JP6207424B2 - Mercaptoalkylglycolurils and their uses - Google Patents

Description

  The present invention relates to a novel mercaptoalkylglycoluril and its use, in particular as a curing agent for epoxy resin, an epoxy resin composition containing the mercaptoalkylglycoluril and an adhesive containing such an epoxy resin composition And a sealant.

  Glycolurils are heterocyclic compounds having four urea nitrogens in the ring structure, and are used for various applications and production of new functional compounds by utilizing the reactivity of the urea nitrogens. Yes.

  For example, it is known that glycoluril is reacted with an aldehyde such as dimethoxyethanal to form an aminoplastic resin, which is used as a crosslinking agent for cellulose (see Patent Document 1).

  In addition, it is known that an emulsion containing a copolymer of vinyl acetate, ethylene, and a self-crosslinkable monomer and tetramethylol glycoluril is used as a binder for a nonwoven fabric (see Patent Document 2). It is also known to use a polyhexamethylene biguanide compound, which is a water-soluble polymer antibacterial agent, as a crosslinking agent for fixing to a fiber (see Patent Document 3).

  On the other hand, compounds having multiple reactive allyl groups in the molecule, such as triallyl isocyanurates, are well known as crosslinking agents for synthetic resins and synthetic rubbers. Tetraallylglycolurils having four allyl groups in a molecule that functions as a crosslinking agent are also known (see Patent Document 4).

  A compound having a plurality of thiol groups in the molecule is also well known as, for example, a curing agent for epoxy resins. For example, an epoxy resin composition that uses a polythiol compound as a curing agent and includes a reaction product of an amine and an epoxy compound as a curing accelerator has been proposed. This epoxy resin composition has a long pot life and is supposed to cure quickly at a relatively low temperature (see Patent Document 5).

  An epoxy resin containing a reaction product of an isocyanate compound having one or more isocyanate groups in the molecule and a compound having at least one primary and / or secondary amino group in the molecule as a curing accelerator A composition has also been proposed, and this epoxy resin composition is also said to have a long pot life and excellent curability (see Patent Document 6).

  Furthermore, tris (3-mercaptopropyl) isocyanurate, also called trithiol isocyanurate, has been proposed as a curing agent that gives an epoxy resin cured product with excellent water resistance since it does not have an ester group in the molecule ( (See Patent Document 7).

  A compound in which a hydrogen atom on at least one nitrogen atom of a glycoluril is substituted with a mercaptoalkyl group is useful as an intermediate for the synthesis of a novel sulfur-containing compound. Those having more than one are expected to be useful as curing agents for epoxy resins, for example. However, such compounds in which at least one hydrogen atom on at least one nitrogen atom of the glycoluril is substituted with a mercaptoalkyl group are not known so far.

JP-A-8-67729 Japanese Patent Laid-Open No. 2-2611851 Japanese Patent Laid-Open No. 7-82665 Japanese Patent Application Laid-Open No. 11-171887 JP-A-6-211969 Japanese Patent Application Laid-Open No. 6-21970 JP 2012-153794 A

  In view of the circumstances described above, the present invention is a novel mercaptoalkylglycoluril and its use, in particular as an epoxy resin curing agent and an epoxy resin composition containing the mercaptoalkylglycoluril as a curing agent, Furthermore, it aims at providing the adhesive agent and sealing agent containing such an epoxy resin composition.

  According to the invention, the general formula (I)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, a mercaptomethyl group or 2-mercaptoethyl group. And a mercaptoalkyl group selected from a 3-mercaptopropyl group and n is 0, 1 or 2.)
The mercaptoalkylglycoluril represented by these is provided.

  In particular, according to the present invention, preferred mercaptoalkylglycolurils are represented by the general formula (I)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, or in the above general formula (I) Partial general formula

Represents the same mercaptoalkyl group, and n is 0, 1 or 2. )
The mercaptoalkylglycoluril represented by these is provided.

  According to this invention, the hardening | curing agent for epoxy resins containing this is provided as utilization of the said mercaptoalkyl glycoluril.

  Moreover, according to this invention, the utilization of the said mercaptoalkylglycoluril provides the epoxy resin composition which contains the said mercaptoalkylglycoluril as a hardening | curing agent and contains the hardening accelerator which consists of amines.

  Furthermore, according to the present invention, there is provided an epoxy resin composition comprising the mercaptoalkylglycoluril as a curing agent and a reaction product of an amine and an epoxy compound as a curing accelerator, and the mercaptoalkylglycol. Curing the reaction product of an isocyanate compound having one or more isocyanate groups in the molecule and a compound having at least one primary and / or secondary amino group in the molecule, containing urils as a curing agent An epoxy resin composition is provided that includes it as an accelerator.

  In addition to the above, according to the present invention, an adhesive and a sealant including the above-described epoxy resin composition are provided.

  The mercaptoalkyl glycoluril according to the present invention is a novel compound in which at least one hydrogen atom on the four nitrogen atoms of the glycoluril is substituted with a mercaptoalkyl group.

  Therefore, such a compound is useful as a synthetic intermediate for a novel sulfur-containing compound, and a compound having two or more mercaptoalkyl groups in the molecule is useful, for example, as a curing agent for epoxy resins. And since it does not have an ester group in a molecule | numerator, it is anticipated to give the epoxy resin hardened | cured material which is excellent in hydrolysis resistance rather than the conventional polythiols.

  In particular, 1,3,4,6-tetrakis (mercaptoalkyl) glycoluril, in which all hydrogen atoms on nitrogen atoms are substituted with mercaptoalkyl groups, is tetrafunctional, for example, as a curing agent for epoxy resins. When used, not only can a cured epoxy resin with excellent hydrolysis resistance be obtained, but also an epoxy resin with a higher crosslink density than when a conventional bifunctional or trifunctional curing agent is used. A cured product, and thus, for example, an epoxy resin cured product having excellent hardness, heat resistance, moisture resistance and the like can be obtained.

  Therefore, according to the present invention, it is possible to obtain an adhesive and a sealant containing such an epoxy resin composition, which are also excellent in hydrolysis resistance and excellent in strength, heat resistance, moisture resistance and the like.

It is IR spectrum of 1, 3- diallyl glycoluril. It is IR spectrum of 1, 3-bis (3-mercaptopropyl) glycoluril. It is an IR spectrum of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril. It is IR spectrum of 1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril. It is IR spectrum of 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril.

