JPS5846136B2 - Heat-resistant epoxy resin composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel heat-resistant epoxy resin composition.

More specifically, an imide ring-containing ester compound having the formula: an integer of ~3], R2 is an aliphatic or aromatic dihydroxy residue) is reacted with an epoxy compound having two epoxy groups in one molecule. By blending an imide epoxy resin and an acid anhydride, it has excellent heat resistance, as detailed below, and can provide a cured resin product with excellent mechanical and electrical properties. The present invention relates to an epoxy resin composition.

A cured epoxy resin is produced by reacting an epoxy compound with a curing agent such as an amine or an acid anhydride.

Although such cured epoxy resin products are widely used in various fields due to their excellent electrical properties and dimensional stability, these epoxy compounds are not fully satisfactory in terms of heat resistance. .

For this reason, many studies have been made to provide heat-resistant epoxy resin cured products.

For example, in Japanese Patent Publication No. 49-12600, a cured epoxy resin with excellent heat resistance is obtained by blending an epoxy resin and a maleimide compound, but in this invention, the bridge density of the maleimide structure is Due to its high temperature, cracks are likely to occur due to heat cycles, and when used for impregnation or casting of large coils, for example, if heat cycles are applied after curing, the coil surface may peel or crack, which poses a serious problem in practice.

Furthermore, in Japanese Patent Publication No. 50-32119, etc.,
An imide epoxy resin produced by the reaction of an imide ring-containing dicarboxylic acid with an epoxy compound has been shown, and although such a cured imide epoxy resin does have excellent heat resistance, it It has problems such as difficulty in reacting with epoxy compounds.

The present inventors have discovered that a cured product that has heat resistance and excellent mechanical properties can be easily spread, and can be used for impregnation, casting, lamination, painting, etc. As a result of various studies to find a suitable epoxy resin composition, we found that an ester compound containing an imide ring (hereinafter referred to as an imido ester compound) having the formula: (wherein R1 and R2 are the same as above) and two ester compounds in one molecule. It was discovered that by blending an imide epoxy resin obtained by reacting an epoxy compound having an epoxy group with an acid anhydride, heat resistance and flexibility could be imparted to the resulting cured product, and the present invention was completed. I ended up doing it.

That is, the heat-resistant epoxy resin composition of the present invention has a melting point lower than that of the imide ring-containing dicarboxylic acid, and
In addition, by using an imide ester compound that has excellent compatibility with epoxy compounds, it is possible to easily spread the imide epoxy resin, and the ester bond within the imide ester compound can impart flexibility to the cured product. In addition, heat resistance can be imparted by reacting with an acid anhydride used as a curing agent.

Furthermore, by changing the diol component of the imidoester compound, cured resin products with different properties can be obtained.

In general, it has been difficult to introduce imide rings into epoxy resins because derivatives with imide rings are poorly soluble. It easily reacts in the presence of a catalyst, etc., and can be mixed with imide epoxy resin.

The imidoester compound used in the present invention can be easily obtained by mixing 1 mole of trimellitic acid or trimethic anhydride, 1 mole of monoaminocarboxylic acid, and 2 moles of diol and causing a heating reaction. can.

Examples of the monoaminocarboxylic acids used here include glycine, β-aminopropionic acid, α-aminobutyric acid, anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, and the like.

Examples of diols include ethylene glycol,
Diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4
-butanediol, hexamethylene glycol, neopentyl glycol, bisphenol A, noidoquinone, hydrogenated bisphenol A, and the like.

Such diols are preferably selected appropriately depending on the intended use of the cured resin material.

For example, in order to obtain a flexible resin cured product, a linear glycol with a large number of carbon atoms is used, and in order to obtain a resin cured product with a high heat distortion temperature, a rigid resin such as a hydrogenated compound of bisphenol A is used. It is better to use a compound that is

As the epoxy compound used in the present invention, for example, bisphenol A diglycidyl ether type Epicote 828.834.1001 or 1004 (the above,
(manufactured by Shell) and the alicyclic type Chinnox 221 or 289 (manufactured by Chisso ■).
It is not limited only to these.

