1, R2, and R3 contain the same reactive functional groups. In this case, it is preferable that R1, R2, and R3 contain different siloxane-containing groups or hydrocarbon groups, thereby improving solubility in solvents and enabling the crosslinking density to be increased through a single crosslinking process.

[0109] The reactive functional groups contained in R1, R2 and R3 can be independently classified into groups (A) to (O) below.

[0110] (A) Hydroxyl

[0111] (B) Amino, acylhydrazide

[0112] (C) Thiol group

[0113] (D) Isoprenyl, crotonamide, crotonate group

[0114] (E) carboxylic acid

[0115] (F) acid anhydride group

[0116] (G) Vinyl, Allyl

[0117] (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group

[0118] (I) Hydroxysilyl

[0119] (J) Epoxy groups, oxetane-butyl groups

[0120] (K)oxazolinyl

[0121] (L) Isocyanate group

[0122] (M) carbodiimine group

[0123] (N)hydroxymethyl

[0124] (O)silanol group, alkoxysilyl group

[0125] The reactive functional groups contained in R1, R2, and R3 can be reactive functional groups classified into different groups as shown in (A) to (O) above.

[0126] At this point, there is a tendency to easily increase solubility in the solvent. For example, the reactive functional groups contained in R1 can be classified into group (A), the reactive functional groups contained in R2 into group (B), and the reactive functional groups contained in R3 into group (C). Among them, R3 does not exist when n=0 or when n≥1 and k=0.

[0127] Furthermore, the reactive functional groups contained in R1, R2, and R3 can be reactive functional groups classified into any two or more groups shown in (A) to (O) above. In this case, there is a tendency to easily improve solubility in the solvent. For example, the reactive functional groups contained in R1 can be classified into group (A), the reactive functional groups contained in R2 into group (A) or group (C), and the reactive functional groups contained in R3 into group (B). Wherein, R3 does not exist when n=0 or when n≥1 and k=0.

[0128] Furthermore, two or more of the reactive functional groups contained in R1, R2, and R3 can be reactive functional groups classified into the same groups shown in (A) to (O) above. In this case, there is a tendency to increase the crosslinking density through a single crosslinking process. For example, the reactive functional groups contained in R1 can be classified into group (A), the reactive functional groups contained in R2 can be classified into group (A), and the reactive functional groups contained in R3 can be classified into group (A) or group (B). Wherein, R3 does not exist when n=0 or when n≥1 and k=0.

[0129] <A1 to A8 in formula (1)>

[0130] In formula (1), A1 to A8 are independently carbonyl groups or single bonds, at least one of A1 and A2 is a carbonyl group, at least one of A3 and A4 is a carbonyl group, at least one of A5 and A6 is a carbonyl group, and at least one of A7 and A8 is a carbonyl group. When one of the two A groups present on both sides of -NH-NH- is a carbonyl group, the decomposition crosslinking agent has a monoacylhydrazine structure and tends to have an increased decomposition rate under the action of oxidants. When both are carbonyl groups, the decomposition crosslinking agent has a diacylhydrazine structure and tends to have decomposition products that are easily soluble in solutions containing oxidants.

[0131] <Z in equation (1)>

[0132] In formula (1), Z is a group containing a siloxane structure, or optionally a hydrocarbon group having heteroatoms. From the viewpoint of decomposition rate and crosslinking density, the number of carbon atoms in the hydrocarbon group is preferably 1 to 700, more preferably 2 to 200, and even more preferably 4 to 50. The hydrocarbon group can have saturated or unsaturated hydrocarbon groups as the main skeleton, and can have a straight-chain structure, a branched structure, or a cyclic structure.

[0133] Hydrocarbon groups can have substituents. Specific examples of substituents include alkoxy, phenoxy, halogen atoms, amino, sulfonyl, cyano, and nitro groups.

[0134] The hydrocarbon group may contain heteroatoms. When heteroatoms are included, the number is preferably 1 to 300, more preferably 1 to 100, and even more preferably 1 to 10. Heteroatoms can be present in the main chain of the hydrocarbon group or in the side chain. Examples of heteroatoms include N, S, O, and P. Examples of structures containing heteroatoms include...

[0135] [Chemical Formula 4] wait.

[0136] The siloxane-containing group has a valence of 2 or higher. The siloxane-containing group includes a -Si-O- bond and can be any of a straight-chain structure, a branched structure, or a cyclic structure. The number of silicon atoms in the siloxane-containing group is preferably 2 to 300, more preferably 2 to 100, and even more preferably 2 to 20.

[0137] The hydrogen atoms bonded to silicon atoms can be substituted. Specific examples of substituents include alkyl, alkoxy, phenoxy, halogen atoms, amino, sulfonyl, cyano, and nitro groups.

[0138] Specific examples of groups containing siloxane structures include polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylsilsesquioxane, and modified polysiloxanes that modify their terminal and / or side chain hydrocarbon groups to include heteroatoms such as N, S, O, and P.

[0139] Z can have reactive functional groups. Examples of reactive functional groups include hydroxyl, amino, hydrazide, thiol, isopentenyl, crotonamide, crotonate, carboxylic acid, anhydride, vinyl, allyl, acrylate, methacrylate, acrylamide, methacrylamide, hydroxysilyl, epoxy, oxacyclobutyl, oxazoline, isocyanate, carbodiimide, hydroxymethyl, silanol, and alkoxysilyl.

[0140] The hydrocarbon group represented by Z can have an asymmetric structure. In this invention, the symmetry of the structure is determined by whether two repeating structures can be obtained when the structure sandwiched by a combination of two hydrazine-derived structures (-A-NH-NH-A-) is divided by a facet. When no facet exists that yields two repeating structures, it is determined to be an asymmetric structure. When a facet exists that yields two repeating structures, it is determined to be a symmetric structure. Specifically, if Z is bonded to three or more hydrazine-derived structures (-A-NH-NH-A-) and no facet exists between a specific combination of two hydrazine-derived structures (-A-NH-NH-A-) that yields two repeating structures, then regardless of whether a facet exists that yields two repeating structures between other combinations of two hydrazine-derived structures (-A-NH-NH-A-), Z is determined to have an asymmetric structure.

[0141] As a specific example of an asymmetric structure, the structures shown in equations (7) to (22) below can be cited.

