JP2911157B2 - Epoxy resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a liquid polybutadiene, a liquid polybutadiene, a liquid, which has good flexibility, water resistance, and transparency, and is generally hardly compatible with an epoxy resin. The present invention relates to polyisoprene, and an epoxy resin composition having excellent compatibility with hydrogenated products thereof, liquid silicone, and a terminal-modified compound thereof.

<Conventional technology> In general, epoxy resin is hard and brittle, so when applied to applications such as adhesives, the peel strength is low, and various coating materials such as cushioning materials or parts where internal stress is applied There is a problem that application as a potting material is difficult.

As a method of imparting flexibility to such an epoxy resin, a method of introducing a polyether skeleton into the resin, as disclosed in JP-B-56-8041, JP-B-62-53527, is often used. Are known. However, the polyether skeleton has a high affinity for water and thus has a high water absorption, and cannot maintain sufficient flexibility under severe conditions such as a hot water resistance test and a moist heat resistance test. Has the disadvantage that it is gradually lost.

On the other hand, polybutadiene-modified epoxy resin and various modified epoxy resins such as silicone-modified epoxy resin are excellent in water resistance, but polybutadiene-modified epoxy resin is inferior in heat resistance, and silicone-modified epoxy resin has a brittle cured product. It has the drawback that sufficient flexibility cannot be obtained.

Even when a plurality of resins having different properties are used in combination, the compatibility of each composition is often poor, and the resulting composition becomes opaque. Therefore, it was impossible to sufficiently exhibit the characteristics of both.

<Problems to be Solved by the Invention> An object of the present invention is to solve the problems of the conventional technology, and a good flexibility having a polyether skeleton,
By having both water resistance such as polybutadiene-modified epoxy resin and silicone-modified epoxy resin, it is possible to obtain a cured product that can be applied well to potting materials, coating materials, adhesives, etc. in the electric and electronic fields. It is to provide a resin composition.

<Means for solving the problem> In order to achieve the object, the present invention has a molecular weight of 500 to 5
000 polybutylene glycol and a compound having an isocyanate group at the terminal obtained by reacting an aliphatic isocyanate having 5 to 20 carbon atoms, a urethane-modified epoxy resin 100 obtained by reacting a compound having an epoxy group and a hydroxyl group with 100 5 to 5 parts by weight of butadiene-modified epoxy resin and / or silicone-modified epoxy resin
An epoxy resin composition comprising 400 parts by weight.

Hereinafter, the epoxy resin composition of the present invention will be described in detail.

The molecular weight of the polybutylene glycol applied to the present invention is from 500 to 5,000. If the molecular weight is less than 500, it is not possible to obtain sufficient flexibility, and if it exceeds 5,000, the resulting urethane-modified epoxy resin and the butadiene-modified epoxy resin described later, the compatibility with the silicone-modified epoxy resin becomes poor, The characteristics of the present invention having good water resistance and flexibility cannot be sufficiently exhibited.

In the epoxy resin composition of the present invention, the molecular weight of polybutylene glycol is preferably from 1,000 to 3,000. In this case, more preferable results are obtained in terms of compatibility, flexibility and the like.

In the present invention, a compound having a terminal isocyanate group is obtained by reacting such polybutylene glycol with an aliphatic isocyanate having 5 to 20 carbon atoms.

By limiting the isocyanate to be applied to the aliphatic isocyanate, it becomes possible to obtain an epoxy resin composition having good compatibility with butadiene-modified epoxy resin and silicone-modified epoxy resin.

The aliphatic isocyanate to be used has 5 carbon atoms.
~ 20. If the number of carbon atoms of the aliphatic isocyanate is less than 5, volatility and the like are high, so that it is not preferable in terms of toxicity. If it exceeds 20, the crystallinity becomes high, and it becomes difficult to handle.

Specific examples of such an aliphatic isocyanate include hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, propane-1,2-diisocyanate, and 2,3-diisocyanate.
Dimethylbutane-2,3-diisocyanate, 2-methylpentane-2,4-diisocyanate, octane-3,6-diisocyanate, octane-1,6-diisocyanate,
3,3-dinitropentane-1,5-diisocyanate, 2,2,
4-trimethylhexamethylene diisocyanate, 2,4,4
-Trimethylhexamethylene diisocyanate and the like are preferably exemplified. Among them, hexamethylene diisocyanate, isophorodiisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate and the like are particularly preferably applied.

