JPS592444B2 - 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 by a new process, and includes a maleimide compound, an epoxy resin,
Heat-resistant, characterized in that a composition consisting of an epoxy resin curing agent, a photopolymerizable acrylic ester or methacrylic ester compound, and a sensitizer is brought into a semi-cured state by irradiation with light, and then heated and cured. The present invention relates to a method for producing a synthetic resin.

The electrical properties of the engineered epoxy compound can be improved by mixing it with a curing agent having a group that reacts with an epoxy group such as an amino group or a carboxylic acid anhydride, and then reacting the epoxy group with these functional groups to obtain a resin composition. It is used in a wide range of fields because it is a resin with excellent properties such as dimensional stability and chemical resistance.

However, it is not necessarily sufficient in terms of heat resistance.
A proposal was made to add a maleimide compound to epoxy resin as a method to improve the heat resistance of epoxy resin (Japanese Patent Publication No. 4)
9-12600, etc.), but although this composition does have good heat resistance, when it is heated to a high temperature for curing, for example when used as an impregnating resin, the viscosity of the resin decreases and it takes a long time to cure. During this process, resin leakage occurs, which causes the resin layer to become thin and create internal voids, which has a particularly negative impact on electrical properties, such as increasing the voltage change (△-nδ) of dielectric loss. , an increase in the number of coronas generated, a decrease in the voltage at which corona generation starts, etc., and the structure may become 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 method of the present invention comprises a maleimide compound, an epoxy resin,
A composition consisting of an epoxy resin curing agent, a photopolymerizable acrylic ester or methacrylic ester compound, and a sensitizer is brought into a semi-cured state by irradiation with light, and then heated and cured. It is something to give. It is already known that maleimide compounds undergo photopolymerization. Furthermore, French Patent No. 1455 shows that polymers of maleimide compounds exhibit extremely high thermal stability.
In No. 514, it is shown that a three-dimensional polyimide can be produced by heating and polymerizing N,N'-disubstituted maleimide alone.
It is becoming clear. In the present invention, the maleimide compound and the acrylic ester or methacrylic ester compound in the composition are polymerized by being irradiated with light at a low temperature in the presence of a sensitizer to form a network structure through three-dimensional crosslinking, By heating the semi-cured state, the epoxy resin is cured, and the reactions of the maleimide compound, acrylic acid, and methacrylic acid ester compound proceed, resulting in complete curing and providing a cured product with high heat resistance. Even if a maleimide compound alone is photopolymerized, the reaction rate is slow, so it can be easily cured by blending an acrylic acid or methacrylic acid ester compound, which has a fast photopolymerization rate.

According to the method of the present invention, by irradiating with light after impregnation,
An impregnated state with no leakage can be achieved, and mold-less casting is also possible.

In the present invention, the maleimide compound has the general formula (where R1 is a divalent organic group having at least 2 carbon atoms, R2 is hydrogen or an alkyl group, and n is on average from 0.5 to 4. ) is used.

Examples of maleimide compounds represented by the general formula 0) include N,N'-(methylenedi-p-phenylene) dimaleimide, N,N'-(oxydi-p-phenylene) dimaleimide, N,N'-m-phenylene rangemaleimide,
N,N'-p-phenylene dimaleimide, N,N/-2
,4-tolylene dimaleimide, N,N'-2,6-tolylene dimaleimide, N,N'-(sulfone di-1p-phenylene) dimaleimide, N,N2-(sulfone di-1m-
Poly(phenylmethylene) dimaleimide, N,N/-m-xylylene dimaleimide, N,N'-p-xylylene dimaleimide, N,N'-hexamethylene dimaleimide, etc. ) There is a polymaleimide.

Examples of epoxy resins that can be used in the present invention include bisphenol A diglycidyl ether type Epicote 828, 834, 1001, and 1004 (Ciel Corporation), GY-260 (Ciba Corporation), and novolac type DEN438 (Tau). There are also alicyclic type Chitsonox 221, 289 (Chitso Corporation), etc.