[0142] [Chemical Formula 5]

[0143] [Chemical Formula 6]

[0144] [Chemical Formula 7]

[0145] [Chemical Formula 8]

[0146] [Chemical Formula 9]

[0147] [Chemical Formula 10]

[0148] [Chemical Formula 11]

[0149] [Chemical Formula 12]

[0150] [Chemical Formula 13]

[0151] [Chemical Formula 14]

[0152] [Chemical Formula 15]

[0153] [Chemical Formula 16]

[0154] [Chemical Formula 17]

[0155] [Chemical Formula 18]

[0156] [Chemical Formula 19]

[0157] [Chemical Formula 20]

[0158] Specific examples of symmetrical structures include straight-chain hydrocarbons such as methylene, ethylene, n-propylene, n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, and n-nonylene; branched-chain hydrocarbons such as isobutylene and 2,2-dimethylpropylene; cyclic hydrocarbons such as cyclohexylene, cyclopentylene, phenylene, and 2,6-pyridylene; ethylene glycol, polyethylene glycol, 1,4-butanediol, 1,6-hexanediamine, 4,4'-diaminodiphenylmethane, bisphenol A, and groups obtained by making these groups trivalent or tetravalent.

[0159] When a decomposable crosslinking agent contains two or more Z atoms with different structures in its molecule, the decomposability can be controlled by selecting the combination of the types of Z atoms. Examples of combinations of two or more Z atoms include, for instance, combinations of Z atoms with high water solubility and Z atoms with low water solubility, which are characteristics of the decomposable product. Furthermore, examples of combinations of hydrophilic and hydrophobic Z atoms, highly polar and low polar Z atoms, and flexible and rigid Z atoms are also possible, as well as combinations of Z atoms before decomposition. Additionally, by using combinations of symmetrical and asymmetrical Z atoms, solvent solubility and miscibility with other compositions can be adjusted.

[0160] The weight-average molecular weight of the decomposable crosslinking agent is preferably 100 to 10,000, more preferably 100 to 2,000. When the molecular weight is within these ranges, it tends to increase the crosslinking density and decomposability.

[0161] The decomposable crosslinking agent is preferably in a liquid state at 30°C to 60°C, and more preferably in a liquid state at 30°C to 40°C. At this temperature, it has advantages such as excellent mixability with other components during composition preparation and the ability to suppress the leaching of other components during molding and processing.

[0162] <Synthetic Methods of Decomposable Crosslinking Agents>

[0163] There are no particular limitations on the synthesis methods of decomposable crosslinking agents. Examples include the reaction of hydrazide compounds, aminourea compounds, or hydrazine carbamate compounds with carbonate compounds, isocyanate compounds, acid anhydrides, acyl halides, or cyclic ester compounds; the reaction of hydrazine with carboxylic acid esters; the reaction of hydrazine with carbonate compounds; the reaction of hydrazine with isocyanate compounds; and so on.

[0164] Examples of acylhydrazides used in the above-mentioned synthetic methods include lactic acid hydrazides, methacrylic acid hydrazides, sebacic acid hydrazides, adipic acid hydrazides, phthalic acid hydrazides, salicylic acid hydrazides, trimellitic acid hydrazides, 4-hydroxybutyric acid hydrazides, 4-hydroxybenzoic acid hydrazides, 6-hydroxyhexanoic acid hydrazides, and citrate hydrazides. Examples of carbonate compounds include allyl N-succinimidyl carbonate and C,C'-(oxydi-2,1-ethanediyl)bisN-succinimidyl carbonate. Examples of isocyanate compounds include ethyl 2-isocyanate methacrylate, hexamethylene diisocyanate, toluene diisocyanate, and polymethylene polyphenyl polyisocyanate. Examples of aminourea compounds include N-allylhydrazine carboxamide, N,N'-1,6-hexanediylbis[hydrazine carboxamide], 4,4'-isophorone bis(aminourea), and 4,4'-(1,3-phenylenedimethyl)bis(aminourea). Examples of hydrazine carbamate compounds include allyl hydrazine carbamate and C,C'-(oxydi-2,1-ethanediyl)bishydrazine carbamate. Examples of acid anhydrides include methacrylic anhydride, succinic anhydride, and pyromellitic dianhydride. Examples of acyl halides include acryloyl chloride, sebacyl chloride, adipic acid chloride, phthaloyl chloride, salicylyl chloride, and pyromellitic tricarboxylic acid chloride. Examples of cyclic ester compounds include propiolactone, butyrolactone, and valproic acid lactone. Examples of carboxylic acid esters include ethyl lactate, methyl p-hydroxybenzoate, monomethyl succinate, diethyl adipate, and trimethyl trimellitate.

[0165] <Composition>

[0166] The compositions of the present invention comprise one or more of the above-described decomposable crosslinking agent and selected from the group consisting of a curable resin, a polymerization initiator, and a solvent. The amount of the decomposable crosslinking agent in the composition is preferably 0.1 to 99% by weight, more preferably 1 to 50% by weight.

[0167] <Curing Resin>

[0168] The curable resin is not particularly limited as long as it has a structure that reacts and crosslinks with the reactive functional groups of the decomposing crosslinking agent. Examples include acrylic resins, phenolic resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, silicone resins, isocyanate compounds, and polyimides. The curable resin can be a thermosetting resin or a photocurable resin. The preferred amount of the curable resin in the composition is 0.1 to 95% by weight, more preferably 1 to 50% by weight.

[0169] <Polymerization Initiator>

[0170] There are no particular limitations on polymerization initiators; any compound capable of catalyzing the polymerization of curable resins can be used, including thermal polymerization initiators and photopolymerization initiators. Examples of polymerization initiators include free radical generating agents such as alkyl benzophenone compounds, benzoin compounds, benzophenone compounds, oxime ester compounds, and phosphine compounds; alkali generating agents such as oxime ester compounds, ammonium compounds, benzoin compounds, dimethoxybenzyl carbamate compounds, and o-nitrobenzyl carbamate compounds; acid generating agents such as onium salts, halogen-containing compounds, diazomethane compounds, sulfone compounds, and sulfonic acid compounds; tin compounds such as dibutyltin dilaurate and dibutyltin diacetate; bismuth compounds such as bismuth octanoate; titanium compounds such as tetraoctyl titanate and ethyl acetoacetate titanium; zirconium compounds such as zirconium monoacetoacetate and zirconium tetraacetoacetate; amines such as triethylenediamine and 1,4-diazabicyclo[2,2,2]octane (DABCO); platinum compounds such as chloroplatinic acid and alkenylsiloxane platinum complexes; iron complexes; and cobalt complexes. The amount of polymerization initiator in the composition is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, relative to 100 parts by weight of the curable resin.

