JPH11323093A - One-pack room temperature-curable epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition with excellent storage stability and curability by including an epoxy resin, an oxazolidine compound and hydrolyzable ester compound(s) in specified proportions. SOLUTION: This composition comprises (A) an epoxy resin having two or more epoxy groups on average in one molecule, (B) an oxazolidine compound [e.g. 2-isopropyl-3-(2-hydroxyethyl)oxazolidine] and (C) at least one hydrolyzable ester compound selected from titanic esters and orthoformic esters; wherein the amounts of the components B and C are 1-50 pts.wt. and 1-25 pts.wt. based on 100 pts.wt. of the component A, and it is preferable that this composition contains (D) 0.01-10 pts.wt. of an organobismuth carboxylate compound and (E) 1-25 pts.wt. of a carbodiimide compound as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a one-part room temperature-curable epoxy resin composition having excellent storage stability and a short curing time.

[0002]

2. Description of the Related Art A general epoxy resin composition is of a two-pack type which usually undergoes a curing reaction by being mixed with a curing agent, a curing accelerator and the like at the time of use. However, mixing at the time of use is complicated, and weighing and mixing errors are likely to occur. Therefore, there is a great demand for a one-part curing type epoxy resin composition.
One-part curable epoxy resin compositions using latent curing agents such as dicyandiamide and imidazoles are known, but they require heating to cure them. Ketimine is known as a room temperature moisture-curable latent curing agent that does not require heating, but has a problem that storage stability is low and the curing reaction takes time. On the other hand, an oxazolidine compound is known as a curing agent having relatively excellent storage stability and curability (JP-A-5-117252). However, the curing rate of the epoxy resin composition with the oxazolidine compound only by moisture is insufficient for practical use. An acid is sometimes used to increase the ring-opening rate of oxazolidine, and the curing rate is improved by the acid, but there is a problem that storage stability is impaired.

[0003]

The conventional one-part curing type epoxy resin composition requires heating, and the room temperature curing type composition has problems in curability and stability. Accordingly, an object of the present invention is to provide a one-part room temperature-curable epoxy resin composition having excellent storage stability and curability.

[0004]

That is, the present invention provides:
(1) (a) an epoxy resin having an average of two or more epoxy groups in one molecule, (b) an oxazolidine compound, and (c) at least one hydrolyzable ester selected from titanates and orthoformates (A) 100 parts by weight, (b) is 1
To 50 parts by weight, (c) 1 to 25 parts by weight of the epoxy resin composition, and (2) the composition according to (1), further comprising (d) an organic bismuth carboxylate compound,
(A) The epoxy resin composition according to (1), which is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight, and further (3)
The composition according to (1) or (2), further comprising (e) a carbodiimide compound with respect to (a) 100 parts by weight.
The epoxy resin composition according to (1) or (2), which contains 1 to 25 parts by weight, is provided.

Hereinafter, the present invention will be described in detail. The epoxy resin (a) used in the present invention is an uncured epoxy prepolymer having an average of two or more epoxy groups in one molecule. Here, the average value of epoxy groups in one molecule refers to a value obtained by dividing the total molecular weight of the epoxy resin by the total epoxy equivalent. Specifically, epoxy resins using amines as precursors include various isomers of tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, and triglycidylaminocresol. Examples of the epoxy resin having a phenol as a precursor include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, and resorcinol type epoxy resin. Can be Among them, preferably, bisphenol A type epoxy resin is used.

The oxazolidine compound (b) used in the present invention is a compound having a saturated 5-membered heterocyclic ring containing oxygen and nitrogen and having an oxazolidine ring which opens in the presence of moisture (water). . Specific examples include N-hydroxyalkyl oxazolidine and its polyisocyanate adduct, oxazolidine silyl ether, carbonate oxazolidine, ester oxazolidine and the like.

