Curable compositions, cured products, and polymer compounds

Abstract

To provide a curable composition that yields a recyclable cured product.SOLUTION: A curable composition includes (A) a monofunctional vinyl monomer having a specific substituent, (B) a polyfunctional vinyl monomer having one or more diacylhydrazine structures, and (C) a polymerization initiator.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable composition, a cured product, and a polymer compound.

Background Art

[0002] Conventionally, curable compositions have been used as adhesives and sealants.

[0003] For example, Patent Document 1 discloses a photosensitive resin composition containing a polyamic acid resin having a radically polymerizable unsaturated bond and a photopolymerization initiator.

[0004] Here, in recent years, warming caused by CO2 generated by incineration of used plastics and leakage of plastics into the natural environment have become global problems. As one of the solutions to these problems, recycling of resins has been studied. Recycling of resins includes (a) technologies for making the resin itself reusable, (b) technologies for chemically decomposing the resin and producing the resin again from the obtained monomers and low molecular weight substances, and (c) technologies for decomposing the matrix resin for reusing valuable substances other than the resin, such as carbon fibers in CFRP.

[0005] Therefore, development of a technology for recycling a cured product obtained by curing a curable composition has been demanded.

[0006] By the way, although it is not a curable composition, as a technology for recycling water-absorbent articles such as disposable diapers, Patent Document 2 discloses a crosslinked polymer compound containing a hydrazine skeleton.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

[0008] However, the conventional technologies described above were insufficient from the standpoint of recycling cured products obtained by curing curable compositions, and there was room for further improvement.

[0009] One embodiment of the present invention has been made in view of the above-mentioned problems, and its object is to provide a curable composition that can provide a recyclable cured product. [Means for solving the problem]

[0010] The inventors diligently studied and conducted research to solve the aforementioned problems, and as a result, have completed the present invention.

[0011] In other words, one embodiment of the present invention includes the following configuration. [1] (A)-C(=O)XR 2 n A monofunctional vinyl monomer having (X is one selected from the group consisting of O, S, and N; R 2 (where n is a monovalent or divalent organic group; n indicates 1 or 2), (B) A polyfunctional vinyl monomer containing one or more structures represented by the following general formula (1) (diacylhydrazine structure) in one molecule, and (C) polymerization initiator, A curable composition containing the following:

[0012] [ka]

[0013] [2] The curable composition according to [1], wherein the polyfunctional vinyl monomer contains one or two structures represented by the general formula (1) in one molecule. [3] The curable composition according to [1] or [2], wherein the polymerization initiator is a photopolymerization initiator. A cured product obtained by curing the curable composition according to any one of [1] to [3] with active energy rays. 〔5〕A polymer compound containing a skeleton represented by the following general formula (2).

[0014]

Chemical formula

[0015] (In General Formula (2), R 1 , R 3 , R 6 each independently represents hydrogen or a monovalent alkyl group having 1 to 6 carbon atoms. X is any one selected from the group consisting of O, S, and N; R 2 is a monovalent or divalent organic group; R 4 , R 5 are each independently a divalent organic group or a single bond; n represents 1 or 2.).

Advantages of the Invention

[0016] According to one embodiment of the present invention, a curable composition capable of providing a recyclable cured product can be provided.

Modes for Carrying Out the Invention

[0017] One embodiment of the present invention is described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications are possible within the scope of the claims. Embodiments or examples obtained by appropriately combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic and patent documents mentioned herein are incorporated herein by reference. Unless otherwise specified herein, "A to B" representing a numerical range means "A or greater (including A and greater than A) and B or less (including B and less than B)". In this specification, "(meth)acrylic" means "acrylic" and / or "methacrylic".

[0018] [1. Curable composition] A curable composition according to one embodiment of the present invention is (A)-C(=O)XR 2 n A monofunctional vinyl monomer having (X is one selected from the group consisting of O, S, and N; R 2 (A) a monovalent or divalent organic group; n indicates 1 or 2), (B) a polyfunctional vinyl monomer containing one or more structures represented by the following general formula (1) (diacylhydrazine structure) in one molecule, and (C) a polymerization initiator.

[0019] [ka]

[0020] In this specification, "(A)-C(=O)XR 2 nThe monofunctional vinyl monomer having, (B) a polyfunctional vinyl monomer containing one or more structures represented by the following general formula (1) in one molecule, and (C) a polymerization initiator may also be referred to as "(A) monofunctional vinyl monomer" or "(A) component," "(B) polyfunctional vinyl monomer" or "(B) component," and "(C) component," respectively. Furthermore, in this specification, "a curable composition according to one embodiment of the present invention" may be referred to as "this curable composition."

[0021] Because this curable composition has the configuration described above, the cured product obtained by curing this curable composition has a diacylhydrazine structure at the crosslinking points. The cured product having the diacylhydrazine structure can be cleaved at the diacylhydrazine structure by treatment with an oxidizing agent. Therefore, the cured product having the diacylhydrazine structure is recyclable. In other words, this curable composition can provide a recyclable cured product. Such effects according to one embodiment of the present invention contribute, for example, to achieving United Nations Sustainable Development Goals (SDGs) Goal 12, "Ensure sustainable consumption and production patterns," and Goal 14, "Conserve and sustainably use the oceans, seas and marine resources for sustainable development."

[0022] (1-1. (A) Monofunctional vinyl monomer) In this specification, a monofunctional vinyl monomer refers to a vinyl monomer having one vinyl group in one molecule. In this specification, the term "vinyl group" also includes cases where the hydrogen atom bonded to the carbon-carbon double bond is substituted with an alkyl group or the like (e.g., a methyl group).

[0023] In one embodiment of the present invention, (A) monofunctional vinyl monomer is -C(=O)XR 2 n (X is one selected from the group consisting of O, S, and N; R 2 (A) has a monovalent or divalent organic group; n indicates 1 or 2). In other words, (A) monofunctional vinyl monomer has an ester bond (-C(=O)OR 2), thioester bond (-C(=O)SR 2 ) and amide bond (-C(=O)NR 2 It has one selected from the group consisting of ). Among these, (A) monofunctional vinyl monomer has an ester bond (-C(=O)OR 2 ) and amide bond (-C(=O)NR 2 Preferably, it has one selected from the group consisting of ), and an ester bond (-C(=O)OR 2 It is particularly preferable that the group has a substituent containing a carbon atom. In this specification, "organic group" refers to a substituent containing a carbon atom.

[0024] Let's explain the case where X is a divalent element such as O or S (hereinafter referred to as Case A). In Case A, R 2 represents a monovalent organic group, and n represents 1. In case A, R 2 The group is not particularly limited as long as it is a monovalent organic group, but examples include any one selected from the group consisting of alkyl groups, hydroxyalkyl groups, aminoalkyl groups, thioalkyl groups, alkyl groups containing phosphate ester groups, alkyl groups containing epoxy groups, alkyl groups containing carboxyl groups, alkyl groups containing ester bonds, alkyl groups containing ether bonds, alkyl groups containing isocyanate groups, oxyalkylene groups, and aryl groups. Among these, alkyl groups, hydroxyalkyl groups, alkyl groups containing phosphate ester groups, alkyl groups containing epoxy groups, alkyl groups containing carboxyl groups, alkyl groups containing ester bonds, alkyl groups containing ether bonds, alkyl groups containing isocyanate groups, oxyalkylene groups, and aryl groups are preferred because they are readily available, highly reactive, easy to handle, and allow for easy adjustment of the physical properties of the cured product. Alkyl groups, hydroxyalkyl groups, alkyl groups containing phosphate ester groups, oxyalkylene groups, and alkyl groups containing ether bonds are more preferred, and alkyl groups, hydroxyalkyl groups, and oxyalkylene groups are even more preferred. This configuration has the advantage of enabling the economical production of recyclable curable compositions.

