JPS6136855B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a fast-curing epoxy resin composition. When curing epoxy resin with an amine curing agent, in order to speed up the curing reaction or cure at a temperature below room temperature, a curing agent such as tris (dimethylaminomethyl) phenol (hereinafter abbreviated as DMP-30) is used. Accelerators are used. Depending on the type of epoxy resin and amine curing agent used,
DMP-30 still has insufficient curing accelerating effect in some cases, and there has been a desire to develop a more effective curing accelerator. For example, when using a diamine with a molecular weight ranging from several thousand to tens of thousands as an amine curing agent,
Even when used in combination with DMP-30, the curing time at room temperature was too long. On the other hand, the use of tertiary aminomethylated vinylphenol polymers as curing agents for epoxy resins has been reported in JP-A-49-10992 and JP-A-Sho.
No. 49-130992. However, in terms of curing speed, epoxy resin is better than DMP-30.
generally 100 to 150
Curing must be carried out at high temperatures such as °C.
In this case, it is stated that the use of amine as a curing accelerator is permissible, but since the curing agent is a tertiary aminomethylated vinylphenol polymer, the amount used is large. As a result, a cured product that is completely different from that obtained when an amine is used as a curing agent can be obtained. As mentioned above, tertiary aminomethylated alkenylphenol polymers cannot be said to have a fast curing speed as a curing agent for epoxy resins themselves, but surprisingly, in the system of epoxy resin and amine curing agent, In particular, it has been found that when a small amount of a dimethylaminated alkenylphenol polymer is used as a curing accelerator, the curing rate is further accelerated than when DM-30 is used as a curing accelerator. Therefore, according to the present invention, epoxy resin (A),
For 100 parts by weight of amine curing agent (B) and (A) and (B),
An epoxy resin composition containing 0.1 to 30 parts by weight of dimethylaminomethylated polyalkenylphenol (C) is provided. The epoxy resin (A) used in the present invention has two or more highly reactive epoxy groups in one molecule, and may be an aliphatic, alicyclic, or aromatic compound. Good too. Specifically, bisphenol A epoxy resin derived from bisphenol A and epichlorohydrin, novolac type epoxy resin, bisphenol F type epoxy resin, polyhydroxybenzene epoxy resin, p-oxybenzoic acid, phthalic acid,
Examples include epoxy resins derived from carboxylic acids such as tetrahydrophthalic acid and epichlorohydrin, glycidyl ether type epoxy resins such as polyalkylene glycol diglycidyl ether, alicyclic epoxy resins, methyl epichlorohydrin type epoxy resins, or mixtures thereof. can do. Although the molecular weight of these epoxy resins is arbitrary, it is usually preferably about 200 to about 1000. The amine curing agent (B) is preferably an aliphatic, alicyclic or aromatic polyamine, and may contain a functional group other than an amino group in the molecule. Specifically, polymethylenediamine, branched polyethylenediamine, polyetherdiamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, iminobispropylamine,
Methyliminobispropylamine, aminoethylethanolamine, menthanediamine, N-aminoethylpiperazine, 1,3-diaminocyclohexane, isophoronediamine, m-xylylenediamine, tetrachlor-p-xylylenediamine, o-phenylenediamine, m-phenylenediamine, 4,4-methylenedianiline, benzidine, 4,4'-thiodianiline, dianisidine,
2,4-toluenediamine, diaminoditolylsulfone, 4-methoxy-6-methyl-m-phenylenediamine, diaminodiphenyl ether, diaminodiphenylsulfone, 4,4-bis(o-
toluidine), methylenebis(o-chloroaniline), bis(3,4-diaminophenyl)sulfone, 2,6-diaminopyridine, 4-chloro-o
-Phenylenediamine, m-aminobenzylamine, etc. can be exemplified. Also, long chain diols such as polypropylene glycol, polyethylene/polypropylene glycol, polytetramethylene glycol, polybutadiene diol, polyester diol, etc., and diisocyanates,
For example, it may be a high molecular weight diamine having a backbone of polyurethane derived from those mentioned below that can be used for the synthesis of component (C) and having amino groups at both ends. Specific examples of such polyurethane diamines are disclosed in Japanese Patent Publications No. 45-2196, Japanese Patent Publication No. 34155-1972, and Japanese Patent Application Laid-Open No. 49-95908. In particular, when such a polyurethane diamine with a molecular weight of about 5,000 to 25,000 is used, the combination with component (C) not only accelerates curing but also improves the heat aging resistance of the cured product. You can also see As component (C) of the present invention, dimethylaminomethylated polyalkenylphenol is used. Polyalkenylphenols herein include homopolymers of alkenylphenols, copolymers of different alkenylphenols, copolymers of one or more alkenylphenols and one or more other vinyl monomers, and homopolymers of these. Alternatively, it refers to a copolymer obtained by partially co-condensing a copolymer and a phenol with formaldehyde.
It is desirable that the copolymer contains 30 mol% or more, particularly 50 mol% or more of alnylphenol component units. Examples of the constituent components of polyalkenylphenol include vinylphenol and isopropenylphenol, with vinylphenol being particularly preferred. The greater the number of dimethylaminomethyl groups in component (C), the more effective it is. For example, it is desirable that the number of dimethylaminomethyl groups in component (C) is 0.5 or more, particularly 1 to 2, per one alkenylphenol component. The number average molecular weight is arbitrary, but considering compatibility and dispersibility in the composition, it is less than 10,000, especially 500 or less.
A value of about 5000 is suitable. The method for producing component (C) is described in detail in the above-mentioned publication. The blending ratio of the epoxy resin (A) and the amine curing agent (B) is such that the ratio of epoxy group in component (A)/amino group active hydrogen in component (B) is 0.5 to 2.0, particularly 0.6 to 2.0.
Preferably it is 1.8. In addition, the component (C) is
It is used in an amount of 0.1 to 30 parts by weight, particularly 1 to 20 parts by weight, based on 100 parts by weight of the epoxy resin (A) and amine curing agent (B). If the proportion of component (C) used exceeds the above range, the reaction between the epoxy resin and the amine curing agent will be hindered, resulting in a slow curing rate. The composition of the present invention may further contain various additives. For example, metal powder, silica, zinc oxide, titanium dioxide, magnesium oxide, calcium oxide, calcium carbide, aluminum sulfate, talc, clay, alumina white, barium sulfate, calcium sulfate, pumice powder, asbestos, diatomaceous earth, glass fiber, Additives such as mica, molybdenum disulfide, carbon black, graphite, inorganic fillers such as lithobon, phenolic resins, petroleum resins, phthalate esters, pigments, etc. may be used. Also other epoxy resin curing accelerators, e.g.
Alcohols, phenols, water, etc. can also be used in combination. The composition of the present invention cures quickly and therefore can be cured even at room temperature. Next, the present invention will be explained in more detail with reference to examples. Reference example 1 Polyvinylphenol (number average molecular weight 3000) 12 in a 200ml flask with stirring device and water-cooled condenser
g and 30 g of methyl alcohol, stir to make a methyl alcohol solution of polyvinylphenol, and then add 21.4 ml of dimethylamine aqueous solution (50%). Thereafter, 17 g of formalin (37% aqueous solution) was slowly added while cooling the reaction product using an ice water bath, and after the addition was completed, the temperature was raised to 80 °C in a hot water bath.
The reaction is carried out after 6 hours at °C. After the reaction was completed, methyl alcohol was removed by distillation, the precipitated reddish-brown solid was washed, and then dried under reduced pressure to form a brown solid 23
I got g. As a result of infrared absorption spectroscopy and nuclear magnetic resonance analysis, the reaction product was found to be composed of two dimethylaminomethyl units per phenol unit95
%, and 5% unreacted. Example 1 A mixed solution consisting of 5 ml of toluene solution and 5 ml of ethylene alcohol containing 0.51 g of triethylenetetramine (B) and 4 g of bisphenol A-based epoxy resin (A) (Mitsui Petrochemical Epoxy Co., Ltd. Epomic R-140) was added. Add the reaction product (C) of Reference Example 1, and add 40
The gelation time at °C was measured. The results are shown in Table 1. Comparative Example 1 Table 1 also shows the results of measuring the gelation time in the same manner as in Example 1 without adding component (C).

