JP2001059013A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition which can make a cured product excellent in heat resistance and useful for epoxy resin-based laminates, coating materials and the like by including a specific alkoxy group-containing silane- modified epoxy resin and a curing agent for epoxy resins. SOLUTION: This composition is obtained by including (A) an alkoxy group- containing silane-modified epoxy resin obtained by conducting alcohol elimination condensation reaction between (i) a bisphenol type epoxy resin preferably comprising bisphenol A type epoxy resin and (ii) a hydrolyzable alkoxysilane preferably comprising a poly(tetramethoxysilane) of the formula (Me is methyl; n is >=0 and the number n of recurring unit(s) is 1 to 7 on average) in the weight ratio of silica equivalent weight of the component ii to the weight of the component i of preferably 0.01 to 3 and (B) a curing agent for epoxy resins preferably comprising a polyamine-based curing agent, in the equivalent ratio of the function group having active hydrogen in the component B to the epoxy group in the component A of preferably around 0.2 to 1.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an epoxy resin composition. The epoxy resin composition of the present invention can be used for various applications such as IC sealing materials, epoxy resin laminates, paints, adhesives, and coating agents for electric and electronic materials.

[0002]

2. Description of the Related Art Heretofore, epoxy resins have generally been used as epoxy resin compositions in combination with curing agents, and such compositions have also been awarded in the field of electric and electronic materials. However, with the recent development of the field of electric and electronic materials, high performance of epoxy resin cured products has been required, and particularly, improvement of heat resistance is desired.

As a method for improving the heat resistance of a cured epoxy resin, for example, a method of mixing a filler such as glass fiber, glass particles, mica and the like in addition to an epoxy resin and a curing agent has been used. However, this method does not provide sufficient heat resistance. Moreover, in this method, the transparency of the cured epoxy resin is lost, and the adhesiveness at the interface between the filler and the resin is poor, so that the mechanical properties such as elongation are insufficient.

As a method for improving the heat resistance of a cured epoxy resin, a method using a composite of an epoxy resin and a metal oxide has been proposed (JP-A-8-1001).
No. 07 publication). The composite is obtained by adding a metal alkoxide to a solution obtained by partially curing an epoxy resin to form a homogeneous sol solution, and then polycondensing the metal alkoxide. However, although the cured product obtained from such a composite has a certain degree of heat resistance improvement compared to a mere epoxy resin cured product, the cured product due to water in the composite, water generated at the time of curing, and alcohol is produced. Void inside (bubbles)
Occurs. In addition, when the amount of metal alkoxide is increased for the purpose of further improving heat resistance, the cured product obtained by agglomeration of silica formed by sol-gel curing loses transparency and whitens, and a large amount of metal alkoxide is added to sol-gel. Requires a large amount of water to form the cured product, resulting in warpage, cracking, and the like of the cured product.

A cured product of a composition obtained by combining a silane-modified epoxy resin obtained by reacting a silicone compound with an epoxy resin and a phenol novolak resin (curing agent) has also been proposed (Japanese Patent Application Laid-Open No. Hei 3-201466). Also, a composition containing a silicone-modified epoxy resin obtained by combining a silane-modified epoxy resin obtained by reacting bisphenol A type epoxy resin, tetrabromobisphenol A and a methoxy group-containing silicone intermediate with a phenol novolak resin (curing agent), Cured products have also been proposed (Japanese Patent Application No. 61-272243, Japanese Patent Application No. 61-272243).
-272244). However, such a cured product of a silane-modified epoxy resin or a cured product of a silicone-modified epoxy resin has insufficient heat resistance because the main constituent unit of the silicone compound or the methoxy group-containing silicone intermediate is a diorganopolysiloxane unit.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an epoxy resin composition which can be a cured product having excellent heat resistance.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as an epoxy resin, part or all of the hydroxyl groups of a bisphenol-type epoxy resin has been modified with a hydrolyzable alkoxysilane. By using the specific silane-modified epoxy resin, it has been found that an epoxy resin composition meeting the above-mentioned object can be obtained, and the present invention has been completed.