[0025] In case A, R 2 The number of carbon atoms contained is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 6, and particularly preferably 1 to 5. This configuration has the advantages of making the curable composition easy to handle, making it easy to adjust various physical properties, and allowing raw materials to be procured at low cost.

[0026] In case A, R 2 More specifically, this includes any one selected from the group consisting of methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, cyclohexyl group, isononyl group, isobornyl group, adamantyl group, 2-hydroxyethyl group, 2-hydroxy-1-methylethyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 2-methoxyethyl group, 2-methoxy-1-methylethyl group, 2-methoxypropyl group, 4-methoxybutyl group, polyethylene glycol group, polyethylene glycol monomethyl ether group, polypropylene glycol group, polypropylene glycol monomethyl ether group, dimethylaminoethyl group, and diethylaminoethyl group. 2Among these, the following are particularly favored due to their ease of availability, high reactivity, and excellent compatibility: methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, cyclohexyl group, isononyl group, isobornyl group, adamantyl group, 2-hydroxyethyl group, 2-hydroxy-1-methylethyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 2-methoxyethyl group, 2-methoxy-1-methylethyl group, 2-methoxypropyl group, 4-methoxybutyl group, polyethylene glycol group, polyethylene glycol monomethyl ether group, polypropylene glycol group, polypropylene Glycol monomethyl ether groups, dimethylaminoethyl groups, and diethylaminoethyl groups are preferred, and methyl groups, ethyl groups, propyl groups, butyl groups, cyclohexyl groups, isononyl groups, isobornyl groups, adamantyl groups, 2-hydroxyethyl groups, 2-hydroxy-1-methylethyl groups, 2-hydroxypropyl groups, 4-hydroxybutyl groups, 2-methoxyethyl groups, 2-methoxy-1-methylethyl groups, 2-methoxypropyl groups, 4-methoxybutyl groups, polyethylene glycol groups, polyethylene glycol monomethyl ether groups, polypropylene glycol groups, polypropylene glycol monomethyl ether groups, dimethylaminoethyl groups, and diethylaminoethyl groups are particularly preferred.

[0027] Let's explain the case where X is a trivalent element like N (hereinafter referred to as Case B). In Case B, R 2 If is a monovalent organic group and n is 2, then (-C(=O)NR 2 2) and R 2 If is a divalent organic group and n is 1, then (-C(=O)NR 2 ) and are possible.

[0028] Monovalent R in case B 2 Since this is the same as what was explained for case A, we will refer to that description and omit the explanation here.

[0029] In case B, the divalent R2 The group is not particularly limited as long as it is a divalent organic group, but for example, one selected from the group consisting of a morphoyl group, a piperidinyl group, and a piperazinyl group can be cited. Among these, the morphoyl group and the piperidinyl group are preferred due to their availability and excellent compatibility, and the morphoyl group is more preferred. This configuration has the advantages of making the curable composition easy to handle, making it easy to adjust various physical properties, and allowing raw materials to be procured at low cost.

[0030] In case B, R 2 The number of carbon atoms contained within is the same as that described for case A, so we will refer to that description and omit the explanation here.

[0031] (A) Specific examples of component include linear or cyclic (meth)acrylic acid ester monomers, (meth)acrylate acid thioester monomers, (meth)acrylamide monomers, and vinyl ester monomers. These may be used individually or in combination of two or more.

[0032] From the perspective of being readily available and having been widely studied, making it easy to adjust the physical properties of the cured product, preferred specific examples of component (A) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, and nonyl (meth) Acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate One or more selected from the group consisting of lylate, isononyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-1-methylethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxy-1-methylethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, polypropylene glycol (meth)acrylate, polypropylene glycol monomethyl ether (meth)acrylate, (meth)acrylamide, diethylaminoethyl (meth)acrylate, and acryloylmorpholine.Of these, from the viewpoint of availability, isononyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-1-methylethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxy-1-methylethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, polypropylene glycol (meth)acrylate, polypropylene glycol monomethyl ether (meth)acrylate, and acryloylmorpholine are more preferred. If isomers exist in the alkyl group or alicyclic group of component (A), either isomer may be used, or a mixture thereof may be used.

[0033] In this specification, component (A) also includes monomers with relatively large molecular weights, such as monomers containing an oligomeric skeleton. Such monomers containing an oligomeric skeleton are also referred to as macromonomers or macromers. As the macromonomer, for example, a (meth)acryloyl group-containing macromonomer can be used. In this specification, "(meth)acryloyl group" means "acryloyl group" and / or "methacryloyl group". Examples of (meth)acryloyl group-containing macromers include compounds having an oligomeric skeleton consisting of a repeating monomer structure and (b) an average of 0.5 to 1.0 (meth)acryloyl groups per molecule. In addition, in a (meth)acryloyl group-containing macromer, the vinyl group that constitutes part of the (meth)acryloyl group corresponds to one vinyl group present per molecule. Furthermore, in (meth)acryloyl group-containing macromers, a structure consisting of a part of the (meth)acryloyl group (-C(=O)O-) and an oligomer skeleton is called -C(=O)XR2 n This corresponds to the structure of (meth)acryloyl group-containing macromer, where X is the oxygen element (O), n is 1, and R 2 It contains an oligomeric skeleton.

[0034] (A) When component (A) is a macromonomer containing a (meth)acryloyl group, the number-average molecular weight of the (meth)acryloyl group-containing macromonomer is preferably 300 to 500,000, more preferably 1,000 to 100,000, and even more preferably 1,000 to 50,000. This configuration has the advantage that the curable composition is easy to handle and that the physical properties derived from the oligomer are easily expressed.

[0035] Examples of oligomers that constitute the oligomeric skeleton in macromonomers include polybutadiene, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, polyisobutylene, polyether, polyester, polycarbonate, polyacrylate, epoxy compound polymers, polyethylene glycol, polyethylene glycol methyl ether, polypropylene glycol, polypropylene glycol methyl ether, and silicone polymers, each of which is a monovalent polymer.

[0036] Among these, when physical properties such as rubber properties, tackiness, adhesion, gas barrier properties, vibration damping properties, heat resistance, and chemical resistance are important, it is preferable that the oligomer constituting the oligomer skeleton be one or more selected from the group consisting of polyolefin-based oligomers such as polybutadiene, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, and polyisobutylene.

