Degradable crosslinking agent

Abstract

The present invention provides a degradable crosslinking agent that has high solubility in a solvent and is not susceptible to poor curing. The present invention is a crosslinking agent comprising a compound represented by formula (1) (In formula (1): n ≥ 0, k ≥ 0, and m ≥ 0; R1, R2, and R3 independently include, at a 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 isoprenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an acid 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 oxetane group, an oxazoline group, an isocyanate group, a carbodiimide group, a methylol group, a silanol group, and an alkoxysilyl group, and includes a single bond, a group including a siloxane structure, or a hydrocarbon group which may have a substituent or a hetero atom; A1 to A8 are independently a carbonyl group or a single bond, and 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; and each Z is independently a group containing a siloxane structure or a hydrocarbon group which may have a hetero atom.) (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) at least one Z having an asymmetric structure is included; and (c) when n ≥ 1 and k ≥ 1, at least one of (c-1) R1, R2, and R3 is different, and / or (c-2) at least one Z having an asymmetric structure Z is included.

Description

Degradable Crosslinking Agents

[0001] The present invention relates to a degradable crosslinking agent.

[0002] Due to their moldability, durability, and light weight, plastic products are used in a variety of fields, including daily necessities, automobiles, and electronic devices. However, they are difficult to decompose after disposal. In recent years, efforts have been made to develop degradable polymers that can be easily decomposed in order to protect the global environment.

[0003] Patent Documents 1 to 3 disclose polymers having a diacylhydrazine structure as degradable polymers. Due to the diacylhydrazine structure, these polymers are stable in air, but are rapidly decomposed by reaction with an oxidizing agent such as sodium hypochlorite. Patent Documents 4 and 5 disclose that compounds containing a hydrazine structure can be used as pharmaceuticals.

[0004] JP 2011-236381 A, International Publication No. 2021 / 131003, JP 2011-052075 A, International Publication No. 00 / 35917, International Publication No. 2014 / 071247

[0005] The diacylhydrazine compounds used as raw materials for polymers described in Patent Documents 1 and 2, and the diacylhydrazine-containing polymer described in Patent Document 3, have low solubility in solvents, and therefore tend to precipitate crystals before curing, which can cause poor curing. Furthermore, even compounds with relatively high solubility in solvents only dissolve in high-boiling aprotic polar solvents or strong acids, which requires a large amount of energy for the process of removing the solvent to obtain a molded product, resulting in a significant environmental impact. Patent Documents 4 and 5 do not suggest that compounds containing a hydrazine structure can be used as crosslinking agents, nor do they suggest decomposition by reaction with an oxidizing agent or solubility in organic solvents.

[0006] An object of the present invention is to provide a decomposable crosslinking agent that is highly soluble in solvents and is less likely to cause poor curing.

[0007] The present inventors have discovered that a crosslinking agent made of a hydrazine derivative containing a specific structure exhibits high solubility in a solvent and can suppress poor curing, and have completed the present invention.

[0008] That is, the present invention provides a compound represented by the following formula (1): (In formula (1), n≧0, k≧0, m≧0. R １ , R ２ , and R ３ are each independently a group consisting of a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isoprenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an acid 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 oxetane group, an oxazoline group, an isocyanate group, a carbodiimide group, a methylol group, a silanol group, and an alkoxysilyl group, and a single bond, a group containing a siloxane structure, or a hydrocarbon group which may have a substituent or a heteroatom. １ ~A ８ are each independently a carbonyl group or a single bond, and A １ and A ２ At least one of A is a carbonyl group, ３ and A ４ At least one of A is a carbonyl group, ５ and A ６ At least one of A is a carbonyl group, ７ and A ８ At least one of the Z's is a carbonyl group; and each Z is independently a group containing a siloxane structure or a hydrocarbon group which may have a heteroatom. １ and R ２ are different, and (b) when n≧1 and k=0, (b−1) R １ and R ２ and / or (b-2) at least one Z having an asymmetric structure, (c) when n≧1 and k≧1, (c-1) R １ , R ２ , and R ３ and / or (c-2) the decomposable crosslinking agent includes at least one Z having an asymmetric structure.

[0009] In the decomposable crosslinking agent, R１ , R ２ , and R ３ are preferably different from each other.

[0010] In the decomposable crosslinking agent, R １ , R ２ , and R ３ It is preferable that the reactive functional groups contained in

[0011] In the decomposable crosslinking agent, n≧1 is satisfied, and at least one Z has an asymmetric structure, and R １ , R ２ , and R ３ are preferably the same.

[0012] In the decomposable crosslinking agent, it is preferable that n≧1 and all Z's have an asymmetric structure.

[0013] In the decomposable crosslinking agent, n≧1, all Zs have a symmetric structure, and R １ , R ２ , and R ３ It is preferred that the reactive functional groups contained in

[0014] In the decomposable crosslinking agent, R １ , R ２ , and R ３ It is preferable that the reactive functional groups contained in the above are classified into the following mutually different groups (A) to (O): (A) hydroxyl group (B) amino group, hydrazide group (C) thiol group (D) isoprenyl group, crotonamide group, crotonate group (E) carboxylic acid (F) acid anhydride group (G) vinyl group, allyl group (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group (I) hydroxysilyl group (J) epoxy group, oxetane group (K) oxazoline group (L) isocyanate group (M) carbodiimide group (N) methylol group (O) silanol group, alkoxysilyl group

[0015] In the decomposable crosslinking agent, R １ , R ２ , and R ３ The reactive functional groups contained in R are each classified into any one of the following groups (A) to (O),１ , R ２ , and R ３ It is preferable that two or more of the reactive functional groups contained in the above be classified into the same group: (A) hydroxyl group (B) amino group, hydrazide group (C) thiol group (D) isoprenyl group, crotonamide group, crotonate group (E) carboxylic acid (F) acid anhydride group (G) vinyl group, allyl group (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group (I) hydroxysilyl group (J) epoxy group, oxetane group (K) oxazoline group (L) isocyanate group (M) carbodiimide group (N) methylol group (O) silanol group, alkoxysilyl group

[0016] The decomposable crosslinking agent is preferably liquid at 30 to 60°C.

[0017] The present invention also relates to a composition comprising the decomposable crosslinking agent and one or more members selected from the group consisting of a curable resin, a polymerization initiator, and a solvent.

[0018] The present invention also relates to a degradable crosslinked product comprising the composition.

[0019] The decomposable crosslinked product is preferably decomposable with an oxidizing agent.

[0020] The present invention also relates to a method for decomposing a decomposable crosslinked product, which comprises a step of contacting the decomposable crosslinked product with an aqueous solution containing an oxidizing agent at 100°C or less.

[0021] The decomposable crosslinking agent of the present invention is highly soluble in solvents and is less likely to cause poor curing.

[0022] <<Degradable Crosslinking Agent>> The decomposable crosslinking agent of the present invention comprises a compound represented by the following formula (1).

[0023] In formula (1), n, m, k, R １ , R ２ , R ３ , Z are as follows: n≧0, k≧0, m≧0. R １ , R ２ , and R ３are each independently a group consisting of a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isoprenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an acid 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 oxetane group, an oxazoline group, an isocyanate group, a carbodiimide group, a methylol group, a silanol group, and an alkoxysilyl group, and a single bond, a group containing a siloxane structure, or a hydrocarbon group which may have a substituent or a heteroatom. １ ~A ８ are each independently a carbonyl group or a single bond, and A １ and A ２ At least one of A is a carbonyl group, ３ and A ４ At least one of A is a carbonyl group, ５ and A ６ At least one of A is a carbonyl group, ７ and A ８ At least one of the above is a carbonyl group. Z's are each independently a group containing a siloxane structure or a hydrocarbon group which may have a heteroatom.

