Shrinkage inhibitor for epoxy resins and use thereof

Abstract

To provide a shrinkage inhibitor of an epoxy-based resin which has an improved effect for inhibiting shrinkage of an epoxy-based resin, and a curing agent composition for an epoxy-based resin, an epoxy-based resin composition, a curing agent kit for an epoxy-based resin, a main agent kit of an epoxy-based resin, and an adhesive composition using the shrinkage inhibitor of the epoxy-based resin.SOLUTION: A shrinkage inhibitor of an epoxy-based resin contains bifunctional cyclic carbonate having a spiro structure. A curing agent composition for an epoxy-based resin contains the shrinkage inhibitor of the epoxy-based resin and a curing agent. An epoxy-based resin composition contains the shrinkage inhibitor of the epoxy-based resin and an epoxy-based resin. A curing agent kit for an epoxy-based resin contains the shrinkage inhibitor of the epoxy-based resin and a curing agent. A main agent kit of an epoxy-based resin has the shrinkage inhibitor of the epoxy-based resin and an epoxy-based resin. An adhesive composition contains the shrinkage inhibitor of the epoxy-based resin, a curing agent, and an epoxy-based resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a shrinkage inhibitor for epoxy resins and uses thereof. Specifically, the present invention relates to a shrinkage inhibitor for epoxy resins, a curing agent composition for epoxy resins, an epoxy resin composition, a curing agent kit for epoxy resins, a base kit for epoxy resins, and an adhesive composition. [Background technology]

[0002] It is known that general-purpose monomers such as methyl methacrylate and propylene oxide undergo volumetric shrinkage during polymerization. Therefore, when a volumetrically shrinkable monomer is used in an adhesive or the like, the volumetric shrinkage during curing can cause problems such as warping, distortion, and peeling, leading to a decrease in adhesive strength. On the other hand, it is known that six-membered cyclic carbonates having various substituents undergo ring-opening polymerization accompanied by volume expansion, and the expansion rate varies from 1.1% to 7.7% by volume depending on the substituent (see, for example, Non-Patent Document 1, etc.). It is also known that volumetric shrinkage can be suppressed by ring-opening copolymerizing such cyclic carbonates with monomers such as epoxides, which undergo volumetric shrinkage during polymerization (see, for example, Non-Patent Document 2, etc.).

[0003] For example, US Pat. No. 5,999,623 discloses the use of at least one six-membered lactone fused to an aromatic or heteroaromatic moiety as a shrinkage inhibitor in amine-cured epoxy compositions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2008-530321 [Non-patent literature]

[0005] [Non-Patent Document 1] Tanaka T et al., “Cyclic carbonates, novel expandable monomers on polymerization.” Macromol. Rapid Commun., Vol. 18, pp. 461-469, 1997. [Non-patent document 2] Morikawa H et al., “Volume-Expandable Monomer 5,5-Dimethyl-1,3-dioxolan-2-one: Its Copolymerization Behavior with Epoxide and Its Applications to Shrinkage-Controlled Epoxy-Curing Systems.”, Journal of Applied Polymer Science, Vol. 96, pp. 372-378, 2005. Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, compounds that have been known to have a volumetric shrinkage suppression effect have an expansion rate of at most 7.7% by volume, and there is a demand for compounds that can exert a sufficient shrinkage suppression effect in smaller amounts.

[0007] The present invention has been made in view of the above circumstances and provides a shrinkage inhibitor for epoxy resins that has an improved effect of inhibiting the shrinkage of epoxy resins, as well as a curing agent composition for epoxy resins, an epoxy resin composition, a curing agent kit for epoxy resins, a base kit for epoxy resins, and an adhesive composition that use the shrinkage inhibitor for epoxy resins. [Means for solving the problem]

[0008] That is, the present invention includes the following aspects. (1) A shrinkage inhibitor for epoxy resins, comprising a bifunctional cyclic carbonate having a spiro structure. (2) The shrinkage inhibitor for epoxy resins according to (1), wherein the bifunctional cyclic carbonate having a spiro structure is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione. (3) A curing agent composition for epoxy resins, comprising the shrinkage inhibitor for epoxy resins according to (1) or (2) and a curing agent. (4) The curing agent composition for epoxy resins according to (3), wherein the curing agent is an amine-based curing agent. (5) The curing agent composition for epoxy resins according to (3) or (4), wherein the curing agent is 2-ethyl-4-methylimidazole. (6) An epoxy resin composition comprising the shrinkage inhibitor for epoxy resins according to (1) or (2) and an epoxy resin. (7) A shrinkage inhibitor for an epoxy resin according to (1) or (2), A hardener; An epoxy resin hardener kit comprising: (8) A shrinkage inhibitor for an epoxy resin according to (1) or (2), an epoxy resin; An epoxy resin base kit comprising: (9) An adhesive composition comprising the shrinkage inhibitor for epoxy resins according to (1) or (2), a curing agent, and an epoxy resin. [Effects of the Invention]

[0009] The shrinkage inhibitor for epoxy resins of the above-mentioned aspect can suppress the volumetric shrinkage of epoxy resins during the effective period. The curing agent composition for epoxy resins, the epoxy resin composition, the curing agent kit for epoxy resins, the base kit for epoxy resins, and the adhesive composition of the above-mentioned aspect use the shrinkage inhibitor for epoxy resins, and can suppress the volumetric shrinkage of epoxy resins during the effective period. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a 1H-NMR spectrum of the reaction product of compound (I) and 2-ethyl-4-methylimidazole (EMIm) in Example 1. [Figure 2] 1 shows gel permeation chromatograms of reaction products of Compound (I) and each amine in Example 1. [Figure 3] 1 shows infrared absorption spectroscopy (IR) spectra of Compound (I) and Polymer 2 in Example 1, measured by attenuated total reflection (ATR) method. [Figure 4] 1 is a graph showing the results of a) thermogravimetry (TGA) measurement and b) differential scanning calorimetry (DSC) measurement of polymer 2 in Example 1. [Figure 5] 1 shows gel permeation chromatograms of the reaction product of glycidyl phenyl ether (GPE) and EMIm (Run 1), the reaction product of glycidyl phenyl ether (GPE), compound (I), and EMIm (Run 2), and the reaction product of compound (I) and EMIm (Run 3) in Example 2. [Figure 6] 1 is a graph showing the results of a) thermogravimetry (TGA) measurement and b) differential scanning calorimetry (DSC) measurement of a mixture of bisphenol A glycidyl ether (BADGE), compound (I), and EMIm (molar ratio: 85 / 15 / 10) in Example 3. [Figure 7] 1 is a graph showing changes in IR spectrum measured by an ATR method for a mixture of bisphenol A glycidyl ether (BADGE), compound (I), and EMIm (molar ratio: 85 / 15 / 10) in Example 3: i) before reaction, ii) after reaction at 130°C for 2 hours, and iii) after further reaction at 170°C for 2 hours. [Figure 8] 1 is a graph showing changes in the IR spectrum of a mixture of bisphenol A glycidyl ether (BADGE), 5,5-dimethyl-1,3-dioxan-2-one (DMDO), and EMIm (molar ratio: 85 / 30 / 10) in Example 3, measured by an ATR method, i) before the reaction, ii) after a 2-hour reaction at 130°C, and iii) after a further 2-hour reaction at 170°C. [Figure 9]1 is a graph showing changes in IR spectrum measured by an ATR method for a mixture of bisphenol A glycidyl ether (BADGE), compound (I), and EMIm (molar ratio: 70 / 30 / 10) in Example 3: i) before reaction, ii) after reaction at 130°C for 2 hours, and iii) after further reaction at 170°C for 2 hours. [Figure 10] 1 is a graph showing the results of TGA measurement of cured products A-1, A-2, and A′-1 in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (hereinafter abbreviated as "present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0012] <Shrinkage inhibitor for epoxy resin> The shrinkage inhibitor for epoxy resins of this embodiment (hereinafter sometimes simply referred to as "the shrinkage inhibitor of this embodiment") contains a bifunctional cyclic carbonate having a spiro structure.