[0037] On the other hand, when physical properties such as viscosity, handling, compatibility with other components, tackiness, adhesion, durability, and heat resistance are important, it is preferable that the oligomer constituting the oligomer skeleton be one or more selected from the group consisting of polyethers, polyesters, polycarbonates, polyacrylates, epoxy compound polymers, polyethylene glycol, polyethylene glycol methyl ether, polypropylene glycol, polypropylene glycol methyl ether, polypropylene glycol, polypropylene glycol methyl ether, and silicone polymers.

[0038] (A) Monofunctional vinyl monomers may be used individually or in combination of two or more. Furthermore, monofunctional vinyl monomers (A) may be used in combination with other monofunctional vinyl monomers. In particular, when using two or more monofunctional vinyl monomers in combination, it is preferable to include a monofunctional vinyl monomer with a molecular weight of 1000 or less among the two or more monofunctional vinyl monomers in order to ensure compatibility of each component.

[0039] Furthermore, when monofunctional vinyl monomer (A) is used in combination with other monofunctional vinyl monomers other than monofunctional vinyl monomer (A), N-vinylpyrrolidone, N-vinylformamide, styrene, vinyl acetate, etc., are preferred as other monofunctional vinyl monomers other than monofunctional vinyl monomer (A) because they have good compatibility and reactivity with other components and their raw materials are readily available.

[0040] (1-2. (B) Polyfunctional vinyl monomer) In this specification, (B) polyfunctional vinyl monomer is a vinyl monomer having two or more vinyl groups in one molecule. The upper limit of the number of vinyl groups in one molecule of component (B) is not particularly limited, but may be, for example, 10. Component (B) acts as a crosslinking point in the resulting cured product. Therefore, if a cured product with high hardness and strength is desired, it is preferable that component (B) has 4 to 10 vinyl groups in one molecule. Conversely, if a cured product with excellent flexibility and elongation is desired, it is preferable that component (B) has 2 to 3 vinyl groups in one molecule. From the viewpoint of availability and ease of synthesis of component (B), it is preferable that component (B) has 2 vinyl groups in one molecule. Component (B) may have vinyl groups as part of (meth)acryloyl groups. That is, component (B) may have two or more (meth)acryloyl groups in one molecule.

[0041] Component (B) contains one or more structures represented by the following general formula (1) (diacylhydrazine structure) in one molecule.

[0042] [ka]

[0043] (B) There is no particular upper limit to the number of diacylhydrazine structures contained in one molecule of component (B), but for example, there may be 10. Component (B) preferably contains 1 to 3 structures (diacylhydrazine structures) represented by the general formula (1) in one molecule, more preferably 1 or 2, and even more preferably 1. This configuration has the advantages of being easy to manufacture and having an excellent effect on the manufacturing cost of component (B).

[0044] The functions of component (B) in this curable composition include (a) adjusting the various physical properties of the cured product, and (b) forming crosslinking points having a hydrazine structure in the cured product. Because this curable composition contains component (B), the resulting cured product (polymer compound) has a hydrazine structure in its backbone, and therefore the cured product can be oxidatively decomposable.

[0045] Component (B) can be produced by constructing a diacylhydrazine structure using hydrazine (or hydrazine hydrate) or hydrazide as a raw material. The method for constructing the diacylhydrazine structure is not particularly limited, and known methods can be applied. For example, (1) a method of introducing a polymerizable double bond to hydrazine (or hydrazine hydrate) or hydrazide, and (2) a method of coupling hydrazide. Examples of (1) include the following formulas (3) to (8).

[0046] [ka]

[0047] Formula (3) shows an example of constructing a diacylhydrazine structure from hydrazine (or hydrazine hydrate) and acryloyl chloride. Here, as long as the reaction mode remains unchanged, the chlorine atom of acryloyl chloride may be replaced with other halogens and known organic leaving groups such as a 4-nitrophenyl group, or it may be replaced with a methacryloyl group having a substituent on the acryloyl group of acryloyl chloride.

[0048] [ka]

[0049] Formula (4) shows an example of constructing a diacylhydrazine structure from a hydrazide and acryloyl chloride. Here, as long as the reaction mode remains unchanged, the chlorine atom of acryloyl chloride may be replaced with other halogens and known organic leaving groups such as a 4-nitrophenyl group, or it may be replaced with a methacryloyl group having a substituent on the acryloyl group of acryloyl chloride.

[0050] [ka]

[0051] Formula (5) shows an example of constructing a diacylhydrazine structure from hydrazine (or hydrated hydrazine) and 2-isocyanate ethyl methacrylate. Here, as long as the reaction mode does not change, the acryloyl group of 2-isocyanate ethyl methacrylate may be replaced with a methacryloyl group having a substituent, or the divalent organic group (in this case, the ethyl group) between the isocyanate group and the ester group of 2-isocyanate ethyl methacrylate may be replaced with another divalent organic group.

[0052] [ka]

[0053] Formula (6) shows an example of constructing a diacylhydrazine structure from a hydrazide and 2-isocyanate ethyl methacrylate. Here, as long as the reaction mode does not change, the acryloyl group of 2-isocyanate ethyl methacrylate may be replaced with a methacryloyl group having a substituent, or the divalent organic group (in this case, the ethyl group) between the isocyanate group and the ester group of 2-isocyanate ethyl methacrylate may be replaced with another divalent organic group.

[0054] [ka]

[0055] Equation (7) shows an example of constructing a diacylhydrazine structure from hydrazine (or hydrated hydrazine) and chloroformate ester. Here, R 7 This represents a monovalent organic group having a polymerizable double bond. Within the range where the reaction mode does not change, the chlorine atom of the chloroformate ester may be replaced with other halogens and known organic leaving groups such as a 4-nitrophenyl group.

[0056] [ka]

[0057] Equation (8) shows an example of constructing a diacylhydrazine structure from a hydrazide and a chloroformate ester. Here, R 7 This represents a monovalent organic group having a polymerizable double bond. Within the range where the reaction mode does not change, the chlorine atom of the chloroformate ester may be replaced with other halogens and known organic leaving groups such as a 4-nitrophenyl group.

[0058] An example of (2) is the following equation (9).

[0059] [ka]

[0060] Equation (9) shows an example of constructing a diacylhydrazine structure by coupling two hydrazide molecules. For example, as described in Japanese Patent Application Publication No. 2011-236381, a diacylhydrazine structure can be constructed by treating a hydrazide with an oxidizing agent mainly composed of hydrogen persulfate.

[0061] From the viewpoint of ease of obtaining raw materials and mass production productivity, for example, the manufacturing methods of formulas (3), (4), and (9) above can be suitably used.

[0062] Examples of component (B) include the compound shown in the following formula.

[0063] [ka] TIFF0007905219000013.tif72169

[0064] The molecular weight of component (B) is not particularly limited, but is preferably 140 to 1000, more preferably 140 to 600, and even more preferably 140 to 500. This configuration has the advantages of being easy to manufacture and handle component (B), as well as having an excellent effect on the manufacturing cost of component (B).