[0024] In a narrow sense, the term "crosslinking agent" can refer to a chemical substance that forms chemical bonds between polymers or within a polymer. In this specification, however, the term also refers to a chemical substance that can form chemical bonds between its own molecules, in addition to a chemical substance that forms chemical bonds between polymers or within a polymer.

[0025] <n, m, k in formula (1)> In formula (1), n ​​and m are all 0 or more, but each independently is preferably 1 or more, more preferably 2 or more. When n is 1 or more, the decomposability of the decomposable crosslinking agent is improved because the crosslinking agent has two or more hydrazine-derived structures (-A-NH-NH-A-). There are no particular upper limits for n and m, but they can each be 50 or less.

[0026] 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 achieved by the decomposable crosslinking agent of the present invention. The upper limit of k is not particularly limited, but can be 50 or less.

[0027] <R in formula (1) １ , R ２ , and R ３ > R １ , R ２ , and R ３ R each independently contains a reactive functional group at its terminal and includes a single bond, a group containing a siloxane structure, or a hydrocarbon group which may have a substituent or a heteroatom. １～３ can be expressed by the following formula (2): ｊ -Q ｊ (2) R １ where j=1 and R ２ where j=2 and R ３ where j=3. ｊ is R １～３ is a reactive functional group contained in ｊ is R １～３ The reactive functional group P is a single bond included in the above, a group containing a siloxane structure, or a hydrocarbon group. ｊ is a single bond, a group containing a siloxane structure, or a hydrocarbon group, ｊ It bonds to a hydrazine-derived structure (-A-NH-NH-A-) via

[0028] Reactive functional group P ｊ is one or more selected from the group consisting of a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isoprenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an acid 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 oxetane group, an oxazoline group, an isocyanate group, a carbodiimide group, a methylol group, a silanol group, and an alkoxysilyl group, and an optimum group can be selected depending on the application and process.

[0029] R １ , R ２ , R ３In the formula, the reactive functional group P ｊ The numbers of are each 1 or more, but are each independently preferably 1 to 4, more preferably 1 to 2. When the number is 2 or more, three-dimensional crosslinking becomes easy, and the strength and reliability of the crosslinked product are improved.

[0030] R １ , R ２ , R ３ each independently represents two or more reactive functional groups P ｊ and may have two or more reactive functional groups P ｊ When the reactive functional group P has the reactive functional group P, various types of curable resins and crosslinking processes can be selected as the crosslinking agent. Furthermore, only specific reactive functional groups can be used in the crosslinking reaction, and the reactive functional groups not used in the crosslinking reaction can be used to contribute to improving other physical properties such as improving adhesion or solubility. ｊ When the number is 1, the decomposition rate tends to improve.

[0031] Hydrocarbon group Q ｊ The number of carbon atoms in the hydrocarbon group Q is preferably 1 to 600, more preferably 1 to 100, and even more preferably 1 to 20, from the viewpoint of the strength of the crosslinked product. ｊ is a saturated or unsaturated hydrocarbon group, which may have a straight-chain structure, a branched structure, or a cyclic structure.

[0032] Hydrocarbon group Q ｊ may have a substituent. Specific examples of the substituent include an alkoxy group, a phenoxy group, a halogen atom, an amino group, a sulfo group, a cyano group, and a nitro group.

[0033] Hydrocarbon group Q ｊ may contain heteroatoms. When heteroatoms are contained, the number thereof is preferably 1 to 300, more preferably 1 to 100, and even more preferably 1 to 10. The heteroatoms are preferably hydrocarbon groups Q ｊ The hydrocarbon group Q may be present in the main chain or in the side chain. Examples of heteroatoms include N, S, O, and P. ｊ As a structure containing a heteroatom included in Examples include:

[0034] Hydrocarbon group Q ｊSpecific examples include linear hydrocarbons such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, ether, urethane, urea, ester, thioether, carbonate, and amide, branched hydrocarbons such as isopropylene, isobutylene, 2,2-dimethylpropylene, and 2-ethyl-2-methylpropylene, cyclic hydrocarbons such as cyclohexylene, cyclopentylene, norbornenylene, phenylene, and naphthylene, PEG chains, and further trivalent or tetravalent groups formed from these groups. The hydrogen atoms of these hydrocarbon groups may be substituted with the aforementioned substituents.

[0035] A group Q containing a siloxane structure ｊ is divalent or higher. The group containing a siloxane structure contains an —Si—O— bond and may have a linear structure, a branched structure, or a cyclic structure. The number of silicon atoms in the group containing a siloxane structure is preferably 2 to 300, more preferably 2 to 100, and even more preferably 2 to 20.

[0036] The hydrogen atoms bonded to the silicon atoms may be substituted. Specific examples of the substituent include alkyl groups, alkoxy groups, phenoxy groups, halogen atoms, amino groups, sulfo groups, cyano groups, and nitro groups.

[0037] A group Q containing a siloxane structure ｊ Specific examples of the silicone include dimethyl silicone, diethyl silicone, ethyl methyl silicone, polymethyl silsesquioxane, and modified silicones obtained by modifying the hydrocarbon groups at the terminals and / or side chains of these silicones to contain heteroatoms such as N, S, O, and P.

[0038] R １ , R ２ , and R ３ may be the same as or different from each other. １ , R ２ , and R ３The following three embodiments are specific examples of the cases in which R is different from the others: - Both the terminal reactive functional group and the single bond, group containing a siloxane structure, or hydrocarbon group are different - The terminal reactive functional groups are the same, and the single bond, group containing a siloxane structure, or hydrocarbon group is different - The terminal reactive functional groups are different, and the single bond, group containing a siloxane structure, or hydrocarbon group is the same １ , R ２ , and R ３ When these are different from each other, the solubility in a solvent tends to be improved.

[0039] R １～３ When two or more reactive functional groups are present in each of R １ , R ２ , and R ３ The phrase "the reactive functional groups are different" means that the reactive functional groups do not completely match, and it is preferable that there are no matching reactive functional groups.

[0040] When n≧1 and k≧2, for example, there are k R ３ , R ３－１ , R ３－２ ...R ３－ｋ When the definition is given as "R １ , R ２ , and R ３ are different from each other" means that R １ , R ２ And, R ３－１ , R ３－２ ...R ３－ｋ means that at least one of １ , R ２ , R ３－１ , R ３－２ ...R ３－ｋ It is preferred that all of "R １ , R ２ , and R ３ "The same" means that R １ , R ２ And, R ３－１ , R ３－２ ...R ３－ｋ means that at least one of １ , R ２ , R ３－１ , R３－２ ...R ３－ｋ It is preferable that all of "R １ , R ２ , and R ３ The reactive functional groups contained in R １ , R ２ and the reactive functional group contained in R ３－１ , R ３－２ ...R ３－ｋ means that the reactive functional groups contained in at least one of R １ , R ２ , R ３－１ , R ３－２ ...R ３－ｋ In the compound represented by formula (1), it is preferable that the reactive functional groups contained in all of R １ , R ２ The number of R is not particularly limited, and each may be present in two or more. １ , R ２ When there are two or more, R １ , R ２ The identity of R ３ can be judged in the same way.

[0041] R １ , R ２ , and R ３ When the reactive functional groups contained in R are the same, the crosslinking density tends to be improved by a single crosslinking process. １ , R ２ , and R ３ are different from each other, but R １ , R ２ , and R ３ When the reactive functional groups contained in the copolymer are the same, the solubility in a solvent tends to be improved and the crosslinking density tends to be improved by a single crosslinking process.