  The mercaptoalkylglycolurils according to the present invention have the general formula (I)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, a mercaptomethyl group or 2-mercaptoethyl group. And a mercaptoalkyl group selected from a 3-mercaptopropyl group and n is 0, 1 or 2.)
It is represented by

In the mercaptoalkylglycoluril represented by the above general formula (I), when R ¹ or R ² is a lower alkyl group, the lower alkyl group usually has 1 to 5 carbon atoms, 1 to 3, most preferably 1, that is, a methyl group.

  In particular, the mercaptoalkylglycolurils according to the invention are preferably of the general formula (I)

(Wherein R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a partial general formula in the above general formula (I) formula

Represents the same mercaptoalkyl group, and n is 0, 1 or 2. )
It is represented by

That is, in the present invention, when one, two or three of R ³ , R ⁴ and R ⁵ are mercaptoalkyl groups in the mercaptoalkylglycolurils represented by the above general formula (I). The mercaptoalkyl groups of the mercaptoalkylglycolurils represented by the general formula (I) are preferably the same.

Accordingly, preferred specific examples of mercaptoalkyl glycolurils according to the present invention include, for example,
1-mercaptomethylglycoluril,
1- (2-mercaptoethyl) glycoluril,
1- (3-mercaptopropyl) glycoluril,
1,3-bis (mercaptomethyl) glycoluril,
1,3-bis (2-mercaptoethyl) glycoluril,
1,3-bis (3-mercaptopropyl) glycoluril,
1,4-bis (mercaptomethyl) glycoluril,
1,4-bis (2-mercaptoethyl) glycoluril,
1,4-bis (3-mercaptopropyl) glycoluril,
1,6-bis (mercaptomethyl) glycoluril,
1,6-bis (2-mercaptoethyl) glycoluril,
1,6-bis (3-mercaptopropyl) glycoluril,
1,3,4-tris (mercaptomethyl) glycoluril,
1,3,4-tris (2-mercaptoethyl) glycoluril,
1,3,4-tris (3-mercaptopropyl) glycoluril,
1,3,4,6-tetrakis (mercaptomethyl) glycoluril,
1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril,
1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril,
1-mercaptomethyl-3a-methylglycoluril,
1-mercaptomethyl-6a-methylglycoluril,
1- (2-mercaptoethyl) -3a-methylglycoluril,
1- (2-mercaptoethyl) -6a-methylglycoluril,
1- (3-mercaptopropyl) -3a-methylglycoluril,
1- (3-mercaptopropyl) -6a-methylglycoluril,
1,3-bis (mercaptomethyl) -3a-methylglycoluril,
1,3-bis (2-mercaptoethyl) -3a-methylglycoluril,
1,3-bis (3-mercaptopropyl) -3a-methylglycoluril,
1,4-bis (mercaptomethyl) -3a-methylglycoluril,
1,4-bis (2-mercaptoethyl) -3a-methylglycoluril,
1,4-bis (3-mercaptopropyl) -3a-methylglycoluril,
1,6-bis (mercaptomethyl) -3a-methylglycoluril,
1,6-bis (mercaptomethyl) -6a-methylglycoluril,
1,6-bis (2-mercaptoethyl) -3a-methylglycoluril,
1,6-bis (2-mercaptoethyl) -6a-methylglycoluril,
1,6-bis (3-mercaptopropyl) -3a-methylglycoluril,
1,6-bis (3-mercaptopropyl) -6a-methylglycoluril,
1,3,4-tris (mercaptomethyl) -3a-methylglycoluril,
1,3,4-tris (mercaptomethyl) -6a-methylglycoluril,
1,3,4-tris (2-mercaptoethyl) -3a-methylglycoluril,
1,3,4-tris (2-mercaptoethyl) -6a-methylglycoluril,
1,3,4-tris (3-mercaptopropyl) -3a-methylglycoluril,
1,3,4-tris (3-mercaptopropyl) -6a-methylglycoluril,
1,3,4,6-tetrakis (mercaptomethyl) -3a-methylglycoluril,
1,3,4,6-tetrakis (2-mercaptoethyl) -3a-methylglycoluril,
1,3,4,6-tetrakis (3-mercaptopropyl) -3a-methylglycoluril,
1-mercaptomethyl-3a, 6a-dimethylglycoluril,
1- (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1- (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1,3-bis (mercaptomethyl) -3a, 6a-dimethylglycoluril,
1,3-bis (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1,3-bis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1,4-bis (mercaptomethyl) -3a, 6a-dimethylglycoluril,
1,4-bis (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1,4-bis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1,6-bis (mercaptomethyl) -3a, 6a-dimethylglycoluril,
1,6-bis (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1,6-bis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1,3,4-tris (mercaptomethyl) -3a, 6a-dimethylglycoluril,
1,3,4-tris (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1,3,4-tris (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1,3,4,6-tetrakis (mercaptomethyl) -3a, 6a-dimethylglycoluril,
1,3,4,6-tetrakis (2-mercaptoethyl) -3a, 6a-dimethylglycoluril,
1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril,
1-mercaptomethyl-3a, 6a-diphenylglycoluril,
1- (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
1- (3-mercaptopropyl) -3a, 6a-diphenylglycoluril,
1,3-bis (mercaptomethyl) -3a, 6a-diphenylglycoluril,
1,3-bis (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
1,3-bis (3-mercaptopropyl) -3a, 6a-diphenylglycoluril,
1,4-bis (mercaptomethyl) -3a, 6a-diphenylglycoluril,
1,4-bis (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
1,4-bis (3-mercaptopropyl) -3a, 6a-diphenylglycoluril,
1,6-bis (mercaptomethyl) -3a, 6a-diphenylglycoluril,
1,6-bis (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
1,6-bis (3-mercaptopropyl) -3a, 6a-diphenylglycoluril,
1,3,4-tris (mercaptomethyl) -3a, 6a-diphenylglycoluril,
1,3,4-tris (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
1,3,4-tris (3-mercaptopropyl) -3a, 6a-diphenylglycoluril,
1,3,4,6-tetrakis (mercaptomethyl) -3a, 6a-diphenylglycoluril,
1,3,4,6-tetrakis (2-mercaptoethyl) -3a, 6a-diphenylglycoluril,
Examples include 1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-diphenylglycoluril.