[0171] Solvent

[0172] Examples of solvents include water and organic solvents. Examples of organic solvents include ether solvents, amide solvents, hydrocarbon solvents, alcohol solvents, ester solvents, aldehyde solvents, ketone solvents, and solvents containing carbon atoms and heteroatoms.

[0173] Examples of ether solvents include propylene glycol monomethyl ether, anisole, 4-methyl anisole, diisopropyl ether, diethyl ether, dibutyl ether, tetrahydrofuran, dimethoxyethane, cyclopentylmethyl ether, and tert-butylmethyl ether. Examples of amide solvents include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Examples of hydrocarbon solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, and cyclohexane; and aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, tert-butylbenzene, trifluoromethylbenzene, nitrobenzene, and chlorobenzene. Examples of alcohol solvents include methanol, ethanol, propanol, butanol, ethylene glycol, and propylene glycol monomethyl ether. Examples of ester solvents include ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate. Examples of aldehyde solvents include formaldehyde and acetaldehyde. Examples of ketone solvents include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of solvents containing carbon atoms and heteroatoms include acetonitrile and dimethyl sulfoxide. The amount of solvents in the composition is preferably 5 to 99% by weight, more preferably 20 to 80% by weight.

[0174] The solvents listed above can be used alone or in combination of two or more. Furthermore, the boiling point of the solvent is preferably below 150°C, more preferably below 130°C, and even more preferably below 110°C. When the boiling point is within these ranges, the solvent can be removed by heating for a shorter time. The composition preferably contains substantially no solvents with a boiling point exceeding 150°C. Here, "substantially contains no solvents with a boiling point exceeding 150°C" means that the amount of solvent in the composition is less than 1% by weight.

[0175] <Decomposable cross-linking compounds>

[0176] The decomposable crosslinking compound of the present invention is obtained by curing a composition comprising a decomposable crosslinking agent and one or more substances selected from the group consisting of a curable resin, a polymerization initiator, and a solvent. The method for manufacturing the decomposable crosslinking compound from the composition can be any method that promotes the polymerization and crosslinking of the curable resin. Those skilled in the art can appropriately select light irradiation conditions, heating conditions, etc., depending on the types of decomposable crosslinking agent, curable resin, and polymerization initiator contained in the composition. For example, when forming the decomposable crosslinking compound into a three-dimensional molded body, methods such as injection molding, compression molding, transfer molding, 3D printing, and photolithography can be used.

[0177] Furthermore, when forming a coating film composed of a decomposable crosslinking agent, the composition can be applied to a substrate to form the coating film, which can then be subjected to light irradiation or heating. The material and shape of the substrate are not particularly limited, and examples include resins, inorganic materials, paper, and cloth. Examples of resins include polyesters such as polyethylene terephthalate, polyethylene naphthalate, polylactic acid, polyhydroxybutyric acid, and polybutylene succinate; polyolefins such as polyethylene, polypropylene, and polymethylpentene; cycloolefins; polystyrene; polytetrafluoroethylene; PMMA; nylon 6; and nylon 66; polyamides such as polycarbonate, polyvinyl acetate, polyvinyl alcohol, polyimide, ABS resin, cellulose, cellulose acetate, silk fibroin, and keratin. Examples of inorganic materials include metals such as glass, Ni, Cu, Cr, Fe, and Si, their oxides, or composite materials.

[0178] Examples of methods for coating a composition onto a substrate include wire rod coating, spin coating, spray coating, dip coating, nozzle coating, gravure coating, reverse roller coating, die coating, air knife coating, doctor blade coating, doctor bar coating, curtain coating, doctor blade coating, transfer roller coating, extrusion coating, dip coating, mortise coating, calendering coating, and extrusion coating.

[0179] There are no particular limitations on the curing conditions of the composition coated on the substrate; for example, curing conditions of 100–2000 mJ / cm² can be achieved by light irradiation. 2The amount of light irradiation. When curing is performed by heating, the heating temperature is preferably 40 to 300°C, more preferably 80 to 120°C. Furthermore, the heating time is preferably 0.5 to 180 minutes, more preferably 0.5 to 10 minutes.

[0180] The thickness of the cured coating is not particularly limited, but is preferably 0.01 to 30 μm, more preferably 0.05 to 10 μm. When the thickness is within this range, the strength of the coating and its adhesion to the substrate can be maintained.

[0181] <Methods for Decomposing Crosslinked Compounds>

[0182] The decomposition method of the decomposable crosslinked compound of the present invention includes a step of contacting the decomposable crosslinked compound with an aqueous solution containing an oxidant at a temperature below 100°C.

[0183] Oxidizing agents

[0184] The oxidizing agent is not particularly limited as long as it is not in the molecular state of oxygen. Examples include sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, ammonium hypochlorite, hydrogen peroxide, peracetic acid, m-chloroperbenzoic acid, perbenzoic acid, ammonium hypobromite, calcium hypobromite, potassium hypobromite, sodium hypobromite, and ozone. One or more of these oxidizing agents can be used alone or in combination. Water-soluble salts such as sodium hypochlorite and sodium hypobromite, or ozone water, are preferred. The aqueous solution containing these oxidizing agents may also contain alkaline agents such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, and tetramethylammonium hydroxide, organic solvents such as alcohols such as ethanol, methanol, and isopropanol, and surfactants. The concentration of the oxidizing agent in the aqueous solution is preferably 0.001–50% by weight, more preferably 0.01–3% by weight.

[0185] The temperature condition for contacting the decomposable crosslinker with the aqueous solution containing the oxidant is below 100°C, preferably 15°C to 50°C. The time condition is preferably below 60 minutes, more preferably below 10 minutes. If necessary, the crosslinker can be shaken or stirred during the reaction with the oxidant. The specific method for contacting the decomposable crosslinker with the aqueous solution containing the oxidant is not particularly limited; examples include impregnating the decomposable crosslinker in the aqueous solution containing the oxidant, spraying or dripping the decomposable crosslinker with the aqueous solution containing the oxidant, etc.

[0186] Examples of decomposition products generated by contact between decomposable crosslinkers and oxidants include N2, H2O, and compounds shown in formulas (3) to (6) below.