In the present invention, such a compound having an isocyanate group at the terminal is reacted with a compound having an epoxy group and a hydroxyl group to obtain a urethane-modified epoxy resin.

The compound having an epoxy group and a hydroxyl group,
For example, it is a compound containing 1 to 3 epoxy groups and 1 to 2 hydroxyl groups in the molecule, and specifically, glycidyl ethers of polyhydric alcohols such as glycidol and glycerin diglycidyl ether. It is preferably exemplified.

There is no particular limitation on the method of synthesizing such a urethane-modified epoxy resin, but as an example, first, a predetermined polybutylene glycol and the above-described aliphatic isocyanate are mixed, and a catalyst is added as necessary, By stirring and reacting at about 80 ° C. for about 4 hours, a compound having an isocyanate group at a terminal is synthesized. The amount ratio of polybutylene glycol and aliphatic isocyanate in this reaction is preferably 1.2 to 5.0 mol, more preferably 1.5 to 3.0 mol of aliphatic isocyanate per mol of polybutylene glycol.
It is about a mole.

In this reaction, n-butyltin dilaurate,
It is preferable to apply a reaction catalyst such as n-butyltin dimaleate. The reaction may be carried out using various solvents as necessary.

Next, the compound having an epoxy group and a hydroxyl group described above is added to the compound having an isocyanate group at the terminal thus obtained, and the mixture is stirred and reacted at about 80 ° C. for about 6 to 10 hours. Urethane-modified epoxy resin.

At this time, the amount ratio of the compound having an epoxy group and a hydroxyl group is preferably 0.3 to 5.0 mol, more preferably 1 mol of the above-mentioned polybutylene glycol.
It is about 0.5 to 3.0 mol.

In the above reaction, various reaction solvents such as benzene, toluene, hexane, and methylene chloride may be used as necessary.

In addition, the urethane-modified epoxy resin obtained in this manner was prepared in such a manner that the molar ratio of hydroxyl groups to isocyanate groups and OH / NCO were 1 or more in order to prevent the resulting urethane-modified epoxy resin from being modified. Is preferably adjusted so that no isocyanate groups remain in the reaction product.

Further, the obtained urethane-modified epoxy resin preferably has an epoxy equivalent of about 400 to 3000 and an average molecular weight of about 800 to 6000.

The epoxy resin composition of the present invention contains 5-400 parts by weight of a butadiene-modified epoxy resin and / or a silicone-modified epoxy resin with respect to 100 parts by weight of such a urethane-modified epoxy resin.

Basically, by having such a composition, the epoxy resin composition of the present invention can be made into a composition by containing two kinds of resins having different characteristics with good compatibility, and even when cured, it is resistant to water. Properties and flexibility.

If the content of the butadiene-modified epoxy resin and the silicone-modified epoxy resin is less than 5 parts by weight, the desired effect cannot be obtained, particularly in terms of water resistance. The compatibility deteriorates, and the water resistance of the obtained cured product also deteriorates.

The applicable butadiene-modified epoxy resin is 1,
All compounds having an epoxy group at the terminal or in the molecule of various polybutadienes such as 4-polybutadiene and 1,2-polybutadiene are applicable, but the average molecular weight is 1000
~ 3500 liquid is preferred, especially with an average molecular weight of 1000
30003000 are preferably applied.

As such a butadiene-modified epoxy resin, specifically, poly BD R45-EPT, poly BD R45-EPI (the above,
Preferable examples include Idemitsu Kosan Co., Ltd.) and BF-1000 (Nippon Soda Co., Ltd.).

In addition, the silicone-modified epoxy resin to be applied has a silicone skeleton in the main chain, and all compounds having an epoxy group at the terminal or in the molecule thereof can be applied, but preferably a liquid liquid having an average molecular weight of 600 to 8000 is preferable. Things apply.

Specific examples of such a silicone-modified epoxy resin include KF-101 (manufactured by Shin-Etsu Chemical Co., Ltd.) and X-22-160.
A (Shin-Etsu Chemical Co., Ltd.) urethane-modified epoxy resin, S
F-8411 (manufactured by Toray Silicone Co., Ltd.) is a preferred example.

In the present invention, a plurality of such butadiene-modified epoxy resins and silicone-modified epoxy resins may be used, in which case the total amount is 5 to 400 parts by weight based on 100 parts by weight of the urethane-modified epoxy resin. What is necessary is just to make it a weight part.

