JPH01254731A - One-component therosetting epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide the title composition of excellent storage stability, rapidly curable at low temperatures, capable of giving cured products of high adhesivity and heat resistance, comprising an epoxy resin and a specific curing agent compound containing urea. CONSTITUTION:The objective composition comprising (A) an epoxy resin having in the molecule more than one epoxy group on average and (B) a curing agent compound formed by reaction, under heating, between (i) an N,N- dialkylaminoalkylamine of the formula (R is 1-4C alkyl; n is 2 or 3), (ii) a dimaine having two primary amine groups, and (iii) urea. Preferably, the component (i) is e.g., N,N-dimethylaminopropylamine, and the component (ii) is e.g., m-xylylenediamine.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application Evoquin compounds having an oxirane ring in the molecule can be combined with various curing agents, and by mixing with these, they can be cured either at room temperature or by heating.

Since the cured product has excellent adhesion to many substances, it has been used in many fields such as adhesives, paints, injection, impregnation, casting, and botting. The purpose of the present invention is to provide an epoxy resin composition that is easy to handle and has excellent curability, and more specifically, it provides an epoxy resin composition that is easy to handle and has excellent curability. The present invention provides a one-component heat-curable epoxy resin composition that can be cured in a short period of time.

BACKGROUND ART AND PROBLEMS Conventionally, most epoxy resin compositions are two-part type in which an epoxy resin and a curing agent or curing accelerator are added and mixed immediately before use. Although two-part epoxy resin compositions can be cured at room temperature or low temperatures, they must be precisely measured and mixed immediately before use. If the originally determined amounts of epoxy resin and curing agent are measured incorrectly, or if the subsequent mixing is not done sufficiently even if the measurements are accurate, the purpose of the cured product may be exceeded. This results in a problem of insufficient performance. Furthermore, conventional two-component epoxy resin compositions have a short pot life, which makes them difficult to apply to automatic machines.

In order to solve these drawbacks, it has been desired to develop a one-component curable composition. - The thermosetting epoxy resin composition requires a curing agent, a so-called latent curing agent, which does not react with the epoxy compound at room temperature, but has the property of starting a reaction and curing when heated. Several latent curing agent compounds have been proposed so far, and representative examples include dicyandiamide, dibasic acid dihydrazide, trifluoroporroamine complex salts, guanamines, melamine, and imidazole compounds. It will be done. However, although mixtures of dicyandiamide, melamine, and guanamine with epoxy compounds have excellent storage stability, they have the disadvantage of requiring long-term curing conditions at high temperatures of 150° C. or higher. In addition, it is widely used to shorten the curing time by using a curing accelerator in combination with these, but although the curing time is shortened by adding a curing accelerator, the disadvantage is that storage stability is significantly impaired. . On the other hand, dibasic acid dihydrazides and imidazoles cure at relatively low temperatures but have poor storage stability. Boron trifluoride amine complex salts have the advantage of excellent storage stability and short curing time, but each has its own disadvantages, such as being corrosive to metals. In view of the current situation, the present invention was developed as a result of research and development of an epoxy resin composition that has excellent storage stability and can be cured at low temperatures and in a short time.

In other words, the present invention is a method for solving the problem of one problem, that is, an epoxy resin having an average of more than one Evoquine group in the molecule, and N represented by the formula (1),
N-dialkylaminoalkylamine, (herein, R is an alkyl group having a carbon number of I to 4, and n represents a number of 2 or 3) prepared by heat-reacting an amine that has 2 pI of amino groups and urea. This article relates to a one-component thermosetting epoxy resin composition containing a curing agent compound as an essential component, which has excellent storage stability and can be rapidly cured at a relatively low temperature (for example, 120°C). The present invention relates to a one-component heat-curable Evoquin resin composition.