[0187] HO-CO-Z(COOH) k -COOH (3)

[0188] HZ(COOH) k-COOH (4)

[0189] HO-CO-Z(H) k -COOH (5)

[0190] HZ(H) k -H (6)

[0191] In equations (3) to (6), Z and k are the same as in equation (1). The H or carboxyl group that is directly bonded to Z can bond to heteroatoms in Z.

[0192] When the structure derived from hydrazine (-A-NH-NH-A-) is bonded to a carbon atom in Z and A is a carbonyl group, the decomposition product contains a carboxyl group. Specific examples of decomposition products containing a carboxyl group include succinic acid, malonic acid, adipic acid, phthalic acid, trimellitic acid, and polyacrylic acid.

[0193] When the hydrazine-derived structure (-A-NH-NH-A-) is bonded to the oxygen atom in Z and A is a carbonyl group, the decomposition product contains a -OH group at the end. Specific examples of decomposition products containing a -OH group at the end include ethylene glycol, diethylene glycol, triethylene glycol, hexanediol, pentosanitol, pentaerythritol, polyethylene glycol, polyvinyl alcohol, resorcinol, and phenolic varnish.

[0194] When the hydrazine-derived structure (-A-NH-NH-A-) is bonded to the nitrogen atom in Z and A is a carbonyl group, the decomposition product contains -NH2 at the end. Specific examples of decomposition products containing -NH2 at the end include hexamethylenediamine, pentamethylenediamine, isophoronediamine, toluenediamine, and diaminodiphenylmethane.

[0195] When the hydrazine-derived structure (-A-NH-NH-A-) is bonded to the sulfur atom in Z and A is a carbonyl group, the decomposition product becomes a thiol. Specific examples of thiols include pentaerythritol tetra(3-mercaptobutyrate), trimethylolpropane tri(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, triazine thiol, and 4-mercaptobenzoic acid.

[0196] There is no particular limitation on the evaluation method for the decomposability of crosslinked compounds through contact with oxidants. The method can be appropriately selected based on the solvent solubility of the crosslinked compound and the solvent solubility of the decomposable compounds. For example, one method is to add 2 ml of a 20% sodium hypochlorite aqueous solution to 2 mg of the crosslinked compound and react at room temperature for 30 minutes. Another method is to mix 2 mg of the crosslinked compound with 0.5 ml of a deuterated solvent such as heavy water, deuterated chloroform, deuterated DMSO, or deuterated methanol, add a few drops of a 20% sodium hypochlorite aqueous solution, and react at room temperature for 5 minutes. After these treatments, complete decomposition of the crosslinked compound is preferred. The decomposable compounds can be identified by NMR.

[0197] <Uses of Decomposable Crosslinking Agents>

[0198] The decomposable crosslinking agent of the present invention exhibits excellent solubility in solvents, and therefore can be used for crosslinking various resins. Examples of applications for crosslinked products utilizing the decomposable crosslinking agent of the present invention include adhesives, binders, water-absorbing resins, resins for three-dimensional modeling, photoresists, release agents, culture media for cell culture, fixation materials for affected areas, and embossed products.

[0199] Example

[0200] The present invention will be described below with examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" or "%" refers to "parts by weight" or "% by weight".

[0201] (Comparative Example 1)

[0202] In a 30 mL two-necked flask, 1.4 g of pyridine, 10.3 g of acetonitrile, and 0.86 g of allyl acetylhydrazine were mixed. Then, 0.82 g of sebacate chloride dissolved in 6.2 g of acetonitrile was added dropwise at below 5 °C, and the mixture was stirred at room temperature for 3 hours. The resulting white solid was washed with 30 g of acetonitrile and dried under reduced pressure at 40 °C to give the compound of formula (A1) in 95% yield.

[0203] [Chemical Formula 21]

[0204] 1H-NMR (DMSO, δppm) 1.25 (8H, S, C8H16), 1.50 (4H, t, C8H16), 2.09 (4H, t, C8H16), 2.17~2.18 (8H, m, C2H4 ), 4.96 (2H, d, C=CH2), 5.05 (2H, d, C=CH2), 5.76~5.87 (2H, m, CH=C), 9.66 (2H, S, NHNH), 9.69 (2H, S, NHNH)

[0205] The solvent solubility of the obtained compound of formula (A1) was evaluated, and the results are recorded in Table 2. When a 5% sodium hypochlorite aqueous solution was added to the powdered compound of formula (A1), foaming and decomposition were confirmed.

[0206] A thermosetting composition solution was obtained by adding 0.3 g of compound of formula (A1), 0.1 g of poly(methylhydrosiloxane), and 4.0 mg of platinum-based catalyst (trade name: CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) to 40 g of a mixed solvent of dimethyl sulfoxide and propylene glycol monomethyl ether (weight ratio 3:1). The solution was coated onto a glass substrate to a cured film thickness of 0.1 μm, and then dried and cured at 150°C for 10 minutes to obtain a decomposable crosslinked material. A small amount of precipitates were visible on the cured coating. The decomposable crosslinked material was generally insoluble in water, but partial dissolution was observed. When the decomposable crosslinked material was immersed in a 10% sodium hypochlorite aqueous solution, foaming and removal from the substrate were observed.

[0207] (Comparative Example 2)

[0208] In a 100 mL three-necked flask, 1.8 g of sodium 5-sulfoisophthalic acid dihydrazide was dissolved in 40 g of methyl sulfoxide, and 3.4 g of diethyl 2-isocyanoglutarate was added. The mixture was stirred overnight at 80 °C. After the reaction mixture was allowed to cool naturally to room temperature, it was diluted with 100 g of pure water, and the aqueous layer was washed three times with 90 g of ethyl acetate. The mixture was then concentrated, and the residue was dried under vacuum. The resulting pale orange solid was transferred to a 30 mL round-bottom flask, and 4.6 g of hydrazine monohydrate was added. The mixture was stirred at room temperature for 4 hours. The reaction mixture was added dropwise to 200 g of methanol, resulting in the precipitation of a white solid. The solid was filtered off and dried under vacuum to give the compound of formula (A2) in 93% yield.