[0007] N-hydroxyalkyloxazolidine can be prepared, for example, by a dehydration condensation reaction between an alkanolamine and a ketone or aldehyde. N
-Hydroxyalkyloxazolidine includes 2-isopropyl-3- (2-hydroxyethyl) oxazolidine (hereinafter referred to as hydroxyalkyloxazolidine (1)), 2- (1-methylbutyl) -3- (2-hydroxyethyl) oxazolidine (Hereinafter referred to as hydroxyalkyloxazolidine (2)), 2-phenyl-3-
(2-hydroxyethyl) oxazolidine (hereinafter referred to as hydroxyalkyloxazolidine (3)), 2-
(P-methoxyphenyl) -3- (2-hydroxyethyl) oxazolidine (hereinafter referred to as hydroxyalkyloxazolidine (4)), 2- (2-methylbutyl)-
3- (2-hydroxyethyl) -5-methyloxazolidine (hereinafter referred to as hydroxyalkyloxazolidine (5)
And the like).

[0008]

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The oxazolidine silyl ether is obtained by mixing the above-mentioned N-hydroxyalkyl oxazolidine with trimethoxysilane, tetramethoxysilane, triethoxysilane, dimethoxydimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltriyl. It is obtained by a reaction with an alkoxysilane such as methoxysilane and γ-glycidoxypropyltriethoxysilane. This reaction is carried out using titanium alkoxide, aluminum alkoxide or divalent Sn as a catalyst.
C. to 160.degree. C., particularly preferably 80.degree.

Specific examples of oxazolidine silyl ether are shown below.

Embedded image

Carbonate oxazolidine is, for example,
And carbonate oxazolidine obtained by the method of JP-A-5-117252. The carbonate oxazolidine is obtained, for example, by reacting a hydroxyalkyl oxazolidine such as the above-described hydroxyalkyl oxazolidine (1) with a carbonate such as diallyl carbonate, dimethyl carbonate or dipropylene carbonate using a polyhydric alcohol such as diethylene glycol or glycerin. be able to. This reaction is carried out in the presence of a transesterification catalyst such as sodium methylate at 60 to 160 ° C, preferably 100 to 14 ° C.
It is performed at a temperature in the range of 0 ° C. The amount of the catalyst to be added is preferably 50 to 1000 ppm based on the total amount of the hydroxyalkyl oxazolidine, carbonate and polyhydric alcohol.

The carbonate oxazolidine thus prepared is represented by the following formula (A).

Embedded image (In the formula, n is an integer of 1 to 10, R ^a and R ^b are each independently an organic group having 1 to 8 carbon atoms. R ^c and R ^c
d is each independently a hydrogen atom or an organic group having 1 to 8 carbon atoms. One specific example of the compound represented by the formula (a) is the following carbonate oxazolidine (1).

[0013]

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As the ester oxazolidine, for example, various ester oxazolidines such as ester oxazolidine obtained by the methods of US Pat. No. 3,661,923 and US Pat. No. 4,138,545 can be used. ) And a lower alkyl ether of a dicarboxylic acid or a polycarboxylic acid. Specific examples include the following ester oxazolidine (1). Further, a commercially available product such as a hardener OZ manufactured by Bayer and represented by the following ester oxazolidine (2) can also be used.

[0015]

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An oxazolidine compound having three or more oxazolidine rings in one molecule may be used. This compound is obtained by reacting an N-hydroxyalkyl oxazolidine represented by the following (B) with a polyisocyanate compound. It is synthesized as a compound having three or more oxazolidine rings in one molecule.

[0017]

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Here, R ¹ is a divalent aliphatic hydrocarbon group having a straight or branched chain having 2 to 3 carbon atoms, such as an alkylene group, an alkenylene group or an alkynylene group. R ² and R ³ each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. The N-hydroxyalkyl oxazolidine represented by the above formula (B) is synthesized from the corresponding aldehyde or ketone and N-hydroxyalkylamine by a known method.