Epoxy resins used in the present invention include, but are not particularly limited to, bisphenol Δ, bisphenol F1 bisphenol S1 hexahydrohisphenol A
1 Tetramethylbisphenol A1 Catechol, resorcin, cresol novolac, tetrabromobisphenol A1 Trihydroxybiphenyl, benzophenone, bisresorcinol, bisphenol hexafluoroacetone, hydroquinone, tetramethylbisphenol A1 Tetramethylbisphenol F, triphenylmethane, tetraphenylethane , glynodyl ether obtained by reacting polyhydric phenol such as bixylenol with epichlorohydrin, or glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol/l/, hexylene glycol, polyethylene glycol, polypropylene Polyglycidyl ether obtained by reacting an aliphatic polyhydric alcohol such as glycol with epichlorohydrin, or a glycidyl ether ester obtained by reacting epichlorohydrin with a hydroxycarboxylic acid such as P-oxybenzoic acid or β-oxynaphthoic acid. Or phthalic acid, methyl phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid,
Endomethylenetetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, trimellitic acid, polyglycidyl esters obtained from polycarboxylic acids such as polymerized fatty acids, or glycylaminoglycidyl ethers obtained from aminophenols, aminoalkylphenols, or amino Glycinolaminoglycidyl ester obtained from benzoic acid, or aniline, toluidine, tribromoaniline, xylylene diamine, diaminocyclohexane, bisaminomethylcyclohexane, 4.4°-diaminodiphenylmethane, 4.4゛-
Glycidylamine obtained from diaminodiphenylsulfone, etc., as well as evoquinated polyolefin, glycidylhydantoin, glycidyl alkylhydantoin,
Examples include monoepoxy compounds represented by triglycidyl cyanurate, butyl glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, benzoic acid glycidyl ester, styrene oxide, etc., and one or more of these can be mixed. It's fine if you did it.

A curing agent compound pi, which is another essential component of the present invention,
It can be obtained by heating and reacting N,N-dialkylaminoalkylamine, an amine having two -class amino groups, and urea.

The N,N-dialkylaminoalkylamines used here are those represented by formula (1), and include dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminopropylamine, and diethylaminopropylamine. Examples include ethylamine, dipropylaminoethylamine, and dibutylaminoethylamine. Among these, dimethylaminopropylamine and diethylaminopropylamine are particularly preferred.

In addition, examples of amines having two -grade amino groups include metaxylylene diamine, l,3-bisamizumedelcyclohexane, isophorone diamine, diaminocyclohexane, phenylene diamine, tolylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, and hexamethylene. Examples include diamine, ethylene diamine, propylene diamine, diaminobutane, 1,12-dodecane diamine, and the like. Among these, the preferable range of the ratio of metaxylylene diamine and amine having two 1,3-bisaminomethylcyclohexane is as follows:
, 0.5 to 2 moles of the amine partially having 2 pI of amino groups per mole of N-dialkylaminoalkylamine. If the amount used is less than 0.5 mol, the melting point of the product will be low, resulting in poor storage stability. Moreover, if the amount is 2 moles or more, the melting point of the product will be high, resulting in poor low-temperature rapid curing properties. The ratio of urea to N,N-dialkylaminoalkylamine and amine having two -grade amino groups is as follows: 0.5 mol.

For synthesis, a dialkylaminoalkylamine, an amine having two -grade amino groups, and urea are placed in a reaction vessel, an inert gas of nitrogen is introduced, and the temperature is increased from 180 to 250 while stirring.
It is maintained at a temperature of 1 to 6 hours. Preferably 20
It is 2 to 5 hours at 0 to 250°C. The resulting product is a non-hygroscopic, stable solid that can be ground to any particle size.

The present invention can basically be obtained by mixing and dispersing a powdered curing agent compound in an epoxy compound. When the epoxy compound is liquid, it is preferable to mix the epoxy compound with the curing agent compound in a predetermined ratio and then further thoroughly mix and disperse using a mortar-like device. A finely ground product is used, and the amount varies depending on the type of epoxy compound, particularly the concentration of epoxy groups contained in the epoxy compound, and is in the range of 1 to 40 parts per 100 parts of the epoxy compound.