[0209] [Chemical Formula 22]

[0210] 1H-NMR (DMSO, δppm) 1.70~1.86 (4H, m, CH2), 1.97~2.09 (4H, m, C=OCH2), 4.13 (2H, q, C=OCH), 4.23 (8H, br, NH2), 6.72 (2H, br, NCO NHC), 8.12 (2H, s, NC=ONHN), 8.30 (2H, s, benzene ring), 8.32 (1H, s, benzene ring), 8.98 (2H, s, CC=ONH), 9.15 (2H, br, CC=ONH), 10.41 (2H, br, CC=ONH)

[0211] The solvent solubility of the obtained compound of formula (A2) was evaluated, and the results are recorded in Table 2. When a 5% sodium hypochlorite aqueous solution was added to the powdered compound of formula (A2), foaming and decomposition were observed.

[0212] 0.3 g of compound (A2) was dissolved in 40 g of N-methylpyrrolidone, and 0.65 g of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation ER828) was added to obtain a thermosetting composition. The cured film was coated onto a glass substrate to a thickness of 2 μm and then dried and cured at 130°C for 30 minutes to obtain a decomposable crosslinked product. A small amount of precipitates were visible on the cured coating. The decomposable crosslinked product was partially soluble in water. When the decomposable crosslinked product was immersed in a 20% sodium hypochlorite aqueous solution, foaming and decomposition were observed.

[0213] (Example 1)

[0214] In a 100 ml flask, 2.9 g of compound (A2) was dissolved in 33 g of dimethyl sulfoxide, and 4.1 g of N-allyloxycarbonyloxysuccinimide was added. The mixture was stirred overnight at room temperature. The reaction mixture was transferred to a separatory funnel and diluted with 105 g of pure water. The aqueous layer was washed three times with 80 g of dichloromethane and then concentrated to give a pale orange solid. This solid was washed three times with 150 g of dichloromethane and dried under vacuum to give compound (B1) in 83% yield.

[0215] [Chemical Formula 24]

[0216] 1H-NMR (DMSO, δppm) 1.72~1.94 (4H, m, CH2), 2.19 (4H, br, C=OCH2), 4.26 (2H, q, C=OCH), 4.50 ~4.55 (8H, m, OCH2), 5.20 (4H, dd, C=CH2), 5.31 (4H, dd, C=CH2), 5.87 ~ 5.95 (2H, m, CH=C), 6.69 (2H, br, NC=ONHC), 8.18 (2H, s, NC=ONHN), 8.28 (2H, s, benzene ring), 8.30 (1H, s, benzene ring), 9.06 (2H, s, OC=O NH), 9.24 (2H, s, OC=ONH), 9.69 (2H, s, CC=ONH), 9.89 (2H, br, CC=ONH), 10.40 (2H, br, CC=ONH)

[0217] The solvent solubility of the obtained compound of formula (B1) was evaluated, and the results are recorded in Table 1. When a small amount of 20% sodium hypochlorite aqueous solution was added to the powdered compound of formula (B1), foaming occurred, and the formation of 5-sulfoisophthalic acid and allyl alcohol as decomposition products was confirmed by 1H-NMR. The obtained compound of formula (B1) is a solid at 60 °C.

[0218] 0.3 g of compound (B1) and 0.22 g of tetraethylene glycol bis(3-mercaptopropionic acid) were dissolved in 4 g of a mixed solvent of methanol and N-methylpyrrolidone (weight ratio 3:1). 8 mg of photopolymerization initiator (Omnirad 907, manufactured by IGM RESINS) and 8 mg of photopolymerization initiator (Omnirad TPO, manufactured by IGM RESINS) were added to obtain a photocurable composition. The above composition was coated onto a glass plate to a dry film thickness of 2 μm and subjected to ultraviolet irradiation at 500 mJ / cm² using a Ushio Electric Corporation (Unicure UVH-1500M). 2 The product was subjected to ultraviolet irradiation to obtain a decomposable molded product. No precipitates were found on the cured coating. The decomposable crosslinker is insoluble in water, but foaming and removal from the substrate were observed when the decomposable crosslinker was immersed in a 20% sodium hypochlorite aqueous solution.

[0219] (Example 2)

[0220] In a 200 ml flask, 2.0 g of 4-hydroxybutyric acid hydrazide was dissolved in 170 g of acetonitrile at 50 °C. Then, 3.4 g of N-allyloxycarbonyloxysuccinimide was added. The mixture was stirred at 40 °C for 1 hour, and then further stirred overnight at room temperature. After concentrating the reaction solution using an evaporator, 30 g of chloroform was added, and N-hydroxysuccinimide precipitated as a white solid. The N-hydroxysuccinimide was removed by filtration, and the solvent was removed by redistillation, thus yielding compound (B2) in 90% yield. The obtained compound (B2) is liquid at 50 °C.

[0221] [Chemical Formula 25]

[0222] 1H-NMR (DMSO, δppm) 1.61~1.68 (2H, m, CH2), 2.12 (2H, t, C=OCH2), 3.89 (2H, q, OCH2), 4.45 (1H, t, OH), 4.51 (2H, q, C=OOCH2), 5.20 (1H, d, C=CH2), 5.30 (1H, d, C=CH2), 5.85~5.96 (1H, m, CH=C), 9.04 (1H, s, NHNH), 9.59 (1H, s, NHNH)

[0223] 0.9 g of the urate modified hexamethylene diisocyanate (BURNOCK DN-901S manufactured by DIC), 1.0 g of the compound of formula (B2), and 0.9 g of tetraethylene glycol bis(3-mercaptopropionic acid) were dissolved in 20 g of a mixed solvent of propylene glycol monomethyl ether and butyl acetate (weight ratio 1:1). 70 mg of dibutyltin curing catalyst (Neostann U-810 manufactured by Nitto Chemical Co., Ltd.), 40 mg of photopolymerization initiator (Omnirad 907 manufactured by IGM RESINS), and 40 mg of photopolymerization initiator (Omnirad TPO manufactured by IGM RESINS) were added to obtain a thermosetting composition solution. The above composition was coated onto a glass plate to achieve a dry film thickness of 10 μm. After drying and curing in a 100°C blower dryer for 120 minutes, it was further subjected to ultraviolet irradiation (Ushio Electric Corporation Unicure UVH-1500M) at 500 mJ / cm². 2 Ultraviolet irradiation yielded a decomposable crosslinking compound. No precipitates were found on the cured coating. The decomposable crosslinking compound is insoluble in water, but foaming and removal from the substrate were observed when it was immersed in a 20% sodium hypochlorite aqueous solution.