[0065] The content of component (B) in this curable composition is not particularly limited, but is preferably 0.001 to 100.0 parts by weight, more preferably 0.001 to 50.0 parts by weight, more preferably 0.001 to 20.0 parts by weight, more preferably 0.001 to 10.0 parts by weight, more preferably 0.001 to 5.0 parts by weight, more preferably 0.001 to 1.0 parts by weight, even more preferably 0.001 to 0.80 parts by weight, and particularly preferably 0.001 to 0.60 parts by weight, per 100 parts by weight of component (A). This configuration has the advantage of excellent decomposition of the cured product and easy adjustment of mechanical properties.

[0066] (1-3. (C) Polymerization initiator) In this specification, (C) polymerization initiator is a compound that generates an active species (e.g., a radical species) capable of initiating monomer polymerization in response to an external stimulus such as light or heat. These compounds are not particularly limited, but include known photopolymerization initiators and thermal polymerization initiators. Compounds described in International Publication No. 2013 / 047314 and Japanese Patent Application Publication No. 2013-216782 can also be cited as components (C).

[0067] As photopolymerization initiators, (a) compounds having a hydroxyl group and a phenyl ketone structure, (b) compounds having a benzophenone structure, and (c) compounds having an acylphosphine oxide structure can be preferably used. As thermal polymerization initiators, (d) azo initiators, (e) peroxides, (f) persulfates, and (g) redox initiators can be preferably used.

[0068] (a) Examples of compounds having a hydroxyl group and a phenyl ketone structure include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, and the like.

[0069] (b) Examples of compounds having a benzophenone structure include benzophenone, 3-methoxybenzophenone, 4-methylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and 4-chloro-4'-benzylbenzophenone.

[0070] (c) Examples of compounds having an acylphosphine oxide structure include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0071] (d) Examples of azo initiators include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2'-azobis(2-amidinopropane) dihydrochloride (VAZO 50), 2,2'-azobis(2,4-dimethylvaleronitrile) (VAZO 52), 2,2'-azobis(isobutyronitrile) (VAZO 64), 2,2'-azobis-2-methylbutyronitrile (VAZO 67), 1,1-azobis(1-cyclohexanecarbonitride) (VAZO 88), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(methylisobutyrate) (V-601).

[0072] (e) Examples of peroxides include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicumyl peroxide, dicetyl peroxydicarbonate, t-butyl peroxyisopropyl monocarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, t-butyl peroxypivalate, and t-butyl peroxy-2-ethylhexanoate.

[0073] (f) Examples of persulfates include potassium persulfate, sodium persulfate, ammonium persulfate, sodium metabisulfite, and sodium bisulfite.

[0074] (g) Examples of redox initiators include combinations of reducing agents such as sodium metabisulfite and sodium bisulfite listed as persulfates; systems based on organic peroxides and tertiary amines, for example, systems based on benzoyl peroxide and dimethylaniline; and systems based on organic hydroperoxides and transition metals, for example, systems based on cumene hydroperoxide and cobalt naphthate.

[0075] In one embodiment of the present invention, the polymerization initiator (C) is preferably a photopolymerization initiator in that it has good curability and storage stability. More specifically, component (C) is preferably one or more selected from the group consisting of benzophenone, 4,4'-bis(diethylamino)benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, or one or more selected from the said group.

[0076] Furthermore, if light irradiation is difficult or heat curing is preferred, component (C) is preferably an azo initiator or a peroxide. More specifically, component (C) is preferably one or more selected from the group consisting of 2,2'-azobis(methyl isobutyrate), t-butyl peroxypivalate, di(4-t-butylcyclohexyl)peroxydicarbonate, t-butyl peroxyisopropyl monocarbonate, dicumyl peroxide, benzoyl peroxide, and mixtures thereof, or one or more selected from the said group.

[0077] Component (C) may be used alone or in combination of two or more types. Alternatively, one or more of component (C) may be used in combination with other compounds. When using component (C) in combination with other compounds, suitable other compounds include amines such as diethanolmethylamine, dimethylethanolamine, and triethanolamine. Component (C) may also be used in combination with the aforementioned amines and iodonium salts such as phenyliodonium chloride. Furthermore, component (C) may also be used in combination with the aforementioned amines and dyes such as methylene blue.

[0078] When using component (C), a polymerization inhibitor may be added as needed. By having component (C) and a polymerization inhibitor coexist in this curable composition, the advantages of preventing unintended curing of the curable composition and making it easier to handle are obtained. Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, benzoquinone, and p-tert-butylcatechol.

[0079] The amount of component (C) is preferably 0.01 to 20.00 parts by weight, more preferably 0.03 to 20.00 parts by weight, even more preferably 0.04 to 10.00 parts by weight, and particularly preferably 0.05 to 5.00 parts by weight, per 100 parts by weight of component (A). When the content of component (C) is 0.01 parts by weight or more per 100 parts by weight of component (A), the effect of component (C) is exerted and good curability is obtained. Furthermore, when the content of component (C) is 20.00 parts by weight or less per 100 parts by weight of component (A), there is the advantage that problems such as unintended heat generation, side reactions, and foaming during curing can be avoided.

[0080] (1-4. Other ingredients) The curable composition may contain other components as needed, as long as they do not impair the effects of the present invention. Examples of other components include additives (e.g., fillers, plasticizers, preservatives, antioxidants, UV absorbers, flame retardants, antistatic agents, and pigments), elastomers (e.g., styrene-based block copolymers, etc.) for adjusting the rubber properties of the cured product, thiol compounds, tertiary amine compounds, adhesion promoters, and solvents.

[0081] (solvent) This curable composition preferably contains a solvent as needed, from the viewpoint of ease of handling and viscosity. The inclusion of a solvent in this curable composition has the advantage of improving various physical properties of the curable composition, such as viscosity, wettability to the substrate, and consequently, adhesion. Furthermore, a curable composition that is easier to handle can be obtained due to the reduced viscosity. Conversely, if high viscosity or thixotropy is required, such as to prevent the coating liquid from dripping, the solvent may be omitted.

[0082] During their intensive research, the inventors have made a novel discovery: surprisingly, the recyclability (whether or not it can be easily acid-decomposed) of the resulting cured product differs depending on the curing conditions of the curable composition. Specifically, the inventors have made a novel discovery: surprisingly, when the temperature of the curable composition (reaction solution) during the curing reaction is low, the resulting cured product exhibits excellent recyclability (it is easily acid-decomposed). When this curable composition contains a solvent, it also has the advantage of reducing the temperature rise of the curable composition (reaction solution) due to the heat of reaction during the curing reaction.

[0083] Examples of solvents include water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, sulfolane, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, hexane, cyclohexane, and toluene. These solvents may be used individually or in combination of two or more. Among these, from the viewpoint of high solubility and low environmental impact, one or more solvents selected from the group consisting of water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, methylene chloride, and chloroform are particularly preferred.

[0084] The solvent content in this curable composition is not particularly limited, but from the viewpoint of reducing the amount of heat generated during the reaction, it is preferably 0 to 500 parts by weight, more preferably 10 to 300 parts by weight, more preferably 20 to 200 parts by weight, more preferably 30 to 150 parts by weight, even more preferably 40 to 120 parts by weight, and particularly preferably 50 to 100 parts by weight, per 100 parts by weight of component (A).