Further, the curing agent that can be used in the present invention has the general formula (wherein R3 is an aliphatic, aromatic, or alicyclic dicarboxylic acid residue, R
4 represents an aliphatic, aromatic, or alicyclic tetracarboxylic acid residue.

), such as phthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, butane anhydride Tetracarboxylic acid etc. or
Tricresyl borate, cobalt acetylacetonate, jitter acetylacetonate, zinc octylate,
Stannic octylate, metal salts such as triethanolamine titanate, metal chelate compounds, BF3, PF5
and metal olefin compounds such as ferrocene, etc., and these can be used in combination as necessary.

In addition, photopolymerizable acrylic esters and methacrylic ester compounds (hereinafter referred to as photopolymerizable monomers) include ethyl acrylate, n-propyl acrylate,
Butyl acrylate, ethyl methacrylate, propyl methacrylate, methyl methacrylate, epoxy arylate obtained by reacting an epoxy compound with acrylic acid, epoxy methacrylate obtained by reacting an epoxy compound with methacrylic acid, and the like can be used.

The composition used in the method of the present invention is desirably blended in a ratio of 6 to 300 parts by weight of the maleimide compound and the photopolymerizable monomer to 100 parts by weight of the above-mentioned epoxy resin and curing agent. . If the blending amount is less than 6 parts by weight, crosslinking by photopolymerization cannot be performed sufficiently, and 30 parts by weight or less.
If it is more than 0 parts by weight, the crosslinking density will increase too much and the mechanical properties will deteriorate. The amount of photopolymerizable monomer in the maleimide compound and photopolymerizable monomer mixture is preferably in the range of 10% to 50%. If it is less than 10%, there is no effect of the photopolymerizable monomer combination, and if it is more than 50%, the heat resistance decreases.

In addition, as sensitizers, polynuclear quinones (e.g. anthraquinone, 1-chloroanthraquinone, etc.), benzoins, benzophenone, azobisisobutyronetrile, etc. are used, and the blending amount is determined so that they can be photopolymerized with maleimide compounds. 0.05 to 10% by weight, based on the monomer mixture, is suitable.

For monomers with low polymerizability, the polymerization reaction can be accelerated by increasing the amount of sensitizer used. The method of the present invention is to process the composition blended as described above into an object to be impregnated or a cast object, and then irradiate it with a low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, etc. to bring it into a semi-cured state, and then heat cure it. By doing so, a resin with excellent heat resistance can be easily obtained.

The method of the present invention will be explained below with reference to Examples. Example 1 40 parts by weight of [Epicote 828], 10 parts by weight of polyphenylmethylene polymaleimide, 32 parts by weight of methyltetrahydrophthalic anhydride, epoxy acrylate obtained by reaction of 1 mole of [Epicote 828] and 2 moles of acrylic acid A composition containing 10 parts by weight of zinc octylate, 0.5 parts by weight of zinc octylate, and 0.5 parts by weight of benzoin as a sensitizer was irradiated with light using a 300 W photographic lamp.

After 20 minutes, the surface was dry to the touch, and it was confirmed that it was semi-cured.

Thereafter, the temperature was raised to 150°C for 10 hours, and the mixture was cured at 200°C 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.

A test bar in which a 400 mm x 3.2 mm x 6.5 mm copper wire was wrapped with a Tetron film and further wrapped with a 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 (nδ) is 0.2%20 at 1KV at 25℃.
“ClKV is 4.5%, Δaddition δ1k-3k is 0.25 (
f), showing a very stable value, and the number of corona occurrences was 10-
At 10 talons, it is as low as 1.0 x 103 IV seconds,
The corona development voltage was as high as 3.2 KV, indicating good electrical properties. Furthermore, the mechanical properties of this resin alone were measured at 25°C, and the bending strength was 15.0 kg/Md, 24
The bending strength after aging at 0°C for 500 hours also maintained 9.0 kg/Md, showing excellent thermal stability and mechanical properties. Example 2 [Epicote 828] 20 parts by weight, [DEN438]
] 10 parts by weight, hexahydrophthalic acid, 20 parts by weight of anhydride, 60 parts by weight of N,N''-(methylenedi-p-funynylene) dimaleimide 50 parts by weight of epoxy acrylate having the same composition as in Example 1, as a sensitizer 2.0 parts by weight of benzoin was added to prepare a composition.