[0224] (Example 3)

[0225] In a 200 ml round-bottom flask, 10.0 g of lactyl hydrazide and 33.1 g of γ-butyrolactone were mixed and stirred at 85 °C for 2 days. 69 g of methyl ethyl ketone was added, and after cooling, a precipitate formed. The solvent was removed using a decanter, and the precipitate was washed twice with 50 g of methyl ethyl ketone. The precipitate was dried under vacuum, yielding compound (B3) in 72% yield. The obtained compound (B3) is liquid at 50 °C.

[0226] [Chemical Formula 26]

[0227] 1H-NMR (DMSO, δppm) 1.24 (3H, dd, CH3), 1.61~1.69 (2H, m, CH2), 2.12~2.17 (2H, m, C=OCH2), 3.39~3.43 (2H , m, OCH2), 4.03~4.11 (1H, m, CH), 4.47 (1H, t, OH), 5.46 (1H, d, OH), 9.47 (1H, br, NHNH), 9.68 (1H, br, NHNH)

[0228] 1.9 g of a ureate-modified hexamethylene diisocyanate (BURNOCK DN-901S, manufactured by DIC) and 1.0 g of the compound of formula (B3) were dissolved in 20 g of a mixed solvent of N-methylpyrrolidone and butyl acetate (weight ratio 1:1). 75 mg of a dibutyltin-based curing catalyst (NEOSTANN U-810, manufactured by Nitto Kasei Corporation) was added to obtain a thermosetting composition solution. The above composition was coated onto a glass plate to a dry film thickness of 10 μm and dried and cured in a forced-air dryer at 100°C for 120 minutes to obtain a decomposable crosslinked product. No precipitates were found on the cured coating. The decomposable crosslinked product is insoluble in water, but when immersed in a 20% sodium hypochlorite aqueous solution, foaming and removal from the substrate were observed.

[0229] (Example 4)

[0230] 5.0 g of 4-hydroxybenzoylhydrazine was dissolved in 65 g of acetone and 65 g of pure water in a 300 ml round-bottom flask. 8.75 g of 2-dodecen-1-ylsuccinic anhydride was added, and the mixture was stirred overnight at room temperature. The reaction solution was concentrated using an evaporator to precipitate the precipitate. After removing the solvent using a decanter, the precipitate was washed with 73 g of pure water and dried under vacuum, thus giving compound (B4) in 86% yield. The obtained compound (B4) is liquid at 50 °C.

[0231] [Chemical Formula 27]

[0232] 1H-NMR (DMSO, δppm) 0.85 (3H, t, CH3), 1.24 (14H, br, CH2), 1.92~2.75 (7H, m, CH, CH2), 5.26~5.38 (1H, m, CH=CH), 5.39~5.47 (1H , m, CH=CH), 6.80 (2H, d, benzene ring), 7.74 (2H, d, benzene ring), 9.78 (1H, br, NHNH), 9.81 (1H, br, NHNH), 10.03 (1H, br, OH), 11.13 (1H, br, C=OOH)

[0233] 3.0 g of compound (B4) was mixed with 2.7 g of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation ER828) at 50 °C, and then 120 mg of benzyl dimethylamine was added to obtain a thermosetting composition. This was coated onto a glass substrate with a cured film thickness of 10 μm and cured at 130 °C for 3 hours to obtain a decomposable crosslinker. No precipitates were found on the cured coating. The decomposable crosslinker is insoluble in water, but when it was immersed in a mixture of 20% sodium hypochlorite aqueous solution and propylene glycol monomethyl ether (weight ratio 2:1), foaming was observed, and it was removed from the substrate.

[0234] (Example 5)

[0235] In a 1L flask, 14.5g of N-hydroxysuccinimide was dissolved in 377g of THF. 9.5g of isophthalic acid and 24.3g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and the mixture was stirred overnight at room temperature. After concentration using an evaporator, 310g of chloroform was added, and the mixture was transferred to a separatory funnel. The organic layer was washed four times with 200g of deionized water. The organic layer was dried with 5.8g of magnesium sulfate and then concentrated using an evaporator. The concentrate was added dropwise to 150g of isopropanol to precipitate a solid. The resulting solid was dried overnight in a vacuum dryer at 25°C. Add 15.3 g of the above-mentioned dried solid to a 100 mL flask containing 13.6 g of 6-hydroxyhexanoyl hydrazide, 18 g of triethylamine, and 40 g of DMF. After stirring overnight at room temperature, the reaction solution is added dropwise to 800 g of acetonitrile, causing a white powder to precipitate. The white powder is filtered off, washed with 200 g of acetonitrile, and dried in a vacuum dryer at 50 °C for 3 hours. Transfer 3 g of the dried white powder to a 100 mL flask and dissolve it in 18 g of DMF. Then add 4.3 g of triethylamine and 4.0 g of di(N-succinimide) carbonate. After stirring at room temperature for 90 minutes, add 1.0 g of succinic dihydrazide and 36 g of DMSO and stir for 3 hours. Then add 0.2 g of succinic dihydrazide and stir overnight. The reaction mixture was added dropwise to 800 g of ethyl acetate. The resulting viscous solid was washed with 100 g of aqueous acetone and dried overnight in a vacuum dryer, thus yielding compound (B5) in 75% yield. The molecular weight, determined by GPC, was 19,000.

[0236] [Chemical Formula 28]

[0237] 1H-NMR (DMSO, δppm) 1.33 (92H, br, CH2), 1.58 (184H, br, CH2), 2.10-2.23 (92H, m, O=CCH2), 2.36 (96H, br, O=CCH2), 4.00 (92H, br, O=COCH2), 4.18 (4H, br, NH2), 7.6 1-7.69 (23H, m, benzene ring), 8.01 (46H, dd, benzene ring), 8.33 (23H, br, benzene ring), 8.95 (46H, br, NHNH), 9 .10(2H,br,NH), 9.67(46H,br,NHNH), 9.91(46H,br,NHNH), 10.37(46H,br,NHNH)

[0238] 1.0 g of compound (B5) was mixed with 0.02 g of phenolic varnish-type epoxy resin (Mitsubishi Chemical Corporation JER152) at 40 °C to obtain a thermosetting composition. This composition was coated onto a Teflon petri dish to a film thickness of 1 mm and heated at 90 °C for 3 hours to obtain a decomposable crosslinker. No precipitates were found in the cured product. The decomposable crosslinker is insoluble in water, but foaming and dissolution were observed when it was immersed in a mixture of 5% sodium hypochlorite aqueous solution and 2% sodium hydroxide aqueous solution (weight ratio 1:1).