[0013] As shown in the examples described below, the volume expansion coefficient of existing cyclic carbonates is 1.1% by volume or more and 7.7% by volume or less depending on the substituent, whereas the bifunctional cyclic carbonate having a spiro structure contained in the shrinkage inhibitor of this embodiment has a significantly higher volume expansion coefficient of approximately 13.8% by volume. Therefore, by containing the bifunctional cyclic carbonate having a spiro structure, the shrinkage inhibitor of this embodiment can effectively suppress the volumetric shrinkage of epoxy resins with smaller amounts than conventional compounds that have a shrinkage suppressing effect. Details of the epoxy resins to which the shrinkage inhibitor of this embodiment can be applied will be described later.

[0014] Next, the bifunctional cyclic carbonate having a spiro structure contained in the shrinkage inhibitor of this embodiment will be described in detail below.

[0015] [Bifunctional cyclic carbonates with spiro structures] The bifunctional cyclic carbonate having a spiro structure is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione (a compound represented by the following general formula (I), hereinafter sometimes referred to as "compound (I)"). The CAS number of compound (I) is 84056-48-4. Compound (I) may be commercially available or may be synthesized using a known method, but it is preferably obtained by the production method shown below, as this allows compound (I) to be obtained easily and in good yield.

[0016] [ka]

[0017] Examples of methods for producing compound (I) include a method including a step of reacting pentaerythritol (PE) with a diaryl carbonate to obtain compound (I) (hereinafter, sometimes referred to as a "synthetic step of compound (I)"), as shown in the following reaction formula. This reaction to obtain compound (I) is a known intramolecular cyclization reaction.

[0018] [ka]

[0019] (Pentaerythritol (PE)) Pentaerythritol (PE) is a compound having the structure shown in the above reaction formula. PE can be synthesized, for example, by condensing acetaldehyde and formaldehyde in a basic environment. Alternatively, commercially available PE may be used. The CAS number of PE is 115-77-5.

[0020] (diaryl carbonate) Examples of diaryl carbonates include a compound represented by the following general formula (III) (hereinafter, sometimes referred to as "compound (III)").

[0021] [ka]

[0022] In general formula (III), Ar 31 and Ar 32 are each independently a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0023] Ar 31 and Ar 32 is an aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms. The aromatic hydrocarbon group may have a substituent. Examples of the substituent in the aromatic hydrocarbon group include an alkyl group, an alkoxy group, a dialkylamino group, a halogen group, a nitro group, a trifluoromethyl group, and a cyano group. Such an Ar 31 and Ar 32 Specifically, examples of the phenyl group, methylphenyl group (each isomer), ethylphenyl group (each isomer), propylphenyl group (each isomer), butylphenyl group (each isomer), pentylphenyl group (each isomer), hexylphenyl group (each isomer), dimethylphenyl group (each isomer), methylethylphenyl group (each isomer), methylpropylphenyl group (each isomer), methylbutylphenyl group (each isomer), methylpentylphenyl group (each isomer), diethylphenyl group (each isomer), ethylpropylphenyl group (each isomer), ethyl Examples thereof include a butylphenyl group (each isomer), a dipropylphenyl group (each isomer), a trimethylphenyl group (each isomer), a triethylphenyl group (each isomer), a naphthyl group (each isomer), a methoxyphenyl group, a dimethoxyphenyl group, a trimethoxyphenyl group, a dimethylaminophenyl group, a chlorophenyl group, a dichlorophenyl group, a trichlorophenyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a perfluorophenyl group, a nitrophenyl group, a dinitrophenyl group, and a trinitrophenyl group. Among these, Ar 31 and Ar 32As the alkyl group, a phenyl group is preferred. Ar 31 and Ar 32 may be the same or different, but from the viewpoint of ease of production, it is preferable that they are the same.

[0024] Preferred diaryl carbonates include Ar 31 and Ar 32 is an aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of such diaryl carbonates include diphenyl carbonate, di(methylphenyl) carbonate (each isomer), di(diethylphenyl) carbonate (each isomer), and di(methylethylphenyl) carbonate (each isomer). Note that these compounds are merely examples of preferred diaryl carbonates, and preferred diaryl carbonates are not limited to these. Furthermore, these diaryl carbonates may be used alone or in combination of two or more. Among these, diphenyl carbonate is particularly preferred as the diaryl carbonate.

[0025] Known methods can be used to produce diaryl carbonate. Among these, a preferred method is described in International Publication No. 2009 / 139061 (Reference 1), in which an organotin compound having a tin-oxygen-carbon bond is reacted with carbon dioxide to produce an aliphatic carbonate, and then an aromatic carbonate (i.e., diaryl carbonate) is produced from the aliphatic carbonate and an aromatic hydroxy compound. The diaryl carbonate can be produced using, for example, the production apparatus described in International Publication No. 2009 / 139061 (Reference 1). Commercially available diaryl carbonates may also be used.