  Of the mercaptoalkylglycolurils represented by the general formula (I) according to the present invention, those in which n is 2, that is, the following general formula (Ia)

(In the formula, R ¹ and R ² are the same as above, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a 3-mercaptopropyl group.)
The 3-mercaptopropyl glycoluril represented by the general formula (a)

(In the formula, R ¹ and R ² are the same as described above, and R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or an allyl group.)
And an thioacetic acid addition reaction in the presence of a catalyst in an appropriate solvent, if necessary, to the allyl glycoluril represented by the general formula (a1)

(In the formula, R ¹ and R ² are the same as described above, and R ⁹ , R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or a 3-acetylthiopropyl group.)
Is obtained as a reaction product, and then the reaction product can be obtained by reduction with a borohydride compound in an appropriate solvent, if necessary.

  In the reaction of allyl glycoluril (a) and thioacetic acid, thioacetic acid is usually used at a ratio of 1.0 to 3.0 equivalents relative to the allyl group of allyl glycoluril (a). Preferably, it is used at a ratio of 1.0 to 1.5 equivalents.

  The reaction of allyl glycoluril (a) and thioacetic acid is carried out in the presence of a catalyst. As the catalyst, azobisisobutyronitrile and benzoyl peroxide are preferably used. Such a catalyst is used in a proportion of 0.001 to 0.2 equivalent, preferably in a proportion of 0.005 to 0.2 equivalent, with respect to the allyl group of allyl glycoluril (a). Used.

  In the reaction of allyl glycoluril (a) and thioacetic acid, the solvent is not particularly limited as long as it does not inhibit the reaction. For example, water, methanol, ethanol, Alcohols such as isopropyl alcohol, aliphatic hydrocarbons such as hexane and heptane, ketones such as acetone and 2-butanone, esters such as ethyl acetate and butyl acetate, benzene, toluene and xylene Aromatic hydrocarbons, halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, chlorotrifluoromethane, dichloroethane, chlorobenzene, dichlorobenzene, diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dimethoxyethane, diethylene glycol dimethyl Ethers such as ether, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, amides such as hexamethylphosphorotriamide, sulfoxides such as dimethyl sulfoxide, etc. Can be mentioned. Such a solvent is used individually or in combination of 2 or more types.

  The reaction of the allyl glycoluril (a) and thioacetic acid is usually performed at a temperature in the range of −10 to 150 ° C., preferably at a temperature in the range of 0 ° C. to 100 ° C. The reaction time is usually in the range of 1 to 48 hours, preferably in the range of 1 to 24 hours, although it depends on the reaction temperature.

  After completion of the reaction between the allyl glycoluril (a) and thioacetic acid, excess thioacetic acid and the solvent were distilled off from the resulting reaction mixture, and then the reaction product obtained as a residue was required. If necessary, the reaction mixture may be reduced with a borohydride compound in an appropriate solvent, and the obtained reaction mixture may be subjected to a reduction treatment with a borohydride compound in an appropriate solvent as necessary. Also good.

  Examples of the borohydride compound include sodium borohydride, potassium borohydride, lithium borohydride, calcium borohydride, magnesium borohydride, and the like. These borohydride compounds are used in a ratio of 0.5 to 10 equivalents, preferably in a ratio of 1.0 to 4.0 equivalents, with respect to the allyl group of the allyl glycoluril used. Used.

  In the reduction treatment with the borohydride compound of the reaction product obtained by the reaction of the allyl glycoluril (a) and thioacetic acid, the solvent, when used, is not particularly limited unless it inhibits the reaction. For example, the same solvent as the solvent used in the reaction of the allyl glycoluril (a) and thioacetic acid can be used.

The reduction treatment with the borohydride compound is usually performed in the range of 0 ° C. to 150 ° C., preferably in the range of room temperature to 100 ° C. Moreover, although reaction time is based also on reaction temperature, it is the range of 1 to 24 hours normally, Preferably, it is the range of 1 to 12 hours.
After the reduction treatment with the borohydride compound, the desired mercaptoalkylglycoluril can be obtained from the resulting reaction mixture by, for example, an extraction operation. If necessary, the desired mercaptoalkylglycoluril can be further purified by washing with a solvent such as water or activated carbon treatment.

  Of the mercaptoalkylglycolurils represented by the general formula (I) according to the present invention, those in which n is 1, that is, the general formula (Ib)

(In the formula, R ¹ and R ² are the same as above, and R ¹² , R ¹³ and R ¹⁴ each independently represent a hydrogen atom or a 2-mercaptoethyl group.)
2-ethyl mercaptoglycoluril represented by the general formula (b)

(In the formula, R ¹ and R ² are the same as described above, and R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom or a 2-hydroxyethyl group.)
The 2-hydroxyethylglycoluril (b) represented by general formula (b1) is reacted with thionyl chloride in an appropriate solvent as necessary.

(In the formula, R ¹ and R ² are the same as described above, and R ¹⁸ , R ¹⁹ and R ²⁰ each independently represent a hydrogen atom or a 2-chloroethyl group.)
A 2-chloroethylglycoluril is obtained, and then the reaction product is treated with disodium trithiocarbonate in an appropriate solvent as necessary to obtain a chlorine atom. Can be obtained by substituting with a mercapto group.

  Similarly, among the mercaptoalkylglycolurils according to the present invention represented by the general formula (I), those in which n is 0, that is, the general formula (Ic)

(In the formula, R ¹ and R ² are the same as above, and R ²¹ , R ²² and R ²³ each independently represent a hydrogen atom or a mercaptomethyl group.)
Can be obtained by the same method as 2-ethyl mercaptoglycoluril.

  That is, the mercaptomethylglycolurils are represented by the general formula (c)

(In the formula, R ¹ and R ² are the same as described above, and R ²⁴ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom or a hydroxymethyl group.)
Is reacted with thionyl chloride in an appropriate solvent, if necessary, to give a compound of the general formula (c1)

(In the formula, R ¹ and R ² are the same as defined above, and R ²⁷ , R ²⁸ and R ²⁹ each independently represent a hydrogen atom or a chloromethyl group.)
Then, the reaction product is treated with disodium trithiocarbonate in an appropriate solvent as necessary to convert the chlorine atom to mercapto. It can be obtained by substituting with a group.

  In the reaction of 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c) with thionyl chloride, thionyl chloride is 2-hydroxyethylglycoluril (b) or hydroxymethylglycoluril (c). Usually, it is used in the ratio of 1.0-10.0 equivalent with respect to the hydroxy group which has, Preferably, it is used in the ratio of 1.0-3.0 equivalent.