[0042] <Structure for Improving Solubility in Solvents> The decomposable crosslinking agent of the present invention has high solubility in solvents due to the following characteristics (a) to (c) in formula (1): (a) when n=0, R １ and R ２ are different, and (b) when n≧1 and k=0, (b−1) R １ and R ２and / or (b-2) at least one Z having an asymmetric structure, (c) when n≧1 and k≧1, (c-1) R １ , R ２ , and R ３ and / or (c-2) at least one Z has an asymmetric structure.

[0043] R １ and R ２ are different, R １ , R ２ , and R ３ and containing at least one Z having an asymmetric structure make the structure of the decomposable crosslinking agent complex and suppress crystallization, thereby contributing to improving solubility in a solvent.

[0044] In addition to the above features (a) to (c), R １ , R ２ , and R ３ In this case, the structure of the decomposable crosslinking agent becomes complex, and the solubility in a solvent is likely to be improved.

[0045] In addition to the above features (a) to (c), R １ , R ２ , and R ３ Furthermore, n≧1, at least one Z having an asymmetric structure, and R １ , R ２ , and R ３ In this case, the crosslinking density can be easily improved by a single crosslinking process.

[0046] In addition to the above features (a) to (c), n may be 1 or greater and all Z's may have an asymmetric structure. In this case, the solubility in a solvent is likely to be improved.

[0047] In addition to the above characteristics (a) to (c), n≧1, all Zs have a symmetric structure, and R １ , R ２ , and R ３ In this case, the reactive functional groups contained in R １ , R ２ , and R ３Preferably, the groups containing a siloxane structure or the hydrocarbon groups contained in the above are different, which allows the crosslinking density to be increased by a single crosslinking process while improving the solubility in a solvent.

[0048] R １ , R ２ , and R ３ The reactive functional groups contained in can be independently classified into the following groups (A) to (O): (A) hydroxyl group (B) amino group, hydrazide group (C) thiol group (D) isoprenyl group, crotonamide group, crotonate group (E) carboxylic acid (F) acid anhydride group (G) vinyl group, allyl group (H) acrylate group, methacrylate group, acrylamide group, methacrylamide group (I) hydroxysilyl group (J) epoxy group, oxetane group (K) oxazoline group (L) isocyanate group (M) carbodiimide group (N) methylol group (O) silanol group, alkoxysilyl group

[0049] R １ The reactive functional group contained in R ２ and the reactive functional group contained in R ３ The reactive functional groups contained in may be classified into different groups shown in (A) to (O). In this case, the solubility in a solvent tends to be improved. For example, R １ The reactive functional groups contained in R are classified into group (A), ２ The reactive functional groups contained in R are classified into group (B), ３ The reactive functional group contained in can be classified into group (C). However, when n=0, or when n≧1 and k=0, R ３ does not exist.

[0050] Also, R １ The reactive functional group contained in R ２ and the reactive functional group contained in R ３ The reactive functional groups contained in may be classified into two or more groups shown in (A) to (O). In this case, the solubility in a solvent tends to be easily improved. For example, R １ The reactive functional groups contained in R are classified into group (A),２ The reactive functional groups contained in R are classified into group (A) or group (C), ３ The reactive functional group contained in can be classified into group (B). However, when n=0, or when n≧1 and k=0, R ３ does not exist.

[0051] Also, R １ The reactive functional group contained in R ２ and the reactive functional group contained in R ３ Two or more of the reactive functional groups contained in R may be classified into the same group shown in (A) to (O). In this case, the crosslinking density tends to be improved by a single crosslinking process. For example, １ The reactive functional groups contained in R are classified into group (A), ２ The reactive functional groups contained in R are classified into group (A), ３ The reactive functional groups contained in the formula (A) can be classified into group (A) or group (B). However, when n=0, or when n≧1 and k=0, R ３ does not exist.

[0052] <A in formula (1) １ ~A ８ > In formula (1), A １ ~A ８ are each independently a carbonyl group or a single bond, and A １ and A ２ At least one of A is a carbonyl group, ３ and A ４ At least one of A is a carbonyl group, ５ and A ６ At least one of A is a carbonyl group, ７ and A ８ At least one of the two A's present on either side of -NH-NH- is a carbonyl group. When one of the two A's is a carbonyl group, the decomposable crosslinker has a monoacylhydrazine structure, and the decomposition rate by an oxidizing agent tends to be improved. When both are carbonyl groups, the decomposable crosslinker has a diacylhydrazine structure, and the decomposition product tends to be easily dissolved in a solution containing an oxidizing agent.

[0053] <Z in Formula (1)> In Formula (1), Z's are each independently a group containing a siloxane structure or a hydrocarbon group which may have a heteroatom. From the viewpoint of decomposition rate and crosslink 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 has a saturated or unsaturated hydrocarbon group as the main skeleton, and may have a linear structure, a branched structure, or a cyclic structure.

[0054] The hydrocarbon group may have a substituent, specific examples of which include an alkoxy group, a phenoxy group, a halogen atom, an amino group, a sulfo group, a cyano group, and a nitro group.

[0055] The hydrocarbon group may contain heteroatoms. When heteroatoms are contained, the number is preferably 1 to 300, more preferably 1 to 100, and even more preferably 1 to 10. The heteroatoms may 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: Examples include:

[0056] The group containing a siloxane structure is divalent or higher. The group containing a siloxane structure contains an —Si—O— bond and may have a linear structure, a branched structure, or a cyclic structure. The number of silicon atoms in the group containing a siloxane structure is preferably 2 to 300, more preferably 2 to 100, and even more preferably 2 to 20.

[0057] The hydrogen atoms bonded to the silicon atoms may be substituted. Specific examples of the substituent include alkyl groups, alkoxy groups, phenoxy groups, halogen atoms, amino groups, sulfo groups, cyano groups, and nitro groups.

[0058] Specific examples of groups containing a siloxane structure include dimethyl silicone, diethyl silicone, ethylmethyl silicone, polymethylsilsesquioxane, and modified silicones obtained by modifying the hydrocarbon groups at the ends and / or side chains of these groups to contain heteroatoms such as N, S, O, and P.

[0059] Z may have a reactive functional group, such as a hydroxyl group, an amino group, a hydrazide group, a thiol group, an isoprenyl group, a crotonamide group, a crotonate group, a carboxylic acid, an acid 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 oxetane group, an oxazoline group, an isocyanate group, a carbodiimide group, a methylol group, a silanol group, or an alkoxysilyl group.

[0060] The hydrocarbon group represented by Z may have an asymmetric structure. In the present invention, the symmetry of a structure is determined by whether or not two overlapping structures can be obtained when a structure sandwiched between a combination of two hydrazine-derived structures (-A-NH-NH-A-) is divided by a plane. When there is no plane from which two overlapping structures can be obtained, the structure is determined to be asymmetric. When there is a plane from which two overlapping structures can be obtained, the structure is determined to be symmetric. However, when Z is bonded to three or more hydrazine-derived structures (-A-NH-NH-A-) and there is no plane from which two overlapping structures can be obtained between a specific combination of two hydrazine-derived structures (-A-NH-NH-A-), Z is determined to have an asymmetric structure, regardless of whether there is a plane from which two overlapping structures can be obtained between a combination of two other hydrazine-derived structures (-A-NH-NH-A-).

[0061] Specific examples of the asymmetric structure include the following formulas (7) to (22): Examples include structures represented by the following formula:

[0062] Specific examples of the symmetrical structure include linear hydrocarbons such as methylene, ethylene, n-propylene, n-butylene, n-pentylene, n-hexylene, n-heptylene, n-octylene, and n-nonylene; branched 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, and bisphenol A; and further, trivalent or tetravalent groups formed from these groups.