As the aldehyde, formaldehyde,
Acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, 2
Aliphatic aldehydes such as -methylbutyraldehyde, 3-methylbutyraldehyde, hexylaldehyde, 2-methylpentylaldehyde, octylaldehyde, 3,5,5-trimethylhexylaldehyde; benzaldehyde, methylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, isopropyl Aromatic aldehydes such as benzaldehyde, isobutylbenzaldehyde, methoxybenzaldehyde, dimethoxybenzaldehyde, and trimethoxybenzaldehyde; are preferred. As the ketone, acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, diethyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl-t-butyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone and the like are preferable.

As the N-hydroxyalkylamine,
Bis-N- (2-hydroxyethyl) amine, bis-N
-(2-hydroxypropyl) amine and N- (2-
(Hydroxyethyl) -N- (2-hydroxypropyl)
Amines are preferred.

The above aldehyde or ketone is reacted with the hydroxyalkylamine in an equimolar amount of nitrogen corresponding to the number of moles of the aldehyde or ketone. Is preferably used. Particularly preferably, 1.01 to 1.1
Range. The reason for this is that unreacted N-hydroxyalkylamine is difficult to separate from the product and reacts with isocyanate, which causes a decrease in storage stability.

The reaction is preferably carried out in a solvent such as toluene or xylene under reflux conditions. The reaction time is
It is desirable to set it as 6 to 24 hours, and it is especially preferable to set it as 8 to 12 hours. The reason for setting the reaction time in this range is that the reaction is incomplete when the reaction time is less than 6 hours, and the reaction mixture is colored when the reaction time is more than 24 hours. Also,
The reaction is preferably performed in a normal atmosphere. After completion of the reaction, excess aldehyde or ketone is distilled off under reduced pressure to obtain N-hydroxyalkyloxazolidin represented by the above formula (B).

The polyisocyanate compound is a polyisocyanate having an organic group, for example, a polyhydric alcohol such as glycerin, hexanetriol, trimethylolpropane or polypropylene glycol, paraphenylene diisocyanate, tolylene diisocyanate, tetramethylene. Reaction products of diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, octadecyl diisocyanate, naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate and modified products thereof, or tetramethylene diisocyanate, hexamethylene diisocyanate (HDI) Diisocyanate compound is trimerized in the presence of a catalyst to give isocyanurate It can be obtained by forming. In the reaction with the N-hydroxyalkyloxazolidine of the formula (B), these polyisocyanate compounds can be used alone,
More than one species may be used in combination.

The N-hydroxyalkyloxazolidine represented by the formula (B) is reacted with a polyisocyanate compound at a reaction temperature of about 50 ° C. to 100 ° C. under normal pressure to form three or more oxazolidine rings in one molecule. Is synthesized. During the synthesis, a solvent such as toluene or xylene may be used for the purpose of lowering the viscosity.

The molar ratio of N-hydroxyalkyl oxazolidine to polyisocyanate compound is preferably 1 mol of the polyisocyanate compound per 1 mol of the hydroxyl group of N-hydroxyalkyl oxazolidine.

Specific examples of such a compound having three or more oxazolidine rings in one molecule include polyfunctional oxazolidine compounds (1) and (2) represented by the following formula.

[0027]

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Further, as another example of the isocyanate oxazolidine compound, a compound represented by the following formula (C) can be shown.

[0029]

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Here, R ¹ is an alkylene group having 2 to 6 carbon atoms, preferably 2 to 3 carbon atoms, more preferably 2 carbon atoms. R ² and R ³ are each independently a hydrogen atom, an alkyl group having 1 or more carbon atoms, an alicyclic alkyl group having 5 to 7 carbon atoms, or an aryl group having 6 to 10 carbon atoms. R ⁴ is an alkylene group having 2 to 6 carbon atoms, an aryl group,
Alternatively, it is an alkylene group having 2 to 6 carbon atoms including a urethane bond or an aryl group including a urethane bond, and is preferably an alkyl group or an aryl group having 1 to 5 carbon atoms having a urethane bond.