  In the reaction of the 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c) with thionyl chloride, the solvent is not particularly limited unless it inhibits the reaction. For example, aliphatic hydrocarbons such as hexane and heptane, ketones such as acetone and 2-butanone, esters such as ethyl acetate and butyl acetate, aromatic carbonization such as benzene, toluene and xylene Hydrogen, methylene chloride, chloroform, carbon tetrachloride, chlorotrifluoromethane, dichloroethane, chlorobenzene, halogenated hydrocarbons such as dichlorobenzene, diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dimethoxyethane, diethylene glycol dimethyl ether Examples of such ethers, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, amides such as hexamethylphosphorotriamide, sulfoxides such as dimethyl sulfoxide, etc. Can do. Such a solvent is used individually or in combination of 2 or more types.

  The reaction of the 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c) with thionyl chloride is usually performed at a temperature in the range of -10 to 150 ° C, preferably 0 to 100 ° C. At a temperature in the range of Moreover, although reaction time is based also on reaction temperature, it is the range of 1 to 24 hours normally, Preferably, it is the range of 1 to 6 hours.

  After completion of the reaction between the 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c) and thionyl chloride, excess thionyl chloride and the solvent were distilled off from the resulting reaction mixture, and the residue If necessary, the reaction product obtained as above may be treated with disodium trithiocarbonate in an appropriate solvent, and the above 2-hydroxyethyl glycolurils (b) or hydroxymethylglycolurils After completion of the reaction between (c) and thionyl chloride, the obtained reaction mixture may be subjected to treatment with disodium trithiocarbonate in an appropriate solvent as necessary.

  The disodium trithiocarbonate is used at a ratio of 1.0 to 10 equivalents with respect to the hydroxy group of the used 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c), preferably Is used in a proportion of 1.0 to 4.0 equivalents.

  In the treatment of the reaction product obtained by the reaction of 2-hydroxyethyl glycoluril (b) or hydroxymethylglycoluril (c) with thionyl chloride with disodium trithiocarbonate, the solvent is As long as the reaction is not inhibited, the solvent is not particularly limited. For example, the same solvent as the solvent used in the reaction of the allyl glycoluril (a) and thioacetic acid can be used.

  The treatment with disodium trithiocarbonate is usually carried out in the range of 0 ° C to 150 ° C, preferably in the range of room temperature to 100 ° C. Moreover, although reaction time is based also on reaction temperature, it is the range of 1 to 24 hours normally, Preferably, it is the range of 1 to 9 hours.

  After the treatment with disodium trithiocarbonate, the desired mercaptoalkylglycoluril can be obtained from the treated mixture by, for example, an extraction operation. If necessary, the desired mercaptoalkylglycoluril can be further purified by washing with a solvent such as water or activated carbon treatment.

  As described above, the mercaptoalkylglycolurils according to the present invention include, as described above, synthetic intermediates for novel sulfur-containing compounds, and those having two or more mercaptoalkyl groups in the molecule, for example, as curing agents for epoxy resins. Useful. That is, the curing agent for epoxy resin according to the present invention contains the mercaptoalkylglycoluril described above.

  In particular, an epoxy resin composition containing 1,3,4,6-tetrakis (mercaptoalkyl) glycoluril as a curing agent according to the present invention is not only excellent in hydrolysis resistance but also conventionally known. Compared with an epoxy resin composition, an epoxy resin cured product having a higher crosslink density, and therefore, an epoxy resin cured product superior in, for example, hardness, heat resistance, moisture resistance and the like is provided.

  That is, the epoxy resin composition according to the present invention contains the mercaptoalkylglycoluril represented by the general formula (I) as a curing agent. Furthermore, the epoxy resin composition according to the present invention is a curing accelerator comprising a reaction product of an amine and an epoxy compound, instead of a curing accelerator comprising an amine, or together with a curing accelerator comprising an amine, and a molecule. A curing accelerator comprising a reaction product of a compound having one or more isocyanate groups in the molecule and a compound having at least one primary and / or secondary amino group in the molecule may be included.

  In the present invention, the above-mentioned epoxy resin means an epoxy compound having two or more epoxy groups per molecule on average. Therefore, as is well known, as such an epoxy resin, for example, bisphenol A is used. Polyglycidyl ethers obtained by reacting polychlorophenols such as bisphenol F, bisphenol AD, catechol and resorcinol, polyhydric alcohols such as glycerin and polyethylene glycol and epichlorohydrin, p-hydroxybenzoic acid, β-hydroxynaphthoic acid Glycidyl ether esters obtained by reacting such a hydroxycarboxylic acid with epichlorohydrin, polyglycidyl esters obtained by reacting a polycarboxylic acid such as phthalic acid or terephthalic acid with epichlorohydrin, and epoxy Phenol novolac resin, epoxidized cresol novolak resin, epoxidized polyolefin, cycloaliphatic epoxy resin, urethane-modified epoxy resin, and the like can be mentioned. However, in the present invention, the epoxy resin is not limited to the above examples. Absent.

Moreover, as the epoxy resin, a glycidyl glycoluril compound having two or more epoxy groups in the molecule can also be used. Examples of such glycidyl glycoluril compounds include:
1,3-diglycidyl glycoluril,
1,4-diglycidyl glycoluril,
1,6-diglycidyl glycoluril,
1,3,4-triglycidyl glycoluril,
1,3,4,6-tetraglycidylglycoluril,
1,3-diglycidyl-3a-methylglycoluril,
1,4-diglycidyl-3a-methylglycoluril,
1,6-diglycidyl-3a-methylglycoluril,
1,3,4-triglycidyl-3a-methylglycoluril,
1,3,4,6-tetraglycidyl-3a-methylglycoluril,
1,3-diglycidyl-3a, 6a-dimethylglycoluril,
1,4-diglycidyl-3a, 6a-dimethylglycoluril,
1,6-diglycidyl-3a, 6a-dimethylglycoluril,
1,3,4-triglycidyl-3a, 6a-dimethylglycoluril,
1,3,4,6-tetraglycidyl-3a, 6a-dimethylglycoluril,
1,3-diglycidyl-3a, 6a-diphenylglycoluril,
1,4-diglycidyl-3a, 6a-diphenylglycoluril,
1,6-diglycidyl-3a, 6a-diphenylglycoluril,
1,3,4-triglycidyl-3a, 6a-diphenylglycoluril,
Examples include 1,3,4,6-tetraglycidyl-3a, 6a-diphenylglycoluril.