That is, the present invention provides an alkoxy group-containing silane-modified epoxy resin (A) obtained by subjecting a bisphenol-type epoxy resin (1) and a hydrolyzable alkoxysilane (2) to a dealcoholization condensation reaction, and a curing method for the epoxy resin. The present invention relates to an epoxy resin composition containing the agent (B).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A bisphenol type epoxy resin (1) which is a raw material of the alkoxy group-containing silane-modified epoxy resin (A) of the present invention is obtained by reacting a bisphenol with a haloepoxide such as epichlorohydrin or β-methylepichlorohydrin. It was obtained by Examples of bisphenols include the reaction of phenol or 2,6-dihalophenol with aldehydes or ketones such as formaldehyde, acetaldehyde, acetone, acetophenone, cyclohexanone, and benzophenone, oxidation of dihydroxyphenyl sulfide by peracid, and hydroquinones. Those obtained by an etherification reaction and the like can be mentioned. Among these bisphenol-type epoxy resins, bisphenol A-type epoxy resins using bisphenol A as the bisphenols are most commonly used, are low in cost, and are preferred.

The bisphenol type epoxy resin (1) has a hydroxyl group capable of undergoing an ester reaction with the hydrolyzable alkoxysilane (2). The hydroxyl group does not need to be possessed by each molecule constituting the bisphenol-type epoxy resin (1), and it is sufficient that the bisphenol-type epoxy resin (1) has a hydroxyl group. For example, bisphenol A type epoxy resin has the general formula (b):

[0011]

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## EQU1 ## If m includes 1 or more, m may include a considerable amount of 0. The epoxy equivalent of the bisphenol-type epoxy resin (1) differs depending on the structure of the bisphenol-type epoxy resin (1), and the epoxy equivalent can be appropriately selected and used according to the application. Normally, when the epoxy equivalent becomes small, the alcoholic hydroxyl group in the epoxy resin decreases, and after the reaction, the bond between the silica component and the epoxy resin decreases, and the silica cannot be dispersed well in the cured epoxy resin. Has a tendency to become a cloudy cured product in which phase separation has occurred, so that the epoxy equivalent of the bisphenol-type epoxy resin (1) is 1
It is preferably 80 or more. On the other hand, when the epoxy equivalent is increased, the number of hydroxyl groups in one polymer chain of the epoxy resin is increased, and it is easy to gel during the dealcoholization condensation reaction with the polyfunctional hydrolyzable alkoxysilane (2). It is preferable that the epoxy equivalent of the epoxy resin (1) is 5000 or less.

In addition, as the hydrolyzable alkoxysilane (2) constituting the alkoxy-containing silane-modified epoxy resin (A) in the present invention, those generally used in a sol-gel method can be used. For example, the general formula: R
¹ _p Si (OR ² ) _4-p (where p represents an integer of 0 or 1. R ¹ is a lower alkyl group, an aryl group or an unsaturated group which may have a functional group directly bonded to a carbon atom. R ² represents a hydrogen atom or a lower alkyl group, and each R ² may be the same or different.) Or a partial condensate thereof. Examples of the functional group include a vinyl group,
Examples thereof include a mercapto group, an epoxy group, and a glycidoxy group. The lower alkyl group refers to a linear or branched alkyl group having 6 or less carbon atoms.

Specific examples of such a hydrolyzable alkoxysilane (2) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane and tetrabutoxysilane; methyltrimethoxysilane. Silane, methyltriethoxysilane, methyltripropoxysilane,
Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3 -Glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3
-Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4
-Trialkoxysilanes such as epoxycyclohexylethyltrimethoxysilane; or partial condensates thereof.