R ⁵ is a group obtained by removing an isocyanate group from n polyisocyanates, and may be any as long as it forms a skeleton of an isocyanate compound. It is preferable that the compound be a skeleton of a diisocyanate or triisocyanate compound. n is 1 to
It is an integer of 4 and preferably 2 or 3. In particular, when n is 2 or 3, a cured product having a good balance between tensile strength and tensile elongation can be obtained. If it exceeds 3, it becomes hard and brittle, and if it is less than 2, curing becomes insufficient.

Specific examples of the isocyanate oxazolidine compound include:

Embedded image TDI base, MDI base, XDI base, H
Polyfunctional oxazolidine such as DI base, etc.,
Commercial products such as Hardener OZ manufactured by Bayern can be used.

Another preferred example of the isocyanate oxazolidine compound is represented by the following formula (D):

Embedded image (Wherein, R ¹ is an aliphatic hydrocarbon group having 5 or more carbon atoms, R ² is a residue obtained by removing an isocyanate group from an organic polyisocyanate, m is an integer of 1 to 6, n is 0 Oxazolidine compound represented by the formula:

In the above formula, R ¹ is an aliphatic hydrocarbon group having 5 or more carbon atoms, preferably 5 to 15 carbon atoms, such as n-pentyl, 2-methylpentyl,
Methylpentyl, 3,5,5-trimethylpentyl, n
-Heptyl, n-octyl, n-nonyl, n-decanyl, n-undecanyl, n-dodecanyl, n-tridecanyl, n-tetradecanyl and the like. Especially, the case of 5-10 carbon atoms is preferable. And R
^When the substituent at position ¹ is an aliphatic hydrocarbon, both of the substituents are too fast to hydrolyze, resulting in poor storage stability. Also, R
^{When 1} is an aromatic group, hydrolysis is slow and curability is poor. Further, when the number of carbon atoms is 4 or less, hydrolysis is relatively fast and storage stability is poor. Conventionally, as oxazolidine compounds, compounds in which R ¹ is an alkyl group having 1 to 6 carbon atoms and the like are disclosed, but the effect as a latent curing agent is specifically determined by a difference in carbon number within this range. No technology recognizes the differences.

R ² is a residue obtained by removing an isocyanate group from an organic polyisocyanate, and may be any of aliphatic, alicyclic and aromatic. For example, aromatic groups such as tolylene, diphenylmethane, phenylene, and polymethylene polyphenylene; aliphatic groups such as hexamethylene; alicyclic hydrocarbon groups such as isophorone; aromatic aliphatic groups such as xylene; And modified groups of isocyanurate and the like, and these are used alone or in combination of two or more.

M is an integer of 1 to 6, particularly preferably 2 to 3 in terms of curability and physical properties of the cured product. Also, n
Is preferably an integer of 0 to 4, particularly preferably 0 to 2 in terms of curability.

The method for producing the isocyanatooxazolidine compound represented by the formula (c) comprises the steps of a. N-hydroxyethyl oxazolidine represented by the following formula (E) is synthesized from diethanolamine and the corresponding aldehyde,

Embedded image (In the formula, R ¹ is an aliphatic hydrocarbon having 5 or more carbon atoms.)

B. It can be synthesized by reacting the obtained N-hydroxyethyloxazolidine represented by the formula (E) with an organic polyisocyanate. If N-hydroxyethyloxazolidine is available in advance,
The desired isocyanate oxazolidine compound can be obtained only by the above step b. a. Is carried out at a reaction temperature of 70 to 150 ° C., with benzene, toluene,
The reaction is performed in the presence of an organic solvent such as xylene. After completion of the reaction, the reaction mixture is refluxed for 5 to 10 hours in an oil bath. B. The reaction of mixing N-hydroxyethyl oxazolidine and organic polyisocyanate,
The reaction is performed at 90 ° C. for 5 to 10 hours. Further, if necessary, the temperature may be changed during the reaction.