[0239] (Example 6)

[0240] In a 200 ml round-bottom flask, 3.0 g of 6-hydroxyhexanoylhydrazide and 6.2 g of triethylamine were dissolved in 90 g of DMF. 4.1 g of N-allyloxycarbonyloxysuccinimide was added, and the mixture was stirred overnight at room temperature. Then, 5.8 g of di(N-succinimide) carbonate was added, and the mixture was stirred again overnight. 2.5 g of 2-hydroxyethyl carbazate was then added. The mixture was stirred overnight at room temperature, and the reaction solution was added dropwise to 70 g of ethyl acetate, causing a viscous solid to precipitate. The solvent was removed by decantation, and the resulting viscous solid was dried overnight using a vacuum dryer, thus giving compound (B6) in 68% yield.

[0241] [Chemical Formula 29]

[0242] 1H-NMR (DMSO, δppm) 1.25-1.38 (2H, m, CH2), 1.51-1.55 (4H, m, CH2), 2.09 (2H, t, O=CCH2), 3.97-4.02 (4H, m, O=COCH2), 4.51 (2H, d, O=COCH2), 5.20 (1H, d, C=CH2), 5.30 (1H, d, C=CH2), 5.85-5.95 (1H, m, CH=C), 9.00 (3H, br, NHNH), 9.60 (1H, br, NHNH)

[0243] 5 g of N-methylpyrrolidone, 1.0 g of ethyl 2-isocyanate acrylate, and 3.0 g of the compound of formula (B6) were mixed, and then 10 g of toluene, 1.0 g of pentaerythritol tetra(3-mercaptobutyrate), 0.05 g of photopolymerization initiator (Omnirad 127 manufactured by IGM RESINS), and 0.05 g of photopolymerization initiator (Omnirad 754 manufactured by IGM RESINS) were added to obtain a thermosetting / photocurable composition solution. The above composition was coated onto a PET film to a dry film thickness of 5 μm, dried in a 120°C blower dryer for 5 minutes, and then subjected to 200 mJ / cm² ultraviolet irradiation using a Ushio Electric Corporation Unicure UVH-1500M irradiation device. 2 Irradiation with ultraviolet light yielded a decomposable crosslinking compound. No precipitates were formed on the coating film. The obtained decomposable crosslinking compound was insoluble in deionized water, but when immersed in a liquid obtained by diluting an aqueous solution (Kao Corporation's Kitchen Haiter) containing sodium hypochlorite, surfactant, and sodium hydroxide (diluted 8 times with tap water), foaming was observed, and the compound was removed from the substrate. When immersed in a 5% aqueous solution of sodium dichloroisocyanurate, foaming was also observed, and the compound was removed from the substrate.

[0244] (Example 7)

[0245] In a 200 ml round-bottom flask, 15 g of trihydrazide citrate was dissolved in a mixed solvent of 40 g of deionized water and 20 g of methanol. 28 g of 4-hydroxybutyl acrylate was added, and the mixture was stirred at room temperature for 5 days. The reaction solution was then added dropwise to 640 g of acetonitrile, and the resulting viscous liquid was recovered by decantation. The solution was then dried overnight in a vacuum dryer at 50 °C, thus giving compound (B7) in 70% yield.

[0246] [Chemical Formula 30]

[0247] 1H-NMR (DMSO, δppm) 1.40-1.48 (6H, m, CH2), 1.56-1.63 (6H, m, CH2), 2.37-2.47 (6H, m, O=CCH2), 2.50 (4H, br, O=CCH2), 2.84-3.00 (6 H, m, NCH2), 3.40 (6H, t, OCH2), 4.01 (6H, t, O=COCH2), 4.41 (3H, br, OH), 4.95 (3H, br, NH), 6.02 (1H, br, OH), 9.08-9.41 (3H, m, O=CNH)

[0248] 1.1 g of polymethylene polyphenyl polyisocyanate (Millionate MR-200, manufactured by Tosoh Corporation) and 2.0 g of the compound of formula (B7) were dissolved in 20 g of a mixed solvent of N-methylpyrrolidone and methyl ethyl ketone (weight ratio 1:1). 75 mg of dibutyltin-based curing catalyst (NEOSTANN U-810, manufactured by Nitto Chemical Co., Ltd.) was added to obtain a thermosetting composition solution. The above composition was coated onto a glass plate to a dry film thickness of 10 μm and dried and cured at 100°C for 60 minutes using a forced-air dryer to obtain a decomposable crosslinked product. No precipitates were found on the cured coating. The decomposable crosslinked product is insoluble in water, but when immersed in a liquid obtained by diluting an aqueous solution containing sodium hypochlorite, a surfactant, and sodium hydroxide (Kitchen Haiter, manufactured by Kao Corporation) with tap water by 8 times, foaming was observed, and the product was removed from the substrate.

[0249] (Example 8)

[0250] In a 500 ml round-bottom flask, 177 g of acetonitrile, 14.5 g of triethylamine, and 7.0 g of 6-hydroxyhexanoic acid hydrazide were mixed, and a solution of acetonitrile containing 10 wt% methacrylic anhydride was added dropwise at 0 °C–10 °C. The mixture was then allowed to return to room temperature and stirred for 1 hour. 50 g of dimethylformamide was added, and the mixture was stirred again at room temperature for 1 hour. After the reaction, 200 g of solvent was removed using an evaporator. The remaining reaction solution was added dropwise to 70 g of butyl acetate, and the viscous liquid obtained by decantation was washed with 70 g of toluene. The mixture was then dried overnight using a vacuum dryer, yielding compound (B8) in 67% of the solution.