[0026] The synthesis of Compound (I) can be carried out in the presence or absence of a solvent. The solvent may be any solvent capable of dissolving PE, and a highly polar solvent having no hydroxyl group is preferred. Specific examples of such solvents include the following:

[0027] (1) Ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone; (2) Nitriles such as acetonitrile, butyronitrile, and caprylnitrile; (3) Esters such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, diamyl phthalate, dibutyl fumarate, dimethyl maleate, diethyl maleate, and dibutyl maleate; (4) Ethers such as furan, tetrahydrofuran, propyl oxide, dioxane, dibenzyl ether, and diphenyl ether; (5) Glycol ether esters such as ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, cyclohexanol acetate, propylene glycol diacetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanediol diacetate; (6) Phosphite esters such as triphenyl phosphite; (7) Sulfur compounds such as dimethyl sulfide, thiophene, and carbon disulfide; (8) Halogenated hydrocarbons such as methyl chloride, ethyl chloride, dichloropropane, dichloroethylene, trichloroethylene, tetrachloroethylene, pentachloroethane, chloroform, methyl bromide, ethyl bromide, methyl iodide, and ethyl iodide; (9) N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N,N-dimethylpropionamide, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1,5-dimethyl-2-pyrrolidone; (10) Pyrrolidines such as 1-acetylpyrrolidine; (11) Ureas such as 1,3-dimethyl-2-imidazolidinone; (12) Sulfoxide compounds such as dimethyl sulfoxide (DMSO), diethyl sulfoxide, dipropyl sulfoxide, dibutyl sulfoxide, diphenyl sulfoxide, methyl ethyl sulfoxide, methyl propyl sulfoxide, methyl butyl sulfoxide, and methyl phenyl sulfoxide.

[0028] These solvents may be used alone or in combination of two or more. When two or more types are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0029] In the synthesis step of Compound (I), for example, the reaction is preferably carried out under an inert gas atmosphere. Examples of the inert gas include argon gas, helium gas, and nitrogen gas.

[0030] In the synthesis process of Compound (I), the amount of PE used, i.e., the concentration of PE in the reaction solution, is preferably 10 mmol / L or more and 100 mmol / L or less, more preferably 10 mmol / L or more and 80 mmol / L or less, even more preferably 10 mmol / L or more and 60 mmol / L or less, particularly preferably 10 mmol / L or more and 40 mmol / L or less, and most preferably 10 mmol / L or more and 30 mmol / L or less, relative to the total volume of the reaction solution. When the concentration of PE is equal to or greater than the lower limit, the PE can be reacted more thoroughly with the diaryl carbonate. On the other hand, when the concentration of PE is equal to or less than the upper limit, the carbonation of PE can occur preferentially intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be further improved.

[0031] In the synthesis of compound (I), the amount of diaryl carbonate used can be expressed as the molar ratio of diaryl carbonate to PE. The molar ratio of diaryl carbonate to PE is preferably 2 / 1 or more and 10 / 1 or less, more preferably 4 / 1 or more and 10 / 1 or less. When the molar ratio of diaryl carbonate to PE is equal to or greater than the above lower limit, carbonation of PE can occur preferentially intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be further improved. When the molar ratio of diaryl carbonate to PE is equal to or less than the above upper limit, the abundance ratio of diaryl carbonate can be prevented from becoming too excessive, and compound (I) can be produced more efficiently while reducing production costs.

[0032] In the synthesis process of compound (I), the reaction temperature can be 20°C or higher and 100°C or lower, preferably 40°C or higher and 100°C or lower, more preferably 50°C or higher and 100°C or lower, and even more preferably 75°C or higher and 100°C or lower. By keeping the reaction temperature at or above the lower limit, carbonation of PE can occur preferentially intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be further improved. On the other hand, by keeping the reaction temperature at or below the upper limit, application of excess heat can be suppressed, and compound (I) can be produced more efficiently while reducing production costs.

[0033] The reaction time can be, for example, 1 hour or more and 24 hours or less, and can be 6 hours or more and 18 hours or less.

[0034] The method for producing compound (I) may further include a step of purifying compound (I) after the step of synthesizing compound (I), i.e., after completion of the reaction.

[0035] In the purification step, compound (I) is isolated by performing post-treatments as needed using known techniques. Specifically, compound (I) is roughly purified by post-treatments such as filtration, washing, extraction, pH adjustment, dehydration, and concentration, either singly or in combination, as needed, followed by concentration, crystallization, reprecipitation, column chromatography, and the like.

[0036] In order to increase the purity of the above-mentioned roughly purified Compound (I), it is preferable to further perform one or more of the following operations as appropriate and necessary: ​​crystallization, reprecipitation, column chromatography, extraction, stirring and washing of the crystals with a solvent, either alone or in combination.

[0037] In the method for producing compound (I), after the synthesis step of compound (I), compound (I) may be used as the shrinkage inhibitor of the present embodiment without undergoing a purification step. However, from the viewpoint of preventing the presence of unnecessary impurities from interfering with the volumetric shrinkage inhibitory effect, it is preferable to perform a purification step of compound (I).

[0038] The structure of Compound (I) can be confirmed by known techniques such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR).

[0039] The shrinkage inhibitor of the present embodiment may be in a solid state such as a powder, or may be in a liquid state dissolved or dispersed in a solvent, etc. As the solvent, the solvent used in the synthesis step of compound (I) is preferably used.

[0040] <Curing agent composition for epoxy resin> The curing agent composition for epoxy resins of the present embodiment contains the above-described shrinkage inhibitor for epoxy resins and a curing agent.

[0041] According to the curing agent composition for epoxy resins of the present embodiment, it is possible to effectively suppress volumetric shrinkage of epoxy resins during curing.

[0042] [Hardening agent] The curing agent is not particularly limited as long as it can form a crosslinked structure with the epoxy resin, and examples thereof include amine-based curing agents, acid anhydride-based curing agents, phenol-based curing agents, etc. Among them, amine-based curing agents are preferred because they are suitable for the ring-opening reaction of the compound (I).