  As conventionally known, the curing accelerator comprising amines in the epoxy resin composition according to the present invention has at least one active hydrogen capable of addition reaction with an epoxy group in the molecule, and a primary amino group. Any group having at least one amino group selected from a group, a secondary amino group and a tertiary amino group in the molecule may be used. Examples of curing accelerators composed of such amines include aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, and 4,4'-diaminodicyclohexylmethane. , Aromatic amines such as 4,4'-diaminodiphenylmethane, o-methylaniline, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline And nitrogen-containing heterocyclic compounds such as piperidine and piperazine. However, in this invention, the hardening accelerator which consists of amines is not limited to the said illustration.

  Furthermore, in the epoxy resin composition according to the present invention, in addition to the above-described curing accelerator composed of amines, a reaction product of amines and an epoxy compound, or one or more isocyanate groups in the molecule. A reaction product of a compound and a compound having at least one primary and / or secondary amino group in the molecule can be used as a curing accelerator.

  The reaction product of the amines and the epoxy compound is a solid insoluble in the epoxy resin at room temperature, solubilized by heating and functions as a curing accelerator, so it is also called a latent curing accelerator. Yes. Hereinafter, the curing accelerator composed of a reaction product of the amines and the epoxy compound is referred to as a latent curing accelerator. Such a latent curing accelerator may be surface-treated with an isocyanate compound or an acidic compound.

  Examples of the epoxy compound used for the production of the latent curing accelerator are obtained by reacting a polyhydric phenol such as bisphenol A, bisphenol F, catechol, and resorcinol, or a polyhydric alcohol such as glycerin and polyethylene glycol with epichlorohydrin. Reaction of polycarboxylic acid such as polyglycidyl ether, p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin and glycidyl ether ester, phthalic acid, terephthalic acid and epichlorohydrin The resulting polyglycidyl ester, 4,4′-diaminodiphenylmethane, m-aminophenol and the like are reacted with epichlorohydrin, and epoxidized phenidyl compounds. Examples include, but are not limited to, polyfunctional epoxy compounds such as urenovolak resins, epoxidized cresol novolak resins, and epoxidized polyolefins, and monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, and glycidyl methacrylate. is not.

  In addition, the amines used in the production of the latent curing accelerator have at least one active hydrogen capable of addition reaction with an epoxy group in the molecule, as well as a primary amino group, a secondary amino group, and a tertiary. What is necessary is just to have at least one amino group selected from amino groups in the molecule.

  Examples of such amines include aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4′-diaminodicyclohexylmethane, 4,4 Aromatic amine compounds such as' -diaminodiphenylmethane, o-methylaniline, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine, piperazine Examples thereof include, but are not limited to, nitrogen-containing heterocyclic compounds.

  Among the amines described above, tertiary amines having a tertiary amino group in the molecule are raw materials that provide a latent curing accelerator having excellent curing acceleration. Specific examples of such tertiary amines include, for example, dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine. Such as amines such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, imidazole compounds such as 2-phenylimidazole, etc. Secondary or secondary amines, 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylamino D 1- (2-hydroxy-3-phenoxypropyl) -2-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3) -Butoxypropyl) -2-methylimidazole, 1- (2-hydroxy-3-butoxypropyl) -2-ethyl-4-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-phenylimidazoline, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazoline, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, N-β-hydroxyethylformoline, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-mercaptoben Zoimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N, N-dimethylaminobenzoic acid, N, N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N, N-dimethylglycine hydrazide, N, Examples thereof include alcohols having a tertiary amino group in the molecule, such as N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, and isonicotinic acid hydrazide, phenols, thiols, carboxylic acids, and hydrazides.

  In order to further improve the storage stability of the epoxy resin composition according to the present invention, an active hydrogen compound having two or more active hydrogens in the molecule is added as a third component when the latent curing accelerator is produced. You can also. Examples of such active hydrogen compounds include polyphenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol and phenol novolac resin, polyhydric alcohols such as trimethylolpropane, adipic acid, Examples include polyvalent carboxylic acids such as phthalic acid, 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, and lactic acid. It is not limited to.

  Furthermore, as the isocyanate compound used as the surface treatment agent in the production of the latent curing accelerator, examples thereof include monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, benzyl isocyanate, and hexamethylene. Diisocyanate, toluylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, etc. Such polyfunctional isocyanate compounds can be mentioned.

  Instead of the polyfunctional isocyanate compound, a terminal isocyanate group-containing compound obtained by a reaction between the polyfunctional isocyanate compound and an active hydrogen compound can also be used. Examples of such compounds include addition reactants having terminal isocyanate groups obtained by reaction of toluylene diisocyanate and trimethylolpropane, addition reactants having terminal isocyanate groups obtained by reaction of toluylene diisocyanate and pentaerythritol, etc. Can be mentioned.

  However, the isocyanate compound used as the surface treatment agent in the production of the latent curing accelerator is not limited to the above.

  In addition, the acidic substance used as the surface treatment agent in the production of the latent curing accelerator may be any of gas, liquid, and solid, and may be any of inorganic acid and organic acid, such as carbon dioxide gas, Sulfurous acid gas, sulfuric acid, hydrochloric acid, oxalic acid, phosphoric acid, acetic acid, formic acid, propionic acid, adipic acid, caproic acid, lactic acid, succinic acid, tartaric acid, sebacic acid, p-toluenesulfonic acid, salicylic acid, boric acid, tannic acid, Examples thereof include alginic acid, polyacrylic acid, polymethacrylic acid, phenol, pyrogallol, phenol resin, resorcin resin, and the like, but are not limited thereto.

  The above-mentioned latent curing accelerator is the above-mentioned epoxy compound, the above amines, and, if necessary, the above active hydrogen compound mixed, reacted at a temperature of room temperature to 200 ° C., then solidified and pulverized, or It can be easily obtained by reacting in a solvent such as methyl ethyl ketone, dioxane, tetrahydrofuran, etc., removing the solvent and then pulverizing the solid.

  In the epoxy resin composition according to the present invention, the mercaptoalkylglycolurils according to the present invention are used so that the ratio of SH equivalent number / epoxy equivalent number ratio is 0.5 to 1.2. Moreover, the said latent hardening accelerator is normally used in 0.1-10 weight part with respect to 100 weight part of epoxy resins.

  A commercial item can be used for the latent curing accelerator. Examples of such commercially available products include “Amicure PN-23” (trade name of Ajinomoto Co., Inc.), “Amicure PN-H” (trade name of Ajinomoto Co., Inc.), and “Amicure MY-24” (Ajinomoto Co., Inc.). Product name), “Novacure HX-3742” (Asahi Kasei Co., Ltd. product name), “Novacure HX-3721” (Asahi Kasei Co., Ltd. product name), and the like, but are not limited thereto.