[0063] When the decomposable crosslinking agent contains two or more Z's with different structures in the molecule, the decomposability can be controlled by selecting a combination of the types of Z's. Examples of combinations of two or more Z's include a combination of a Z's with high water solubility in the decomposition product and a Z's with low water solubility in the decomposition product. Furthermore, examples of properties before decomposition include a combination of a hydrophilic Z's with a hydrophobic Z's, a combination of a highly polar Z's with a low polar Z's, and a combination of a flexible Z's with a rigid Z's. Furthermore, by using a combination of a symmetrical Z's with an asymmetrical Z's, it is possible to adjust the solvent solubility and miscibility with other compositions.

[0064] The decomposable crosslinking agent preferably has a weight average molecular weight of 100 to 10,000, more preferably 100 to 2,000. When the molecular weight is within this range, the crosslink density and decomposability tend to be improved.

[0065] The decomposable crosslinking agent is preferably liquid at 30 to 60° C., more preferably liquid at 30 to 40° C. This has advantages such as excellent miscibility with other components when preparing the composition and the ability to suppress precipitation of other components during molding.

[0066] <Method for Synthesizing Decomposable Crosslinking Agent> The method for synthesizing the decomposable crosslinking agent is not particularly limited, and examples thereof include a reaction between a hydrazide compound, a semicarbazide compound, or a carbazate compound and a carbonate compound, an isocyanate compound, an acid anhydride, an acid halide, or a cyclic ester compound; a reaction between hydrazine and a carboxylic acid ester; a reaction between hydrazine and a carbonate compound; and a reaction between hydrazine and an isocyanate compound.

[0067] Examples of hydrazide compounds used in the above synthesis method include lactic acid hydrazide, methacrylic acid hydrazide, sebacic acid dihydrazide, adipic acid dihydrazide, phthalic acid dihydrazide, salicylic acid dihydrazide, trimellitic acid trihydrazide, 4-hydroxybutyric acid hydrazide, 4-hydroxybenzohydrazide, 6-hydroxyhexanoic acid hydrazide, and citric acid trihydrazide. Examples of carbonate compounds include allyl N-succinimidyl carbonate and C,C'-(oxydi-2,1-ethanediyl)bisN-succinimidyl carbonate. Examples of isocyanate compounds include 2-isocyanatoethyl methacrylate, hexamethylene diisocyanate, toluene diisocyanate, and polymethylene polyphenyl polyisocyanate. Examples of semicarbazide compounds include N-allylhydrazinecarboxamide, N,N'-1,6-hexanediylbis[hydrazinecarboxamide], 4,4'-isophoronebis(semicarbazide), and 4,4'-(1,3-phenylenebismethylene)bis(semicarbazide). Examples of carbazate compounds include allylcarbazate and C,C'-(oxydi-2,1-ethanediyl)biscarbazate. Examples of acid anhydrides include methacrylic anhydride, succinic anhydride, and pyromellitic dianhydride. Examples of acid halides include acrylic acid chloride, sebacic acid dichloride, adipic acid dichloride, phthalic acid dichloride, salicylic acid dichloride, and trimesic acid trichloride. Examples of cyclic ester compounds include propiolactone, butyrolactone, valerolactone, etc. Examples of carboxylic acid esters include ethyl lactate, methylparaben, monomethyl succinate, diethyl adipate, trimethyl trimellitate, etc.

[0068] <Composition> The composition of the present invention contains the decomposable crosslinking agent and one or more 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 wt %, more preferably 1 to 50 wt %.

[0069] <Curable Resin> The curable resin is not particularly limited as long as it has a structure that reacts with the reactive functional group of the decomposable crosslinking agent to crosslink, and examples thereof 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 may be a thermosetting resin or a photocurable resin. The amount of the curable resin in the composition is preferably 0.1 to 95% by weight, and more preferably 1 to 50% by weight.

[0070] <Polymerization Initiator> The polymerization initiator is not particularly limited as long as it is a compound that can catalyze the polymerization of the curable resin, and either a thermal polymerization initiator or a photopolymerization initiator can be used. Examples of the polymerization initiator include radical generators such as alkylphenone compounds, benzoin compounds, benzophenone compounds, oxime ester compounds, and phosphine compounds; base generators such as oxime ester compounds, ammonium compounds, benzoin compounds, dimethoxybenzyl urethane compounds, and orthonitrobenzyl urethane compounds; acid generators 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 octoate; titanium compounds such as tetraoctyl titanate and titanium ethyl acetoacetate; zirconium compounds such as zirconium monoacetylacetate and zirconium tetraacetylacetate; 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 the polymerization initiator in the composition is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, per 100 parts by weight of the curable resin.

[0071] <Solvent> Examples of the solvent include water and organic solvents, such as ether solvents, amide solvents, hydrocarbon solvents, alcohol solvents, ester solvents, aldehyde solvents, ketone solvents, and solvents containing carbon atoms, such as solvents containing carbon atoms and hetero atoms.

[0072] Examples of ether-based solvents include propylene glycol monomethyl ether, anisole, 4-methylanisole, diisopropyl ether, diethyl ether, dibutyl ether, tetrahydrofuran, dimethoxyethane, cyclopentyl methyl ether, and tert-butyl methyl ether. Examples of amide-based solvents include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Examples of hydrocarbon-based solvents include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, xylene, mesitylene, ethylbenzene, tert-butylbenzene, trifluoromethylbenzene, nitrobenzene, and chlorobenzene. Examples of alcohol-based solvents include methanol, ethanol, propanol, butanol, ethylene glycol, and propylene glycol monomethyl ether. Examples of ester-based solvents include ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate. Examples of aldehyde-based 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 the solvent in the composition is preferably 5 to 99% by weight, and more preferably 20 to 80% by weight.

[0073] The solvents listed above may be used alone or in combination of two or more. The boiling point of the solvent is preferably 150°C or lower, more preferably 130°C or lower, and even more preferably 110°C or lower. When the boiling point is within these ranges, the solvent can be removed by heating for a relatively short period of time. It is preferable that the composition is substantially free of solvents with a boiling point exceeding 150°C. Here, "substantially free of solvents with a boiling point exceeding 150°C" means that the amount in the composition is less than 1% by weight.

[0074] <Degradable Crosslinked Product> The degradable crosslinked product of the present invention can be obtained by curing a composition containing a degradable crosslinking agent and one or more selected from the group consisting of a curable resin, a polymerization initiator, and a solvent. The method for producing a degradable crosslinked product from the composition can be any method that promotes polymerization and crosslinking of the curable resin, and those skilled in the art can appropriately select light irradiation conditions, heating conditions, etc. depending on the types of degradable crosslinking agent, curable resin, and polymerization initiator contained in the composition. For example, when the degradable crosslinked product is made into a three-dimensional molded product, methods such as injection molding, compression molding, transfer molding, three-dimensional printing, and photolithography can be used.

[0075] Furthermore, when forming a coating film made of a decomposable crosslinked material, the composition can be applied to a substrate to form a coating film, and the coating film can then be irradiated with light or heated. The material and shape of the substrate are not particularly limited, and examples thereof 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, polyamides such as nylon 6 and nylon 66; polycarbonates; polyvinyl acetate, polyvinyl alcohol, polyimides, ABS resins, cellulose, cellulose acetate, fibroin, and keratin. Examples of inorganic materials include glass, metals such as Ni, Cu, Cr, Fe, and Si, and oxides and composite materials thereof.

[0076] Examples of methods for applying the composition onto a substrate include bar coating, spin coating, spray coating, dip coating, nozzle coating, gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, curtain coating, knife coating, transfer roll coating, squeeze coating, impregnation coating, kiss coating, calendar coating, and extrusion coating.