[0043] Examples of amine-based curing agents include primary amines, secondary amines, and tertiary amines, and among these, tertiary amines are preferred due to their reactivity. Examples of tertiary amines include aliphatic tertiary amines, aromatic tertiary amines, and heterocyclic tertiary amines. Among these, heterocyclic tertiary amines are preferred. Examples of aliphatic tertiary amines include triethylamine, 3-dimethylaminopropylamine, 3-diethylaminopropylamine, 3-dibutylaminopropylamine, 2-diethylaminoethylamine, 1-diethylamino-4-aminopentane, N-(3-aminopropyl)-N-methylpropanediamine, and 3-(3-dimethylaminopropyl)propylamine. Examples of aromatic tertiary amines include dimethylbenzylamine and 2,4,6-tris(dimethylaminomethyl)phenol. Examples of heterocyclic tertiary amines include pyridine, 4-dimethylaminopyridine (DMAP), 1-(2-aminoethyl)piperazine, 4-(2-aminoethyl)morpholine, 4-(3-aminopropyl)morpholine, diazabicycloundecene (DBU), 1,4-diazabicyclo[2.2.2]octane (DABCO), imidazole, 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, and 2-heptamethylimidazole. Examples include decyl imidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-ethyl-1-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethyl-5-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, and 1-aminoethyl-2-methylimidazole. Among these, 2-ethyl-4-methylimidazole is preferred because it is suitable for the ring-opening reaction of the compound (I), is not too basic, and is easy to handle.

[0044] The curing agent composition for epoxy resins of this embodiment may be a mixed powder in which the shrinkage inhibitor for epoxy resins and the curing agent are mixed in a solid state such as powder, or may be in a liquid state in which they are dissolved or dispersed in a solvent, etc. As the solvent, the one used in the synthesis step of compound (I) is preferably used.

[0045] In the epoxy resin curing agent composition of this embodiment, the content ratio of the shrinkage inhibitor for the epoxy resin and the curing agent can be appropriately changed depending on the type and amount of the epoxy resin used. When the epoxy resin curing agent composition of this embodiment is mixed with the epoxy resin, the preferred ratio of the molar amount of the curable group in the curing agent (preferably the amino group in an amine curing agent) and the molar amount of the six-membered ring cyclic carbonate group in the shrinkage inhibitor for the epoxy resin relative to the molar amount of the epoxy group in the epoxy resin will be described in detail later in the adhesive composition section.

[0046] <Epoxy Resin Composition> The epoxy resin composition of the present embodiment contains the above-described shrinkage inhibitor for epoxy resins and an epoxy resin.

[0047] According to the epoxy resin composition of the present embodiment, it is possible to effectively suppress volumetric shrinkage of the epoxy resin during curing.

[0048] [Epoxy resin] The epoxy resin may be any resin having one or more epoxy groups, and examples thereof include C4-C28 alkyl glycidyl ethers; C2-C28 alkyl and alkenyl glycidyl esters; C1-C28 alkyl mono- and polyphenol glycidyl ethers; polyglycidyl ethers of pyrocatechol, resorcinol, hydroquinone, 4,4'-dihydroxydiphenylmethane (bisphenol F), 4,4'-dihydroxy-3,3'-dimethyldiphenylmethane, 4,4'-dihydroxydiphenyldimethylmethane (bisphenol A), 4,4'-dihydroxydiphenylmethylmethane, 4,4'-dihydroxydiphenylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenylpropane, 4,4'-dihydroxydiphenylsulfone, and tris(4-hydroxyphenyl)methane; and polyglycidyl ethers of transition metal complex chlorination and bromination products of the above diphenols. ethers; polyglycidyl ethers of novolacs; polyglycidyl ethers of diphenols obtained by esterifying diphenol ethers obtained by esterifying salts of aromatic hydrocarboxylic acids with dihaloalkanes or dihalogen dialkyl ethers; polyglycidyl ethers of polyphenols obtained by condensing phenols with long-chain halogenated paraffins containing at least two halogen atoms; N,N'-diglycidyl aniline; N,N'-dimethyl-N,N'-diglycidyl-4,4'-diaminodiphenylmethane; N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; N,N'-diglycidyl-4-aminophenyl glycidyl ether; N,N,N',N'-tetraglycidyl-1,3-propylene-bis-4-aminobenzoate; phenol novolac epoxy resins; cresol novolac epoxy resins, etc. These epoxy resins may be used alone or in combination. Among these, glycidyl phenyl ether (GPE) or bisphenol A glycidyl ether (BADGE) is preferred.

[0049] The epoxy resin composition of this embodiment may be a mixed powder in which the shrinkage inhibitor for epoxy resin and the epoxy resin are mixed in a solid state such as powder, or may be a liquid state in which they are dissolved or dispersed in a solvent, etc. As the solvent, the one used in the synthesis step of compound (I) is preferably used.

[0050] In the epoxy resin composition of this embodiment, the content ratio of the shrinkage inhibitor for the epoxy resin and the epoxy resin can be expressed as the ratio of the molar amount of six-membered cyclic carbonate groups in the shrinkage inhibitor for the epoxy resin to the molar amount of epoxy groups in the epoxy resin ([six-membered cyclic carbonate groups] / [epoxy groups]), which is typically 1 / 99 to 80 / 20, preferably 5 / 95 to 60 / 40, more preferably 10 / 90 to 55 / 45, even more preferably 15 / 85 to 55 / 45, particularly preferably 20 / 80 to 50 / 50, and most preferably 30 / 70 to 50 / 50. When the [six-membered cyclic carbonate groups] / [epoxy groups] ratio is within the above lower limit, the six-membered cyclic carbonate groups are more fully consumed, causing volume expansion and more effectively suppressing volumetric shrinkage of the epoxy resin. On the other hand, by ensuring that the ratio of [six-membered cyclic carbonate group] / [epoxy group] is equal to or less than the upper limit, the amount of remaining unopened six-membered cyclic carbonate groups can be reduced, and the physical properties of the resulting cured product, such as strength, can be improved. Furthermore, in the epoxy resin composition of the present embodiment, compound (I) has two six-membered cyclic carbonate groups and has an excellent effect of inhibiting volumetric shrinkage, so that the content ratio of the compound (I) can be made lower than that of conventional shrinkage inhibitors for epoxy resins.

[0051] <Epoxy Resin Hardener Kit> The epoxy resin curing agent kit of this embodiment includes the above-described shrinkage inhibitor for epoxy resin and a curing agent.

[0052] According to the epoxy resin curing agent kit of this embodiment, volumetric shrinkage of the epoxy resin during curing can be effectively suppressed.

[0053] As the shrinkage inhibitor for the epoxy resin contained in the epoxy resin curing agent kit of this embodiment, those exemplified in the above "Shrinkage inhibitor for epoxy resin" can be preferably used. As the curing agent, those exemplified in the above "Curing agent composition for epoxy resin" can also be preferably used.

[0054] In the epoxy resin curing agent kit of this embodiment, the shrinkage inhibitor and the curing agent for the epoxy resin may each be in a solid state such as a powder, or in a liquid state dissolved or dispersed in a solvent, etc. In either state, the shrinkage inhibitor and the curing agent for the epoxy resin are provided in a sealed state in a container of a known form corresponding to the respective properties.

