JPS592445B2 - Manufacturing method of heat-resistant resin - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for producing a heat-resistant resin, in which a composition comprising a maleimide compound, an epoxy resin, an epoxy resin curing agent, and a sensitizer is brought into a semi-cured state by irradiating the composition with light. The present invention relates to a method for producing a heat-resistant resin, which is characterized in that the heat-resistant resin is then cured by heating.

Epoxy compounds are mixed with a curing agent having a group that reacts with epoxy groups such as amino groups and carboxylic acid anhydrides, and the epoxy groups are reacted with these functional groups to obtain a resin composition. It is a resin with excellent properties such as stability and chemical resistance, and is used in a wide range of fields.

However, it is not necessarily sufficient in terms of heat resistance. To improve the heat resistance of epoxy resin, a method of adding a maleimide compound to epoxy resin (Japanese Patent Publication No. 49-12
600), etc., and although this composition does have good heat resistance, if the temperature is high during curing, the viscosity of the resin decreases, resin leakage occurs during the curing process, and the resin layer deteriorates. For example, △Ta
In some cases, the nδ value becomes large, the number of coronas generated increases, the voltage at which corona generation starts decreases, etc., and the structure becomes unusable as an insulating structure. The inventors have made earnest efforts to achieve these points, that is, to improve the heat resistance of the epoxy resin and to use a process that causes less resin leakage during impregnation and casting, and as a result, the present invention was achieved. The present invention provides a heat-resistant resin by irradiating a composition comprising a maleimide compound, an epoxy resin, an epoxy resin curing agent, and a sensitizer to a semi-cured state, and then heating and curing the composition.

It is already known that maleimide compounds undergo photopolymerization.

Furthermore, French patent No. 1455514 shows that polymers of maleimide compounds exhibit extremely high heat resistance.
- disubstituted maleimide maleimide alone is thermally polymerized,
It has become clear that three-dimensional polyimides can be produced. In the present invention, the maleimide compound in the composition is polymerized by being irradiated with light at a low temperature in the presence of a sensitizer, forms a network structure through three-dimensional crosslinking, becomes semi-cured, and is then thermally cured. As a result, the epoxy resin is cured and the reaction of the maleimide compound progresses, resulting in complete curing and providing a cured product with high heat resistance. According to the method of the present invention, by irradiating with light after impregnation, it is possible to obtain an impregnated condition without leakage, and mold-less casting is also possible.

Maleimide compounds that can be used in the present invention include the general formula and (wherein R1 is a divalent organic group having at least two carbon atoms, R2 is hydrogen or an alkyl group, and n is 0.5 on average. (indicating a number from 5 to 5) is used.

As a maleimide compound represented by general formula (1), N
, N/-(methylenedi-p-phenylene) dimaleimide, N,N~(oxydi-p-phenylene) dimaleimide, N,N-m-phenylene dimaleimide, N,N'-p
-phenylene dimaleimide, N,-2,4-tolylene dimaleimide, N,N-2,6-tolylene dimaleimide,
N,N-(sulfone di-1-p-phenylene) dimaleimide, N,N'-(sulfone di-1-m-phenylene) dimaleimide, N,-m-xylylene dimaleimide, N,N-p
-xylylene dimaleimide, N,N/-hexamethylene dimaleimide, and poly(phenylmethylene) polymaleimide represented by the general formula (H).

Further, as the epoxy resin that can be used in the present invention, for example, bisphenol A diglycidyl ether type Epicote 828, 834, 1001, 1004
.

Further, the curing agent that can be used in the present invention is represented by the general formula or -.

(Here, R3 represents an aliphatic, aromatic, or alicyclic dicarboxylic acid residue, and R4 represents an aliphatic, aromatic, or alicyclic tetracarboxylic acid residue).

Acid anhydrides, such as phthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, butanetetracarboxylic anhydride Acids, etc., or metal salts such as tricresyl borate, cobalt acetylacetonate, zinc acetylacetonate, zinc octylate, stannic octylate, triethanolamine titanate, metal chelate compounds, Lewis acids such as BF2, PF5, and amines. complexes, metal olefin compounds such as ferrocene, etc., and these can be used in combination as necessary.

In the present invention, it is desirable to blend 5 to 200 parts by weight of the maleimide compound with respect to 100 parts by weight of the mixture of the epoxy resin and curing agent shown above.

If the amount of the maleimide compound in the mixture of epoxy resin and curing agent is less than 5 parts by weight, sufficient heat resistance will not be obtained, and if it exceeds 200 parts by weight, heat resistance will improve but mechanical strength will decrease. In addition, as a sensitizer,
Polynuclear quinones (for example, anthraquinone, 1-chloroanthraquinone, etc.), benzoin, benzophenone, azobisisobutyronitrile, etc. are used, and the appropriate amount is 0.05 to 10% by weight based on the maleimide compound. . For monomers with low polymerizability, the polymerization reaction can be accelerated by increasing the amount of sensitizer used. The present invention applies the composition shown above to an impregnated object or
After the cast body is treated, it is irradiated with light using a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, etc. to bring it into a semi-cured state, and then heat-cured.

The method of the present invention will be specifically explained below with reference to Examples. Example 1 47 parts by weight of [Epicote 828], 15 parts by weight of poly(phenylmethylene) polymaleimide, 37 parts by weight of methyltetrahydrophthalic anhydride, 0.2 parts by weight of [DMP-30], 0 parts by weight of benzoin as a sensitizer The composition to which 0.5 parts by weight had been added was irradiated with light using a 300W photographic lamp.