[0077] The curing conditions for the composition applied to the substrate are not particularly limited. When the composition is cured by light irradiation, the curing conditions are 100 to 2000 mJ / cm. ２When curing is performed by heating, the heating temperature is preferably 40 to 300° C., and more preferably 80 to 120° C. The heating time is preferably 0.5 to 180 minutes, and more preferably 0.5 to 10 minutes.

[0078] The thickness of the cured coating film is not particularly limited, but is preferably 0.01 to 30 μm, and more preferably 0.05 to 10 μm, within which the strength of the coating film and adhesion to the substrate can be maintained.

[0079] <Method for Decomposing Degradable Crosslinked Material> The method for decomposing a decomposable crosslinked material of the present invention includes a step of contacting the decomposable crosslinked material with an aqueous solution containing an oxidizing agent at 100°C or less.

[0080] <Oxidizing Agent> The oxidizing agent is not particularly limited as long as it is an oxidizing agent other than molecular 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. These may be used alone or in combination of two or more. Among these, water-soluble salts such as sodium hypochlorite and sodium hypobromite, and ozone water are preferred. Aqueous solutions containing these oxidizing agents may contain alkalis 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 to 50% by weight, more preferably 0.01 to 3% by weight.

[0081] The temperature condition for contacting the decomposable crosslinked product with the aqueous solution containing an oxidizing agent is 100°C or less, preferably 15 to 50°C. The time condition is preferably 60 minutes or less, more preferably 10 minutes or less. If necessary, the crosslinked product may be shaken or stirred during the reaction with the oxidizing agent. The specific method for contacting the decomposable crosslinked product with the aqueous solution containing an oxidizing agent is not particularly limited, and examples include a method of immersing the decomposable crosslinked product in an aqueous solution containing an oxidizing agent, and a method of spraying or dropping the aqueous solution containing an oxidizing agent onto the decomposable crosslinked product.

[0082] Decomposition products produced by contacting the decomposable crosslinked material with an oxidizing agent include N ２ , H ２ O and compounds represented by the following formulas (3) to (6): HO—CO—Z(COOH) ｋ -COOH (3) H-Z(COOH) ｋ -COOH (4) HO-CO-Z(H) ｋ -COOH (5) H-Z(H) ｋ —H (6) In formulas (3) to (6), Z and k are the same as in formula (1). H or a carboxyl group directly bonded to Z may be bonded to a heteroatom in Z.

[0083] When the hydrazine-derived structure (-A-NH-NH-A-) is bonded to the 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.

[0084] When a 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 —OH at the terminal. Specific examples of decomposition products containing —OH at the terminal include ethylene glycol, diethylene glycol, triethylene glycol, hexanediol, pentitol, pentaerythritol, polyethylene glycol, polyvinyl alcohol, resorcinol, and phenol novolak.

[0085] When a hydrazine-derived structure (-A-NH-NH-A-) is bonded to the nitrogen atom in Z and A is a carbonyl group, the decomposition product has -NH at the end.２ Contains -NH at the end ２ Specific examples of decomposition products containing the above include hexamethylenediamine, pentamethylenediamine, isophoronediamine, toluenediamine, and diaminodiphenylmethane.

[0086] When a hydrazine-derived structure (-A-NH-NH-A-) bonds with the sulfur atom in Z and A is a carbonyl group, the decomposition product becomes a thiol. Specific examples of thiols include pentaerythritol tetrakis(3-mercaptobutyrate), trimethylolpropane tris(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, triazinethiol, and 4-mercaptobenzoic acid.

[0087] The method for evaluating the decomposition of a decomposable crosslinked product by contact with an oxidizing agent is not particularly limited and can be appropriately selected depending on the solvent solubility of the decomposable crosslinked product and the solvent solubility of the decomposition product. For example, a method can be used in which 2 ml of a 20% aqueous solution of sodium hypochlorite is added to 2 mg of the decomposable crosslinked product and the reaction is allowed to proceed at room temperature for 30 minutes. Another method can be used in which 2 mg of the decomposable crosslinked product is mixed with 0.5 ml of a heavy solvent such as heavy water, heavy chloroform, heavy DMSO, or heavy methanol, and a few drops of a 20% aqueous solution of sodium hypochlorite is added and the reaction is allowed to proceed at room temperature for 5 minutes. After these treatments, it is preferable that the decomposable crosslinked product is completely decomposed. The decomposition product can be confirmed by NMR.

[0088] <Uses of Degradable Crosslinking Agent> The degradable crosslinking agent of the present invention has excellent solubility in solvents and can be used for crosslinking various resins. Uses of crosslinked products using the degradable crosslinking agent of the present invention include adhesives, pressure-sensitive adhesives, water-absorbent resins, resins for three-dimensional modeling, photoresists, release agents, cell culture media, materials for fixing affected areas, and imprinted molded products.

[0089] The present invention will be described below with reference to examples, but is not limited to the following examples. Hereinafter, "parts" and "%" mean "parts by weight" and "% by weight", respectively, unless otherwise specified.

[0090] Comparative Example 1: 1.4 g of pyridine, 10.3 g of acetonitrile, and 0.86 g of allylacetohydrazide were mixed in a 30 ml two-neck flask, and 0.82 g of sebacoyl chloride dissolved in 6.2 g of acetonitrile was added dropwise at 5° C. or below, followed by stirring at room temperature for 3 hours. The obtained white solid was washed with 30 g of acetonitrile and dried in a vacuum dryer at 40° C. to obtain the compound of formula (A1) in a yield of 95%.

[0091] 1 H-NMR (DMSO, δppm) 1.25 (8H, S, C8H16), 1.50 (4H, t, C8H16), 2.09 (4H, t, C8H16), 2.17 to 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)

[0092] The solvent solubility of the obtained compound of formula (A1) was evaluated, and the results are shown in Table 2. When a 5% aqueous solution of sodium hypochlorite was added to the powdered compound of formula (A1), foaming and decomposition were observed.

[0093] A thermosetting composition solution was obtained by adding 0.3 g of the compound of formula (A1), 0.1 g of poly(methylhydrosiloxane), and 4.0 mg of a platinum catalyst (product 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 applied to a glass substrate so that the film thickness after curing would be 0.1 μm, and then dried and cured at 150°C for 10 minutes to obtain a decomposable crosslinked product. A small amount of precipitate was observed on the cured coating film. The decomposable crosslinked product was generally insoluble in water, but some dissolution was observed. When the decomposable crosslinked product was immersed in a 10% aqueous sodium hypochlorite solution, foaming and removal from the substrate were observed.

[0094] Comparative Example 2: In a 100 mL three-neck flask, 1.8 g of 5-sulfoisophthalic acid dihydrazide sodium was dissolved in 40 g of methyl sulfoxide, and 3.4 g of 2-isocyanatoglutarate diethyl was added and stirred overnight at 80°C. The reaction mixture was allowed to cool to room temperature, then diluted with 100 g of purified water. The aqueous layer was washed three times with 90 g of ethyl acetate and then concentrated. The resulting residue was dried under vacuum. The resulting pale orange solid was transferred to a 30 mL recovery flask, to which 4.6 g of hydrazine monohydrate was added and 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 resulting solid was collected by filtration and then dried under vacuum, yielding the compound of formula (A2) in a 93% yield.

[0095] 1H-NMR (DMSO, δppm) 1.70-1.86 (4H, m, CH ２ ), 1.97-2.09 (4H, m, C=OCH ２ ), 4.13 (2H, q, C=OCH), 4.23 (8H, br, NH ２ ), 6.72 (2H, br, NCONHC), 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)

[0096] The solvent solubility of the obtained compound of formula (A2) was evaluated, and the results are shown in Table 2. When a 5% aqueous solution of sodium hypochlorite was added to the powdered compound of formula (A2), foaming and decomposition were observed.