The one-component heat-curable Evoquin resin composition of the present invention includes:
For example, it is also possible to use in combination with various curing agent compounds conventionally known as latent curing agents, such as acid anhydrides, dicyandiamide, melamine, guanamine, dibasic acid hydrazides, imidazoles, and guanamines. Further, other additives may be added to the one-component heat-curable epoxy resin composition according to the present invention, if necessary. Examples of such additives include alumina, silica, silica powder, talc, bentonite, calcium carbonate, inorganic material powder such as cement, asbestos, glass traverse, synthetic fibers, mica, metal powder, etc. Examples include thixotropy imparting materials and the like.

Further, other diluents, flame retardants, etc. may be added to the composition of the present invention, if necessary.

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited to the scope of these examples.

Hardening agent compound production example 1 Dimethylaminopropylamine 102
．． 0 g (1,0 mol), 1,3-bisaminomethylcyclohexane 217.5. g (1,5 mol) and urea 1
20.0 g (2.0 mol) is blended. The mixture was gradually heated to 240°C while stirring under a nitrogen stream.
This temperature was maintained for 3 hours. The obtained reaction product was a colorless and transparent solid with an amine value of 143 and was easily pulverized.

The curing agent compound obtained here is designated as A.

Production Example 2 102.0 g (1.0 mol) of dimethylaminopropylamine, 127.5 g (0.75 mol) of isophoronediamine and 75.0 g (0.75 mol) of urea were prepared in the same manner as in Production Example 1.
The reaction product obtained by reacting 1.25 mol) at 230° C. for 3 hours was a colorless and transparent solid with an amine value of 213 and was easily pulverized.

The curing agent compound obtained here is designated as B.

Production Example 3 Dimethylaminopropylamine 102. og (1,0 mol), isophorone diamine 85.0 g (0,5 mol), metaxylylene diamine 6
8.0 g (0.5 mol) and 90.0 g (1.5 mol) of urea were reacted at 220° C. for 3 hours. The obtained reaction product was a colorless and transparent solid with an amine value of 183 and was easily crushed. The curing agent compound obtained here is designated as C.

Production Example 4 Dimethylaminopropylamine 102. og (1,0 mol), isophoronediamine 85.0 g (0,5 mol), 1,3-bisaminomethylcyclohexane 71.0 g (0,5 mol) and urea 9
0.0 g (1.5 mol) was reacted at 220° C. for 3 hours. The obtained reaction product was a colorless and transparent solid with an amine value of 187 and was easily pulverized. The curing agent compound obtained here is designated as D.

Production Example 5 2.0 g (1.0 mol) of dimethylaminopropylamine IO and 142.0 g (1.0 mol) of 1,3-bisaminomethylcyclohexane were prepared in the same manner as in Production Example I.
and 90.0 g (1.5 mol) of urea were reacted at 210° C. for 3 hours. The obtained reaction product was a colorless and transparent solid with an amine value of 180 and was easily crushed. The curing agent compound obtained here is designated as E.

Production Example 6 Dimethylaminopropylamine I0 2.0g (1.0 mol), 1.3=bisaminomethylcyclohexane 177.5g (1.25 mol) by the same method as Production Example 1
and 105.0 g (1.75 mol) of urea were reacted at 210° C. for 3 hours. The resulting reaction product has an amine value of 16
It was a colorless, transparent, and easily pulverized solid. The curing agent compound obtained here is designated as F.

Example 1-16 Curing agent compound A- obtained in Curing agent compound production examples 1 to 6
F was added and dispersed in Araldite GY-260 (manufactured by Kuchimoto Jiba Geigy Co., Ltd.), which is a liquid epoxy resin with an epoxy equivalent of 190 synthesized from bisphenol A and epichlorohydrin, and these compositions were tested for the properties shown below.

1. Evaluation of Curability 1.1 Curing start temperature (Ts) and peak temperature (Tp) were measured using a differential scanning calorimeter (DSC). (The sample was approximately 10 mg, α-alumina was used as a reference material, the heating rate was 5°C/lll1r1, the unit was °C) 1.2 1
Approximately 0.1 to 0.2 g of the sample was placed on an iron plate at 20° C., and the time (min) until stringiness disappeared was measured.

