JPH0446968B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a one-component epoxy resin composition.
More specifically, the present invention relates to an epoxy resin composition that uses an alicyclic epoxy resin, has a low-temperature fast curing agent, can yield a better cured product, and has excellent stability at room temperature. [Prior art and problems to be solved by the invention] Among epoxy resins, alicyclic epoxy resins such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate have good weather resistance. known as. Furthermore, since it does not contain any chlorine impurity, which is often a problem with bisphenol-type glycidyl ether epoxy resins, it is ideal for sealing electronic components that dislike impurity ions. One-component epoxy resins are more desirable than conventional two-component ones because of their ability to prevent mixing errors, to be continuous, and to enable production lines, and various types of epoxy resins have been used. One-component epoxy resins have been proposed. However, a one-component epoxy resin using the above-mentioned alicyclic epoxy resin is not yet known. [Means for solving the problem] The present inventors have previously developed (a) a polyfunctional epoxy compound,
(b) OH group, SH group, COOH group and
CONHNH A compound that has at least one of the _two functional groups and a tertiary amino group;
Among organic compounds having more than one active hydrogen, (a)
It was proposed that an addition compound obtained by reacting and (b) or (a), (b), and (c) would be a latent curing agent with excellent low-temperature, rapid curing properties and storage stability ( As a result of further investigation, by combining the above-mentioned addition compound and a polybasic acid hydrazide compound, it has become possible to form alicyclic epoxy resin into a single component, which has been impossible until now. It was discovered that a cured product with excellent curability at low temperatures and good transparency could be obtained, and the present invention was completed. That is, the present invention provides (1) alicyclic epoxy resin (2) polybasic acid hydrazide compound (3) (a) polyfunctional epoxy compound, (b) OH in the molecule.
(c) organic compounds having two _or more active hydrogens in the molecule; a) and (b) or (a) and (b) and (c)
It relates to a one-component epoxy resin composition containing an epoxy tree-based latent curing agent consisting of an addition compound obtained by reacting with the present invention. As the alicyclic epoxy resin that can be used in the present invention, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (“FRL-
4221''), bis(3,4-epoxycyclohexylmethyl)adipate (Union Carbide, USA, ``ERL-4229''), 2-(3,4-epoxycyclohexyl-5,5-spiro3,4-epoxy)cyclohexane Examples include -meta-dioxane ("ERL-4224" manufactured by Union Carbide, USA), diisodecyl epoxy hexahydrophthalate ("Recaresin E-10" manufactured by Shin Nippon Chemical Co., Ltd.), and the like.
It is also possible to use these alicyclic epoxy resins in combination with other epoxy resins such as bisphenol A diglycidyl ether. Examples of the polybasic acid hydrazide compound used in the present invention include succinic acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, dodecanoic acid dihydrazide, eicosanoic acid dihydrazide, sebacic acid dihydrazide, etc., and the blending amount is 100% by weight of the above epoxy resin. 5 for the department
~50 parts by weight is preferred. The latent curing agent for epoxy resin used in the present invention can be prepared by the method described in JP-A-60-4524. That is, (a) a polyfunctional epoxy compound, (b) OH group, SH group, COOH group and
CONHNH A compound that has at least one of the _two functional groups and a tertiary amino group;
Among organic compounds having more than one active hydrogen, (a)
It can be obtained by reacting (b) or (a), (b), and (c). The polyfunctional epoxy compound (a) used as a raw material for this latent curing agent may be any compound having two or more epoxy groups in one molecule. Polyglycidyl ethers obtained by reacting epichlorohydrin with compounds generally well known in this field, such as polyhydric phenols such as bisphenol A, bisphenol F, catechol, and resorcinol, or polyhydric alcohols such as glycerin and polyethylene glycol. ,
Glycidyl ether esters obtained by reacting hydroxycarboxylic acids such as p-oxybenzoic acid and β-oxynaphthoic acid with epichlorohydrin; polyglycidyl esters obtained from polycarboxylic acids such as phthalic acid and terephthalic acid; 4.