The epoxy curing agent used in the present invention has the formula: %Formula% The imide epoxy resin has an epoxy group of 1.6 to 5 in the epoxy compound per equivalent of hydroxyl group in the imide ester compound.
Mixed in a ratio of 0 equivalents, no catalyst or acid,
0 at a temperature of 150-270°C in the presence of a base catalyst etc.
．． It can be obtained by reacting for 5 to 5 hours.

Next, the heat-resistant epoxy resin composition of the present invention is changed by blending an acid anhydride into the imide epoxy resin at a ratio of 0.6 to 1.2 equivalents of acid anhydride per equivalent of the epoxy end group.

The reason why the blending ratio of the epoxy compound is set to 1.6 to 50 equivalents per equivalent of hydroxyl group of the imidoester compound is that if it is less than that, the molecular weight of the product increases too much and the compatibility with hardening agents etc. decreases. However, this is because workability deteriorates, and furthermore, the heat resistance of the cured product obtained is insufficient.

Although the reaction is preferably carried out without a solvent, an appropriate amount of a polar solvent such as N-methylpyrrolidone or N-N-dimethylacetamide may be used to further accelerate the reaction.

Furthermore, the blending ratio of acid anhydride was set to 0.6 to 1.2 equivalents because if the amount is less than 0.6 equivalents, sufficient crosslinking will not occur and the properties will deteriorate, and if the amount is more than 1 or 2 equivalents This is because the crosslinking density becomes too high and the mechanical properties in particular deteriorate.

Next, the heat-resistant epoxy resin composition of the present invention will be explained with reference to Examples and Comparative Examples.

The structural formulas and abbreviations of the imidoester compounds used in each example are shown below.

Example 1 Imidoester compound 60 represented by structural formula IE-1.
Or (0.3 equivalents) and 38Of (2.0 equivalents) of Epicote 828, which is a bisphenol A diglycidyl ether type epoxy compound with an epoxy equivalent weight of 190, were mixed and reacted at 200° C. for 1 hour.

The product was a colored liquid and had an epoxy equivalent of 270 by the hydrochloric acid-dioxane method.

In addition, as a result of infrared absorption spectrum analysis, 910CIfL
”The epoxy group characteristic absorption near 1780cIr decreases.
L'', 1725cIfL' and 725cIrL-1 exhibited absorption characteristic of imide groups, confirming the production of imide epoxy resin.

270f of the obtained imide epoxy resin? (1 equivalent) to methyltetrahydrophthalic anhydride 150S' (0,g
equivalent amount) and heated at 150°C for 5 hours, then at 180°C for 1 hour.
A cured product was obtained by heating for 0 hours.

The bending strength of this product is 14.5kg/x at 25℃
i, and the flexural modulus was 260 kllil/M.

Furthermore, the weight loss rate when heated in air at 240° C. for 500 hours was 4.5%.

The heat distortion temperature of this material by TMA method is 98°C,
It withstood thermal shock from 0 to 200°C using the Oliphant washer method.

Furthermore, in the T-peel peel test, the pressure was 10.8 psi (25
°C).

Example 2 Imidoester compound represented by structural formula IE-2 24.
2f? (0,1 equivalent) and Epicote 828033.2fI (o, is equivalent), which is a bisphenol A diglycidyl ether type epoxy compound with an epoxy equivalent of 190, were dissolved in N-methylpyrrolidone, and C8H170K as a catalyst was further added. It was heated at 210°C for 1 hour.

The obtained product was a black and colored resinous material, and the epoxy equivalent weight determined by the hydrochloric acid-dioxane method was 720.

In addition, as a result of infrared absorption spectrum analysis, 910cIIL
”The characteristic absorption of epoxy groups in the vicinity decreases, and 1785cIr
L-1゜1726CrrL'' and 725cIrL
"Absorption characteristic of imide groups was observed, and the formation of imide epoxy resin was confirmed.