The epoxy resin composition according to the present invention can contain various additives such as a filler, a diluent, a solvent, a pigment, a flexibility imparting agent, a coupling agent, and an antioxidant as necessary.
In the epoxy resin composition according to the present invention, when an isocyanate group-containing compound is used as the additive, the adhesive force can be improved without significantly impairing the curability of the epoxy resin composition.

  Such an isocyanate group-containing compound is not particularly limited. For example, n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2 -Ethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylyl Range isocyanate, paraphenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, Bishi Russia triisocyanate, and the like.

  Such an isocyanate group-containing compound is usually used in the range of 0.1 to 20 parts by weight with respect to 100 parts by weight of the epoxy resin.

  According to the present invention, the reaction product of a compound having one or more isocyanate groups in the molecule and a compound having at least one primary and / or secondary amino group in the molecule is also used as a curing accelerator. Can be used.

  Such a curing accelerator is obtained by reacting an isocyanate compound having one or more isocyanate groups in the molecule with a compound having a primary and / or secondary amino group in an organic solvent such as dichloromethane. Can do.

  Examples of the isocyanate compound having one or more isocyanate groups in the molecule include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-bromophenyl isocyanate, m-chlorophenyl isocyanate, and o-chlorophenyl. Isocyanate, p-chlorophenyl isocyanate, 2,5-dichlorophenyl isocyanate, 3,4-dichlorophenyl isocyanate, 2,6-dimethylphenyl isocyanate, o-fluorophenyl isocyanate, p-fluorophenyl isocyanate, m-tolyl isocyanate, p-tolyl isocyanate O-trifluoromethylphenyl isocyanate, m-trifluoromethylphenyl isocyanate, Diisocyanate, hexamethylene diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2-dimethyldiphenylmethane-4,4 '-Diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanate methyl) cyclohexane, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, tris- (3 -Isocyanato-4-methylphenyl) isocyanurate, tris- (6-isocyanatohexyl) isocyanurate, and the like. The present invention is not limited to, et al.

  Examples of the compound having at least one primary and / or secondary amino group in the molecule include dimethylamine, diethylamine, di-n-propylamine, di-n-butylamine, di-n-. Hexylamine, di-n-octylamine, di-n-ethanolamine, dimethylaminopropylamine, diethylaminopropylamine, morpholine, piperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, piperazine Pyrrolidine, benzylamine, N-methylbenzylamine, cyclohexylamine, metaxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, isophoronediamine, N-aminoethylpiperazine, 2-methylimidazole, 2-ethyl-4 -Methylimidazole, 2 Undecyl imidazole, 2-phenylimidazole, there may be mentioned 1,1-dimethylhydrazine and the like, but is not limited thereto.

  In the epoxy resin composition according to the present invention, the mercaptoalkylglycolurils are used so that the SH equivalent number / epoxy equivalent number is 0.5 to 1.2, and one or more isocyanate groups are contained in the molecule. The curing accelerator which is a reaction product obtained by the reaction between the compound having the compound and the compound having at least one primary and / or secondary amino group in the molecule is 1 to 100 parts by weight of the epoxy resin. It is used in the range of 10 parts by weight.

  As described above, the epoxy resin composition according to the present invention is superior in hydrolysis resistance as compared to conventionally known epoxy resin compositions, and further in heat resistance, moisture resistance, and the like. It can be suitably used as an adhesive or a sealant. That is, the adhesive according to the present invention includes the above-described epoxy resin composition, and the sealant according to the present invention includes the above-described epoxy resin composition.

  The adhesive and sealant according to the present invention may further contain an additive. Examples of such additives include flow behavior modifiers such as silicic acid, magnesium silicate, and barium sulfate, thermal conductivity imparting agents such as alumina, conductivity imparting agents such as silver and carbon, and coloring such as pigments and dyes. An agent etc. can be mentioned. These additives can be mixed into the above-described epoxy resin composition using a conventionally known ordinary mixer such as a three-roll or planetary mixer.

  The present invention will be described below with reference to examples, but the present invention is not particularly limited to these examples.

(Synthesis of allyl glycoluril)
In the following, thioacetic acid is manufactured by Tokyo Chemical Industry Co., Ltd., azobisisobutyronitrile is manufactured by Sigma-Aldrich, thionyl chloride and sodium borohydride are manufactured by Wako Pure Chemical Industries, Ltd., 40% aqueous solution of disodium trithiocarbonate. Was manufactured by BOC Science.

Reference example 1
(Synthesis of 1,3,4,6-tetraallylglycoluril)
The compound was synthesized according to the method described in JP-A-11-171887.

  Glycoluril (14.2 g, 100 mmol), sodium hydroxide (16.0 g, 400 mmol) and dimethyl sulfoxide (140 mL) were mixed, heated and stirred at 40 ° C. for 1 hour, and then allyl chloride (34.4 g, 400 mmol) was added at the same temperature for 20 minutes. It was dripped over. After completion of the dropwise addition, the mixture was further heated and stirred at 40 ° C. for 2 hours to complete the reaction.

  The resulting reaction mixture was evaporated to dryness. The obtained dried product was subjected to liquid separation extraction with 400 mL of ethyl acetate and 400 mL of water. The ethyl acetate layer was washed with 100 mL of water and then with 100 mL of saturated brine, and then dried over anhydrous sodium sulfate. Ethyl acetate was distilled off under reduced pressure, and 1,3,4,6-tetraallylglycoluril 27. 4 g were obtained as a colorless oil. Yield 90%.

Reference example 2
(Synthesis of 1,3,4,6-tetraallyl-3a, 6a-dimethylglycoluril)
The compound was synthesized according to the method described in JP-A-11-171887.

  After mixing 17.0 g (100 mmol) of 3a, 6a-dimethylglycoluril, 16.0 g (400 mmol) of sodium hydroxide and 150 mL of dimethyl sulfoxide, the mixture was heated and stirred at 40 ° C. for 1 hour, and then 34.4 g of allyl chloride ( 400 mmol) was added dropwise over 20 minutes. After completion of the dropwise addition, the mixture was further heated and stirred at 40 ° C. for 2 hours to complete the reaction. Thereafter, the same post treatment as in Reference Example 1 was carried out to obtain 26.1 g of 1,3,4,6-tetraallyl-3a, 6a-dimethylglycoluril as crystals. Yield 79%.