Examples of the aldehyde used include n-hexanal, 2-methylpentanal, 2-methylheptanal, n-octanal, 3,5,5-trimethylhexanal, n-decanal, n-undecanal and n-undecanal.
-Dodecanal, n-tridecanal, n-tetradecanal, n-pentadecanal and the like, and these aldehydes are commercially available.

As the organic polyisocyanate used for synthesizing the isocyanate oxazolidine compound, any of aliphatic, alicyclic and aromatic can be used. For example, aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, and polymethylene polyphenylene polyisocyanate Aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate; aromatic aliphatic polyisocyanates such as xylene diisocyanate; and carbodiimide-modified or isocyanurate-modified polyisocyanates. Used as one kind or a combination of two or more kinds.

The isocyanate oxazolidine compound obtained as described above has properties such as being able to adjust various physical properties.

Other preferred examples of the component (b) are oxazolidinyl silyl ethers, for example, (i) obtained by reacting a hydroxyl group-containing oxazolidine with an alkoxysilane, or (ii) oxazolidine having a hydroxyl group. It can be synthesized by a reaction with a silyl halide compound or the like. The reaction (i) is carried out at 40 to 160 ° C. using titanium alkoxide, aluminum alkoxide or a divalent tin compound (Sn ²⁺ ) as a catalyst.
It is particularly preferably carried out at 80 to 140 ° C. The catalyst may be used as it is, or may be used after being dissolved in a solution of an organic solvent such as xylene. The use amount of such a catalyst is 0.01 to 100 parts by weight of oxazolidine.
It is preferably 5 parts by weight, particularly preferably 0.1 to 2 parts by weight, in view of the reaction time and the purity of the product.

The oxazolidine silyl ether is preferably a compound represented by the following formula (F).

Embedded image In the formula, n is an integer of 0 to 3.

R represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxyalkyl group, an alicyclic group, an alkoxy group, an acryloxyalkyl group, an aminoalkyl group or a mercaptoalkyl group; a vinyl group, phenyl Groups, amino groups and the like, for example, methyl group, ethyl group, vinyl group, methacryloxypropyl group, epoxycyclohexyl group, glycidoxypropyl group, aminoethyl group, aminopropyl group, phenyl group, amino group, An example is a mercaptopropyl group. When n is 2 or more, the R groups may be each independently another group or the same group.

R ² is preferably an alkyl group having 2 or 3 carbon atoms, particularly, an ethyl group or an isopropyl group. R
³ is preferably a hydrogen atom or a methyl group.
R ⁴ and R ⁵ each independently represent a hydrogen atom or a carbon atom
20 hydrocarbon groups. Furthermore, the number of carbon atoms is 3-12.
Is preferably at, specifically, an isopropyl group, an isopentyl group, a phenyl group, for example, an alkoxyphenyl group such as a methoxyphenyl group, among them R ^4,
One of R ⁵ is a hydrogen atom, which indicates storage stability;
It is preferable in terms of curability.

Specific examples include oxazolidine silyl ether compounds (1) to (7) represented by the following formulas.

[0047]

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The oxazolidine compound preferably used as the component (b) of the present invention is a compound represented by the following formula (8).

Embedded image

Here, R ⁶ is a linear or branched aliphatic hydrocarbon group having 1 or more carbon atoms, such as an alkyl group, an alkenyl group or an alkylene group. Also, R
⁷ and R ⁸ each independently represent a hydrogen atom or a carbon atom
And 20 hydrocarbon groups. Preferred examples of these are shown below.

[0050]

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The amount of the oxazolidine compound (b) added to the composition of the present invention is 1 to 50 parts by weight, preferably 5 parts by weight or more, based on 100 parts by weight of the epoxy resin (a). It is preferably at least 10 parts by weight.
The oxazolidine compound opens a ring in the presence of moisture (water) to generate an imino group and a hydroxyl group, and reacts with an epoxy group to catalyze a curing reaction. Further, the addition of an acid promotes the ring opening reaction.