[0055] In the epoxy resin curing agent kit of this embodiment, the preferred amounts and ratios of the shrinkage inhibitor and curing agent for the epoxy resin can be changed as appropriate depending on the type and amount of the epoxy resin used. In the epoxy resin curing agent kit of this embodiment, the preferred ratios of the molar amount of the crosslinkable functional group in the curing agent (preferably the amino group in an amine curing agent) and the molar amount of the six-membered cyclic carbonate group in the shrinkage inhibitor for the epoxy resin to the molar amount of the epoxy groups in the epoxy resin when the shrinkage inhibitor for the epoxy resin, the curing agent, and the epoxy resin are mixed will be described in detail below in the adhesive composition section.

[0056] <Epoxy resin base kit> The epoxy resin base kit of this embodiment includes the above-described shrinkage inhibitor for epoxy resin and epoxy resin.

[0057] According to the epoxy resin base kit of this embodiment, volumetric shrinkage of the epoxy resin during curing can be effectively suppressed.

[0058] As the shrinkage inhibitor for the epoxy resin contained in the epoxy resin main component kit of this embodiment, those exemplified in the above "Shrinkage inhibitor for epoxy resin" can be preferably used. Furthermore, as the epoxy resin, those exemplified in the above "Epoxy resin composition" can also be preferably used.

[0059] In the epoxy resin main component kit of this embodiment, the shrinkage inhibitor for the epoxy resin and the epoxy resin may each be in a solid state such as a powder, or in a liquid state dissolved or dispersed in a solvent, etc. In either state, the shrinkage inhibitor for the epoxy resin and the epoxy resin are each provided in a sealed state in a container of a known form appropriate for the property.

[0060] In the epoxy resin base kit of this embodiment, the ratio of the shrinkage inhibitor for the epoxy resin to the molar amount of epoxy groups in the epoxy resin shrinkage inhibitor can be expressed as the ratio of the molar amount of six-membered cyclic carbonate groups in the shrinkage inhibitor for the epoxy resin to the molar amount of epoxy groups in the epoxy resin ([six-membered cyclic carbonate groups] / [epoxy groups]), which can usually be 1 / 99 to 80 / 20, preferably 5 / 95 to 60 / 40, more preferably 10 / 90 to 55 / 45, even more preferably 15 / 85 to 55 / 45, particularly preferably 20 / 80 to 50 / 50, and most preferably 30 / 70 to 50 / 50. When the [six-membered cyclic carbonate groups] / [epoxy groups] ratio is within the above lower limit, the six-membered cyclic carbonate groups are more fully consumed, causing the volume to expand and more effectively suppressing the volumetric shrinkage of the epoxy resin. On the other hand, by ensuring that the ratio of [six-membered cyclic carbonate group] / [epoxy group] is equal to or less than the upper limit, the amount of remaining unopened six-membered cyclic carbonate groups can be reduced, and the physical properties of the resulting cured product, such as strength, can be improved. Furthermore, in the epoxy resin main component kit of this embodiment, compound (I) has two six-membered cyclic carbonate groups and has an excellent volumetric shrinkage suppression effect, so the content ratio thereof can be lower than that of conventional shrinkage suppressors for epoxy resins.

[0061] <Adhesive composition> The adhesive composition of this embodiment contains the above-described shrinkage inhibitor for epoxy-based resins, a curing agent, and an epoxy-based resin.

[0062] According to the adhesive composition of this embodiment, it is possible to effectively suppress volumetric shrinkage of the epoxy resin during curing.

[0063] In one embodiment, the adhesive may be provided as an adhesive kit including the above-described shrinkage inhibitor for epoxy resin, a curing agent, and epoxy resin.

[0064] As the shrinkage inhibitor for the epoxy resin contained in the adhesive composition of this embodiment, those exemplified above in "Shrinkage inhibitor for epoxy resin" can be preferably used. Furthermore, as the curing agent and epoxy resin, those exemplified above in "Curing agent composition for epoxy resin" and "Epoxy resin composition" can be preferably used, respectively.

[0065] In the adhesive composition of this embodiment, the content ratio of the curing agent to the epoxy resin can be expressed as the ratio of the molar amount of crosslinkable functional groups in the curing agent (preferably, amino groups in an amine curing agent) to the molar amount of epoxy groups in the epoxy resin. When the curing agent is a tertiary amine, the ratio of the molar amount of amino groups to the molar amount of epoxy groups ([amino group] / [epoxy group]) can usually be 0.1 / 99.9 or more and 30 / 70 or less, preferably 1 / 99 or more and 20 / 80 or less, and more preferably 3 / 97 or more and 15 / 85 or less. When the [amino group] / [epoxy group] ratio is equal to or greater than the above lower limit, the curing reaction can proceed more sufficiently, and the amount of remaining unreacted epoxy resin can be effectively reduced. On the other hand, when the [amino group] / [epoxy group] ratio is equal to or less than the above upper limit, the content of the curing agent can be further reduced, and the physical properties such as strength of the resulting cured product can be improved.

[0066] In the adhesive composition of this embodiment, the content ratio of the shrinkage inhibitor for the epoxy resin to the epoxy resin can be expressed as the ratio of the molar amount of six-membered cyclic carbonate groups in the shrinkage inhibitor for the epoxy resin to the molar amount of epoxy groups in the epoxy resin ([six-membered cyclic carbonate groups] / [epoxy groups]), which is typically 1 / 99 to 80 / 20, preferably 5 / 95 to 60 / 40, more preferably 10 / 90 to 55 / 45, even more preferably 15 / 85 to 55 / 45, particularly preferably 20 / 80 to 50 / 50, and most preferably 30 / 70 to 50 / 50. When the [six-membered cyclic carbonate groups] / [epoxy groups] ratio is within the above lower limit, the six-membered cyclic carbonate groups are more fully consumed, causing volume expansion and more effectively suppressing volumetric shrinkage of the epoxy resin. On the other hand, by ensuring that the ratio of [six-membered cyclic carbonate group] / [epoxy group] is equal to or less than the upper limit, the amount of remaining unopened six-membered cyclic carbonate groups can be reduced, and the physical properties of the resulting cured product, such as strength, can be improved. Furthermore, in the adhesive composition of this embodiment, compound (I) has two six-membered cyclic carbonate groups and has an excellent effect of inhibiting volumetric shrinkage, so the content ratio thereof can be lower than that of conventional shrinkage inhibitors for epoxy resins.