Reference example 3
(Synthesis of 1,3-diallylglycoluril)
A 100 mL flask equipped with a thermometer was charged with 3.00 g (50.0 mmol) of urea and 8.71 g (60.0 mmol) of 40% aqueous glyoxal solution. Two drops of 40% aqueous sodium hydroxide solution were added to this mixture at room temperature, and the mixture was stirred at 80 ° C. for 1 hour. Subsequently, the reaction mixture was concentrated under reduced pressure. To the resulting concentrate, 7.00 g (50.0 mmol) of diallylurea, 50 mL of acetic acid and 490 mg (5.0 mmol) of sulfuric acid were added, and stirred at 110 ° C. overnight. Then, after cooling the reaction mixture to room temperature, 50 mL of acetone was added, and the precipitated crystals were separated by filtration and dried to obtain 1,3-diallylglycoluril as a white viscous oil. Yield 39%.

The IR spectrum of the obtained 1,3-diallylglycoluril is shown in FIG. The ¹ H-NMR spectrum (d6-DMSO) δ value was as follows.

7.52 (s, 2H), 5.69-5.84 (m, 2H), 5.08-5.23 (m, 6H), 3.92-3.97 (m, 2H), 3. 52 (dd, 2H)
(Synthesis of mercaptoalkylglycolurils)

Example 1
(Synthesis of 1,3-bis (3-mercaptopropyl) glycoluril)
A 50 mL flask equipped with a thermometer was charged with 560 mg (2.5 mmol) of 1,3-diallylglycoluril, 457 mg (6.0 mmol) of thioacetic acid and 10 mL of tetrahydrofuran, and 25 mg (0.15 mmol) of azobisisobutyronitrile was added thereto. ) Was added, followed by reaction at 60 ° C. for 16 hours with stirring.

  The obtained reaction mixture was cooled and then concentrated under reduced pressure, and 10 mL of methanol was added to the obtained concentrate. After adding 189 mg (5.0 mmol) of sodium borohydride to the obtained mixture at room temperature, the mixture was stirred at 60 ° C. overnight with stirring. After completion of the reaction, the reaction mixture was cooled to 5 ° C., 30 mL of saturated aqueous ammonium chloride solution was added, and the mixture was stirred for 30 minutes.

  Extraction operation was performed with 30 mL of chloroform from the obtained reaction mixture, and the obtained organic layer was washed with 15 mL of water three times. The obtained organic layer was concentrated under reduced pressure to obtain 336 mg of 1,3-bis (3-mercaptopropyl) glycoluril as a brown oil. Yield 46%.

The IR spectrum of the obtained 1,3-bis (3-mercaptopropyl) glycoluril is shown in FIG. Further, the δ value in the ¹ H-NMR spectrum (d6-DMSO) was as follows.

  7.52 (br, 2H), 5.27 (s, 2H), 3.22-3.35 (m, 4H), 2.65-2.89 (m, 4H), 1.72-1. 90 (m, 4H)

Example 2
(Synthesis of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril)
A 100 mL flask equipped with a thermometer was charged with 3.03 g (10.0 mmol) of 1,3,4,6-tetraallylglycoluril, 3.65 g (48.0 mmol) of thioacetic acid and 20 mL of tetrahydrofuran, and azobisiso After adding butyronitrile 66 mg (0.4 mmol), the reaction was carried out at 60 ° C. for 18 hours with stirring.

  The obtained reaction mixture was cooled and then concentrated under reduced pressure, and 20 mL of methanol was added to the obtained concentrate. To the obtained mixture, 1.51 g (40.0 mmol) of sodium borohydride was added at room temperature, and then stirred at 60 ° C. overnight with stirring.

  After completion of the reaction, the reaction mixture was cooled to 5 ° C., 30 mL of saturated aqueous ammonium chloride solution was added, and the mixture was stirred for 30 minutes. After performing extraction operation with 30 mL of chloroform from the obtained reaction mixture, the organic layer was washed 3 times with 15 mL of water. The obtained organic layer was concentrated under reduced pressure to obtain 3.12 g of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril as a pale yellow oil. Yield 65%.

The IR spectrum of the obtained 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril is shown in FIG. Further, the δ value in the ¹ H-NMR spectrum (d6-DMSO) was as follows.

  5.32 (s, 2H), 3.43-3.50 (m, 4H), 3.12-3.20 (m, 4H), 2.43-2.51 (m, 8H), 1. 69-1.86 (m, 8H)

Example 3
(Synthesis of 1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril)
A 100 mL flask equipped with a thermometer was charged with 1,3,4,6-tetraallyl-3a, 6a-dimethylglycoluril 3.30 g (10.0 mmol), 3.65 g (48.0 mmol) thioacetic acid and 20 mL of tetrahydrofuran, After adding 66 mg (0.4 mmol) of azobisisobutyronitrile to this, reaction was performed at 60 ° C. for 18 hours while stirring.

  The obtained reaction mixture was cooled and then concentrated under reduced pressure, and 20 mL of methanol was added to the obtained concentrate. To the obtained mixture, 1.51 g (40.0 mmol) of sodium borohydride was added at room temperature, and then stirred at 60 ° C. overnight with stirring. After completion of the reaction, the reaction mixture was cooled to 5 ° C., and 30 mL of a saturated aqueous ammonium chloride solution was added, followed by stirring for 30 minutes. Extraction operation was performed with 30 mL of chloroform from the obtained reaction mixture. The obtained organic layer was washed with 15 mL of water three times, and the obtained organic layer was concentrated under reduced pressure to obtain 1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril. 2.17 g was obtained as a pale yellow oil. Yield 46%.

FIG. 4 shows the IR spectrum of the obtained 1,3,4,6-tetrakis (3-mercaptopropyl) -3a, 6a-dimethylglycoluril. Further, the δ value in the ¹ H-NMR spectrum (d6-DMSO) was as follows.

  3.31-3.42 (m, 8H), 2.47-2.59 (m, 8H), 1.82-1.89 (m, 8H), 1.53 (t, 4H), 1. 47 (s, 6H)

Example 4
(Synthesis of 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril)
To a 50 mL flask equipped with a thermometer, 3.18 g (10.0 mmol) of 1,3,4,6-tetrakis (2-hydroxyethyl) glycoluril and 4.76 g (40.0 mmol) of thionyl chloride were added and stirred. The reaction was carried out at 70 ° C. for 5 hours.