Further, it may contain both a butadiene-modified epoxy resin and a silicone-modified epoxy resin.
In this case, the content ratio of the two is not particularly limited, and may be appropriately determined according to the use. The total content of both may be 5 to 400 parts by weight based on 100 parts by weight of the urethane-modified epoxy resin.

Basically, the epoxy resin composition of the present invention having such a composition has good compatibility with liquid silicone, liquid polybutadiene, and hydrogenated products thereof, which were not compatible with the conventional epoxy resin composition. It is also possible to mix them and apply them to various uses.

The mixing ratio when mixing the epoxy resin composition of the present invention, liquid silicone, and liquid polybutadiene is not particularly limited, but preferably the epoxy resin composition 100 of the present invention.
Liquid silicone and liquid polybutadiene are less than about 100 parts by weight based on parts by weight.

Compositions containing such an epoxy resin composition and liquid silicone, liquid polybutadiene are particularly flexible,
Since it has excellent properties such as water resistance and heat resistance, it is suitably applied to uses such as potting materials.

When curing the epoxy resin composition of the present invention, various curing agents may be applied in the same manner as in a normal epoxy resin composition, and acid anhydrides, primary amines, secondary amines, tertiary amines, imidazoles And an organic metal complex are preferably exemplified.

Specifically, as the acid anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride,
Examples thereof include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhymic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, and chlorendic anhydride.

Primary amines include isophoronediamine, diethylenetriamine, triethylenetetramine, dipropylenediamine, diethylaminopropylamine, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, mensendiamine, 4,4'-diaminodicyclohexyl Methane, 1,3-bisminomethylcyclohexane, xylenediamine, metaphenylenediamine, diaminodiphenylmethane and the like can be mentioned.

Examples of the secondary amine include piperidine, diethanolamine, dibenzylamine and the like.

Examples of the tertiary amine include dimethylcyclohexylamine, dimethylbenzylamine, dimethylhexylamine, dimethylaminomethylphenol, dimethylamino p-cresol, pyridine, triethanolamine, and triethylenediamine.

Examples of imidazoles include 2-methylimidazole,
2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole,
1-cyanoethyl-2-ethyl-4-methylimidazole and the like.

Examples of the organic metal complex include aluminum acetylacetonato, acetylacetonatocobalt, acetylacetonatochromium, acetylacetonatomanganese, zinc octylate, tin octylate, and zinc naphthenate.

In the epoxy resin composition of the present invention, the addition amount of such a curing agent may be a stoichiometric amount relative to the epoxy equivalent of the epoxy resin composition of the present invention.

In addition, these curing catalysts, one or more,
May be added.

The curing time and temperature are not particularly limited, and the optimal curing time and temperature may be appropriately set according to the applied curing agent.

Epoxy resin composition of the present invention, in addition to the above components,
If necessary, other resin components may be contained as long as the properties of the present invention are not impaired. Also, surface treatment agents, anti-aging agents, flame retardants, pigments, dyes, inorganic and organic fillers, etc. It goes without saying that may be used together.

<Example> Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

First, various urethane-modified epoxy resins shown below were prepared.

Epoxy resin A Polybutylene glycol [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., weight average molecular weight (hereinafter, referred to as Mw) 2000] 500 g, 500 g
2.025 4'-dicyclohexylmethane diisocyanate
The reaction was added at 80 ° C. for 4 hours. In the reaction, 50 ppm of n-butyltin dilaurate was used as a catalyst.
Was added.

Next, 2.05 equivalents of glycidol was added to the reaction product, and the mixture was reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin A having an epoxy group at a terminal.

Epoxy resin B polybutylene glycol [manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Mw
= 5000) To 1000 g, 2 equivalents of isophorone diisocyanate were added and reacted at 80 ° C. for 4 hours. At the time of the reaction, 50 ppm of n-butyltin dilaurate was added as a catalyst.

Next, 2.025 equivalents of glycidol was added to the reaction product and reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin B having an epoxy group at a terminal.

Epoxy resin C polybutylene glycol [manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Mw
= 500) To 1000 g, add 2 hexamethylene diisocyanate
The reaction was added at 80 ° C. for 4 hours. In the reaction, 50 ppm of n-butyltin dilaurate was used as a catalyst.
Was added.