[0067] The adhesive composition of this embodiment can be cured by heating the curing agent to promote a ring-opening copolymerization reaction between the epoxy resin and compound (I). When the curing agent is a tertiary amine, the curing reaction can be carried out at a temperature typically in the range of 60°C to 250°C, preferably 100°C to 200°C.

[0068] Furthermore, as will be shown in the Examples described later, when the epoxy resin has viscosity, for example, the epoxy resin and compound (I) can be stirred and mixed in a temperature range of about 50°C or higher and lower than 100°C to obtain a uniform mixture of compound (I) and the epoxy resin, and then a curing agent can be added to carry out the curing reaction.

[0069] [Application] The adhesive composition of this embodiment is suitable for use as an adhesive for substrates made of, for example, metals (e.g., aluminum, titanium, magnesium, brass, steel, galvanized steel, HDG-steel, EG-steel, etc.); silicates (e.g., glass, quartz); metal oxides; concrete; wood; electronic chip materials (e.g., semiconductor chip materials); polymers (e.g., polyimide, polycarbonate), etc. The adhesive composition of this embodiment can also be used as a sealant or coating material for the above substrates. [Example]

[0070] Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples. However, the present embodiment is not limited in any way by the following examples and comparative examples as long as they do not depart from the gist of the present embodiment.

[0071] [Example 1] (Synthesis of network polymer by ring-opening polymerization of compound (I)) First, compound (I) was reacted alone in dimethyl sulfoxide (DMSO) at 100°C for 24 hours using 10 mol% 2-ethyl-4-methylimidazole (EMIm) as a curing agent. However, the solution remained homogeneous and did not gel even after 24 hours of reaction, suggesting that the expected network polymer was not produced. In addition, a portion of the solution after the reaction was diluted with deuterated DMSO (DMSO-d6) to obtain a polymerizable network polymer. 1 H NMR measurements were performed. The conversion rate of compound (I) was calculated using CH2Cl2 as an internal standard. In each test described below, the conversion rate was calculated in the same manner. The results are shown in Figure 1.

[0072] As shown in Figure 1, the conversion rate of compound (I) was approximately 50 mol%, suggesting that a linear polycarbonate (hereinafter sometimes referred to as "polymer 1") having a cyclic carbonate moiety in a side chain formed by ring-opening of only one of the two cyclic carbonate moieties of compound (I) or a corresponding oligomer was produced.

[0073] Therefore, we investigated the effect of 5 mol% of different basic amines, specifically, 4-dimethylaminopyridine (DMAP), 1,4-diazabicyclo[2.2.2]octane (DABCO), diazabicycloundecene (DBU), and 2-ethyl-4-methylimidazole (EMIm). The chemical formulas of these amines are shown below.

[0074] [ka]

[0075] The reaction was carried out in the presence of these amines in DMSO at 80°C for 24 hours, and the conversion of Compound (I) was estimated and the DMSO solution was observed for gelation. The results are shown in Table 1.

[0076] [Table 1]

[0077] As shown in Table 1, gelation was observed only when DBU was used, and the conversion of compound (I) was approximately 91 mol%, which was higher than when other amines were used (approximately 62 mol% or more and 70 mol% or less). A portion of each reaction solution (or the supernatant for the reaction in which gelation was achieved using DBU) was analyzed by gel permeation chromatography (GPC), and the results are shown in Figure 2. In Figure 2, "Run 1" shows the measurement results for the reaction solution using DMAP, "Run 2" shows the reaction solution using DABCO, "Run 3" shows the supernatant after the reaction using DBU, and "Run 4" shows the reaction solution using EMIm.

[0078] As shown in Figure 2, the molecular weight of the polymer using DMAP and DABCO was 1×10 in terms of polystyrene. 5 While peaks were observed in the above regions, similar peaks were not observed in the samples using EMIm and DBU (soluble portion). These results suggest that some of the cyclic carbonates in the side chains of polymer 1 are ring-opened to form cross-linked polymers between polymer chains.

[0079] Based on the above results, a network polymer was synthesized by the following method. Under a nitrogen atmosphere, compound (I) (1.00 g, 5.32 mmol) was dissolved in dry DMSO (12 mL), and DBU (39.8 μL, 0.27 mmol, 5 mol% relative to compound (I)) was added. The mixture was stirred at 80 ° C for 15 hours to react. After returning to room temperature, acetic acid (76 μL, 1.33 mmol) was added to stop the reaction. The insoluble matter was then collected by suction filtration, washed with N,N-dimethylformamide (DMF) (approximately 50 mL) and acetone (approximately 50 mL) to remove unreacted compound (I) and DBU, and dried at 110 ° C under reduced pressure to obtain a network polymer (hereinafter sometimes referred to as "polymer 2") (815 mg, yield 82% by mass). The structure of polymer 2 is estimated to be as shown in the following formula:

[0080] [ka]

[0081] The isolated polymer 2 was subjected to IR measurement by attenuated total reflectance (ATR) method, and the results are shown in FIG. As shown in Figure 3, the C=O stretching vibration of compound (I) at 1736 cm -1 The absorption peak of the chain carbonate C=O stretching vibration is at 1745 cm -1 In addition, the C=O stretching vibration of the cyclic carbonate formed by the ring opening of only one of the two cyclic carbonate moieties of compound (I) was observed at 1790 cm. -1 No absorption peak was observed around this point, suggesting that almost all of the cyclic carbonates in polymer 2 were ring-opened.

[0082] Furthermore, the obtained polymer 2 was subjected to thermal analysis by thermogravimetry (TGA) measurement and differential scanning calorimetry (DSC) measurement, and the results are shown in FIG. As shown in Figure 4a, the 5% weight loss temperature T d 5% =218℃, 10% weight loss temperature T d 10% = 223°C, and as shown in Fig. 4b, the temperature range (T d 5% The reason why no clear glass transition was observed is thought to be that the thermal motion of the polymer chains was suppressed by the network structure of polymer 2.

[0083] Next, the densities of Compound (I) and Polymer 2 were measured using a dry automatic density meter, Accupyc 1330, manufactured by Shimadzu Corporation. The specific measurement method is as follows. The sample was transferred to a density measurement container and degassed by reducing the pressure at room temperature for 15 minutes. The density was then measured using a Shimadzu Accupyc 1330 dry automatic density meter (room temperature = approximately 21°C). The density was measured multiple times, and the average value of the measurement results was calculated. The results are shown in Table 2. In Table 2, the values ​​of density and volume change rate of compounds other than compound (I) are listed as reference values ​​from Non-Patent Document 1. In addition, (c), (l), and (s) in the density column respectively refer to the properties of the compound, specifically, (c) means crystal, (l) means liquid, and (s) means solid.

