JPH1060095A - Curing composition for epoxy resin - Google Patents

Abstract

(57) [Problem] To provide a curing agent composition for an epoxy resin which can satisfy storage stability, curability and adhesiveness only with a curing agent. SOLUTION: The curing agent composition for an epoxy resin of the present invention comprises (A) a ketimine compound of a polyoxyalkylene polyamine represented by the following general formula (I):
9% by weight and (B) 40 to 1% by weight of a ketimine compound of an aliphatic amine represented by the following general formula (II). Embedded image Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curing agent composition for an epoxy resin in which a ketimine compound having a polyether structure is used in combination with another ketimine compound as a curing agent for an epoxy resin, and more particularly to a curing agent for an epoxy resin. The present invention relates to a curing agent composition for an epoxy resin which is excellent in storage stability and curability such as tack-free time by using a ketimine compound having a polyether structure as a main component and a ketimine compound which is a derivative of an aliphatic polyamine as a main component.

[0002]

BACKGROUND OF THE INVENTION An epoxy resin composition comprising an epoxy resin and a curing agent has many excellent properties such as adhesion to various substrates, heat resistance, chemical resistance, electrical properties, and mechanical properties. It has been awarded in a wide range of industrial fields, especially in the fields of paints, adhesives, and surface modifiers.

[0003] As the epoxy resin composition comprising the epoxy resin and the curing agent, a two-part curing type in which two kinds of liquids of the epoxy resin and the curing agent are mixed on site at the time of use is usually used. This is to prevent a trouble that, if mixed from the beginning, causes phenomena such as an increase in viscosity and hardening during storage, making it unusable. However, the two-part curing type, which requires on-site mixing, is inferior in workability. Therefore, a one-part curing type epoxy resin composition is desired.

[0004] As a method for improving the storage stability of a one-part curable epoxy resin composition, the compound itself does not act as a curing agent, but reacts with moisture in the atmosphere at the time of use to produce a primary amine compound. As an excellent curing agent,
Ketimine-based curing agents are disclosed in JP-A-61-12723,
JP-A-3-195724 and JP-A-4-122
No. 0 proposes this.

However, the ketimine compounds proposed so far have insufficient storage stability in the case of a type obtained by reacting an alkylamine with a ketone. Japanese Patent Application Laid-Open No. 5-132541 proposes a ketimine compound of a type obtained by reacting a polyoxyalkyleneamine and a ketone as a curing agent having excellent storage stability, but the curing time is too long to be practical. Was.

[0006] Japanese Patent Application Laid-Open No. Hei 7-188634 discloses an excellent resin composition containing a modified silicone resin as a main component, a catalyst for a modified silicone resin, an epoxy resin, a ketimine-based curing agent and a tack improver. It has been proposed to provide a one-part curable epoxy resin-based adhesive agent that has both improved storage stability and adhesiveness. As described above, it is difficult to prepare a one-part curable epoxy resin composition excellent in storability and curability only with a curing agent by a known method, and it is necessary to combine it with another curable resin or the like, Such a method has a problem in that the intrinsic physical properties of the epoxy resin are impaired.

Accordingly, an object of the present invention is to provide a curing agent composition for an epoxy resin which can satisfy storage stability, curability and adhesiveness only with a curing agent.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a ketimine compound having a polyether structure and a ketimine compound derived from an alkylamine are used together in a specific weight ratio, It has been found that the above object can be achieved.

The present invention has been made based on the above-mentioned findings, and (A) a ketimine compound of a polyoxyalkylene polyamine represented by the following general formula (I) of the following [formula 3] (same as the above [formula 1]): 60-99% by weight and (B)
An object of the present invention is to provide a curing agent composition for an epoxy resin, comprising 40 to 1% by weight of a ketimine compound of an aliphatic amine represented by the general formula (II) (same as the above [Chemical formula 2]).

[0010]

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[0011]

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[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A ketimine compound of a polyoxyalkylene polyamine represented by the above general formula (I) which is the component (A) used in the present invention, and a general formula (II) which is the above component (B) In the ketimine compound of an aliphatic amine represented by the formula, as the alkyl group having 1 to 6 carbon atoms represented by R ^{1 to} R ⁶ , methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl ,
Second pentyl, tertiary pentyl, hexyl, second hexyl, tertiary hexyl and the like.

When A in the general formula (I) represents a polyoxyalkylenediamine residue, A is represented by the following general formula (III).

[0014]

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When A in the general formula (I) represents a residue of a polyoxyalkylene triamine, A is represented by the following general formula (IV).