Among these, tetramethoxysilane,
Tetraalkoxysilanes such as tetraethoxysilane or partial condensates thereof are preferred. In particular, the general formula (a):

[0016]

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(Wherein Me represents a methyl group, n is an integer of 0 or more, and the average number of repeating units of n is 1 to 7), which is a partial condensate of tetramethoxysilane. (Tetramethoxysilane) is preferred. The poly (tetramethoxysilane) has a number average molecular weight of 26.
Those having about 0 to 1200 are preferable. The poly (tetramethoxysilane) is preferable in the reaction operation because tetramethoxysilane evaporates together with methanol in the methanol removal reaction and does not distill out of the system. Also, poly (tetramethoxysilane) does not have the toxicity as seen in tetramethoxysilane. On the other hand, in the general formula (a), when the value of the average number of repeating units exceeds 7, the solubility is deteriorated, and the bisphenol type epoxy resin (1) or the organic solvent is easily insoluble. ) And the reactivity tends to decrease.

The hydrolyzable alkoxysilane (2)
Can be used without particular limitation, but when trialkoxysilanes or their polycondensates are used, usually the hydrolyzable alkoxysilane (2)
Of these, it is preferable to use together with tetraalkoxysilanes or partial condensates thereof at a ratio of 40% by weight or less.

The alkoxy group-containing silane-modified epoxy resin (A) of the present invention is obtained by a dealcoholization condensation reaction between the bisphenol type epoxy resin (1) and the hydrolyzable alkoxysilane (2). Bisphenol type epoxy resin (1) and hydrolyzable alkoxysilane (2)
The use ratio of is not particularly limited as long as the alkoxy group is substantially left in the obtained alkoxy group-containing silane-modified epoxy resin (A), but the hydrolyzable alkoxy silane (2) is converted to silica. Weight / the weight (weight ratio) of the bisphenol-type epoxy resin (1) is 0.0
It is preferred to be in the range of 1-3.

However, the bisphenol type epoxy resin (1) is a high molecular weight resin having an epoxy equivalent of 800 or more, and the equivalent of the alkoxy group of the hydrolyzable alkoxysilane (2) / the hydroxyl group of the bisphenol type epoxy resin (1). If the equivalent (equivalent ratio) is around 1 (equivalent to stoichiometrically), the progress of the dealcoholation reaction tends to increase the viscosity and gelation of the solution. Need to be adjusted. That is, the equivalent ratio is adjusted to be less than 1 or more than 1 so that either the equivalent of the hydroxyl group of the bisphenol-type epoxy resin (1) or the equivalent of the alkoxy group of the hydrolyzable alkoxysilane (2) increases. Is preferred. In particular,
Preferably, the equivalent ratio is adjusted to less than 0.8 or more than 1.2.

The bisphenol type epoxy resin (1) has a high molecular weight of 400 or more in epoxy equivalent, and the hydrolyzable alkoxysilane (2) is poly (tetramethoxysilane) of the above formula (a). In the case where the above-mentioned equivalent ratio is close to 1, when either the hydroxyl group of the bisphenol-type epoxy resin (1) or the alkoxy group of the hydrolyzable alkoxysilane (2) disappears completely, When the dealcoholization condensation reaction is performed, the molecular weight of the product in the reaction system may be too high, and a tendency to increase the viscosity and gel may be observed.
In such a case, the dealcoholation reaction is performed during the reaction,
High viscosity and gelation are prevented by methods such as stopping.
For example, a method may be employed in which the reaction system is changed to a reflux system at the time of increasing the viscosity, the amount of methanol removed from the reaction system is adjusted, or the reaction system is cooled to terminate the reaction.

The production of the silane-modified epoxy resin (A) is carried out, for example, by charging the above-mentioned components and subjecting them to a dealcoholization condensation reaction while distilling off alcohol produced by heating. The reaction temperature is about 50 to 130 ° C, preferably 70 to 110 ° C, and the total reaction time is 1
It is about 15 hours. This reaction is preferably performed under substantially anhydrous conditions in order to prevent a polycondensation reaction of the hydrolyzable alkoxysilane (2) itself.