[0084] [Table 2]

[0085] From Table 2, the densities of Compound (I) and Polymer 2 are D I =1.634g / cm 3 , D poly2 =1.409g / cm 3Furthermore, the volume change rate (Volume Change% (VC)) was calculated from these densities using the following formula:

[0086] (Volume Change%(VC)) ={(D I )-(D poly2 )} / D I ×100

[0087] As a result, it was found that compound (I) was converted to polymer 2 by ring-opening polymerization, with a volume expansion of 13.8%. This volume expansion rate is the highest among cyclic carbonate derivatives reported to date, and the volume change per molar mass of compound (I) (VC / (g mol -1 )) was up to approximately 1.7 times higher than other carbonates.

[0088] [Example 2] (Ring-opening copolymerization of compound (I) with glycidyl phenyl ether) To verify whether ring-opening copolymerization of compound (I) with an epoxy resin (bisphenol A diglycidyl ether (BADGE)) proceeds, compound (I) was reacted with glycidyl phenyl ether (GPE) in the presence of EMIm in DMSO at 110°C for 24 hours as a model reaction. The reaction formula is shown below. The molar ratios of GPE, compound (I), and EMIm were varied as shown in Table 3.

[0089] [ka]

[0090] As shown in Table 3, the conversion rates of the reaction in the mixed system of compound (I) and GPE (molar ratio: [GPE] / [compound (I)] / [EMIm]=100 / 25 / 5) were over 99 mol% and approximately 75 mol%, respectively. These values ​​were increased compared to the conversion rates of each monomer in the reaction of compound (I) alone (molar ratio: [GPE] / [compound (I)] / [EMIm]=0 / 25 / 5) and GPE alone (molar ratio: [GPE] / [compound (I)] / [EMIm]=100 / 0 / 5) (approximately 44 mol% and approximately 62 mol%, respectively). Therefore, it was considered that compound (I) and GPE were copolymerized.

[0091] [Table 3]

[0092] Furthermore, the reaction solution obtained by copolymerizing Compound (I) and GPE was subjected to GPC measurement, and the results are shown in Figure 5. As shown in Figure 5, the peak of compound (I) almost completely disappeared, and peaks thought to be oligomers were mainly observed. Furthermore, these peaks were observed with both RI and UV detectors, suggesting that at least compound (I) and GPE reacted with each other.

[0093] [Example 3] (Ring-opening copolymerization of compound (I) with bisphenol A glycidyl ether) As a result of the model reaction in Example 2, it was found that compound (I) undergoes ring-opening copolymerization with epoxide. Therefore, ring-opening copolymerization of compound (I) and BADGE was carried out using EMIm as a base (curing agent), and the volume change before and after the reaction was estimated. The reaction formula is as follows:

[0094] [ka]

[0095] However, when compound (I), which is a white solid, was mixed with BADGE, which is a viscous liquid at room temperature, it dispersed but did not dissolve, and it was not possible to prepare a uniform mixture. Therefore, compound (I) was mixed with BADGE to form a slurry, and the reaction was carried out. Specifically, the ground compound (I) (1.33 g, 7.1 mmol) was added to BADGE (13.6 g, 40 mmol), and the mixture was stirred at 80°C under reduced pressure for 30 minutes, mixed, and degassed to obtain a slurry mixture A in which compound (I) was dispersed. 85 / 15 The molar ratio of [BADGE] / [Compound (I)] was adjusted to 85 / 15. After cooling to room temperature, the slurry mixture A was 85 / 15 (5.87 g) was transferred to a vial, EMIm (204 mg, 1.85 mmol) was added, and the mixture was stirred at room temperature under reduced pressure for 30 minutes to give mixture A 85 / 15 / 10 The molar ratio was adjusted to [BADGE] / [Compound (I)] / [EMIm]=85 / 15 / 10. A portion of this was used for IR measurement, density measurement, DSC, and TG-DTA measurement.

[0096] The results of the thermal analysis measurements (DSC and TG-DTA) are shown in FIG. As shown in Figure 6(a), exothermic peaks were observed at 121°C and 130°C. Therefore, the temperature was fixed at 130°C, and TG-DTA measurements were performed to confirm that mixture A 85 / 15 / 10 As shown in Figure 6b), the exothermic peak leveled off after about 30 minutes and then appeared to gradually decrease.

[0097] Based on the results of the thermal analysis, Mixture A 85 / 15 / 10 A portion (2.00 g) of the mixture was transferred to a PTFE (polytetrafluoroethylene) Petri dish, degassed at room temperature under reduced pressure, and then reacted for 2 hours at 130°C under a nitrogen atmosphere. The progress of the reaction was monitored by IR measurement using an attenuated total reflectance (ATR) method using a sample taken from the dish. The results are shown in Figure 7. As shown in Fig. 7 i) and ii), -1 The peak at 1795 cm due to the epoxy group has almost disappeared, while the peak at 1795 cm -1A peak was observed around 1740 cm due to the C=O stretching vibration of the cyclic carbonate formed by ring-opening one of the two cyclic carbonate moieties of compound (I). -1 The peak due to the C=O stretching vibration of compound (I) observed around 1748 cm after the reaction -1 The latter peak almost coincides with the wave number of the peak due to the C=O stretching vibration of acyclic carbonate, which was also observed in Polymer 2 of Example 1. From these facts, it is clear that Mixture A 85 / 15 / 10 It was suggested that the reaction was heated at 130°C for 2 hours, and most of the epoxide group of BADGE was ring-opened, and most of the cyclic carbonate moiety on one side of compound (I) was ring-opened. However, because unreacted cyclic carbonate moieties were still present, the cured sample was further heated at 170°C for 2 hours and then subjected to IR measurement. The results are shown in Figure 7. As shown in Figure 7(iii), 1795 cm -1 The peaks around this point almost disappeared, indicating that the curing reaction was nearly complete.

[0098] Mixture A before hardening 85 / 15 / 10 The density of the cured product A-1 after heating (curing) was measured by the following method. Mixture A 85 / 15 / 10 The mixture (0.7251 g) was transferred to a density measurement container and degassed by reducing the pressure at room temperature for 15 minutes. The density was then measured using a Shimadzu Accupyc 1330 dry automatic density meter (room temperature = approximately 21°C). The density was measured multiple times, and the average value of the measurement results was calculated. This was used as the density before curing (D before On the other hand, the cured product A-1 was crushed to a size that could fit into a density measurement container, and the density was measured in the same manner (excluding the degassing operation). after ) was estimated. In addition, for comparison, a sample (mixture A') in which the blending molar ratio of BADGE, compound (I), and EMIm was [BADGE] / [compound (I)] / [EMIm]=100 / 0 / 10 was used. 100 / 0 / 10A cured product A'-1) was also prepared. Samples of BADGE / EMIm before and after curing 100 / 10 The density of the above mixture A was also measured. 85 / 15 / 10 The same procedure was followed as for the cured product A-1. The results are shown in Table 4. In Table 4, the density (D before ) is the density of compound (I), and the density after curing (D after ) is the density of Polymer 2, and is referred to as the value measured in Example 1.

