JPS5817490B2 - Curable epoxy resin composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to novel epoxy resin compositions.

More specifically, the present invention relates to a curable epoxy resin composition containing a new acid anhydride-based latent curing agent, which curing agent has excellent compatibility with epoxy resins and furthermore, In addition to improving the storage stability and pot life of the epoxy resin composition obtained by using the epoxy resin composition, the curable epoxy resin composition also cures rapidly during heat curing, and the resulting resin exfoliate has significantly improved electrical properties. relating to things.

Conventionally, if acid anhydride is used as a curing agent in epoxy resin,
It is known that cured products with excellent mechanical, electrical, chemical, or thermal properties can be obtained, but epoxy resin compositions using acid anhydrides have poor storage stability and pot life. Although it has excellent properties, it has the disadvantage of poor curing properties.

Therefore, in order to improve the curing properties, amines, usually tertiary amines, are added as curing accelerators. , the pot life is significantly shortened.

Therefore, a complex compound of boron trifluoride and amines is recognized as a representative example of a so-called latent curing agent developed to improve these drawbacks.
When applied to an epoxy resin composition using an acid anhydride as a curing agent, it does not exhibit a sufficiently satisfactory pot life, and the cured product obtained has particularly poor electrical properties.

Further, the complex compound itself has problems such as being easily hygroscopic and deteriorating in quality, and having poor compatibility with epoxy resins.

As described above, epoxy resin compositions using conventionally known curing agents and curing accelerators have various problems and cannot be said to be necessarily satisfactory. Therefore, there is a strong desire to develop a curing agent or curing accelerator that has a long pot life, cures quickly during heat curing, and can impart excellent properties to the resulting cured product.

In order to overcome the above-mentioned drawbacks, the inventors of the present invention have conducted various studies to improve the storage stability, pot life, and curing properties of epoxy resins. When curing the polyepoxy compound having the following properties at high temperature in the presence of a curing agent, at least one kind of acid anhydride, at least one kind of β-diketone, and a chelate compound of a metal are used as the curing agent, and the latter is used in an amount of 0.05 to 1 mole of the former. 0001 to 1 mol, preferably 0.001 to 1 mol
By using reaction products mixed and reacted in proportions in the range of 0.5 molar, a new curable epoxy has the most remarkable effect of eliminating all the drawbacks of slanting and yet achieving the above object. The inventors have discovered that it is possible to provide a palm oil composition, and have completed the present invention.

That is, the novel latent curing agent used in the present invention has excellent compatibility with epoxy resins, improves the storage stability and pot life of epoxy resin compositions prepared using the same, and quickly cures during heat curing. The cured product that is cured and cured is a curable epoxy resin composition with significantly improved electrical properties.

The epoxy resin used in the present invention is not particularly limited, and includes polyhydric phenols such as bisphenol A, catechol, and resolunol; Epoquinated novolak obtained from and epichlorohydrin,
Polyolefin epoxy resins synthesized by peroxidation method such as ihacyclopentadiene oquindo and cyclohexene oquindo, polygrindyl ether obtained from polybasic acid and epichlorohydrin, epoxy resin obtained from phenolphthalein and epichlorohydrin, epoxylated vegetable oil, etc. Common epoxy resins are mentioned, and are appropriately used as base materials for curable epoxy resins.

The curing agent that is a feature of the present invention uses a reaction product of an acid anhydride in the proportions described above, a β-diketone, and a chelate compound of a metal. Preferably, THPA (tetrahydrophthalic anhydride), methylated THPA, HHPA (hexahydrophthalic anhydride), methylated HHPA,! Examples include todenylsuccinic anhydride, methylnadic anhydride, chlorendic anhydride, and pyromellitic anhydride. Chelate compounds of β-diketones and metals include 2,4-pentanedione (acetylacetone), 4,4,4- 1-
IJ fluoro-1-phenylroot 3-butanedione, 2
・2,6,6-titramethyl-3,5-pentanedione, 1,1,105,5,5-hekigafluoropencune-
Examples include metal chelate compounds such as 2,4-dione, and more preferably the metal chelate compounds described above in which the metal is cobalt, manganese, zinc, nickel, aluminum, zirconium, or iron.

The reaction is carried out at a reaction temperature of about room temperature to 300°C, preferably about 80 to 200°C, with thorough stirring in an inert gas until the reaction mixture becomes transparent or homogeneous.

The obtained curing agent has good compatibility with the epoxy resin and can be obtained very easily in the form of a stable liquid or semi-solid state.

Alternatively, the curing agent may be produced by first producing a masterbatch containing a high concentration of metal chelate compound, and diluting this with an acid anhydride to a predetermined ratio.

The amount of the curing agent used is not particularly limited, depending on its curing characteristics or the type of curing agent, and is similar to the amount used in conventional epoxy resin compositions, for example, from 0.4 to 1 mole of epoxy group. 1.2 preferably 0.6 to 1.
It is used in the range of 0 equivalents.

The curable epoxy resin composition of the present invention is used for impregnation, casting, and other molding processes, but depending on the intended molded product, modifying agents such as fillers and diluents may be added to the resin composition. They may be used together as appropriate.

Next, the curable epoxy resin composition of the present invention will be explained with reference to Examples, Reference Examples, and Comparative Examples.

Reference Example 1 Production Example of New Curing Agent 1 mole of methylated THPA (mentioned above) and 0.02 mole of Co(AA)2 (metal chelate compound of cobalt and acetylacetone) were heated at 120° while stirring well in a nitrogen gas stream. The reaction was carried out at C for about 3 hours.

