JPH0745560B2 - Epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin composition containing an inorganic filler.

(Prior Art) Epoxy resin blends containing silica powder, inorganic fillers such as aluminum, talc, calcium carbonate, etc., alone or in combination of two or more, are especially used for casting, molding, impregnation, adhesives, paints, and construction. It is used for modified epoxy resin products.

Epoxy resins mixed with these inorganic fillers have a problem that the inorganic fillers tend to settle or solidify during transportation or during warm storage, and as a countermeasure for this, ultrafine quartz powder ( Trade name: Aerosil) or benton and other thixotropic agents can be kneaded together with an inorganic filler.

(Problems to be Solved by the Invention) However, regarding the method of mixing the above-mentioned quartz and the like, there is a problem that workability and productivity are deteriorated because the viscosity of the epoxy resin composition is increased by the addition of quartz and the like. is there.

Therefore, in the epoxy resin composition containing the inorganic filler, a method for preventing the solidification of the inorganic filler is required without adding quartz, benton, etc. which increase the viscosity. As a method for this purpose, a surfactant is added to the epoxy resin itself to have a surface active effect, and the wettability of the mixed inorganic filler with the epoxy resin is modified to disperse the inorganic filler. A method of improving the properties and preventing the solidification of the inorganic filler can be considered. However, when a surfactant is added, the defoaming property is remarkably deteriorated, and the resulting cured molded article has a problem of increasing bubbles and weakening, so that it has not been put into practical use.

Therefore, an object of the present invention is to provide an epoxy resin composition in which solidification of an inorganic filler is prevented by addition of a surfactant, but defoaming property is not deteriorated.

(Means for Solving Problems) By incorporating a surfactant into the epoxy resin, the solidification of the inorganic filler can be solved. But that alone
Epoxy resin compound mixed with inorganic filler has defoaming property.
The defoaming property is remarkably poor, and the physical properties of the cured product are poor, making it unusable in practice. Therefore, the present inventors, in addition to the above-mentioned formulation,
By adding a silane coupling agent,
It was found that the defoaming property and defoaming property can be improved, and the solidification of the inorganic filler can be solved. Further, as a result of intensive research on the mixing ratio and the like, the present invention has been completed.

That is, the epoxy resin composition of the present invention is formed by adding an anionic surfactant and a silane coupling agent to an epoxy resin containing an inorganic filler.

Preferably, the epoxy resin composition of the present invention has an epoxy resin of 100 parts by weight, an inorganic filler of 5 to 700 parts by weight, an anionic surfactant of 0.01 to 5.0 parts by weight, and particularly preferably 0.05.
To 1.00 parts by weight, 0.001 to 10.0 parts by weight of the silane coupling agent, and particularly preferably 0.01 to 1.00 parts by weight.

The amount of anionic surfactant depends on the amount of the inorganic filler, but less than 0.01 parts by weight with respect to 100 parts by weight of the epoxy resin has no effect, and higher than 5.00 parts by weight, the defoaming property is significantly deteriorated. Since the effect of the silane coupling agent is not exerted, the range was 0.01 to 5.00 parts by weight. Further, if it is less than 0.05 parts by weight, the solidification state of the inorganic filler is slightly improved, but the effect is not practically obtained. Further, in the range of 1.00 to 5.00 parts by weight, the surfactant effect is sufficiently obtained, but since the defoaming property and the defoaming property are deteriorated, the effect of the silane coupling agent becomes difficult to reach, and a large amount is required to obtain the effect. Since it requires the silane coupling agent, the glass transition temperature of the cured product is lowered and the price of the composition is increased, which is not suitable for practical use. Therefore, the range of 0.05 to 1.00 parts by weight is particularly preferable.