After 20 minutes, the surface was dry to the touch and it was confirmed that it was in a semi-hardened state.

Thereafter, the temperature was raised to 150°C, and the mixture was cured for 10 hours and then at 2000C for 5 hours to obtain a cured product. During this time, almost no sagging of the resin was observed, and the effect of light irradiation was obvious. 400
A test bar, in which a Tetron film was wrapped around a copper wire measuring mm x 3.2 mm x 6.5 mm and further wrapped with glass tape, was impregnated with the resin and then cured using the above curing process, but the resin did not sag.

In addition, the dielectric loss Tanδ is 0.1% at 25 C1KV,
3.0% at 2000C1KV, △Tanδ1KV-3K
V shows a very stable value of 0.3%, and the number of coronas generated is 0.90 x 103 pieces/at 10-10 coulombs.
The corona initiation voltage was as high as 3.0 KV, indicating good electrical properties. Furthermore, the mechanical properties of this resin alone have a bending strength of 14.5 when measured at 25°C.
kf/M77i, 24'C5OO The bending strength after aging was maintained at 10.1 kf/M77f, showing excellent thermal stability and mechanical properties. Example 2 [Epicote 828] 10 parts by weight, [DEN438] 1
0 parts by weight, [Chitsonox 221] 5 parts by weight, 20 parts by weight of hexahydrophthalic anhydride, 10 parts by weight of N,N'-(methylenedi-p-phenylene dimaleimide), 40 parts by weight of poly(phenylmethylene) polymaleimide A composition was prepared by adding 0.5 parts by weight of benzoin ethyl ether as a sensitizer.9 This composition was impregnated into a glass cloth.
Irradiation was performed for 30 minutes using a 0W high-pressure mercury lamp.

Thereafter, it was heated at 1500C for 10 hours and at 180C for 10 hours to perform post-curing. During this period, the resin did not sag, and the effect of light irradiation was observed. This cured resin showed a bending strength of 14.0 kg/M7lL at 25°C, and after deteriorating in air for 24°C, 500 hours,
．． It exhibited a bending strength of 5k7/Md. The results from the same test bar as in Example 1 show that the Tan δ value is 0 at 25°C IKV.
．． 20%, 200℃3.0%, △Tanδ1KV
-3K was 0.30%, and the corona properties also showed good properties almost equivalent to those of Example 1.

Example 3 [Epicote 828] 60 parts by weight, 40 parts by weight of methyltetrahydrophthalic anhydride, 1 part by weight of tris(dimethylaminomethino(ha)phenol), 5 parts by weight of N,V-(-oxydi-p-phenylene) dimaleimide Sound 15. 0.8 parts by weight of 1-chloroanthraquinone was added as a sensitizer to prepare a composition.

This composition was cured in the same manner as in Example 2, and the resin did not sag during the curing process. The characteristics of this cured resin are:
It exhibits a bending strength of 14.5ky/M7i at 25°C, 24
``C. After aging in air for 5 hours, it exhibited a bending strength of 9.2 kf/M77t.

As a result of the same test bar as in the example, the Tanδ value was 2.
5. 0.1% at C1KV, 4.5% at 200℃, Δ
Tan δ1KV/3KV was 0.50%, and the corona properties were almost the same as in Example 1, showing good properties. Example 4 [Epicote 828] 65 parts by weight, 35 parts by weight of poly(phenylmethylene) polymaleimide, 0.5 parts by weight of tricresyl borate, 0.5 parts by weight of triethanolamine titanate, and 1 part by weight of anthraquinone as a sensitizer. .0 part by weight was added to prepare a composition.

This composition was cured in the same manner as in Example 1.
During this time, there was no dripping of the resin. This cured resin exhibits a bending strength of 15.0 h/i at 25°C,
9.2k7/M after aging in air for 500 hours at 240℃
It showed a bending strength of 7i. The results from the same test bar as in Example 1 show that Tan δ (direction is 0.2 at 25 steps C1KV)
5%, 4.5% at 200℃, △Tanδ value 1KV-3K
V was 0.60%, and the corona properties were almost the same as in Example 1, showing good values. Examples 1 to 4 all exhibited good thermal stability, mechanical properties, and electrical properties. Next, a comparative example will be shown.

Comparative Example 1 47 parts by weight of [Epicote 828] corresponding to the composition of Example 1, 15 parts by weight of polyphenylmethylene polymaleimide, 37 parts by weight of methyltetrahydrophthalic anhydride, [D
A test bar similar to that in Example 1 was impregnated with a composition consisting of 0.2 parts by weight of MP-30 and heated at 150°C for 10 hours at 200°C.
It was left to stand and cure at ℃ for 5 hours.

Claims (1)

[Claims] 1 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (In the formula, R_1 is 2 having at least 2 carbon atoms) at least one maleimide compound represented by a valent organic group, R_2 represents hydrogen or an alkyl group, and n represents a number from 0.5 to 4 on average), an epoxy resin, an epoxy resin curing agent, and a sensitizer. 1. A method for producing a heat-resistant resin, which comprises irradiating a composition comprising an agent with light to bring it into a semi-cured state, and then heating and curing the composition.