  The obtained reaction mixture was concentrated under reduced pressure, and 20 mL of water was added to the obtained concentrate. To the obtained mixture, 15.4 g (40.0 mmol) of 40% aqueous solution of disodium trithiocarbonate was added dropwise at room temperature, followed by stirring at 100 ° C. for 6 hours while stirring. After completion of the reaction, the resulting reaction mixture was cooled to 5 ° C., 50 mL of chloroform was added thereto, and the mixture was stirred for 30 minutes. The aqueous layer was removed from this mixture, and the resulting organic layer was concentrated under reduced pressure to give 3.26 g of 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril as a yellow oil. Yield 85%.

FIG. 5 shows an IR spectrum of the obtained 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril. The δ value in the ¹ H-NMR spectrum (CDCl ₃ ) was as follows.

  5.55 (s, 2H), 3.71-3.78 (m, 4H), 3.31-3.39 (m, 4H), 2.83-2.92 (m, 4H), 2. 67-2.76 (m, 4H), 1.46 (t, 4H)

(Preparation of epoxy resin composition)
In the following, 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril obtained in Example 2 and an epoxy resin (“jER828” manufactured by Mitsubishi Chemical Corporation) and obtained in Example 4 above. 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril obtained as a curing agent, and a solid dispersion type amine adduct-based latent curing accelerator (manufactured by Ajinomoto Fine Techno Co., Ltd.) as a curing accelerator “Amicure PN-23”) was blended to prepare an epoxy resin composition.

  For comparison, as a curing agent, the following formula (1)

1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (made by Showa Denko KK) "Karenz MT NR1", hereinafter referred to as thiol compound (1)) and the following formula (2)

The same as above except that trimethylolpropane tris (3-mercaptopropionate) represented by the formula ("TMMP" manufactured by SC Organic Chemical Co., Ltd., hereinafter referred to as thiol compound (2)) was used as a curing agent. Thus, an epoxy resin composition was prepared.

Example 5
An epoxy resin composition was prepared by mixing 100 parts by weight of an epoxy resin with 64 parts by weight of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril and 3 parts by weight of a latent curing accelerator.

Example 6
An epoxy resin composition was prepared by mixing 56 parts by weight of 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril and 3 parts by weight of a latent curing accelerator with 100 parts by weight of the epoxy resin.

Comparative Example 1
In Example 5, the epoxy resin composition was similarly used except that 107 parts by weight of the thiol compound (1) was used instead of 64 parts by weight of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril. A product was prepared.

Comparative Example 2
In Example 5, an epoxy resin composition was similarly obtained except that 75 parts by weight of the thiol compound (2) was used instead of 64 parts by weight of 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril. A product was prepared.

(Measurement of glass transition temperature of cured product of epoxy resin composition)
The glass transition temperature (Tg) of the cured product of the epoxy resin composition obtained in Examples 5 and 6 and Comparative Examples 1 and 2 was a differential scanning calorimeter (“EXSTAR 6000” manufactured by SII NanoTechnology Inc.). It measured using. That is, the epoxy resin composition was cured by heating from 30 ° C. to 270 ° C. at a rate of temperature increase of 10 ° C./min, and then the cured product thus obtained was cooled at a rate of −50 ° C./min. Was cooled from 270 ° C. to 10 ° C., and then heated from 10 ° C. to 100 ° C. at a rate of temperature increase of 10 ° C./min, and the glass transition temperature of the cured product was measured. The results are shown in Table 1.

  An epoxy resin composition comprising 1,3,4,6-tetrakis (3-mercaptopropyl) glycoluril and 1,3,4,6-tetrakis (2-mercaptoethyl) glycoluril according to the present invention as curing agents, respectively. It is shown that the cured product has a high glass transition temperature and excellent heat resistance as compared with the cured product of the epoxy resin composition containing the thiol compound (1) and the thiol compound (2) as curing agents.

  The mercaptoalkylglycolurils according to the present invention are useful as intermediates for synthesizing novel sulfur-containing compounds, and particularly those having two or more mercaptoalkyl groups in the molecule are useful as curing agents for epoxy resins. .

Further, as described above, the epoxy resin composition containing the mercaptoalkyl glycoluril according to the present invention as a curing agent can be suitably used for applications such as adhesion, sealing, sealing, casting, molding, painting, and coating. .

Claims (6)

Formula (II)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, a mercaptomethyl group or 2-mercaptoethyl group. A mercaptoalkyl group selected from a group and a 3-mercaptopropyl group, wherein the molecule has two or more of the mercaptoalkyl groups, and n is 0, 1 or 2.)
The hardening | curing agent for epoxy resins containing the mercaptoalkylglycoluril represented by these . Formula (II)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, a lower alkyl group or a phenyl group; ^Three , R ^Four And R ^Five Are each independently a hydrogen atom or a partial general formula in the above general formula (II)

And the same mercaptoalkyl group, and having two or more mercaptoalkyl groups in the molecule, n is 0, 1 or 2. )
The hardening | curing agent for epoxy resins containing the mercaptoalkylglycoluril represented by these. Formula (II)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, a mercaptomethyl group or 2-mercaptoethyl group. A mercaptoalkyl group selected from a group and a 3-mercaptopropyl group, wherein the molecule has two or more of the mercaptoalkyl groups, and n is 0, 1 or 2.)
The adhesive agent containing the epoxy resin composition containing the mercaptoalkylglycoluril represented by these . Formula (II)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, a lower alkyl group or a phenyl group; ^Three , R ^Four And R ^Five Are each independently a hydrogen atom or a partial general formula in the above general formula (II)

And the same mercaptoalkyl group, and having two or more mercaptoalkyl groups in the molecule, n is 0, 1 or 2. )
The adhesive agent containing the epoxy resin composition containing the mercaptoalkylglycoluril represented by these. Formula (II)

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a lower alkyl group or a phenyl group, and R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, a mercaptomethyl group or 2-mercaptoethyl group. A mercaptoalkyl group selected from a group and a 3-mercaptopropyl group, wherein the molecule has two or more of the mercaptoalkyl groups, and n is 0, 1 or 2.)
The sealing agent containing the epoxy resin composition containing the mercaptoalkylglycoluril represented by these . Formula (II)

(Wherein R ¹ And R ² Each independently represents a hydrogen atom, a lower alkyl group or a phenyl group; ^Three , R ^Four And R ^Five Are each independently a hydrogen atom or a partial general formula in the above general formula (II)

And the same mercaptoalkyl group, and having two or more mercaptoalkyl groups in the molecule, n is 0, 1 or 2. )
The sealing agent containing the epoxy resin composition containing the mercaptoalkylglycoluril represented by these.

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