[0085] In a preferred embodiment, the curable composition comprises (A) 100 parts by weight of a monofunctional monomer, (B) 0.1 to 100.0 parts by weight of a polyfunctional vinyl monomer, and (C) 0.1 to 20.0 parts by weight of a polymerization initiator. This configuration has the advantage of being highly oxidatively degradable and recyclable.

[0086] In a preferred embodiment, the curable composition comprises (A) 100 parts by weight of a monofunctional monomer, (B) 0.1 to 100.0 parts by weight of a polyfunctional vinyl monomer, (C) 0.1 to 20 parts by weight of a polymerization initiator, and 0.1 to 200 parts by weight of a solvent. This configuration provides the advantage that the cured product obtained from the curable composition has excellent recyclability and also possesses desirable physical properties (e.g., flexibility).

[0087] (1-5. Physical properties of this curable composition) From the viewpoint of ease of handling, this curable composition is preferably liquid at room temperature. Furthermore, since it is easy to obtain a composition with excellent curability by photocuring, this curable composition is preferably colorless and transparent, pale yellow and transparent, pale yellow and translucent, or white and translucent.

[0088] The viscosity of this curable composition is not particularly limited, but in order to accommodate various coating or filling methods, it is preferable that the viscosity at 25°C be 0.0001 Pa·sec to 10000 Pa·sec, more preferably 0.001 Pa·sec to 5000 Pa·sec, and from the viewpoint of ease of handling, it is even more preferable that it be 0.01 Pa·sec to 3000 Pa·sec, even more preferably 0.1 Pa·sec to 1000 Pa·sec, and particularly preferably 0.1 Pa·sec to 500 Pa·sec.

[0089] When applying or filling the curable composition using a method suitable for coating or filling low-viscosity compositions (e.g., spray, inkjet, and screen printing, caulking gun, spray gun, etc.), the viscosity of the curable composition at 25°C is preferably, for example, 0.0001 Pa·sec to 5000 Pa·sec, more preferably 0.0001 Pa·sec to 3000 Pa·sec, even more preferably 0.0001 Pa·sec to 1000 Pa·sec, and particularly preferably 0.0001 Pa·sec to 500 Pa·sec. If the viscosity of the curable composition is within the above range, it is easy to handle and can be easily discharged from the discharge port.

[0090] When this curable composition is used in applications such as form-in-place gaskets (FIPG), cured-in-place gaskets (CIPG), mold-in-place gaskets (MIPG), liquid injection molding (LIM), and other dispensing applications, the viscosity of this curable composition at 25°C is preferably, for example, 0.001 Pa·sec to 10,000 Pa·sec, more preferably 0.001 Pa·sec to 5,000 Pa·sec, even more preferably 0.01 Pa·sec to 5,000 Pa·sec, and particularly preferably 0.01 Pa·sec to 3,000 Pa·sec. If the viscosity of this curable composition at 25°C is 0.001 Pa·sec or higher, good thixotropy is obtained, which has the advantage of being easy to mold into the desired shape. Furthermore, if the viscosity of this curable composition at 25°C is 10,000 Pa·sec or lower, it can be dispensed at a good discharge speed, which has the advantage of preventing a decrease in productivity.

[0091] The viscosity of the curable composition can be measured at a measurement temperature of 25°C using a cone plate type viscometer TVE-25H manufactured by Toki Sangyo Co., Ltd.

[0092] (1-6. Form of this curable composition) The curable composition may be a one-component type, a two-component type, or a multi-component type with three or more components. When the curable composition is a two-component type or a multi-component type with three or more components, it is preferable that the viscosity of each component is within the range detailed in (1-4. Physical Properties of the Curable Composition). Furthermore, in the case of a multi-component type, components with similar viscosities are easier to mix and often facilitate the development of various physical properties. Therefore, in the case of a multi-component type, it is preferable that the difference in viscosity between the components is within 50%, more preferably within 30%, and even more preferably within 10%.

[0093] A one-component curable composition is one in which all components are pre-mixed and combined, and the resulting mixture is sealed and stored. A one-component curable composition is preferable from the viewpoint of preventing quality defects such as poor curing, as it eliminates the need to mix and knead multiple components during application and also eliminates measurement errors that may occur in such a process.

[0094] A two-component curable composition is one in which the components are divided into two liquids, A and B, and mixed together, taking into consideration the storage stability of the curable composition. The resulting A and B liquids are then mixed before use. Various combinations of methods for dividing each component into two liquids are possible, taking into consideration the mixing ratio of the curable composition, storage stability, mixing method, pot life, etc.

[0095] If necessary, a third component can be added in addition to liquids A and B to create a three-component curable composition, and further divisions can be adjusted as needed.

[0096] The method of mixing the ingredients is not particularly limited and may include using a hand mixer, static mixer, planetary mixer, disper, roll, kneader, single-screw extruder, twin-screw extruder, Banbury mixer, Brabender, high-shear mixer, etc. Mixing may be carried out in the dark if necessary.

[0097] The mixing temperature of the components is preferably between 0°C and less than 140°C, more preferably between 0°C and 100°C, and even more preferably between 10°C and 80°C. As described later, if the mixing temperature of the components exceeds 140°C, the diacylhydrazine moiety may become cyclic due to a dehydration cyclization reaction, which can reduce oxidative decomposition and recyclability, so this is undesirable. The mixing time of the components is preferably between 1 minute and 5 hours, and more preferably between 10 minutes and 3 hours.

[0098] (1-7. Method of applying or filling the curable composition) The method for applying or filling the curable composition onto a substrate is not particularly limited, and known methods for applying or filling sealants and adhesives can be used. Such methods include dispensing using an automatic dispenser, spraying, inkjet printing, screen printing, gravure printing, dipping, spin coating, and filling using a caulking gun and a spray gun.

[0099] If the viscosity of this curable composition is high at room temperature and difficult to handle, it may be heated to the desired viscosity. The temperature at which this is done is preferably 100°C or lower, and more preferably 80°C or lower. Heating the curable composition at 100°C or lower reduces the volatilization of component (C). This provides safety advantages and the advantage of preventing changes in the mixing ratio of each component in the curable composition.

[0100] [2. Cured product] A cured product according to one embodiment of the present invention is a cured product obtained by curing the curable composition described in the section [1. Curable Composition].

[0101] Furthermore, this cured product is a polymer compound containing a skeleton represented by the following general formula (2).

[0102] [ka]

[0103] (In general formula (2), R 1 , R 3 , R 6 Each independently represents hydrogen or a monovalent alkyl group having 1 to 6 carbon atoms. X is selected from the group consisting of O, S, and N; R 2 R is a monovalent organic group; 4 , R 5 Each of these independently represents a divalent organic group or a single bond. Because this cured product (polymer compound) has the aforementioned structure, it can be cleaved at the diacylhydrazine structure by treatment with an oxidizing agent. Therefore, this cured product (polymer compound) has the advantage of being recyclable.

[0104] In general formula (2), R 1 , R 3 , R 6 Each of these is independently either hydrogen or a monovalent alkyl group having 1 to 6 carbon atoms, but is not particularly limited. Specifically, examples include hydrogen, methyl group, ethyl group, propyl group, butyl group, pentyl group, and hexyl group.