In the above-mentioned dealcoholization condensation reaction, among the conventionally known catalysts, those which do not open the epoxy ring can be used to promote the reaction. Examples of the catalyst include lithium, sodium, potassium,
Rubidium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum,
Metals such as titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium and manganese; oxides, organic acid salts, halides, alkoxides and the like of these metals. Of these,
Particularly, organic tin and organic acid tin are preferable, and specifically, dibutyltin dilaurate, tin octylate and the like are effective.

The above reaction can be carried out with or without a solvent. The solvent is not particularly limited as long as it is an organic solvent that dissolves the bisphenol-type epoxy resin (1) and the hydrolyzable alkoxysilane (2) and is inactive against them. Examples of such an organic solvent include aprotic polar solvents such as dimethylformamide, dimethylacetamide, tetrahydrofuran, and methyl ethyl ketone.

The alkoxy group-containing silane-modified epoxy resin (A) of the present invention thus obtained contains, as a main component, an epoxy resin in which the hydroxyl group in the bisphenol type epoxy resin (1) is silane-modified. The group-containing silane-modified epoxy resin (A) may contain unreacted bisphenol-type epoxy resin (1) or hydrolyzable alkoxysilane (2). The unreacted hydrolyzable alkoxysilane (2) can be converted into silica by hydrolysis and polycondensation. To promote hydrolysis and polycondensation, use of an alkoxy group-containing silane-modified epoxy resin (A) is preferred. In doing so, a small amount of water can be included. The alkoxy group-containing silane-modified epoxy resin (A) of the present invention has an alkoxy group derived from the hydrolyzable alkoxysilane (2) in its molecule. The content of the alkoxy group is not particularly limited, but the alkoxy group is bonded to each other by a sol-gel reaction or dealcohol condensation by evaporation or heat treatment of a solvent or by reaction with water (moisture). In order to form a cured product, the alkoxy group-containing silane-modified epoxy resin (A) is usually used in an amount of 50 to 95 mol%, preferably 50 to 95 mol% of the alkoxy group of the hydrolyzable alkoxy silane (2) as a reaction raw material. It is preferable to keep 60 to 95 mol% unreacted. Such a cured product has a gelled fine silica site (high-order network structure of siloxane bonds).

In the present invention, an epoxy resin composition obtained by combining such an alkoxy group-containing silane-modified epoxy resin (A) and a curing agent for epoxy resin (B) is used. In applying the epoxy resin composition of the present invention to various uses, various epoxy resins can be used in combination depending on the use. Examples of the epoxy resin that can be used in combination include the above-mentioned bisphenol-type epoxy resin (1), a novolak-type epoxy resin such as an ortho-cresol novolak-type epoxy resin, and a phenol novolak-type epoxy resin described as a component of the present invention; phthalic acid, dimer acid A glycidyl ester type epoxy resin obtained by reacting a polybasic acid such as e.g. and epichlorohydrin;
Glycidylamine type epoxy resin obtained by reacting polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; linear aliphatic epoxy resin obtained by oxidizing an olefin bond with a peracid such as peracetic acid; and alicyclic ring And epoxy resins of the formula.