Next, 2.025 equivalents of glycidol was added to the reaction product and reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin C having an epoxy group at a terminal.

Epoxy resin D polytetramethylene glycol (manufactured by Mitsubishi Kasei Corporation,
(Mw = 2000) To 1000 g, 2.025 equivalents of 4,4'-dicyclohexylmethane diisocyanate was added and reacted at 80 ° C. for 4 hours. At the time of the reaction, 50 ppm of n-butyltin dilaurate was added as a catalyst.

Next, 2.05 equivalents of glycidol was added to the reaction product, and the mixture was reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin D having an epoxy group at a terminal.

Epoxy resin E polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., Mw = 10
00) To 1000 g, 2.025 hexamethylene diisocyanate
The reaction was added at 80 ° C. for 4 hours. In the reaction, 50 ppm of n-butyltin dilaurate was used as a catalyst.
Was added.

Next, 2.025 equivalents of glycidol was added to the reaction product, and the mixture was reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin E having an epoxy group at the terminal.

Epoxy resin F polypropylene glycol (manufactured by Sanyo Chemical Co., Ltd., Mw =
1000) To 1000 g, 2.025 equivalents of isophorone diisocyanate was added and reacted at 80 ° C. for 4 hours. At the time of the reaction, 50 ppm of n-butyltin dilaurate was added as a catalyst.

Next, 2.05 equivalents of glycidol was added to the reaction product, and the mixture was reacted at 80 ° C. for 10 hours to obtain a urethane-modified epoxy resin F having an epoxy group at a terminal.

Epoxy resin G Urethane-modified epoxy resin (EPU-6, manufactured by Asahi Denka Co., Ltd.)
Epoxy equivalent 230) Next, the following various polybutadiene-modified epoxy resins, silicone-modified epoxy resins, and bisphenol A type epoxy resins were prepared.

Bisphenol A type epoxy resin EP-4100 (Asahi Denka Co., Ltd. epoxy equivalent 190) Polybutadiene modified epoxy resin A Poly BD R45-EPT (Idemitsu Kosan Co., Ltd. Mw = about 2800) Polybutadiene modified epoxy resin B Poly BD R45- EPI (Idemitsu Kosan Co., Ltd. Mw = about 2800) Polybutadiene-modified epoxy resin C BF-1000 (Nippon Soda Co., Ltd., Mw = about 1000) Silicone-modified epoxy resin A KF-101 (Shin-Etsu Chemical Co., Ltd. Mw) = Approximately 700) Silicone-modified epoxy resin B To 1000 g of silicone-modified polyol (X-22-160A manufactured by Shin-Etsu Chemical Co., Ltd.), 2.025 equivalents of isophorone diisocyanate was added and reacted at 80 ° C. for 4 hours. During the reaction, n-butyltin dilaurate was used as a catalyst.
ppm was added.

Next, 2.05 equivalents of glycidol was added to the reaction product and reacted at 80 ° C. for 10 hours to obtain a silicone-modified epoxy resin B having a terminal epoxy group.

Example 1 The above epoxy resins A to G, a bisphenol A type epoxy resin, a polybutadiene-modified epoxy resin C and a silicone-modified epoxy resin A were mixed and evaluated for compatibility.

 Table 1 shows the results.

 The evaluation was evaluated as: ○: compatible (transparent) Δ: translucent ×: not compatible (cloudy).

As shown in Table 1, the epoxy resin composition of the present invention comprising a urethane-modified epoxy resin derived from polybutylene glycol and a polybutadiene-modified epoxy resin or a silicone-modified epoxy resin has good compatibility.

On the other hand, the urethane-modified epoxy resin made of polyethylene glycol, polytetramethylene glycol, or the like was compatible with the bisphenol A type epoxy resin, but was not compatible with the polybutadiene-modified epoxy resin and the silicone-modified epoxy resin.

[Example 2] Various epoxy resin compositions were prepared using the epoxy resins A to G and the polybutadiene-modified epoxy resins A to C. The composition of each epoxy resin is shown in Table 2 in parts by weight.

Each such epoxy composition is cured using stoichiometric isophoronediamine, and these are used as samples to obtain elongation (flexibility), compatibility of each composition, water absorption, breaking strength, and breaking strength after water resistance test. The test was performed for each of the items.

 Table 2 shows the results.

The compatibility was evaluated in the same manner as in Example 1, and the elongation (flexibility), the water absorption, the breaking strength, and the breaking strength after the water resistance test were performed as follows.