[0097] A thermosetting composition was obtained by dissolving 0.3 g of the compound of formula (A2) in 40 g of N-methylpyrrolidone and adding 0.65 g of bisphenol A epoxy resin (jER828, manufactured by Mitsubishi Chemical Corporation). The composition was applied to a glass substrate so that the film thickness after curing would be 2 μm, and then dried and cured at 130°C for 30 minutes to obtain a decomposable crosslinked product. A small amount of precipitate was observed on the cured coating film. The decomposable crosslinked product was partially dissolved in water. When the decomposable crosslinked product was immersed in a 20% aqueous solution of sodium hypochlorite, foaming and decomposition were observed.

[0098] Example 1 In a 100 mL recovery flask, 2.9 g of the compound of formula (A2) was dissolved in 33 g of dimethyl sulfoxide, and 4.1 g of N-allyloxycarbonyloxysuccinimide was added and stirred overnight at room temperature. The reaction solution was transferred to a separatory funnel and diluted with 105 g of pure water. The resulting aqueous layer was washed three times with 80 g of methylene chloride and then concentrated to obtain a pale orange solid. This solid was washed three times with 150 g of methylene chloride and then vacuum dried to obtain the compound of formula (B1) in a yield of 83%.

[0099] 1H-NMR (DMSO, δppm) 1.72-1.94 (4H, m, CH ２ ), 2.19 (4H, br, C=OCH ２ ), 4.26 (2H, q, C=OCH), 4.50 to 4.55 (8H, m, OCH ２ ), 5.20 (4H, dd, C=CH ２ ), 5.31 (4H, dd, C=CH ２ ), 5.87 to 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=ONH), 9.24 (2H, s, OC=ONH), 9.69 (2H, s, CC=ONH), 9.89 (2H, br, CC=ONH), 10.40 (2H, br, CC=ONH)

[0100] The solvent solubility of the obtained compound of formula (B1) was evaluated, and the results are shown in Table 1. When a small amount of 20% aqueous sodium hypochlorite 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 1 H-NMR. The obtained compound of formula (B1) was a solid at 60°C.

[0101] 0.3 g of the compound of formula (B1) and 0.22 g of tetraethylene glycol bis(3-mercaptopropionate) were dissolved in 4 g of a mixed solvent of methanol and N-methylpyrrolidone (weight ratio 3:1), and 8 mg of a photopolymerization initiator (Omnirad 907 manufactured by IGM Resinside) and 8 mg of a photopolymerization initiator (Omnirad TPO manufactured by IGM Resinside) were added to obtain a photocurable composition. The composition was coated on a glass plate to a dry film thickness of 2 μm, and then irradiated with an ultraviolet ray from a UV ray irradiation device (Uniqure UVH-1500M manufactured by Ushio Inc.) at 500 mJ / cm. ２ The decomposable crosslinked product was irradiated with ultraviolet light for 10 seconds to obtain a decomposable molded product. No precipitates were observed on the cured coating film. The decomposable crosslinked product did not dissolve in water, but when the decomposable crosslinked product was immersed in a 20% aqueous solution of sodium hypochlorite, it was observed that the product foamed and was removed from the substrate.

[0102] Example 2 In a 200 ml recovery flask, 2.0 g of 4-hydroxybutyric acid hydrazide was dissolved in 170 g of acetonitrile at 50°C, and 3.4 g of N-allyloxycarbonyloxysuccinimide was added. The mixture was stirred at 40°C for 1 hour and then at room temperature overnight. The reaction solution was concentrated using an evaporator, and 30 g of chloroform was added, resulting in the precipitation of N-hydroxysuccinimide as a white solid. The N-hydroxysuccinimide was removed by filtration, and the solvent was again distilled off, yielding the compound of formula (B2) in a 90% yield. The resulting compound of formula (B2) was liquid at 50°C.

[0103] 1H-NMR (DMSO, δppm) 1.61-1.68 (2H, m, CH ２ ), 2.12 (2H, t, C=OCH ２ ), 3.89 (2H, q, OCH ２ ), 4.45 (1H, t, OH), 4.51 (2H, q, C=OOCH ２ ), 5.20 (1H, d, C=CH2), 5.30 (1H, d, C=CH2), 5.85 to 5.96 (1H, m, CH=C), 9.04 (1H, s, NHNH), 9.59 (1H, s, NHNH)

[0104] 0.9 g of a nurate-modified hexamethylene diisocyanate (BURNOCK DN-901S manufactured by DIC Corporation), 1.0 g of the compound of formula (B2), and 0.9 g of tetraethylene glycol bis(3-mercaptopropionate) were dissolved in 20 g of a mixed solvent of propylene glycol monomethyl ether and butyl acetate (weight ratio 1:1), and 70 mg of a dibutyltin-based curing catalyst (NEOSTAN U-810 manufactured by Nitto Kasei Co., Ltd.), 40 mg of a photopolymerization initiator (OMNIRAD 907 manufactured by IGM RESINS), and 40 mg of a photopolymerization initiator (OMNIRAD TPO manufactured by IGM RESINS) were added to obtain a thermosetting composition solution. The composition was applied to a glass plate so that the dry film thickness was 10 μm, dried and cured for 120 minutes in a 100°C air dryer, and then further cured with an ultraviolet irradiation device (Ushio Inc., Uniqure UVH-1500M) at 500 mJ / cm ２ The decomposable crosslinked product was subjected to ultraviolet irradiation for 10 seconds, yielding a decomposable crosslinked product. No precipitates were observed on the cured coating film. The decomposable crosslinked product did not dissolve in water, but when the decomposable crosslinked product was immersed in a 20% aqueous solution of sodium hypochlorite, it was observed that foaming occurred and the product was removed from the substrate.

[0105] Example 3: 10.0 g of lactic acid hydrazide and 33.1 g of γ-butyrolactone were mixed in a 200 ml recovery flask and stirred at 85°C for 2 days. 69 g of methyl ethyl ketone was added and the mixture was cooled on ice to produce a precipitate. The solvent was removed by decantation, and the precipitate was washed twice with 50 g of methyl ethyl ketone. The precipitate was dried in a vacuum to obtain the compound of formula (B3) in a 72% yield. The obtained compound of formula (B3) was liquid at 50°C.

[0106] 1H-NMR (DMSO, δppm) 1.24 (3H, dd, CH ３ ), 1.61 to 1.69 (2H, m, CH ２ ), 2.12 to 2.17 (2H, m, C=OCH ２ ), 3.39-3.43 (2H, m, OCH ２ ), 4.03 to 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)

[0107] 1.9 g of a nurate-modified hexamethylene diisocyanate (Burnoc DN-901S, manufactured by DIC Corporation) 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), and 75 mg of a dibutyltin-based curing catalyst (Neostan U-810, manufactured by Nitto Kasei Co., Ltd.) was added to obtain a thermosetting composition solution. The composition was coated on a glass plate to a dry film thickness of 10 μm, and then dried and cured for 120 minutes in a 100°C air dryer to obtain a decomposable crosslinked product. No precipitates were observed on the cured coating film. The decomposable crosslinked product did not dissolve in water, but when immersed in a 20% aqueous sodium hypochlorite solution, foaming and removal from the substrate were observed.

[0108] Example 4: In a 300 ml recovery flask, 5.0 g of 4-hydroxybenzohydrazide was dissolved in 65 g of acetone and 65 g of pure water, and 8.75 g of 2-dodecen-1-ylsuccinic anhydride was added, followed by stirring overnight at room temperature. The reaction solution was concentrated using an evaporator to separate out a precipitate. After removing the solvent by decantation, the precipitate was washed with 73 g of pure water and dried in vacuo to obtain the compound of formula (B4) in an 86% yield. The obtained compound of formula (B4) was liquid at 50°C.