[0016]

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Further, X ¹ , X in the above general formula (II)
² and R ⁷ in the above general formulas (III) and (IV),
As the alkylene group represented by R ⁹ , ethylene, 1,2
-Propylene, 1,3-propylene, 1,4-butylene, hexamethylene, linear or branched alkylene groups such as 2,4,4-trimethylhexamethylene,
Examples of the cycloalkylene group include a cyclohexylene group and a cyclohexylene group substituted with an alkyl group, which may be the same or different within a single part depending on m and n.

R ⁸ in the general formula (IV) is an oxygen atom such as an aliphatic trihydroxy compound such as glycerin or trimethylolpropane, triethanolamine, pentaerythritol monofatty acid ester or pentaerythritol monomethyl ether; Examples include a residue of an aliphatic trihydroxy compound having a sulfur atom, a nitrogen atom, an ester bond and the like.

The curing agent composition for an epoxy resin of the present invention comprises:
Ketimine compounds 60 to 99 represented by the above general formula (I)
% By weight and the ketimine compound 4 represented by the general formula (II)
A mixture of a ketimine compound having a composition of 0 to 1% by weight. If the compound represented by the general formula (I) is less than the lower limit of the above range, storage stability is poor, and if it is more than the upper limit of the above range, The curing time is too long to be practical.

In the ketimine compound represented by the general formula (II), when m is 1 or more, the imino group contained in the ketimine compound is styrene oxide, butyl glycidyl ether, allyl glycidyl ether,
-T-butylphenyl glycidyl ether, p-sec
-Butylphenyl glycidyl ether, m, p-cresyl glycidyl ether, p-cresyl glycidyl ether, vinylcyclohexenedioxide, glycidyl versatate, cardanol-modified glycidyl ether, glycidyl dimer, 1,6-hexanediol glycidyl ether , Resorcinol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether,
It has been reacted with at least one of 1,4-butanediol glycidyl ether and neopentyl glycol diglycidyl ether. This modification of the imino group is required to improve the storage stability.

The epoxy resin to which the curing agent composition of the present invention is applied may be any commonly used compound having an average of more than one epoxy group in the molecule, and its structure is not particularly limited. However, an epoxy resin having more than one glycidyl ether group, glycidyl ester group, glycidyl amino group or other glycidyl group in the molecule is particularly preferable.

The epoxy resin having a glycidyl ether group is obtained by subjecting a phenolic or alcoholic hydroxyl group to glycidyl ether by a well-known method. Examples thereof include resorcinol, hydroquinone, pyrocatechol, phloroglucinol, dihydroxynaphthalene, Biphenol, methylenebisphenol (bisphenol F), methylenebis (orthocresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis (orthocresol), tetrabromobisphenol A, bis (hydroxyphenyl) phenylmethane, bis (hydroxy Phenyl) cyclohexylmethane, cyclohexylidenebisphenol, thiobisphenol, sulfobisphenol (biphenyl) Phenol S), oxy bisphenol, 1,3-bis (4-hydroxycumyl) benzene, 1,4-bis (4-hydroxycumyl) benzene,
Phenol-polyglycidyl ethers of mononuclear or polynuclear polyphenols such as formaldehyde condensates and ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, Bisphenol A
-Glycidyl ethers of polyhydric alcohols such as ethylene oxide adducts.

Examples of the epoxy resin having a glycidyl ester group include maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, and the like.
Adipic acid, azelaic acid, sebacic acid, dimer acid,
Trimer acid, phthalic acid, isophthalic acid, terephthalic acid,
Glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endmethylenetetrahydrophthalic acid and homopolymers of glycidyl methacrylate Or a copolymer.

Examples of the epoxy resin having a glycidylamino group include N, N-diglycidylaniline and bis (4- (N-methyl-N-glycidylamino) phenyl) methane.

In addition, the curing agent composition of the present invention comprises epoxidized natural oils such as epoxidized soybean oil, epoxidized linseed oil, epoxidized safflower oil, epoxidized tall oil, vinylcyclohexene diepoxide, dicyclopentadienediene. Epoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, bis (3,4- Epoxy compounds of cyclic olefin compounds such as (epoxy-6-methylcyclohexylmethyl) adipate, epoxidized conjugated diene polymers such as epoxidized polybutadiene, epoxidized styrene-butadiene copolymer, and heterocyclic compounds such as triglycidyl isocyanurate. It can be effectively used.

These epoxy resins can be used alone or as a mixture of two or more kinds, and a solvent, a monoepoxy compound or the like can be added as needed.