As the epoxy resin curing agent (B), phenol resin-based curing agents, polyamine-based curing agents, polycarboxylic acid-based curing agents, etc., which are usually used as epoxy resin curing agents, are particularly limited. Can be used without. Specifically, phenolic resin-based ones include phenol novolak resin, bisphenol novolak resin, poly-p-vinylphenol, etc., and polyamine-based curing agents such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dicyandiamide, Polyamidoamine (polyamide resin), ketimine compound, isophoronediamine, m-xylenediamine, m
-Phenylenediamine, 1,3-bis (aminomethyl)
Cyclohexane, N-aminoethylpiperazine, 4,
4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, diaminodiphenylsulfone, and the like. Polycarboxylic acid-based curing agents include phthalic anhydride, tetrahydrophthalic anhydride, and methyltetrahydroanhydride. Phthalic acid, 3,6-endomethylenetetrahydrophthalic anhydride, hexachloroendmethylenetetrahydrophthalic anhydride, methyl-3,6
-Endomethylene tetrahydrophthalic anhydride. The epoxy resin curing agent (B) not only reacts with the epoxy ring to effect ring-opening curing, but also causes siloxane condensation of alkoxysilyl sites and alkoxy groups in the alkoxy group-containing silane-modified epoxy resin (A). Also serves as a catalyst for the reaction. The above curing agent for epoxy resin (B)
Among them, a polyamine-based curing agent is most suitable as a curing catalyst for an alkoxysilyl moiety or an alkoxy group, and is most suitable as a curing agent (B) for an alkoxy group-containing silane-modified epoxy resin (A).

The epoxy resin curing agent (B) is usually used in an amount of 0.2 equivalent of the functional group having active hydrogen in the curing agent to 1 equivalent of epoxy group in the alkoxy group-containing silane-modified epoxy resin composition. It is prepared by mixing at a ratio of about 1.5 equivalents.

The epoxy resin composition may contain a curing accelerator for accelerating the curing reaction between the epoxy resin and the curing agent. For example, tertiary amines such as 1,8-diaza-bicyclo [5.4.0] undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol; Imidazoles such as -methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and 2-heptadecylimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine; Tetraphenyls such as tetraphenylphosphonium / tetraphenylborate, 2-ethyl-4-methylimidazole / tetraphenylborate, and N-methylmorpholine / tetraphenylborate Such as boron salt can be mentioned. The curing accelerator is preferably used in a ratio of 0.1 to 5 parts by weight based on 100 parts by weight of the epoxy resin.

The concentration of the epoxy resin composition can be appropriately adjusted by a solvent. As the solvent, those similar to those used for producing the alkoxy group-containing silane-modified epoxy resin (A) can be used. In addition, the epoxy resin composition may contain a filler, a release agent, a surface treatment agent, a flame retardant, a viscosity modifier, a plasticizer, an antibacterial agent, and / or the like, as long as the effects of the present invention are not impaired. A mold, a leveling agent, an antifoaming agent, a coloring agent, a stabilizer, a coupling agent and the like may be added.

[0031]

According to the present invention, it is possible to provide a cured epoxy resin which has excellent heat resistance and does not generate voids (bubbles).

[0032]

The present invention will be described below in detail with reference to examples and comparative examples. In each case,% is based on weight unless otherwise specified.

Production Example 1 (Alkoxy group-containing silane-modified
Manufacture of epoxy resin) A reaction apparatus equipped with a stirrer, cooling pipe, and thermometer
Nord A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name
"Epotote YD-011", epoxy equivalent 475 g /
eq) 850 g and 850 g of dimethylformamide
In addition, it was melted at 90 ° C. In addition, poly (tetramethoxysi
Run) (Tama Chemical Co., Ltd., product name "Methyl silicate"
51 ") 419.4 g with dibutyltin laurée as catalyst
2 g, and subjected to a methanol removal reaction at 90 ° C. for 5 hours.
And the active ingredient (after curing) is 50% alkoxy-containing silicone.
A run-modified epoxy resin solution was obtained. In addition, at the time of preparation
(Silica equivalent weight of hydrolyzable methoxysilane (2) /
(Weight of epoxy resin (1)) = 0.25, (hydrolyzability)
Equivalent of methoxy group of methoxysilane (2) / epoxy tree
(Equivalent of hydroxyl group of fat (1)) = 4.6. The resin solution
of¹H-NMR (CDCl _ThreeSolution) from the epoxy ring
100% peak (around 3.3 ppm)
And the peak of the hydroxyl group in the epoxy resin (3.8
Around 5 ppm) was reduced by about 55%.
Was. The obtained alkoxy group-containing silane-modified epoxy resin
The epoxy equivalent of the solution was 1191.