[0099] [Table 4]

[0100] As shown in Table 4, the density of the cured product A-1 (containing EMIm used as a curing agent) was 1.192 g / cm 3 Mixture A before hardening 85 / 15 / 10 density (1.177g / cm 3 ), and the volume change rate was -1.3% by volume ((-) indicates volume shrinkage, (+) indicates volume expansion). On the other hand, the volume change rate after the curing reaction of Sample No. 4, which was composed of BADGE and EMIm (molar ratio: [BADGE] / [Compound (I)] / [EMIm]=100 / 0 / 10) and did not contain Compound (I), was -2.4% by volume (including EMIm used as a curing agent). From the above, it was revealed that compound (I) functions as an inhibitor of volumetric shrinkage during curing of BADGE.

[0101] As a control, a slurry mixture B was prepared by mixing 5,5-dimethyl-1,3-dioxan-2-one (DMDO) in place of compound (I) at a molar ratio of [BADGE] / [DMDO] / [EMIm]=85 / 30 / 10. 85 / 30 / 10 Mixture A 85 / 15 / 10 The mixture was heated in the same manner as in Example 1 (transferred to a PTFE Petri dish, degassed at room temperature under reduced pressure, and then reacted at 130°C for 2 hours and then at 170°C for 2 hours in a nitrogen atmosphere) to obtain a cured product, which was then crushed and washed to obtain Cured Product B-1. 85 / 30 / 10The results of the reaction tracking by IR measurement are shown in FIG.

[0102] Figure 8 suggests that DMDO barely reacted, which is thought to be because the reactivity of DMDO is significantly lower than that of compound (I).

[0103] Next, in order to increase the molar ratio of compound (I) and make the volume change due to copolymerization of BADGE and compound (I) > 0 vol%, a slurry-like mixture A was prepared by mixing BADGE at a molar ratio of [BADGE] / [Compound (I)] / [EMIm] = 70 / 30 / 10. 70 / 30 / 10 Mixture A 85 / 15 / 10 The mixture was heated in the same manner as in Example 1 (transferred to a PTFE Petri dish, degassed at room temperature under reduced pressure, and then reacted at 130°C for 2 hours and then at 170°C for 2 hours in a nitrogen atmosphere) to obtain a cured product, which was then crushed and washed, and the density of the cured product A-2 was measured. Mixture A 70 / 30 / 10 The results of tracking the reaction by IR measurement are shown in Figure 9. The results of density measurement are shown in Table 4 above.

[0104] As shown in Figure 9, the IR measurement results showed that Mixture A 85 / 15 / 10 The results were almost the same as those shown in Table 1. The density of the cured product A-2 was 1.204 g / cm 3 Mixture A before hardening 70 / 30 / 10 density (1.208g / cm 3 ), and the volume change rate was +0.3% by volume ((+) indicates volume expansion). In other words, the volume shrinkage after the reaction was completely suppressed.

[0105] Next, the thermal properties of the resulting cured products A-1, A-2, and A'-1 were examined by TG measurement and DSC measurement. The results are shown in Figure 10. As shown in FIG. 10, the temperature at which weight loss begins is the temperature at which thermal decomposition of carbonate groups begins, similar to that of polymer 2. Therefore, the 5% weight loss temperature T d 5% and 10% weight loss temperature T d 10%The T d 5% No clear glass transition was observed.

[0106] [Example 4] (Adhesion test) Mixture A prepared in Example 3 85 / 15 / 10 and mixture A' 100 / 0 / 10 Each mixture was applied to one end (25 mm × 12.5 mm) of an untreated stainless steel substrate (austenitic SUS304, 25 mm × 100 mm) and bonded to another stainless steel substrate. The two stainless steel substrates bonded together with each mixture were then clamped using two clips and heated at 130°C for 2 hours and then at 170°C for 2 hours (adhesive layer thickness after heating: approximately 0.005 mm to 0.015 mm). The substrate tensile shear strength was then measured at a rate of 1 mm / min (room temperature) using a tensile strength tester (Shimadzu Corporation, EZ Test EZ-L). The shear adhesive strength was calculated from the average of three measurements. The results are shown in Table 5.

[0107] [Table 5]

[0108] As shown in Table 5, when cured without adding Compound (I) (Sample No. 1), the shear adhesive strength was 8.4 MPa. On the other hand, when cured with 15 mol% of Compound (I) added (Sample No. 2), the shear adhesive strength was 8.7 MPa, which is a slight increase in strength. [Industrial Applicability]

[0109] The shrinkage inhibitor of this embodiment can suppress the volumetric shrinkage of an epoxy-based resin during its effective period. The epoxy-based resin curing agent composition, epoxy-based resin composition, epoxy-based resin curing agent kit, epoxy-based resin base kit, and adhesive composition of this embodiment use the shrinkage inhibitor for epoxy-based resins, and can suppress the volumetric shrinkage of an epoxy-based resin during its effective period.

Claims

1. It contains a bifunctional cyclic carbonate having a spiro structure, A shrinkage inhibitor for epoxy resins, wherein the bifunctional cyclic carbonate having a spiro structure is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione.

2. A curing agent composition for epoxy resins, comprising the shrinkage inhibitor for epoxy resins according to claim 1 and a curing agent.

3. 3. The epoxy resin curing agent composition according to claim 2, wherein the curing agent is an amine curing agent.

4. 4. The epoxy resin curing agent composition according to claim 2, wherein the curing agent is 2-ethyl-4-methylimidazole.

5. An epoxy resin composition comprising the shrinkage inhibitor for epoxy resins according to claim 1 and an epoxy resin.

6. The shrinkage inhibitor for epoxy resins according to claim 1, A hardener; An epoxy resin hardener kit comprising:

7. The shrinkage inhibitor for epoxy resins according to claim 1, an epoxy resin; An epoxy resin base kit comprising:

8. An adhesive composition comprising the shrinkage inhibitor for epoxy resins according to claim 1, a curing agent, and an epoxy resin.

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