The mixing ratio of the curing agent composition of the present invention to the above epoxy resin is preferably 1 / 0.6 to 1 / 1.4, preferably 1 / 0.6 to 1 / 1.4, in terms of the ratio of the epoxy equivalent to the active hydrogen equivalent of the curing agent composition. /0.8 to 1 / 1.1 is more preferred. When the amount of the curing agent composition of the present invention is small, the mechanical strength of the obtained cured product may be small, and when the amount of the curing agent composition of the present invention is too large, the curing speed is increased, but it is economically disadvantageous. Therefore, it is preferable to be within the above range.

The curing agent composition for an epoxy resin of the present invention comprises:
In addition to the above epoxy resin, if necessary, a commonly used curing agent, modified silicone resin and catalyst for modified silicone resin, reactive diluent, non-reactive diluent, filler, reinforcing agent, pigment, dye, solvent A curable composition can be formed by using common additives such as a plasticizer, a leveling agent, a thixotropic agent, a flame retardant, a release agent, and a dehydrating agent.

The curable composition is applied to a substrate by an appropriate method, for example, a method such as brushing, roller, spray, spatula, press coating, doctor blade coating, electrodeposition coating, and dip coating. It is used as an undercoat or intermediate coating, filler, sealing material, protective coating, coating material, sealing material, mortar, coating material and the like.

[0030]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by the following examples.

[Example 1] Epoxy resin (EP-410)
0) 100 parts by weight of a ketimine compound [ketimine (I),
(II)] (described in [Table 1] below) was added so that the epoxy equivalent / active hydrogen = 1/1 to obtain an evaluation sample. The sample was sealed in a glass bottle after purging with nitrogen, and the change in viscosity after 7 days and 28 days at 50 ° C. was observed. The storage stability was evaluated as ○ when no change was observed, Δ when the viscosity was increased, and × when the gel was obtained. did. Also, apply the sample to a slate plate at a thickness of 0.5 mm, gently rub the center of the coated surface with a fingertip after 1 day, 2 days, and 3 days at 20 ° C. and 50% humidity, and rub the coated surface. Tack-free was evaluated as ○ when no trace was observed, Δ when abrasion was observed, and X when sticky on the fingertip. Furthermore, the adhesiveness after 7 days and 28 days was measured under the same conditions as the tack-free condition using a single-axis type adhesive strength tester, and the state of the adhesive interface at that time was observed. When the substrate was peeled off at the interface, it was rated X, when the substrate was broken, and when the substrate was partially peeled and the substrate was broken.
The results are shown in Table 1 below.

[0032]

[Table 1]

* 1 to * 6 in the above Table 1 mean the following, respectively. * 1: Condensate of polyoxypropylene diamine (molecular weight 400) and methyl isobutyl ketone * 2: Condensate of polyoxypropylene triamine (molecular weight 400) and methyl isobutyl ketone * 3: Polyoxyethylene / propylene (1/1) ) Condensate of diamine (molecular weight 400) and methyl isobutyl ketone * 4: Condensate of polyoxyethylene diamine (molecular weight 208) and methyl isobutyl ketone * 5: Condensate of hexamethylene diamine and methyl isobutyl ketone * 6: Diethylene triamine Butyl glycidyl ether was added dropwise to the condensate of
What was obtained by reacting at ~ 90 ° C for 2 hours

As is clear from the above Examples and Comparative Examples, the ketimine compound represented by the general formula (I) alone has excellent storage stability, but has poor curability and lacks tack-free time, and has sufficient adhesion. It is not practical because it requires a long time until it is obtained (Comparative Example 1). The ketimine compound represented by the general formula (II) alone has excellent curability, but has poor storage stability and is unsuitable for obtaining a one-part curable epoxy resin composition (Comparative Example 3). When a mixture of the ketimine compounds represented by the general formula (I) and the general formula (II) is used, the mixture of the ketimine compounds within the above-mentioned weight ratio according to the present invention has the preservability and curability. (Examples 1 to 5). On the other hand, if the amount of the ketimine compound represented by the general formula (II) increases beyond the range of the weight ratio according to the present invention, it becomes impractical in storage stability (Comparative Examples 2 and 4).

[0035]

The curing agent composition for an epoxy resin of the present invention is a composition having a specific weight ratio of a ketimine compound having a polyether structure and a ketimine compound of an aliphatic amine type, and has storage stability, curing time, It has excellent adhesion and is provided as a curing agent composition for a one-part curable epoxy resin.

Claims (1)

[Claims] (A) 60 to 99% by weight of a ketimine compound of a polyoxyalkylene polyamine represented by the following general formula (I) represented by the following general formula (I) and (B) a general formula (I)
Ketimine compounds of aliphatic amines represented by I) 40-1
% By weight of a curing agent composition for an epoxy resin. Embedded image Embedded image