[0251] [Chemical Formula 30]

[0252] 1H-NMR (DMSO, δppm) 1.20-1.33 (2H, m, CH2), 1.35-1.45 (2H, m, CH2), 1.48-1.55 (2H, m, CH2), 1.86 (3H, s, CH3), 2.12 ( 2H, t, O=CCH2), 3.37 (2H, br, OCH2), 4.36 (1H, br, OH), 5.43 (1H, br, C=CH2), 5.73 (1H, br, C=CH2), 9.63 (2H, br, NHNH)

[0253] 0.4 g of compound (B8), 6.6 g of butyl acrylate, 3.0 g of isobornyl methacrylate, 5 g of ethyl acetate, and 5 g of dimethylformamide were mixed, and 0.01 g of 2,2'-azobisisobutyronitrile was added. After stirring at 65°C for 6 hours, the mixture was allowed to return to room temperature. Then, 0.25 g of polymethylene polyphenyl polyisocyanate (Millionate MR-200 manufactured by Tosoh Corporation), 0.03 g of dibutyltin dilaurate, and 10 g of methyl isobutyl ketone were mixed to obtain a thermosetting composition solution. The above composition was coated onto a PET film with a dry film thickness of 15 μm, and dried and cured in a blower dryer at 120°C for 2 minutes to obtain an adhesive decomposition crosslinked product. No precipitates were found on the cured coating. The decomposable crosslinker is insoluble in water, but when it is immersed in a mixture of 2% sodium hypochlorite aqueous solution and isopropanol (weight ratio 5:1), foaming and removal from the substrate are confirmed.

[0254] (Evaluation of solvent solubility)

[0255] 0.5 ml of the solvent listed in Tables 1 and 2 was added to 2 mg of the decomposable crosslinking agent in Examples 1-8 and Comparative Examples 1-2, and the mixture was stirred. Dissolution was visually confirmed. If residual dissolution was found after stirring at room temperature for 2 minutes, the mixture was heated with a hot air gun while stirring for 2 minutes, and visual confirmation was performed again. Complete dissolution at room temperature was scored as 3 points, complete dissolution after heating with residual dissolution at room temperature was scored as 2 points, a small amount of residual dissolution after heating was scored as 1 point, and a large amount of residual dissolution after heating was scored as 0 points. The results are shown in Tables 1 and 2.

[0256] [Table 1]

[0257]

[0258] [Table 2]

[0259]

[0260] The compounds of Comparative Examples 1 and 2 exhibited low solubility in any solvent. The compounds of Examples 1 to 8 showed high solubility in a variety of solvents. In particular, the compound of Example 1 showed high solubility in solvents compared to Comparative Example 2, which had a similar structure.

Claims

1. A decomposable crosslinking agent which is a decomposable crosslinking agent comprising a compound represented by the following formula (1), in the formula (1), n > 0, k > 0, m > 0; R1, R2, and R3 independently of one another contain at the terminal end one or more reactive functional groups selected from the group consisting of a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isopentenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an anhydride group, a vinyl group, an allyl group, an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group, a hydroxysilyl group, an epoxy group, an oxetanyl group, an oxazoline group, an isocyanate group, a carbodiimide group, a hydroxymethyl group, a silanol group, and an alkoxysilyl group, and contain a single bond, a siloxane- containing structure, or a hydrocarbon group optionally having a substituent or a heteroatom; A1 to A8 are independently of one another a carbonyl group or a single bond, at least one of A1 and A2 is a carbonyl group, at least one of A3 and A4 is a carbonyl group, at least one of A5 and A6 is a carbonyl group, and at least one of A7 and A8 is a carbonyl group; Z is independently of one another a siloxane-containing structure, or a hydrocarbon group optionally having a heteroatom, in the decomposable crosslinking agent, (a) when n = 0, R1 and R2 are different; (b) when n > 1 and k = 0, (b-1) R1 and R2 are different, and / or (b-2) Z contains at least one asymmetric structure; (c) when n > 1 and k > 1, (c-1) at least one of R1, R2, and R3 is different, and / or (c-2) Z contains at least one asymmetric structure.

2. The degradable crosslinker of claim 1, wherein, R1, R2, and R3 are different from one another.

3. The degradable crosslinking agent according to claim 1 or 2, wherein, The reactive functional groups contained in R1, R2, and R3 are the same.

4. The degradable crosslinking agent according to any one of claims 1 to 3, wherein, n > 1, Z contains at least one asymmetric structure, and R1, R2, and R3 are the same.

5. The degradable crosslinking agent according to any one of claims 1 to 3, wherein, n > 1, all of Z are asymmetric structures.

6. The degradable crosslinking agent according to any one of claims 1 to 3, wherein, n > 1, all of Z are symmetric structures, and the reactive functional groups contained in R1, R2, and R3 are the same.

7. The degradable crosslinking agent according to any one of claims 1 to 6, wherein, The reactive functional groups contained in R1, R2, and R3 are respectively classified into mutually different groups shown in the following (A) to (O), (A) a hydroxyl group; (B) an amino group, a hydrazide group; (C) a thiol group; (D) an isopentenyl group, a crotonamide group, a crotonate group; (E) a carboxylic acid; (F) an anhydride group; (G) a vinyl group, an allyl group; (H) an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group; (I) a hydroxysilyl group; (J) an epoxy group, an oxetanyl group; (K) an oxazoline group; (L) an isocyanate group; (M) a carbodiimide group; (N) a hydroxymethyl group; (O) a silanol group, an alkoxysilyl group.

8. The degradable crosslinking agent according to any one of claims 1 to 7, wherein, The reactive functional groups contained in R1, R2, and R3 are respectively classified into any one of the following (A) to (O), and two or more of the reactive functional groups contained in R1, R2, and R3 are classified into the same group, (A) a hydroxyl group; (B) an amino group, a hydrazide group; (C) a thiol group; (D) an isopentenyl group, a crotonamide group, a crotonate group; (E) a carboxylic acid; (F) an anhydride group; (G) a vinyl group, an allyl group; (H) an acrylate group, a methacrylate group, an acrylamide group, a methacrylamide group; (I) a hydroxysilyl group; (J) epoxy group, oxetanyl group; (K) oxazolinyl group; (L) isocyanate group; (M) carbodiimide group; (N) methylol group; (O) silanol group, alkoxysilyl group.

9. The degradable crosslinking agent according to any one of claims 1 to 8, wherein, The decomposable crosslinking agent is liquid at 30°C to 60°C.

10. A composition comprising the decomposable crosslinking agent according to any one of claims 1 to 9 and one or more selected from the group consisting of a curable resin, a polymerization initiator, and a solvent.

11. A decomposable crosslinked product comprising the composition according to claim 10.

12. The degradable crosslinked polymer of claim 11, wherein, The decomposable crosslinked product is capable of being decomposed with an oxidizing agent.

13. A method for decomposing a decomposable crosslinked product, comprising a step of contacting the decomposable crosslinked product according to claim 11 or 12 with an aqueous solution containing an oxidizing agent at 100°C or lower.

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