A glass cloth was impregnated with this composition and irradiated with a 100 W high pressure mercury lamp for 30 minutes.

Thereafter, post-curing was performed by heating at 150° C. for 10 hours and at 180° C. for 10 hours. During this period, the resin did not sag, and the effect of light irradiation was observed. This cured resin has a bending strength of 15.5 kg/Mi at 25°C. 9.5k after aging in air at 240℃ for 500 hours
The bending strength is shown in g/Mit. According to the results of the same test bar as in Example 1, the Rnδ value was 0.0 at 25°C and 1K.
30%, 5.5% at 200℃, 1KV, △addition δ1
kv-3kv was 0.50%, and the corona properties also showed good properties almost equivalent to those of Example 1. Example 3 [Epicote 828] 80 parts by weight, methyltetrahydrophthalic anhydride 60 parts by weight, [DMP-30') 0.
A composition was prepared by adding 5 parts by weight of N,N'-(oxydi-p-phenylene) dimaleimide, 3 parts by weight of the epoxy acrylate shown in Example 1, and 1 part by weight of 1-chloroanthraquinone as a sensitizer. .

This composition was cured in the same manner as in Example 2, but
During this time, there was no dripping of the resin. The characteristics of this cured resin are that it exhibits a bending strength of 15.0k9/Md at 25°C,
8.9kg/77 after aging in air at 240℃ for 500 hours
! The bending strength of d was shown.

As a result of the bar test similar to Example 1, the additive δ value was 25
It showed 0.1% at 1KV at 200C, 6.5% at 1KV at 200C, and 0.50% at Δ+δ1kv-3kv, and the corona properties were almost the same as in Example 1 and showed good properties. Example 4 65 parts by weight of [Epicoat 828], 30 parts by weight of poly(phenylmethylene) polymaleimide, 0.5 parts by weight of tricresyl borate, and 0.5 parts by weight of triethalamine titanate.
5 parts by weight, 20 parts by weight of epoxy acrylate having the same composition as in Example 1, and 2.0 parts by weight of benzoin as a sensitizer.
A composition was prepared by adding parts by weight.

This composition was cured in the same manner as in Example 1,
There was no dripping of the resin. This resin cured product was heated at 25°C.
, 14.0kg/m! Indicates the bending strength of t, 2
8.5k9/TL after aging in air for 500 hours at 40℃
The bending strength of d was shown.

According to the results from the same test bar as in Example 1, the additive δ value was 0.20% at 25°C and 1KV, 5.5% at 200°C,
The Δadditional δ value of 1kv-3kv was 0.50%, and the corona properties were also almost the same as in Example 1 and showed good values. As described above, Examples 1 to 4 all exhibited good heat resistance, mechanical properties, and electrical properties.

Comparative Example 1 A composition consisting of 47 parts by weight of [Epicote 828], 15 parts by weight of poly(phenylmethylene) polymaleimide, 37 parts by weight of methyltetrahydrophthalic anhydride, and 0.2 parts by weight of [DMP-303] was prepared in Example 1. It was impregnated into a test bar similar to the above, and cured by standing at 200° C. for 15 ClO hours 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) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1 in the formula is a divalent organic group having at least 2 carbon atoms, R_2 represents hydrogen or an alkyl group, and n represents a number from 0.5 to 4 on average); Epoxy resin and
Heat resistant, characterized in that a composition consisting of an epoxy resin curing agent, an acrylic ester or methacrylic ester compound, and a sensitizer is brought into a semi-cured state by irradiation with light, and then heated and cured. Method of manufacturing resin.