The epoxy resin composition of the present invention comprises (c)
At least one hydrolyzable ester compound selected from titanates and orthoformates is used.

The titanate is a compound represented by the following general formula (12). Ti (OR) ₄
(12) R in the formula (12) represents an alkyl group or an aryl group.

The orthoformate is represented by the following general formula (13)
It is a compound represented by these.

Embedded image Here, R ⁹ , R ¹⁰ and R ¹¹ represent an alkyl group or an aryl group. Examples of the orthoformate include methyl orthoformate and ethyl orthoformate.

The amount of the (c) hydrolyzable ester compound to be added to the composition of the present invention is 1 to 25 parts by weight, preferably 2 to 100 parts by weight of the epoxy resin (a).
To 20 parts by weight, particularly preferably 5 to 15 parts by weight.

The hydrolyzable ester compound supplies an acid by being hydrolyzed, whereby it can act as a catalyst for the ring-opening reaction of the oxazolidine ring. By adding a hydrolyzable ester compound to the composition of the present invention, an acid can be supplied at the time of curing, and curing of the composition can be promoted without impairing storage stability.

The organic bismuth carboxylate compound (d) used in the present invention is represented by the following general formula (14).

Embedded image Here, R ¹² , R ¹³ and R ¹⁴ are exemplified by a hydrogen atom, an alkyl group having one carbon atom, an alkoxyalkyl group, an alicyclic group, an alkoxy group, an acryloxyalkyl group and the like.

The amount of the organic bismuth carboxylate compound (d) added to the composition of the present invention is 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin (a).
It is preferably 0.1 to 5 parts by weight, particularly preferably 1 to 5 parts by weight.

The organic bismuth carboxylate compound has an effect similar to an amine-based curing agent on an epoxy resin, and acts as a ring-opening accelerator on an oxazolidine compound. Therefore, the curing reaction can be effectively promoted by using the organic bismuth carboxylate compound as the composition component of the present invention.

The carbodiimide compound (e) used in the present invention is a compound represented by the following general formula (15).

Embedded image

Here, R ¹⁵ and R ¹⁶ are each independently substituted by an alkyl group having 1 to 20 carbon atoms, an aryl group optionally substituted by an alkyl group, an alicyclic alkyl group, or an alkyl group. An alicyclic alkyl group or an alkylene group containing a heterocyclic ring. The alkylene group containing a heterocycle contains a nitrogen atom and an oxygen atom in the heterocycle, and the alkylene group preferably has 1 to 2 carbon atoms. It is preferably a cyclohexyl group, a toluyl group, a morpholinoalkyl group or the like, and more preferably a cyclohexyl group, a p-toluyl group, a morpholinoethyl group, 2,4- or 2,6.
-A diisopropylphenyl group.

The carbodiimide compounds used in such a reaction include N, N'-dicyclohexylcarbodiimide (DDC), 1-cyclohexyl-3- (2-morpholinoethyl) carbodiimide, and N, N'-p-toluoylcarbodiimide. , N, N'-2,6-diisopropylphenylcarbodiimide (stabacol I),
Starbuck Bar PCD and the like.

The amount of the carbodiimide compound (e) used in the composition of the present invention is 1 to 25 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the epoxy resin (a).
0 parts by weight, particularly preferably 1 to 5 parts by weight.

The carbodiimide compound captures water and a free acid and contributes to storage stability in the present composition. The carbodiimide compound is highly reactive, and particularly promotes the formation of an amide bond between an amino acid derivative or a peptide derivative, dehydration condensation between a phosphoric acid monoester or diester, and dehydration condensation between a carboxylic acid and a hydroxy compound under mild conditions.