Elongation (flexibility) A 1 mm thick sheet was prepared and punched out with a plastic No. 2 dumbbell to obtain a tensile test sample.

This sample is pulled at a pulling speed of 5 mm / min,
The elongation at break was measured.

Water absorption rate Cut each sample into a size of 50mm x 50mm x 1mm, 23 ℃
Was immersed in water for 23 hours, and the change in weight (%) was measured.

Breaking strength A sample was formed into a sheet having a thickness of 1 mm, punched out with a plastic No. 2 dumbbell, and evaluated for tensile strength at a tensile speed of 50 mm / min.

Breaking strength after water resistance test A sample immersed in warm water of 80 ° C for one week was tested for breaking strength in the same manner as described above.

The breaking strength retention was calculated by the following formula [I].

Formula [I] Example 3 An epoxy resin composition was prepared in the same manner as in Example 2 except that the polybutadiene-modified epoxy resins A to C were replaced with the silicone-modified epoxy resins A and B, and the same test was performed. Table 3 shows the composition and test results of each epoxy resin.
Shown in

From the results shown in Tables 2 and 3, it can be seen that the epoxy resin composition of the present invention has good compatibility of each composition. Further, the cured product has a large elongation (flexibility), a low water absorption, and is excellent in rupture strength and also in rupture strength retention after a water resistance test.

On the other hand, even if the composition has the same components as the present invention, if the blending amount of the polybutadiene-modified epoxy resin or silicone-modified epoxy resin exceeds 400 parts by weight, the compatibility of each component is reduced, and the water resistance of the cured product is reduced. Also worse. If the blending amount of the polybutadiene-modified epoxy resin or the silicone-modified epoxy resin is less than 5 parts by weight, the water resistance (the retention of rupture strength after a water resistance test) is slightly deteriorated.

Example 4 Various epoxy resin compositions were prepared using the urethane-modified epoxy resins A and G, the polybutadiene-modified epoxy resin A, and the silicone-modified epoxy resin A.

Silicone oil (KF96 100cp)
Shin-Etsu Chemical Co., Ltd.) or liquid polybutadiene (B-1
000 Nippon Soda Co., Ltd.)
The water absorption and the vertical tensile strength of the cured product were examined.

 Table 4 shows the composition of each composition and the test results.

The tests for compatibility and water absorption are the same as those described above. The vertical tensile strength was determined by the following method.

Vertical tensile strength JIS A6916 was referred to.

Each composition is applied to a 50 mm x 50 mm glass epoxy board (manufactured by Japan Test Panel Co., Ltd.) to a thickness of 1 mm, cured, and then a 20 mm diameter aluminum jig is attached. (Made by elcometer) and pulled in a vertical direction, and the force at that time was measured.

From the results shown in Table 4, the epoxy resin composition of the present invention is excellent in compatibility with silicone oil and liquid polybutadiene, which has been difficult with conventional epoxy resins. Further, it can be seen that the cured product has a low water absorption and a high vertical tensile strength.

 From the above results, the effect of the present invention is clear.

<Effects of the Invention> As described in detail above, the epoxy resin composition of the present invention has good compatibility of each composition and excellent transparency. In addition, unlike conventional epoxy resin compositions, liquid silicone, liquid polybutadiene, and also have good compatibility with hydrogenated products thereof, so that they can be suitably applied as a base of these blended compositions. .

In addition, the epoxy resin composition of the present invention and a composition containing the same provide a cured product having excellent flexibility and water resistance and high strength, and therefore, particularly, an electric / electronic component which is required to have such properties. It can be suitably applied to potting agents, coating agents, adhesives and the like.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08G 59/20-59/38 C08G 59/14 C08L 63/00-63/10

Claims (2)

(57) [Claims] A compound having an epoxy group and a hydroxyl group is reacted with a compound having an isocyanate group at a terminal obtained by reacting a polybutylene glycol having a molecular weight of 500 to 5000 with an aliphatic isocyanate having a carbon number of 5 to 20. An epoxy resin composition comprising 5 to 400 parts by weight of a butadiene-modified epoxy resin and / or a silicone-modified epoxy resin with respect to 100 parts by weight of a urethane-modified epoxy resin obtained by the above method. 2. The epoxy resin composition according to claim 1, which contains liquid silicone and / or liquid polybutadiene.