[0105] In general formula (2), R 2 The group is not particularly limited as long as it is a monovalent or divalent organic group, and the specific substituents are the same as those described in section (2-1. (A) Monofunctional vinyl monomers), so we will refer to that description and omit the explanation here.

[0106] In general formula (2), R 4 and R 5 This is not particularly limited as long as it is a divalent organic group or a single bond. 4 and R 5 This may be a divalent hydrocarbon group, and more specifically, examples include alkylene groups such as methylene, ethylene, propylene, butylene, pentylene, and hexylene. 4 and R 5 The divalent organic group may contain one or more structures represented by the following general formula (1) (diacylhydrazine structure).

[0107] [ka]

[0108] The mechanism by which this cured product (polymer compound) becomes recyclable due to having the above-mentioned structure will be described in detail below.

[0109] As represented by the general formula (2) above, this cured product has a hydrazine structure, and this structure constitutes a crosslinked structure within the cured product. When this cured product having a hydrazine structure is treated with an oxidizing agent, the hydrazine structure is oxidized to an azodicarbonyl group. Next, the azodicarbonyl group is further reacted with water molecules and the oxidizing agent in the system, generating a carboxylic acid, nitrogen, and water, and it is thought that the diacylhydrazine structure is cleaved. Since the diacylhydrazine structure is a crosslinking point in the cured product, this oxidation reaction causes the crosslinked structure of the cured product to separate, and the resulting product can be processed again by heating and reuse, or recovered by dissolving it in a solvent, similar to thermoplastic resins, thus enabling recycling. It can also be said that this cured product has oxidative decomposition properties due to having a hydrazine structure.

[0110] [ka]

[0111] The oxidizing agent that can be used to cleave the hydrazine structure of the cured product is not particularly limited, but is preferably sodium hypochlorite, hypochlorous acid, chlorine, bromine, hydrogen peroxide, N-chlorosuccinimide, N-bromosuccinimide, potassium permanganate, persulfates, and hydrogen persulfates. From the viewpoint of low raw material costs, sodium hypochlorite, hypochlorous acid, chlorine, bromine, hydrogen peroxide, N-chlorosuccinimide, and N-bromosuccinimide are more preferred, and sodium hypochlorite, hypochlorous acid, chlorine, bromine, and hydrogen peroxide are even more preferred.

[0112] Furthermore, carrying out the decomposition reaction under alkaline conditions is preferable because the resulting carboxylic acid becomes more easily soluble in aqueous solution, making it easier to handle.

[0113] Furthermore, methods for treating the cured product with an oxidizing agent when cleaving the hydrazine structure of the cured product include adding the cured product to an aqueous solution containing an oxidizing agent and stirring, and spraying the aqueous solution containing an oxidizing agent onto the cured product.

[0114] When using a method in which the cured product is added to an aqueous solution containing an oxidizing agent and stirred, the concentration of the aqueous solution containing the oxidizing agent is not particularly limited, but is preferably 0.01% to 50%, more preferably 0.1% to 30%, and even more preferably 0.1% to 20%. This configuration has the advantage of ensuring safety during the decomposition process.

[0115] When using a method in which the cured product is added to an aqueous solution containing an oxidizing agent and stirred, the temperature during the addition of the oxidizing agent and stirring is not particularly limited, but is preferably between 0°C and 100°C, and more preferably between 10°C and 80°C. This configuration has the advantage of improving the oxidative decomposition and recyclability of the cured product.

[0116] When using a method in which the cured product is added to an aqueous solution containing an oxidizing agent and stirred, the stirring time after adding the oxidizing agent is not particularly limited, but is preferably 168 hours or less, more preferably 72 hours or less, and even more preferably 24 hours or less. This configuration has the advantage of increasing the productivity of the recycling process.

[0117] The method for evaluating the oxidative decomposition properties of the cured product will be described in detail in the following examples.

[0118] (2-1.Curing method) The curing method according to one embodiment of the present invention is not particularly limited, as long as it includes a step of curing the curable composition described in the section [1. Curable Composition] above. "Curing method" can also be called "method for manufacturing a cured product". In other words, the method for manufacturing a cured product according to one embodiment of the present invention can also be said to be a manufacturing method that includes a step of curing the curable composition described in the section [1. Curable Composition] above.

[0119] A curing method according to one embodiment of the present invention preferably includes a step of curing the curable composition described in the section [1. Curable Composition] using active energy rays. A method for producing a cured product according to one embodiment of the present invention preferably includes a step of curing the curable composition described in the section [1. Curable Composition] using active energy rays. In other words, it is preferable that the cured product is obtained by curing the curable composition described in the section [1. Curable Composition] using active energy rays.

[0120] In this specification, active energy rays encompass all light in a broad sense, including, for example, radiation such as alpha rays and beta rays, electromagnetic waves such as gamma rays and X-rays, electron beams (EB), ultraviolet rays (wavelengths 100 nm to 400 nm), and visible light (wavelengths 400 nm to 800 nm). From the viewpoint of agreement with the absorption spectrum of the polymerization initiator of component (C), the active energy rays are preferably ultraviolet rays. Examples of light sources for active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, LEDs, fluorescent lamps, sunlight, electron beam irradiation devices, lasers, and the like.

[0121] The irradiation dose of active energy rays is not particularly limited, but is 0.1 mW / cm². 2 More than 1,000mW / cm 2 Preferably, the following conditions apply, with an illuminance of 1.0 mW / cm². 2 More than 1,000mW / cm 2 The following is more preferable, with an illuminance of 1.0 mW / cm². 2 More than 500mW / cm2 The following is even more preferable. This configuration has the advantage of suppressing heat generation during curing and obtaining a cured product with high oxidative decomposition and recyclability.

[0122] The irradiation time of the active energy ray is not particularly limited, but is preferably 0.001 seconds to 1 hour, more preferably 0.001 seconds to 30 minutes, and even more preferably 0.01 seconds to 10 minutes. This configuration has the advantage of increasing the productivity of cured products.

[0123] The irradiation dose of active energy rays is not particularly limited, but the cumulative light dose is 0.1 mJ / cm². 2 More than 100,000mJ / cm 2 Preferably, the cumulative light intensity is 1.0 mJ / cm². 2 More than 10,000mJ / cm 2 It is more preferable that the following conditions are met, with an integrated light intensity of 10.0 mJ / cm². 2 More than 10,000mJ / cm 2 It is even more preferable that the cumulative light intensity is 0.1 mJ / cm². 2 If the above conditions are met, the curable composition can be sufficiently cured. Also, the cumulative light intensity is 100,000 mJ / cm². 2 The following conditions offer the advantage of suppressing heat generation during curing and obtaining a cured product with high oxidative decomposition and recyclability.

[0124] The irradiation dose and irradiation time of the active energy rays described above are weaker (slower) conditions compared to the curing conditions of conventional curable compositions. As described above, surprisingly, the recyclability (whether or not it can be easily acid-decomposed) of the resulting cured product differs depending on the curing conditions of the curable composition. Specifically, the inventors have independently obtained a novel finding that, surprisingly, curing a curable composition under weaker (slower) conditions (specifically, the irradiation dose and / or irradiation time of the active energy rays described above) compared to the curing conditions of conventional curable compositions results in a curable product with excellent recyclability (easily acid-decomposed).