The composition of the present invention comprises (a) an epoxy resin,
(B) an oxazolidine compound, and (c) a hydrolyzable ester compound, and may further contain (d) an organic bismuth carboxylate compound, or (e) a carbodiimide compound, (D) and (e) may be simultaneously contained.

The composition of the present invention may contain, in addition to the above compounds, a filler, an antioxidant, a pigment, a solvent and the like within a range not to impair the curing of the present invention. Fillers include carbon black, calcium carbonate, titanium oxide,
Examples include silica and aluminum hydroxide. Examples of the anti-aging agent include hindered amines and hindered phenols. Examples of the pigment include carbon black and zinc oxide. Examples of the solvent include methanol, ethanol, propanol, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and the like.

The epoxy resin composition of the present invention comprises (a) an epoxy resin, (b) an oxazolidine compound, and
It is produced by mixing (c) a hydrolyzable ester compound and, if necessary, (d) an organic bismuth carboxylate compound, (e) a carbodiimide compound, and other necessary additives in a conventional manner, and puts it in a sealed container. Will be saved. Preferably, the epoxy resin is heated and dehydrated under reduced pressure, and then the other components are kneaded under reduced pressure or under an atmosphere of N ₂ substitution. When used, it is cured by moisture in the air.

[0068]

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

(Examples 1 to 6 and Examples 1 and 2) (1) Epoxy resin Raw material components were mixed at the ratios shown in Table 1 below to produce various epoxy resin compositions.

(2) Evaluation The following evaluation was performed for each of the epoxy resin compositions produced in (1), and the results are shown in Table 1 below. (I) Tack free time (TFT) Tack free time is calculated by dividing each of the obtained compositions by 100
mm × 100mm × 5mm thick sheet shape,
The time (hour) until the molded product did not adhere to the finger even when the molded product was pressed with a finger was measured. (Ii) Viscosity The initial viscosity was measured using a B-type viscometer. Also, at 20 ° C
The viscosity for 4 weeks was measured using a B-type viscometer after storing at 20 ° C for 4 weeks.

[0071]

[Table 1]

Note) In the table, the amounts of the respective components represent parts by weight. The composition components in the table are as follows. Epicoat 828 Bisphenol type epoxy resin (epoxy equivalent: 184-194) manufactured by Yuka Shell Chemical Co., Ltd. FLEP 60 Polysulfide-modified epoxy resin manufactured by Toray Thiokol Co., Ltd. Oxazoline I Compound represented by the above formula (9) Oxazoline II manufactured by ANGUS , MS-PLUS The chemical structural formula is represented by the above formula (10). Orthoformate ester Permaflow OF titanate ester manufactured by Nippo Chemical Co., Ltd. TPT-100 organic bismuth carboxylate compound manufactured by Nippon Soda Co., Ltd. COSCAT # 83 carbodiimide manufactured by Nitto Kasei Co., Ltd. Starbacol I manufactured by Bayer Corporation Ketimine H-3 manufactured by Yuka Shell Epoxy Co., Ltd.

[0073]

The one-part room temperature-curable epoxy resin composition of the present invention has excellent curability and storage stability.

Claims (3)

[Claims] 1. An epoxy resin having (a) an average of two or more epoxy groups in one molecule, (b) an oxazolidine compound, and (c) at least one hydrolysis selected from titanates and orthoformates. Containing a reactive ester compound, based on 100 parts by weight of (a)
An epoxy resin composition wherein (b) is 1 to 50 parts by weight and (c) is 1 to 25 parts by weight. 2. The composition according to claim 1, further comprising (d)
An organic bismuth carboxylate compound was prepared by (a) 100
The epoxy resin composition according to claim 1, which is contained in an amount of 0.01 to 10 parts by weight based on part by weight. 3. The composition according to claim 1 or 2,
Further, (e) a carbodiimide compound is converted to (a) 100
The epoxy resin composition according to claim 1, which is contained in an amount of 1 to 25 parts by weight based on parts by weight.