The amount of the silane coupling agent varies depending on the amount of the anionic surfactant, but if the amount is less than 0.001 part by weight relative to 100 parts by weight of the epoxy resin, there is no effect, and if it is more than 10.0 parts by weight, the addition amount is large. Since the glass transition temperature becomes too low and the glass transition temperature becomes low, the amount was made 0.001 to 10.0 parts by weight. If it is less than 0.01 part by weight, a slight improvement in defoaming and defoaming properties can be seen, but it takes time in the actual degassing step and the workability becomes poor.
In the range of up to 10.0 parts by weight, the defoaming and defoaming properties can be sufficiently improved, but due to the large amount of addition, the glass transition temperature of the cured product will be low, the heat resistance will decrease, and the price of the composition will rise. It is not suitable for practical use. Therefore, the range of 0.01 to 1.00 parts by weight is particularly preferable.

Any type of epoxy resin may be used,
Liquid epoxy resins such as bisphenol A type, bisphenol F type, bisphenol A / F type and alicyclic type are preferable.

Surfactants include cationic, nonionic, block copolymer or anionic surfactants, but in cationic, nonionic or block copolymer surfactants, silane coupling agents are used. It is not possible to improve the defoaming property even if added, and since only the anionic surfactant is improved in the defoaming property by the silane coupling agent, the anionic surfactant is used in the present invention. . Examples of the anionic surfactant that can be used include sodium polyoxyethylene lauryl ether sulfate, triethanolamine polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium alkyl sulfate, and triethanolamine alkyl sulfate.

As the silane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc. can be used.

(Function) In the epoxy resin composition of the present invention, since the surfactant is added, the dispersibility of the inorganic filler is increased and solidification and sedimentation are prevented. Further, since the silane coupling agent is contained, the decrease in defoaming property due to the surfactant is eliminated. Therefore, the inorganic filler is unlikely to solidify and settle, and the resin has good defoaming properties, and when used as an epoxy resin for casting or molding, a high-quality cured molded article can be produced.

(Example) Hereinafter, the present invention will be described in more detail based on Examples.

Example 1: 100 parts by weight of a bisphenol A type liquid epoxy resin having an epoxy equivalent of 189 (Araldite GY 260 manufactured by CIBA-GEIGY), 0.10 parts by weight of polyoxyethylene lauryl ether sulfate triethanolamine, and γ-glycidoxypropyltrimethoxy. A resin composition was obtained by mixing 0.02 part by weight of silane and 50 parts by weight of crystalline silica powder (trade name: 3H, Nagase & Co., Ltd.).

Example 2: Bisphenol F type liquid epoxy resin (Epiclo manufactured by DIC)
n 830-S) 100 parts by weight, polyoxyethylene lauryl ether triethanolamine sulfate 0.10 parts by weight, Υ-glycidoxypropyltrimethoxysilane 0.02 parts by weight, and the silica powder 50 parts by weight to prepare a resin composition. Obtained.

Comparative Example 1: 100 parts by weight of bisphenol A type liquid epoxy resin (CIBA-GEIGY Araldite GY260) and 50 parts of silica powder.
A resin composition was obtained by blending parts by weight.

Comparative Example 2: Bisphenol F type liquid epoxy resin (DIC Epicl
on 830-S) 100 parts by weight and 50 parts by weight of the above silica powder were blended to obtain a resin composition.

Test Example 1: 300 g of each of the epoxy resin compositions of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 was put in a 300 ml mayonnaise bottle, and Takarazuka-Tokyo (about 1000 km, 1 round trip for 3 to 4 days). Was subjected to 3 round trips (12 days) by a truck flight, and then the solidified state was examined to conduct a transportation test. The results are shown in Table 1.

The epoxy resin compositions of Examples 1 and 2 were the epoxy resin compositions of the present invention, and could be easily stirred without solidification even if silica precipitated. In addition, Comparative Examples 1 and 2
The epoxy resin composition of No. 1 does not contain the anionic surfactant and the silane coupling agent of the epoxy resin compositions of Examples 1 and 2, but they were all solidified.