[Table] Example 2 High molecular weight urethanediamine (B) (number average molecular weight
From 3000 polyoxypropylene glycol and hexamethylene diisocyanate to JP-A-49-95908
It was synthesized using the method in No. Number average molecular weight 9000) 12g,
The reaction product (C) of Reference Example 1 was added to a mixed solution consisting of 1.7 ml of toluene solution containing 1.02 g of epoxy resin R-140 (A) and 20 ml of ethanol, and the gelation time at 50°C was measured. The results are shown in Table 2. Comparative Example 2 Table 2 also shows the results of measuring the gelation time in the same manner as in Example 2 without adding component (C). Comparative Example 3 Table 2 shows the results of carrying out the same procedure as in Example 2 using tris(dimethylaminomethyl)phenol instead of component (C).

[Table] Example 3 50 g of high molecular weight urethane diamine of Example 2, 1 g of the reaction product (C) of Reference Example 1, and Neugen EA-130T
(Nippon Oil & Fats Co., Ltd. surfactant) was mixed, and then 11 ml of a 0.2N hydrochloric acid aqueous solution, 30 ml of water, and 50 g of calcium carbonate were mixed to prepare a high molecular weight urethane diamine emulsion. This emulsion is 3
It remained stable for over a month. Add 6.5g of epoxy resin R-140 and Aronix M-8030 to this emulsion.
(Toagosei Co., Ltd., acrylic oligomer) 3.1g, Aronix M-6100 (Toagosei Co., Ltd., acrylic oligomer) 5.7g, Nitsusanpronone 208 (Nippon Oil Co., Ltd., surfactant) 0.5g, and water 16g were mixed. Mix 5g of hardener emulsion and make it 15mm thick.
A test piece was made, and changes in hardness at 25°C and changes in hardness (measured according to JIS K6301) before and after a heat aging test (90°C x 7 days) were investigated. The results are shown in Table 3. Comparative Example 4 Table 3 also shows the results obtained in the same manner as in Example 3 except that component (C) was not used.

【table】

Claims (1)

[Claims] 1. Epoxy resin (A), amine curing agent (B) and (A)
An epoxy resin composition containing 0.1 to 30 parts by weight of dimethylaminomethylated polyalkenylphenol (C) per 100 parts by weight of (B). 2 As component (C), 1 alkenylphenol unit
2. The composition according to claim 1, wherein 0.5 or more dimethylaminomethyl units are bonded to each other.