Production Example 2 (Production of alkoxy group-containing silane-modified epoxy resin) Epototo YD-011 was placed in the same reactor as in Production Example 1.
And dimethylformamide (800 g) were added and dissolved at 90 ° C. In addition, methyl silicate 51
23.5 g and 2 g of dibutyltin laurate were added, and 9
A methanol removal reaction was performed at 0 ° C. for 5 hours to obtain an alkoxy group-containing silane-modified epoxy resin solution containing 50% of an active ingredient (after curing). At the time of preparation, (weight in terms of silica of hydrolyzable methoxysilane (2) / epoxy resin (1)
Weight) = 0.33, hydrolyzable methoxysilane (2)
Methoxy group equivalent / hydroxyl group equivalent of epoxy resin (1)) = 6.1. ¹ H-NMR (CD
Cl ₃ solution) to the methine peak of the epoxy ring (3.3p
pm) and the peak of hydroxyl groups in the epoxy resin (around 3.85 ppm) was reduced by about 50%. The epoxy equivalent of the obtained alkoxy group-containing silane-modified epoxy resin solution was 1,269 g / eq.

Production Example 3 (Production of Alkoxy Group-Containing Silane-Modified Epoxy Resin) Epotote YD-011 was placed in the same reactor as in Production Example 1.
And 850 g of methyl ethyl ketone,
Dissolved at 70 ° C. Furthermore, methyl silicate 51 was added to 41
9.4 g and 2 g of dibutyltin laurate are added, and 90
A methanol removal reaction was performed at 5 ° C. for 5 hours to obtain an alkoxy group-containing silane-modified epoxy resin solution containing 50% of an active ingredient (after curing). In addition, (weight in terms of silica of hydrolyzable methoxysilane (2) / weight of epoxy resin (1)) at the time of preparation = 0.25, (hydrolyzable methoxysilane (2))
Methoxy group equivalent / hydroxyl group equivalent of epoxy resin (1)) = 4.6. ¹ H-NMR (CDC
l ₃ solution) from the epoxy ring methine peak (3.3Pp
m) and the peak of hydroxyl groups in the epoxy resin (around 3.85 ppm) is about 6%.
It was confirmed that it was reduced by 0%. The epoxy equivalent of the obtained alkoxy group-containing silane-modified epoxy resin solution was 1,269.

Production Example 4 (Production of Alkoxy Group-Containing Silane-Modified Epoxy Resin) A bisphenol A type epoxy resin (trade name "YD-12" manufactured by Toto Kasei Co., Ltd.) was used in the same reactor as in Production Example 1.
7 ", 950 g of epoxy equivalent (185 g / eq) and 950 g of dimethylformamide were added and dissolved at 90 ° C. Further, 304.6 g of methyl silicate 51 and 2 g of dibutyltin laurate were added, and the mixture was subjected to a methanol removal reaction at 90 ° C. for 6 hours to obtain an alkoxy group-containing silane-modified epoxy resin solution containing 50% of an active ingredient (after curing). At the time of preparation, (weight in terms of silica of hydrolyzable methoxysilane (2) / weight of epoxy resin (1)) = 0.1
4, methoxy group equivalent of hydrolyzable methoxysilane (2) / hydroxyl group equivalent of epoxy resin (1)) = 23.7. In this production example, the reaction was performed while removing the generated methanol from the reaction system in order to completely perform the dealcoholization reaction. From the ¹ H-NMR (CDCl ₃ solution) of the resin solution, 100% of the methine peak of the epoxy ring (around 3.3 ppm) is retained, and the peak of the hydroxyl group in the epoxy resin (around 3.8 ppm) is completely eliminated. It was confirmed that it had disappeared. The epoxy equivalent of the obtained alkoxy group-containing silane-modified epoxy resin solution was 431.