Test Example 2: Each of the epoxy resin compositions of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 was placed in a test tube (30φ × 200 mm) with a height of 1 mm.
The test tube was placed so as to be 80 mm, and the test tube was placed vertically in a hot air circulation type oven and subjected to a heating aging test at 80 ° C./24 hours and 120 ° C./8 hours. In this test, the inside of the test tube is divided into three layers, a clear A layer, a filler dispersed B layer, and an excessive filler C layer. Height of each layer (A
Layer: a mm, B layer: b mm, C layer: c mm) was measured, and the sedimentation degree was calculated according to the following formula. The larger the value of the sedimentation degree, the more the filler is well dispersed in the resin and not solidified.

Further, the solidified state was evaluated according to the same criteria as in Test Example 1. The results are shown in Table 2.

From the table, the epoxy resin compositions of Examples 1 and 2 can be easily re-stirred without solidifying even when silica is precipitated during the heat aging test, and the epoxy resin compositions of Comparative Examples are seen from the degree of precipitation. Also, from the viewpoint of the solidified state, it is clear that the sedimentation and solidification of the inorganic filler is remarkable as compared with the epoxy resin compositions of the examples.

Test Example 3: An epoxy resin composition having the same composition as in Example 1 was prepared in the same manner as in Test Example 2 except that the silane coupling agent was not contained and the amount of the anionic surfactant was different from each other. Then, a heating aging test was performed at 80 ° C./24 h.

The amount of anionic surfactant in each epoxy resin composition and the test results are shown in Table 3 below.

As is clear from the table, when the silane coupling agent is not added, the defoaming property deteriorates when the anionic surfactant is added. The defoaming property becomes worse as the amount of the anionic surfactant increases, and when it is 0.50 parts by weight or more, the defoaming property does not occur at all. The sedimentation degree is good in all cases.

Test Example 4: For an epoxy resin composition having the same composition as in Example 1 except that the amount of the silane coupling agent was different,
A heat aging test was performed at 80 ° C./24 h in the same manner as in Test Example 2 above. The amount of the silane coupling agent in each epoxy resin composition and the test results are shown in Table 4 below.

From the table, it is clear that the amount of the silane coupling agent is 0.015 parts by weight or more and is effective. Further, the sedimentation degree is good regardless of the amount of the silane coupling agent, but those containing no surfactant and only the silane coupling agent have a low sedimentation degree and are in a solidified state. It is clear.

Test Example 5: Using a cationic surfactant, a nonionic surfactant or a block copolymer surfactant instead of the anionic surfactant, and whether or not the addition of the silane coupling agent or the addition amount is Apart from the differences,
The epoxy resin composition having the same composition as in Example 1 was tested for defoaming property, sedimentation degree and solidified state. Each test was performed according to the method of Test Examples 1 to 3.
(However, the sedimentation degree was performed only at 80 ° C./24 h.) The results are shown in Table 5 below.

From this test, it is clear that when a cationic surfactant or a nonionic surfactant is used as the surfactant, the defoaming property is poor and the solidified state is not improved. Incidentally, it has been clarified by a separate test that the defoaming properties of these surfactants are not improved regardless of the amount of the silane coupling agent added. Further, it is clear from the present test that the block copolymer surfactant is improved in the solidified state and the degree of sedimentation, but the defoaming property is not improved by the addition of the silane coupling agent.

(Effects of the Invention) The epoxy resin composition of the present invention has almost no precipitation or solidification of the inorganic filler during transportation or during heat storage,
Further, even if it is precipitated and solidified, it can be easily stirred again. Moreover, the viscosity of the epoxy resin composition does not increase, and the defoaming property does not increase and the cured molded article does not become brittle. Therefore, when used as a casting or molding resin, a high-quality cured molded product can be obtained with good workability and good productivity.

Claims (1)

[Claims] 1. An epoxy resin composition obtained by adding an anionic surfactant and a silane coupling agent to an epoxy resin containing an inorganic filler.