Examples include glycidylamine compounds obtained from 4'-diaminodiphenylmethane and m-aminophenol, as well as epoxidized novolacs and epoxidized polyolefins. (b) used to react with these polyfunctional epoxy compounds
OH group, SH group, COOH group and
The general formula of a compound having both a functional group of at least one of the _two CONHNH groups and a tertiary amino group is as follows. In the formula, X is an OH group, a SH group, a COOH group, and
CONHNH ₂ groups, R ₁ and R ₂ are alkyl groups with 1 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, aralkyl groups such as benzyl groups, and some of the above groups are other than carbon. , such as oxygen, halogen, or a functional group such as the one represented by X above, and R ₃ is the same as R ₁ ,
It is a divalent residue of the same group as R ₂ . Also R ₁ and R ₂
Alternatively, R ₁ , R ₂ , and R ₃ may be bonded to each other to form a ring, for example, the heterocycle contains a tertiary amino group as shown in the following general formulas () and (). Compounds are also effective. In the formula, R ₄ , R ₅ , R ₆ , a hydrogen atom, each group similar to R ₁ and R ₂ shown in the above general formula (), or a functional group represented by X, and R ₇ are R ₁ , R ₂ and It is similar,
At least one of R ₄ , R ₅ , R ₆ and R ₇ contains a functional group represented by X. In the formula, R ₈ is a functional group represented by X, or
A group similar to R ₁ and R ₂ that contains a functional group represented by OH group, SH group, COOH group and
Specific examples of compounds having both a functional group of at least one of the _two CONHNH groups and a tertiary amino group include the following. Namely, 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2
-diethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 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-
Hydroxyethylmorpholine, 2-dimethylaminoethanethiol, methimazole, 2-mercaptopyridine, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptopyridine, 4-mercaptopyridine, N,
N-dimethylaminobenzoic acid, N,N-dimethylglycine, Nα,Nα-dimethyl-N-ε-lauroyl lysine, nicotinic acid, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide,
Examples include N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide, and the like. Furthermore, active hydrogen in the organic compound having two or more active hydrogens in the molecule, which is component (c), refers to hydrogen atoms bonded to oxygen, nitrogen, sulfur, etc. other than carbon, and -OH, =NH , −NH ₂ , −SH, −
Examples include hydrogen atoms contained in functional groups such as COOH and _-CONHNH2 . Examples of organic compounds having two or more active hydrogens in the molecule are as follows. That is, bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, polyhydric phenols of phenol novolak resin, polyhydric alcohols such as trimethylolpropane, piperazine,
Amine compounds such as aniline and cyclohexylamine, adipic acid, phthalic acid, 3,9-bis(2-
polybasic carboxylic acids such as (carboxyethyl)-2,4,8,10-tetrooxaspiro[5,5]undecane, polyvalent thiols such as 1,2-dimercaptoethane and 2-mercaptoethyl ether, and phenyl acetic acid. Hydrazide compounds such as hydrazide, amino acids such as alanine and valine, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-
It is a compound having two or more functional groups such as propanol, mercaptoacetic acid, N-methylethanolamine, diethanolamine, hydroxyaniline, N-methyl-o-aminobenzoic acid, anthranilic acid, sarcosine, hydroxybenzoic acid, and lactic acid. When producing addition compounds that are latent hardeners.
When composed of components (a) and (b), the reaction ratio of both components (a) and (b) is determined by the reaction rate between the tertiary amino group and the active hydrogen-containing functional group (OH) in the molecule of component (b). group, SH group,
0.8 to 2.5, preferably 0.9 epoxy groups of the polyfunctional epoxy compound which is component (a) per equivalent of active hydrogen of the compound having (COOH group, CONHNH ₂ groups)
~1.5 equivalents, and if the epoxy group is less than 0.8 equivalents per equivalent of active hydrogen, the softening temperature of the addition compound will be low and pulverization will be difficult, and if it is blended into the epoxy resin as a latent curing agent, Sufficient storage stability cannot be obtained. In addition, the epoxy group is 2,
If the amount exceeds 5 equivalents, part of the addition compound becomes three-dimensional and becomes an infusible solid, and when this compound is blended into an epoxy resin as a latent curing agent, it does not exhibit fast curing properties and hardens. It has the disadvantage that things become uneven. Furthermore, when producing a latent curing agent using the three components (a), (b), and (c), it is preferable to use the component (c) in an amount equal to or less than the mole of the component (b). If the amount of component (c) exceeds an equimolar amount, there is a drawback that curability decreases. Furthermore, the reaction ratio of the three components (a), (b), and (c) is 0.8 to 2.5 times the equivalent number of epoxy groups in component (a) to the sum of the number of active hydrogen equivalents in both components (b) and (c). , especially 0.9 to 1.5 times equivalent (a),