Production Example 5 (Production of alkoxy group-containing silane-modified epoxy resin) In the same reactor as in Production Example 1, Epotote YD-011 was added.
Was added at 450 ° C. and 1000 g of methyl isobutyl ketone, and dissolved at 90 ° C. Further, 1207 g of methyl silicate 51 and 2 g of dibutyltin laurate were added, and 9
The reaction was carried out at 0 ° C. for 5 hours while removing methanol. 5
After cooling to 0 ° C. and reducing the pressure at 13.3 kPa for 30 minutes,
The methanol was completely removed, and 500 g of methyl isobutyl ketone was distilled off.
Was obtained. At the time of preparation (weight in terms of silica of hydrolyzable methoxysilane (2) / weight of epoxy resin (1))
= 1.41, equivalent of methoxy group of hydrolyzable methoxysilane (2) / equivalent of hydroxyl group of epoxy resin (1)) = 2
5.0. From the ¹ H-NMR (CDCl ₃ solution) of the present resin solution, 100% of the methine peak of the epoxy ring (around 3.3 ppm) is retained, and the peak of the hydroxyl group in the epoxy resin (around 3.85 ppm) is completely eliminated. It was confirmed that it had disappeared. The epoxy equivalent of the obtained alkoxy-containing silane-modified epoxy resin solution was 230.
It was 0 g / eq.

Comparative Production Example 1 Epotote YD-011 was dissolved in dimethylformamide to prepare a resin solution having a nonvolatile content of 50%. The epoxy equivalent of the epoxy resin solution was 950.

Comparative Production Example 2 To 85 g of Epotohto YD-011, 85 g of dimethylformamide and 41.9 g of methyl silicate 51 were added to obtain a 50% epoxy resin-alkoxysilane solution of the active ingredient. The epoxy equivalent of the obtained epoxy resin-alkoxysilane solution was 950.

COMPARATIVE PREPARATION EXAMPLE 3 68.6 g of dimethylformamide and 41.9 g of methyl silicate 51 were added to 85 g of Epotohto YD-011.
g was added to obtain an epoxy resin-alkoxysilane solution.

Comparative Production Example 4 Epotote YD-127 was dissolved in dimethylformamide to prepare a resin solution having a nonvolatile content of 50%. The epoxy equivalent of the obtained epoxy resin solution was 370.

Examples 1-4 Each 15% solution of dicyandiamide in dimethylformamide was added to each of the resin solutions obtained in Production Examples 1-4, by the equivalent of the amino group of dicyandiamide / the equivalent of the epoxy group in the resin solution = 0.8. And each epoxy resin composition was prepared.

Example 5 Preparation Example 5 and Comparative Example The resin solutions obtained in Preparation Example 1 were mixed at a weight ratio of 1: 1. A 15% solution of dicyandiamide in dimethylformamide was prepared by adding the equivalent of the amino group of dicyandiamide / the resin solution. An epoxy resin composition was prepared by adding so that the equivalent of the epoxy group became 0.8.

Comparative Examples 1, 2 and 4 To each of the resin solutions of Comparative Production Examples 1, 2 and 4, a 15% solution of dicyandiamide in dimethylformamide was added with the equivalent of amino groups of dicyandiamide / the equivalent of epoxy groups in the resin solution = 0. , And each epoxy resin composition was prepared.

Comparative Example 3 To the resin solution of Comparative Production Example 3, 20.1 g of a 15% solution of dicyandiamide in dimethylformamide (equivalent of dicyandiamide amino group / equivalent of epoxy group in resin solution = 0.8) and water 16 Was added, and a sol-gel reaction was performed at room temperature for 2 hours. When the reaction solution was allowed to stand, it gelled three hours after the reaction.