2. Storage stability A sample was placed in a constant temperature bath at 45°C, and the number of days until fluidity disappeared was measured.

3 Glass Transition Temperature The glass transition temperature (Tg) of a sample cured at a predetermined temperature and time was measured using DSC. (The sample is approximately 10m
α-alumina is used as the g% reference material, heating rate is 5℃
/min, units are °C) After adhesion was carried out using the lap area, pressure was applied with a clip, and the adhesive was cured under predetermined conditions, the tensile shear adhesive strength was measured at room temperature of 21 to 23°C. (Unit: Kg/am') The test results for the above characteristics are shown in the table.

Example 17 Epicote 1002 (product of Yuka Soel Eboxy Co., Ltd.) 1, a solid epoxy resin with an epoxy equivalent of 750 synthesized from bisphenol A and epichlorohydrin
00g was finely ground in a mortar. 5g of ground hardening agent compound A was added thereto and mixed well. This powder was placed on a 150x50xl (11M each) aluminum plate using a space coater with a 200μ shoulder. This material was placed in a hot air constant temperature bath at 120°C.
When left for a while, a hard and tough film was formed on the surface of the aluminum plate.

Example 18 100 g of the same pulverized epoxy tree Ill as in Example 17 and 5 g of pulverized curing agent compound B were thoroughly mixed in a mortar. When this material was similarly applied onto an aluminum plate and left in a hot air constant temperature bath at 120° C. for 1 hour, a hard and tough film was formed on the surface of the aluminum plate.

Example 19 100 g of the same pulverized Evokin resin as in Example 17 and 5 g of pulverized curing agent compound C were thoroughly mixed in a mortar. When this product was left in a hot air constant temperature bath at 120° C. for 1 hour, a hard and tough film was formed on the surface of the aluminum plate.

Comparative Example 1 2E-4Li Z -CN(
(Shikoku Kasei Kogyo products) were mixed using a mortar.

When this product was stored in a constant temperature bath at 45°C, it took on a gel state after one day.

Comparative Example 2 10 parts of the same epoxy resin as in the above example was mixed with 10 parts of 2MZ-CN (product of Shikoku Kasei Kogyo), which is an imidazole compound, using a mortar.

When this product was stored in a constant temperature bath at 45°C, it took on a gel state after one day.

Comparative Example 3 10 parts of dicyandiamide was mixed with 100 parts of the same epoxy resin as in the above example using a mortar. When this product was stored in a constant temperature bath at 45°C, it was stable for 30 days or more. However, even when this material was heated at 130° C. for 1 hour, it did not harden.

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Effects of the Invention According to the above explanation, the present invention has excellent storage stability,
Moreover, it is clear that it can provide an epoxy resin composition that can be cured rapidly at low temperatures, and it is also a one-component curable epoxy resin composition that provides a cured product with excellent adhesiveness and practical heat resistance. It is clear that there is something that can be provided.

Patent applicant: Fuji Kasei Kogyo Co., Ltd. Agent: Katabu 1 (Okaya fF Yazen Death Shi)

Claims (1)

[Claims] 1) An epoxy resin having an average of more than one epoxy group in the molecule and an N,N-dialkylaminoalkylamine represented by formula (1), ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼……………………(1
) (Here, R is an alkyl group having 1 to 4 carbon atoms, and n represents 2 or 3) Contains as essential components an amine having two primary amino groups and a curing agent compound obtained by heat-reacting urea. A one-component heat-curable epoxy resin composition. 2) The one-component system according to claim 1, wherein the N,N-dialkylaminoalkylamine, which is a raw material constituting the curing agent compound, is N,N-dimethylaminopropylamine or N,N-diethylaminopropylamine. Heat-curable epoxy resin composition. 3) The diamine having two primary amino groups, which is the raw material constituting the curing agent compound, is metaxylylene diamine, 1,3
The one-component heat-curable epoxy resin composition according to claim 1, which is bisaminomethylcyclohexane and isophorone diamine.