[0125] Efficient curing can be achieved by matching the wavelength of the active energy rays emitted from the light source with the absorption wavelength (and / or maximum absorption wavelength) of component (C) as closely as possible.

[0126] Gomes et al. have reported that the diacylhydrazine structure undergoes dehydration cyclization to form an oxadiazole ring when heated to 140-160°C (Polymer, 44, 2003, 3633). Once the diacylhydrazine structure becomes an oxadiazole ring, it is thought to lose its degradability under oxidative conditions. The cured product according to one embodiment of the present invention is preferably manufactured under conditions that minimize the above-mentioned dehydration cyclization reaction.

[0127] Therefore, in one embodiment of the present invention, even when the curable composition (reaction solution) is significantly heated by the heat of reaction, it is preferable to maintain the temperature of the curable composition (reaction solution) during the curing reaction at 140°C or below, more preferably at 120°C or below, even more preferably at 100°C or below, and particularly preferably at 80°C or below. By carrying out the curing reaction under these temperature conditions, the oxidative decomposition properties of the cured product can be further enhanced. The temperature during the curing reaction can be reduced by the solvent content in the curable composition, the irradiation amount of active energy rays (illuminance and integrated light amount) and irradiation time, and the heating temperature and heating time described later.

[0128] (C) If component is a thermal polymerization initiator, the curable composition is cured by heat. The heating temperature and heating time are not particularly limited and vary depending on the type of thermal polymerization initiator used, but are generally preferably 30°C to 150°C, and more preferably 30°C to 100°C. The heating time (curing time) varies depending on the type of thermal polymerization initiator used, additives, heating temperature (reaction temperature), etc., but is generally in the range of 1 minute to 5 hours.

[0129] The curable composition can be cured under various atmospheres, including air, nitrogen, and argon. Curing the composition under air is preferable because it does not require special equipment and can be carried out easily. Furthermore, if there are concerns about curing inhibition by oxygen in the air, curing under an inert gas such as nitrogen and argon is preferable.

[0130] [3.Applications] The cured product obtained by the present invention can be used in various forms such as adhesives, sealants, films, tubes, sheets, fibers, sealants, coatings, surface coatings, paints, gaskets, coverings, resists, core materials, vibration damping materials, shock absorbers, cushioning materials, electrical insulating materials, foams, inks, casting agents, potting agents, molding materials, underfill materials, die bond materials, fillers, optical materials, electrical and electronic components, medical devices and medical components, battery materials, automobile parts, ship parts, aircraft parts, building components, and acoustic components.

[0131] Furthermore, it is preferable that the cured product used for these applications be used in various forms such as sheets (films), tapes, and molded bodies (packings, O-rings, belts, tubes, valves, hoses, etc.). [Examples]

[0132] The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

[0133] (Synthesis Example 1) Synthesis of Hydrazine Group-Containing Polyfunctional Acrylate 1 7.0 g of dihydrazide adipic acid, 12.0 g of potassium carbonate, and 70 ml of tetrahydrofuran were mixed at room temperature, and the mixture was cooled to 0°C while stirring. Subsequently, while continuing to stir the mixture, a mixture of 6.7 ml of acryloyl chloride and 20 ml of tetrahydrofuran was added dropwise over 30 minutes. The resulting mixture was then returned to room temperature, and stirring was continued for another 24 hours. Next, the precipitate from the resulting mixture was filtered, and the obtained filtrate was repeatedly washed with pure water until the pH of the washing solution reached 7-8. The resulting white solid was dried under reduced pressure to obtain hydrazine group-containing polyfunctional acrylate 1.

[0134] (Synthesis Example 2) Synthesis of Hydrazine Group-Containing Polyfunctional Acrylate 2 5.0 g of hydrazine monohydrate, 30.5 g of potassium carbonate, and 300 ml of tetrahydrofuran were mixed at room temperature, and the mixture was cooled to 0°C while stirring. Subsequently, while continuing to stir the mixture, 17.0 ml of acryloyl chloride and 50 ml of tetrahydrofuran were added dropwise to the mixture over 60 minutes. The resulting mixture was then returned to room temperature, and stirring was continued for another 24 hours. Next, the precipitate from the resulting mixture was filtered, and the obtained filtrate was repeatedly washed with pure water until the pH of the washing solution reached 7-8. The resulting white solid was dried under reduced pressure to obtain hydrazine group-containing polyfunctional acrylate 2.

[0135] [Materials used in the examples and comparative examples] The materials used in the following examples and comparative examples are as follows: <(A) component> • Acryloylmorpholine (manufactured by KJ Chemicals) • Methoxyethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) • 2-hydroxyethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) • Polyethylene glycol methyl ether acrylate (average molecular weight: 483, trade name "Light Acrylate 130A", manufactured by Kyoeisha Chemical Co., Ltd.) <(B) component> • Hydrazine group-containing polyfunctional acrylate 1 synthesized in Synthesis Example 1 • Hydrazine group-containing polyfunctional acrylate 2 synthesized in Synthesis Example 2 <(B) Polyfunctional vinyl monomers other than component> • 1,6-Hexanediol diacrylate (product name "Light Acrylate 1,6HX-A", manufactured by Kyoeisha Chemical Co., Ltd.) <(C) component> • 2-Hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by Ciba Specialty Chemicals, trade name: Darocure 1173) • Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (BASF Japan, product name: Irgacure819) • 1-Hydroxycyclohexylphenyl ketone (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 184) <Solvent (other components)> • Ethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) ·Pure water (Example 1) Acryloylmorpholine, hydrazine group-containing polyfunctional acrylate 1, Darocure 1173, Irgacure 819, and ethanol were mixed in the weight ratios shown in Table 1, stirred at room temperature for 12 hours, and then allowed to stand at room temperature for 12 hours. The supernatant of the resulting curable composition was added to a polyethylene container and irradiated with UV light using a UV irradiation device (Fusion UV Systems Japan Co., Ltd., Model: LH6) (irradiation conditions: illuminance 100 mW / cm²). 2 , light intensity 2000mJ / cm 2The curable composition was cured by ) to obtain a cured product. Approximately 0.05 g of the obtained cured product was added to 20 g of a 5 wt / wt% sodium hypochlorite aqueous solution, and the resulting mixture was stirred at room temperature for 24 hours. Bubbles were observed immediately after stirring. After stirring for 24 hours, the aqueous solution was visually observed and found to be a homogeneous solution, thus confirming that the cured product obtained in Example 1 decomposes, i.e., has oxidative decomposition properties. In this specification, a cured product having oxidative decomposition properties means that after treating the cured product with an oxidizing agent and stirring, 50% or more of the cured product decomposes within 24 hours. In Example 1, after treating the obtained cured product with an oxidizing agent and stirring for 24 hours, the aqueous solution was visually observed and found to be a homogeneous solution. A homogeneous aqueous solution means that 100% of the cured product has decomposed.