The obtained reaction product was a pale red, low viscosity liquid, and had good compatibility with the epoxy resin.

Reference example 2 Production example of new curing agent 1 mol of HHPA (mentioned above) and zn(AA)2 (metal chelate compound of zinc and acetylacetone) o, o o
While stirring s mol in a nitrogen gas stream, 10
The reaction was carried out at 0°C for about 5 hours.

The resulting reaction product was a slightly opaque white, low viscosity liquid at 100°C and a white solid at room temperature.

The compatibility with the epoxy resin at 100°C was good.

Reference Example 3 Production example of new curing agent 1 mol of methylnadic anhydride and 2.
0.2 mol of a metal chelate compound of 2,6,6-titramethyl-3,5-pentanedione was stirred well in a nitrogen gas stream and reacted at 80° C. until the compound became transparent.

The obtained reaction product was a slightly opaque viscous liquid at room temperature, and had good compatibility with the epoxy resin.

Reference example 4 Production example of new curing agent 1 mol of dodenylsuccinic anhydride and 1.1 nickel
・1・5・5・5-heki size fluoropenkun-2・4-
0.05 mol of a metal chelate compound with dione was reacted with stirring at 160° C. for about 40 minutes in a nitrogen gas stream.

The obtained reaction product was a green transparent viscous liquid and had good compatibility with the epoxy resin.

Example 1 0.6 mol of the curing agent described in Reference Example 1 was added to Epicote 828 (trade name of Noepokine resin manufactured by Neru Chemical Co., diglyndyl ether of bisphenol A, Epokin equivalent weight: about 190) (acid anhydride before reaction). (the same applies hereinafter) were added and mixed to obtain a curable epoxy resin composition.

Although the composition was left at room temperature for 3 months, it did not gel and had a long pot life.

In addition, the gelation time at 150°C and the electrical properties at high temperatures of the cured product when cured under the curing conditions of 90°C x 16 hours + 150°C x 24 hours [from the HDT (heat distortion temperature) of the cured product] ρ■ (volume resistivity) at a temperature approximately 30° C. higher, where ρV is the value 1 minute after the application of a DC voltage of 500 V] was measured.

The results are shown in Table 1.

Example 2 DEN-4,38 (trade name of epoxy resin manufactured by Dow Chemical Company, epoxylated novolak, epoxy equivalent weight approximately 18
0) was added and mixed with 1.0 mol of the curing agent described in Reference Example 2 to obtain a curable epoxy resin composition.

Although the composition was left at room temperature for 3 months, it did not gel and had a long pot life.

In addition, the gelation time of the composition at 150°C and the electrical properties of the cured product at high temperatures were measured in the same manner as in Example 1.

The results are shown in Table 1. Example 3 Araltai 1-CY-183 (trade name of epoxy resin manufactured by Ciba Geigy, digrindyl ester of hexahydrophthalic acid, Epoquine equivalent: about 160) was added to Reference Example 3.
A curable epoxy resin was obtained by adding and mixing 0.7 mol of the curing agent described in .

The composition did not gel for 3 months at room temperature and had a long pot life.

In addition, gelation time and electrical properties of the cured product at high temperatures were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 4 Chissonox-221 (trade name of epoxy resin manufactured by Chisso, 3,4-epoxy resin ￥ normethyl-3,4
- Epoquine cyclohexane carpoquinate, epoxy equivalent (approximately 133) and the curing agent described in Reference Example 4 at 0.6
The moles were added and mixed to obtain a curable epoxy resin composition.

Although the composition was left at room temperature for 3 months, it did not gel and had a long pot life.

Further, the gelation time of the composition at 150°C and the electrical properties of the cured product at high temperatures were measured in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Examples 1 to 2 As a curing accelerator, 2 phr of a complex compound of BF3 and monoethylamine (parts by weight based on 100 parts by weight of epoxy resin, the same applies hereinafter: Comparative Example 1) and 0.5 phr of benzyldimethylamine (Comparative Example 2) were used. Curable epoxy resin compositions were obtained using the same epoxy resin and acid anhydride curing agent (before reaction) in the same proportions as in Example 1, except that they were used.

When these compositions were left at room temperature for one month, they all turned into gels.

Furthermore, the gelation time of these compositions at 150° C. and the electrical properties of the cured products at high temperatures were measured in the same manner as in Example 1.

The results are shown in Table 1. Comparative Examples 3 to 4 Comparative Example 1 except that 2 phr of a complex compound of BF3 and monoethylamine (Comparative Example 3) and 0.5 phr of benzyldimethylamine (Comparative Example 4) were used as curing accelerators.
Curable epoxy resin compositions similar to those in Example 3 were obtained in the same manner as described in Sections 2 to 2.

When these compositions were left at room temperature for one month, they all turned into gels.

Furthermore, the gelation time of these compositions at 150° C. and the electrical properties of the cured products at high temperatures were measured in the same manner as in Example 1.

The results are shown in Table 1. As is clear from Table 1,
The curable Epoquine resin composition of the present invention has significantly better storage stability than the conventional Epoquine resin composition (comparative example), and has a short gelation time at high temperatures (150°C) and is quick-curing. This also shows that the electrical properties of the cured product are also good.

Claims (1)

[Scope of Claims] 1. It is characterized by using as a curing agent a reaction product obtained by reacting an epoxy resin with at least one kind of acid anhydride, at least one kind of β-diketone, and a chelate compound of a metal. A curable epoxy resin composition. 2 In the chelate compound of β-diketone and metal,
The curable epoxy resin composition according to claim 1, which uses a metal chelate compound whose metals are cobalt, manganese, zinc, nickel, aluminum, zirconium, and iron.