Methyl nadic acid anhydride 340y (1,
80 equivalents) was added and heated at 150°C for 15 hours to obtain a cured product.

The bending strength of this product is 15.4kg/m at 25℃
1N, and the flexural modulus was 265 kg/xi.

Moreover, the weight loss rate when heated in air at 240° C. for 500 hours was 3.2%.

The thermal deformation temperature of this material by TMA method was 115° C., and it withstood thermal shock of 0 to 200° C. by Oliphant-Fuscher method.

The T-peel peel test showed a value of 13.0 psi (25°C).

Example 3 Imidoester compound represented by structural formula IE-3 35.
10 of Chissonox 289, an alicyclic type epoxy compound with 4F (0,1 equivalent) and epoxy equivalent of 210.
5Or (5,0 equivalents) and CH30 as catalyst
1. Of was added and heated at 230°C for 1 hour.

The product was a colored liquid with an epoxy equivalent of 220.

As a result of infrared absorption spectrum analysis, the characteristic absorption of epoxy groups around 910 cm' decreased, and 1780 cIIL'',
Absorption characteristic of imide groups was observed in 1724cIrL-1 and 720CrfL-1, and production of imide epoxy resin was confirmed.

220f of the obtained imide epoxy resin? (1 equivalent) to 100% butanetetracarboxylic dianhydride as a curing agent
．． 5P (1.0 equivalent) was added and heated at 150°C for 5 hours and then at 180°C for 5 hours to obtain a cured product.

The bending strength of this product is i6. at 25°C. Okg
/mri, and the bending elastic modulus was 300ky/door d.

Furthermore, the weight loss rate when heated in air at 240° C. for 500 hours was 4.3%.

The thermal deformation temperature of this material by TMA method was 125° C., and it withstood thermal shock of 0 to 200° C. by Oliphant washer method.

It showed a value of 10.0 psi (25°C) in the T-peel peel test.

Example 4 Imidoester compound 108 represented by structural formula IE-4
．． 6P (0,3 equivalents) and 380S' (2 equivalents) of Epicote 828, the same as used in Examples 1 and 2 above.
were mixed and heated at 230°C for 2 hours.

The product was a colored liquid with an epoxy equivalent weight of 310.

As a result of infrared absorption spectrum analysis, the formation of imide epoxy resin was confirmed.

Methyltetrahydrophthalic anhydride xsoy (0, g equivalent) was added to 310y (1 equivalent) of the obtained imide epoxy resin and heated at 150°C for 5 hours and then at 180°C for 5 hours to obtain a cured product.

The bending strength of this product was 15.5 to 19/- at 25°C, and the bending modulus was 310 kg/-.

The thermal deformation temperature of this product by the TMA method was 135°C, and it withstood thermal shock of 0 to 200°C by the Oliphant washer method.

The T-peel peel test showed a value of 11.8 psi (25°C).

Comparative Example Same Epicote 828 used in Examples 1.2 and 4.
Methyltetrahydrophthalic anhydride 308@ (1,8 equivalents) was added to 38Of (2,0 equivalents) and the mixture was heated to 150°C.
The mixture was heated for 5 hours and then at 180° C. for 10 hours to obtain a cured product.

The bending strength of this product is i 4.5kg/ at 25℃
m4, and the flexural modulus was 340 kg/ma.

Furthermore, the heat distortion temperature by the TMA method is 130°C, and 2
The weight loss rate of the product heated in air at 40°C for 500 hours was 18.0%, and it was
Cracks occurred due to thermal shock at ~200°C.

The T-peel peel test showed a value of 4.1 psi (25°C).

Claims (1)

[Claims] 1 Reaction of an imide ring-containing ester having the formula: [an integer of ~3], R2 is an aliphatic or aromatic dihydroxy residue) with an epoxy compound having two epoxy groups in one molecule A heat-resistant epoxy resin composition characterized by blending an imide epoxy resin and an acid anhydride.