[0136] (Example 2) A curable composition was prepared in the same manner as in Example 1, except that hydrazine group-containing polyfunctional acrylate 2 was used in the weight ratio shown in Table 1. A cured product was obtained, and the decomposition properties of the cured product were evaluated. Bubbles were observed to form from the cured product during the decomposition test, and the aqueous solution after the decomposition test was homogeneous, confirming that the cured product obtained in Example 2 also decomposes (100% decomposed).

[0137] (Example 3) A curable composition was prepared in the same manner as in Example 1, except that hydrazine group-containing polyfunctional acrylate 1, Darocure 1173, Irgacure 819, and pure water were used in the weight ratios shown in Table 1. A cured product was obtained, and the decomposition properties of the cured product were evaluated. Bubbles were observed to form from the cured product during the decomposition test, and the aqueous solution after the decomposition test was homogeneous, confirming that the cured product obtained in Example 3 also decomposes (100% decomposed).

[0138] (Example 4) A curable composition was prepared in the same manner as in Example 3, except that Darocure 1173 and Irgacure 819 were used in the weight ratios shown in Table 1, and no solvent was added. A cured product was obtained, and the decomposition properties of the cured product were evaluated. Bubbles were observed to form from the cured product during the decomposition test, and the aqueous solution after the decomposition test was homogeneous, confirming that the cured product obtained in Example 4 also decomposes (100% decomposed).

[0139] (Example 5) A curable composition was prepared in the same manner as in Example 1, except that acryloylmorpholine, ethyl acrylate, hydrazine group-containing polyfunctional acrylate 1, Darocure 1173, and Irgacure 819 were used in the weight ratios shown in Table 1. A cured product was obtained, and its decomposition properties were evaluated. Bubbles were observed from the cured product during the decomposition test, and the aqueous solution after the decomposition test was homogeneous, confirming that the cured product obtained in Example 5 also decomposes (100% decomposed).

[0140] (Example 6) A curable composition was prepared in the same manner as in Example 1, except that acryloylmorpholine, 2-hydroxyethyl methacrylate (2-hydroxyethyl methacrylate), hydrazine group-containing polyfunctional acrylate 1, Darocure 1173, and Irgacure 819 were used in the weight ratios shown in Table 1, and no solvent was added. A cured product was obtained. Approximately 0.05 g of the obtained cured product was added to a mixed solvent of 20 g of 5 wt / wt% aqueous sodium hypochlorite solution and 10 g of N,N-dimethylacetamide, and the resulting mixture was stirred at room temperature for 24 hours. Bubbles were observed to form from the cured product during the decomposition test. After 24 hours of stirring, a small amount of gel remained in the aqueous solution, so it was filtered, and the gel was washed with pure water until the pH of the washing solution was 7-8. Then, the pure water was removed under reduced pressure at 100°C to obtain the "cured product after decomposition test". Let W1 be the weight of the cured product before decomposition, and W2 be the dry weight of the cured product after the decomposition test. The percentage of decomposed resin was calculated using the following formula and found to be 54.7%. Therefore, the cured product obtained in Example 6 was shown to be oxidatively decomposable: (Formula) (W1−W2) / W1×100 (%).

[0141] (Example 7) A curable composition was prepared in the same manner as in Example 1, except that polyethylene glycol methyl acrylate, hydrazine group-containing polyfunctional acrylate 1, Darocure 1173, Irgacure 819, and Irgacure 184 were used in the weight ratios shown in Table 1, and no solvent was added. A cured product was obtained, and the decomposition properties of the cured product were evaluated. Bubbles were observed to form from the cured product during the decomposition test, and the aqueous solution after the decomposition test was homogeneous, confirming that the cured product obtained in Example 7 also decomposes (100% decomposition).

[0142] (Example 8) To investigate the oxidative decomposition method of the cured product, the decomposition properties were evaluated under the following conditions. Approximately 0.05 g of the cured product obtained in Example 7 was added to a mixed solvent of 20 g of 5% sodium hypochlorite aqueous solution, 10 g of toluene, and 0.005 g of tetramethylammonium chloride, and stirred at room temperature for 24 hours. After that, stirring was stopped and the mixture was allowed to stand for another 24 hours. Upon examination of the mixture, no gel was observed. Therefore, it was confirmed that the cured product obtained in Example 7 decomposed. From these results, it became clear that, for example, by adding a phase transfer catalyst (e.g., tetramethylammonium chloride) to transport sodium hypochlorite dissolved in the aqueous phase to the organic phase, and creating a two-phase system of aqueous / organic phase, it is possible to decompose highly lipophilic cured products. Furthermore, it was shown that the resulting cured product decomposes even when toluene, an organic solvent, is present.

[0143] (Comparative Example 1) A curable composition was prepared in the same manner as in Example 1, except that acryloylmorpholine, 1,6-hexanediol diacrylate, Darocure 1173, Irgacure 819, and ethanol were used in the weight ratios shown in Table 1. A cured product was obtained, and the decomposition properties of the cured product were evaluated. No bubbles were observed from the resin during the decomposition test. Furthermore, a swollen gel remained in the aqueous solution after the decomposition test, indicating that the cured product obtained in Comparative Example 1 did not decompose.

[0144] [Table 1] [Industrial applicability]

[0145] One aspect of the present invention can be suitably used in fields such as adhesives, sealants, films, tubes, sheets, fibers, sealing materials, coating materials, surface coating materials, paints, gasket materials, covering materials, resist materials, core materials, vibration damping materials, shock absorbing materials, cushioning materials, electrical insulating materials, foams, inks, casting agents, potting agents, molding materials, underfill materials, die bond materials, fillers, optical materials, electrical and electronic components, medical devices and medical components, battery materials, automotive parts, marine components, aircraft components, building components, and acoustic components.

Claims

1. (A)-C(=O)XR ２ ｎ A monofunctional vinyl monomer having (X is one selected from the group consisting of O, S, and N; R ２ (where is a monovalent or divalent organic group; n indicates 1 or 2, and if X is N, then R 2 is a divalent organic group that forms a morpholyl group, and n is 1) (B) A polyfunctional vinyl monomer containing one or more structures represented by the following general formula (1) (diacylhydrazine structure) in one molecule, and (C) Polymerization initiator, (D) Solvent, A curable composition containing the following: 【Chemistry 1】

2. The curable composition according to claim 1, wherein the polyfunctional vinyl monomer contains one or two structures represented by the general formula (1) in one molecule.

3. The curable composition according to claim 1 or 2, wherein the polymerization initiator is a photopolymerization initiator.

4. A cured product obtained by curing the curable composition described in claim 1 with active energy rays.

5. A polymer compound containing the skeleton shown in the following general formula (2). 【Chemistry 2】 (In general formula (2), R １ , R ３ , R ６ each independently represents hydrogen or a monovalent alkyl group having 1 to 6 carbon atoms. X is any one selected from the group consisting of O, S, and N; R ２ is a monovalent or divalent organic group; R ４ , R ５ each independently represents a divalent organic group or a single bond; n represents 1 or 2, and when X is N, R 2 is a divalent organic group forming a morpholyl group, and n is 1.)

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