[0109] 1H-NMR (DMSO, δppm) 0.85 (3H, t, CH ３ ), 1.24 (14H, br, CH ２ ), 1.92 to 2.75 (7H, m, CH, CH ２ ), 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)

[0110] 3.0 g of the compound of formula (B4) and 2.7 g of bisphenol A epoxy resin (jER828, manufactured by Mitsubishi Chemical Corporation) were mixed at 50°C, and 120 mg of benzyldimethylamine was added to obtain a thermosetting composition. The composition was applied to a glass substrate so that the cured film thickness was 10 μm, and then cured at 130°C for 3 hours to obtain a decomposable crosslinked product. No precipitates were observed on the cured coating film. The decomposable crosslinked product did not dissolve in water, but when immersed in a mixed solution of 20% aqueous sodium hypochlorite and propylene glycol monomethyl ether (weight ratio 2:1), foaming and removal from the substrate were observed.

[0111] Example 5: In a 1 L recovery flask, 14.5 g of N-hydroxysuccinimide was dissolved in 377 g of THF, and 9.5 g of isophthalic acid and 24.3 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added and stirred overnight at room temperature. After concentrating using an evaporator, 310 g of chloroform was added and transferred to a separatory funnel, and the organic layer was washed four times with 200 g of ion-exchanged water. The organic layer was dried over 5.8 g of magnesium sulfate and then concentrated using an evaporator. The concentrated solution was added dropwise to 150 g of isopropanol to precipitate a solid. The resulting solid was dried overnight in a vacuum dryer at 25°C. To a 100 mL recovery flask containing a mixture of 13.6 g of 6-hydroxyhexanoic acid hydrazide, 18 g of triethylamine, and 40 g of DMF, 15.3 g of the dried solid was added and stirred overnight at room temperature. The reaction solution was then added dropwise to 800 g of acetonitrile to precipitate a white powder. This white powder was collected by filtration, washed with 200 g of acetonitrile, and dried in a vacuum oven at 50°C for 3 hours. 3 g of the dried white powder was transferred to a 100 mL recovery flask and dissolved in 18 g of DMF. 4.3 g of triethylamine and 4.0 g of di(N-succinimidyl)carbonate were added and stirred at room temperature for 90 minutes. 1.0 g of succinic acid dihydrazide and 36 g of DMSO were then added and stirred for 3 hours. 0.2 g of succinic acid dihydrazide was then added and stirred overnight. The reaction mixture was added dropwise to 800 g of ethyl acetate to precipitate a viscous solid. The precipitate was washed with 100 g of aqueous acetone and dried overnight in a vacuum dryer to obtain the compound of formula (B5) in a 75% yield. The molecular weight measured by GPC was 19,000.

[0112] 1H-NMR (DMSO, δppm) 1.33 (92H, br, CH ２ ), 1.58 (184H, br, CH ２ ), 2.10-2.23 (92H, m, O=CCH ２ ), 2.36 (96H, br, O=CCH ２ ), 4.00 (92H, br, O=COCH ２ ), 4.18 (4H, br, NH ２), 7.61-7.69 (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)

[0113] A thermosetting composition was obtained by mixing 1.0 g of the compound of formula (B5) and 0.02 g of a phenol novolac epoxy resin (jER152 manufactured by Mitsubishi Chemical Corporation) at 40°C. The composition was applied to a Teflon petri dish to a film thickness of 1 mm and heated at 90°C for 3 hours to obtain a decomposable crosslinked product. No precipitates were observed in the cured molded product. The decomposable crosslinked product did not dissolve in water, but when it was immersed in a mixed solution of 5% aqueous sodium hypochlorite and 2% aqueous sodium hydroxide (weight ratio 1:1), foaming and dissolution were observed.

[0114] Example 6 In a 200 ml recovery flask, 3.0 g of 6-hydroxyhexanoic acid hydrazide and 6.2 g of triethylamine were dissolved in 90 g of DMF, and 4.1 g of N-allyloxycarbonyloxysuccinimide was added and stirred overnight at room temperature. Subsequently, 5.8 g of di(N-succinimidyl) carbonate was added, and the mixture was further stirred overnight, followed by the addition of 2.5 g of 2-hydroxyethyl carbazate. After stirring overnight at room temperature, the reaction solution was added dropwise to 70 g of ethyl acetate to precipitate a viscous solid. The solvent was removed by decantation, and the resulting viscous solid was dried overnight in a vacuum dryer to obtain the compound of formula (B6) in a 68% yield.

[0115] 1H-NMR (DMSO, δppm) 1.25-1.38 (2H, m, CH ２ ), 1.51-1.55 (4H, m, CH ２ ), 2.09 (2H, t, O=CCH ２ ), 3.97-4.02 (4H, m, O=COCH ２ ), 4.51 (2H, d, O=COCH ２ ), 5.20 (1H, d, C=CH ２ ), 5.30 (1H, d, C=CH ２), 5.85-5.95 (1H, m, CH=C), 9.00 (3H, br, NHNH), 9.60 (1H, br, NHNH)

[0116] 5 g of N-methylpyrrolidone, 1.0 g of 2-isocyanatoethyl acrylate, and 3.0 g of the compound of formula (B6) were mixed, and then 10 g of toluene, 1.0 g of pentaerythritol tetrakis(3-mercaptobutyrate), 0.05 g of a photopolymerization initiator (Omnirad 127 manufactured by IGM ResinS), and 0.05 g of a photopolymerization initiator (Omnirad 754 manufactured by IGM ResinS) were added to obtain a thermally and photocurable composition solution. The composition was applied to a PET film to a dry film thickness of 5 μm, dried for 5 minutes in a 120°C air dryer, and then irradiated with an ultraviolet ray irradiation device (Uniqure UVH-1500M manufactured by Ushio Inc.) at 200 mJ / cm. ２ The resulting degradable crosslinked product was then irradiated with ultraviolet light for 10 seconds, yielding a degradable crosslinked product. No precipitates were formed on the coating film. The resulting degradable crosslinked product was insoluble in ion-exchanged water, but when immersed in a solution containing sodium hypochlorite, a surfactant, and sodium hydroxide (Kitchen Haiter, manufactured by Kao Corporation) diluted 8 times with tap water, it was observed that the product foamed and was removed from the substrate. When immersed in a 5% aqueous solution of sodium dichloroisocyanurate, it was observed that the product foamed and was removed from the substrate.

[0117] Example 7: In a 200 ml recovery flask, 15 g of citric acid trihydrazide was dissolved in a mixed solvent of 40 g of ion-exchanged water and 20 g of methanol, and 28 g of 4-hydroxybutyl acrylate was added and stirred at room temperature for 5 days. This reaction solution was added dropwise to 640 g of acetonitrile, and the resulting viscous liquid was recovered by decantation. The mixture was then dried overnight in a vacuum dryer at 50°C to obtain the compound of formula (B7) in a 70% yield.

[0118] 1H-NMR (DMSO, δppm) 1.40-1.48 (6H, m, CH ２ ), 1.56-1.63 (6H, m, CH ２ ), 2.37-2.47 (6H, m, O=CCH ２ ), 2.50 (4H, br, O=CCH ２), 2.84-3.00 (6H, m, NCH ２ ), 3.40 (6H, t, OCH ２ ), 4.01 (6H, t, O=COCH ２ ), 4.41 (3H, br, OH), 4.95 (3H, br, NH), 6.02 (1H, br, OH), 9.08-9.41 (3H, m, O=CNH)

[0119] 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 (1:1 weight ratio), and 75 mg of a dibutyltin-based curing catalyst (Neostan U-810, manufactured by Nitto Kasei Co., Ltd.) was added to obtain a thermosetting composition solution. The composition was coated on a glass plate to a dry film thickness of 10 μm, and then dried and cured for 60 minutes in a 100°C air dryer to obtain a decomposable crosslinked product. No precipitates were observed on the cured coating film. The decomposable crosslinked product did not dissolve in water, but when immersed in a solution containing sodium hypochlorite, a surfactant, and sodium hydroxide (Kitchen Haiter, manufactured by Kao Corporation) diluted 8 times with tap water, foaming and removal from the substrate were observed.