Each of the resin compositions obtained in the Examples and Comparative Examples was poured into a container (length × width × depth = 10 cm × 10 cm × 1.5 cm) coated with a fluororesin, and was heated at 135 ° C.
For 1 hour at 175 ° C. for 2 hours to remove and cure the solvent. The state of the obtained cured product (bubbles, degree of shrinkage,
(Appearance) was evaluated based on the following criteria. Table 1 shows the results.

(Evaluation of air bubbles) A: There are no air bubbles in the cured product. Δ: 1 to 4 air bubbles are present in the cured product. X: Five or more air bubbles are present in the cured product.

(Evaluation of shrinkage) A: There is no crack in the cured product. C: Cracks are present in the cured product. ×: The cured product has many cracks.

(Appearance evaluation) ：: Transparent. Δ: Cloudy. ×: Whitened.

[0050]

【table 1】

From Table 1, it can be seen that each of the epoxy resin compositions of the examples was a transparent cured film (about 0.4 mm thick).
However, with the epoxy resin composition of Comparative Example 3, foaming and shrinkage during curing were severe, and a practical cured film could not be obtained. Although a cured film was obtained with the epoxy resin composition of Comparative Example 2, it was whitened due to phase separation between the epoxy resin and silica, and was very brittle.

(Heat Resistance) The cured films obtained in Examples 2, 3, 4, 5 and Comparative Examples 1 and 4 were cut into 6 mm × 25 mm, and were subjected to a viscoelasticity measuring device (trade name “DV manufactured by Rheology Co., Ltd.”).
E-V4 ", measurement conditions: amplitude 1 μm, frequency 10 Hz,
The dynamic storage modulus was measured using a slope of 3 ° C./min) to evaluate the heat resistance. The measurement results are shown in FIGS.

As is clear from FIG. 1, in Comparative Example 1,
Although the glass transition of the cured film (cured epoxy resin) is observed, the glass transition of the cured film completely disappears in Example 2, and the glass transition tends to disappear also in Example 3. Is recognized. Further, in Example 5, exactly the same results as in Example 2 were obtained. As described above, the cured films of the examples have no glass transition even at high temperatures and have excellent heat resistance.

As is clear from FIG. 2, the glass transition point (T
g) is high, the high temperature elastic modulus is excellent, and the heat resistance is excellent.

[Brief description of the drawings]

FIG. 1 shows a second embodiment (a fifth embodiment is not shown) and a third embodiment.
6 shows the evaluation results of the heat resistance of the cured film obtained in Comparative Example 1 and Comparative Example 1.

FIG. 2 shows the evaluation results of heat resistance of the cured films obtained in Example 4 and Comparative Example 4.

Claims (5)

[Claims] 1. An alkoxy group-containing silane-modified epoxy resin (A) obtained by subjecting a bisphenol type epoxy resin (1) and a hydrolyzable alkoxysilane (2) to a dealcoholization condensation reaction, and a curing agent (B) for an epoxy resin. An epoxy resin composition comprising: 2. Bisphenol type epoxy resin (1)
The epoxy resin composition according to claim 1, wherein is a bisphenol A type epoxy resin. 3. The method of claim 1, wherein the hydrolyzable alkoxysilane (2) is
General formula (a): (Wherein Me represents a methyl group, n is an integer of 0 or more, and the average number of repeating units of n is 1 to 7), and is poly (tetramethoxysilane). The epoxy resin composition according to the above. 4. Bisphenol type epoxy resin (1)
And the use ratio of the hydrolyzable alkoxysilane (2) is
Silica-equivalent weight of hydrolyzable alkoxysilane (2) /
Weight (weight ratio) of bisphenol type epoxy resin (1)
The epoxy resin composition according to claim 1, 2 or 3, wherein 5. The epoxy resin composition according to claim 1, wherein the epoxy resin curing agent (B) is a polyamine-based curing agent.