(b) It is preferable for the same reason as the two-component system. The preferred addition compound as the latent curing agent used in the present invention is one that satisfies the above-mentioned equivalence relationship between active hydrogen and epoxy group and has a softening temperature of about 60 to 180°C. If the softening temperature is less than 60°C, the storage stability at room temperature will be poor, and if it exceeds 180°C, the curing property will be poor. The latent curing agent used in the present invention can be obtained by mixing two or more compounds for each of the components (a), (b), and (c), as long as the above-mentioned equivalence relationship between active hydrogen and epoxy group is satisfied. Furthermore, by changing the type and mixing ratio of each component compound, an addition compound having an arbitrary softening temperature can be obtained. These latent curing agents are (a), (b) or (a), (b),
(c) Components are thoroughly mixed, gelled at room temperature, and then the reaction is completed at a temperature of 80 to 150°C, cooled, solidified, and pulverized, or tetrahydrofuran,
It can be easily obtained by carrying out an addition reaction in a solvent such as dioxane or methyl ethyl ketone, removing the solvent, and then pulverizing the solid. The amount of the latent curing agent to be added is preferably 0.5 to 40 parts by weight per 100 parts by weight of the epoxy resin. Further, other curing agents and fillers may be added to the one-component epoxy resin composition of the present invention, if necessary. [Example] Next, the usefulness of the present invention will be specifically explained using Examples. In addition, as the latent curing agent (3), curing agents A and B were synthesized as follows. Synthesis Example 1 Synthesis of Curing Agent A 200ml3 equipped with reflux condenser and stirring device
10.6 g of 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole in a neck flask.
(0.05 equivalent), bisphenol A5.7g (0.05 equivalent),
Add 50 ml of methyl ethyl ketone as a solvent, and dropwise add 19 g (0.1 equivalent) of "Epicote 828" dissolved in 30 ml of methyl ethyl ketone while heating and stirring (30 minutes). After the addition was completed, the mixture was heated under reflux for 2 hours while stirring. The solvent methyl ethyl ketone was distilled off under reduced pressure, and upon cooling, a pale yellow solid adduct was obtained. This solid was pulverized to obtain hardening agent A. Synthesis example 2 Synthesis of curing agent B 33.4g (0.176 equivalent) of "Epicote 828" and 2,
Weigh out 26.5 g (0.1 equivalent) of 4,6-tris(dimethylaminomethyl)phenol into a beaker,
Mix well at room temperature and gradually raise the temperature while stirring. The reaction progresses rapidly at around 70℃ and lasts about 1 hour.
Keep at 100℃. After the reaction was completed, the mixture was cooled to obtain a pale yellow solid. This was crushed to obtain a curing agent B. Examples In order to demonstrate the usefulness of the present invention, formulations were prepared at the blending ratios shown in Table 1, and their curability and storage stability were evaluated. 1 Evaluation of curability (1-1) Curing initiation temperature and peak temperature were measured by differential thermal analysis. Sample: Approximately 10 mg Reference material α-alumina Heating rate: 5°C/min (1-2) The sample was placed in a gear oven at a constant temperature and its hardening state was observed. 2. Storage Stability A sample was placed in a constant temperature bath at a predetermined temperature (40°C), and the number of days until fluidity disappeared was measured. 3 Glass transition temperature (Tg) Using a thermomechanical analyzer (TMA, manufactured by Rigaku Denki Co., Ltd.), the sample was cured for a specified period of time.
Tg was measured by TMA penetration method. Temperature increase rate: 10°C/Amount: 10g Needle diameter: 1mm The results obtained are shown in Table 2. The results of the comparative examples in Table 2 show that (1) alicyclic epoxy resin and (2) hydrazide compound alone did not cure at temperatures below 150°C, and (2) liquid acid anhydride was used instead of hydrazide compound. It was found that the storage stability was poor in some cases, and the effects of the present invention are clear.

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Claims (1)

[Scope of Claims] 1 (1) Alicyclic epoxy resin (2) Polybasic acid hydrazide compound (3) (a) polyfunctional epoxy compound, (b) in the molecule
Compounds having at least one functional group among OH group, SH group, COOH group, and CONHNH2 group and a tertiary amino group, and (c) organic compounds having two or more active hydrogens in the molecule, ( A one-component epoxy resin composition containing a latent curing agent for epoxy resin, which is an addition compound obtained by reacting a) and (b) or (a), (b), and (c).