[0120] Example 8: 177 g of acetonitrile, 14.5 g of triethylamine, and 7.0 g of 6-hydroxyhexanoic acid hydrazide were mixed in a 500 ml recovery flask, and an acetonitrile solution containing 10 wt % of methacrylic anhydride was added dropwise at 0 to 10°C. The mixture was then returned to room temperature and stirred for 1 hour, after which 50 g of dimethylformamide was added and 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 and then dried overnight in a vacuum dryer, yielding the compound of formula (B8) in a 67% yield.

[0121] 1H-NMR (DMSO, δppm) 1.20-1.33 (2H, m, CH ２ ), 1.35-1.45 (2H, m, CH ２ ), 1.48-1.55 (2H, m, CH ２), 1.86 (3H, s, CH ３ ), 2.12 (2H, t, O=CCH ２ ), 3.37 (2H, br, OCH ２ ), 4.36 (1H, br, OH), 5.43 (1H, br, C=CH ２ ), 5.73 (1H, br, C=CH ２ ), 9.63 (2H, br, NHNH)

[0122] 0.4 g of the compound of formula (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'-azodiisobutyronitrile was added. The mixture was stirred at 65°C for 6 hours, then returned to room temperature. 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 composition was applied to a PET film to a dry film thickness of 15 μm, and the mixture was dried and cured in a 120°C air dryer for 2 minutes, yielding a decomposable crosslinked product with adhesive properties. No precipitates were observed on the cured coating film. The decomposable crosslinked material did not dissolve in water, but when it was immersed in a mixed solution of 2% aqueous sodium hypochlorite solution and isopropanol (weight ratio 5:1), it was confirmed that it foamed and was removed from the substrate.

[0123] (Evaluation of Solvent Solubility) 0.5 ml of a solvent shown in Tables 1 and 2 was added to 2 mg of the decomposable crosslinking agent of Examples 1 to 8 and Comparative Examples 1 and 2, and the mixture was stirred, and dissolution was confirmed visually. If there was any residue left after stirring for 2 minutes at room temperature, the mixture was heated with a heat gun while stirring for 2 minutes, and then visually checked again. A sample that was completely dissolved at room temperature was given a score of 3, a sample that was left partially dissolved at room temperature but completely dissolved after heating was given a score of 2, a sample that had a small amount of residue left after heating was given a score of 1, and a sample that had a large amount of residue left after heating was given a score of 0. The results are shown in Tables 1 and 2.

[0124]

[0125] The compounds of Comparative Examples 1 and 2 had low solubility in any solvent. The compounds of Examples 1 to 8 showed high solubility in multiple solvents. In particular, the compound of Example 1 showed higher solubility in solvents than the compound of Comparative Example 2, which has a similar structure.

Claims

1. Formula (1) below: 【Chemistry 1】 (In formula (1), n≧0, k≧0, m≧0. ・R １ , R ２ , and R ３ Each group independently contains at its terminal one or more reactive functional groups selected from the group consisting of hydroxyl groups, amino groups, hydrazide groups, thiol groups, isoprenyl groups, crotonamide groups, crotonate groups, carboxylic acids, acid anhydride groups, vinyl groups, allyl groups, acrylate groups, methacrylate groups, acrylamide groups, methacrylamide groups, hydroxysilyl groups, epoxy groups, oxetane groups, oxazoline groups, isocyanate groups, carbodiimide groups, methylol groups, silanol groups, and alkoxysilyl groups, and It contains single bonds, groups containing siloxane structures, or hydrocarbon groups which may have substituents or heteroatoms. - A １ ~ A ８ are independently of each other a carbonyl group or a single bond, and at least one of A １ and A ２ is a carbonyl group, and at least one of A ３ and A ４ is a carbonyl group, and at least one of A ５ and A ６ is a carbonyl group, and at least one of A ７ and A ８ is a carbonyl group. (Z is a hydrocarbon group that independently contains a siloxane structure or may have a heteroatom.) A degradable crosslinking agent comprising a compound represented by the following: (a) When n = 0, R １ and R ２ They are different, (b) When n≧1 and k=0, (b-1)R １ and R ２ It includes at least one Z which is different and / or has an asymmetric structure (b-2), (c) When n≧1 and k≧1, (c-1)R １ , R ２ , and R ３ At least one of the elements is different and / or includes at least one Z which has a (c-2) asymmetric structure, A biodegradable crosslinking agent.

2. R １ , R ２ , and R ３ A degradable crosslinking agent according to claim 1, wherein the two elements are different from each other.

3. R １ , R ２ , and R ３ The degradable crosslinking agent according to claim 1 or 2, wherein the reactive functional group contained therein is the same.

4. n ≥ 1, and includes at least one asymmetric structure Z, R １ , R ２ , and R ３ The degradable crosslinking agent according to claim 1, wherein the same property is present.

5. The degradable crosslinking agent according to claim 1 or 2, wherein n ≥ 1 and all Z have an asymmetric structure.

6. n ≥ 1, all Z are symmetric structures, and R １ , R ２ , and R ３ A degradable crosslinking agent according to claim 1 or 2, wherein the reactive functional groups contained are the same.

7. R １ , R ２ , and R ３ The degradable crosslinking agent according to claim 1 or 2, wherein the reactive functional groups contained therein are classified into different groups shown below (A) to (O). (A) Hydroxyl group (B) Amino group, hydrazide group (C) Thiol group (D) Isoprenyl group, crotonamide group, crotonate group (E) Carboxylic acid (F) Acid anhydride group (G) vinyl group, allyl group (H) Acrylate group, methacrylate group, acrylamide group, methacrylamide group (I) Hydroxysilyl group (J) Epoxy group, oxetane group (K) Oxazoline group (L) Isocyanate group (M) Carbodiimide group (N) Methylol group (O) Silanol group, alkoxysilyl group

8. R １ , R ２ , and R ３ Each reactive functional group contained therein is classified into one of the following groups (A) to (O): R １ , R ２ , and R ３ Two or more of the reactive functional groups contained in it are classified into the same group. A degradable crosslinking agent according to claim 1 or 2. (A) Hydroxyl group (B) Amino group, hydrazide group (C) Thiol group (D) Isoprenyl group, crotonamide group, crotonate group (E) Carboxylic acid (F) Acid anhydride group (G) vinyl group, allyl group (H) Acrylate group, methacrylate group, acrylamide group, methacrylamide group (I) Hydroxysilyl group (J) Epoxy group, oxetane group (K) Oxazoline group (L) Isocyanate group (M) Carbodiimide group (N) Methylol group (O) Silanol group, alkoxysilyl group

9. A degradable crosslinking agent according to claim 1 or 2, which is liquid at 30 to 60°C.

10. A composition comprising a degradable crosslinking agent according to claim 1 or 2, and one or more selected from the group consisting of a curable resin, a polymerization initiator, and a solvent.

11. A degradable crosslinked product comprising the composition described in claim 10.

12. A degradable crosslinked product according to claim 11, which can be decomposed by an oxidizing agent.

13. A method for decomposing a decomposable crosslinked product, comprising the step of bringing the decomposable crosslinked product described in claim 11 into contact with an aqueous solution containing an oxidizing agent at a temperature of 100°C or lower.

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