JPS60243124A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:A composition, containing a polyfunctional maleimide, polyhydric phenol and/or aminophenol and polyfunctional allyl ester of a polyfunctional carboxylic acid mutually well dissolved therein, and having a low viscosity, improved curability and high heat resistance. CONSTITUTION:A thermosetting resin composition containing (A) a polyfunctional maleimide, (B) a polyhydric phenol and/or aminophenol and (C) allyl ester of a polyfunctional carboxylic acid. A trifunctional maleimide compound, etc. obtained by reacting tris-(4-aminophenyl) phosphate with maleic anhydride, etc. may be used as the component (A). Triallyl isocyanurate is preferred for the component (C). The amount of the component (A) to be used is 0.1-1.0 equivalent, preferably 0.2-0.8 equivalent, based on one equivalent component (A), and the amount of the component (C) to be used is 10-300pts.wt., preferably 20- 200pts.wt. based on the total amount of the components (A) and (B).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thermosetting resin composition of six heat resistance classes (1000 or more) and its prepolymer, and in particular, as a solvent-free phenol, it can be used for impregnation, casting, lamination, This invention relates to thermosetting resin compositions and prepolymers thereof suitable for applications such as molding and adhesion.

[Background of the invention]

In recent years, there has been a growing trend toward smaller and lighter electrical equipment and harsher usage conditions, and with this trend, there is a growing demand for insulating materials to have improved heat resistance.

It is desirable that varnish for coil impregnation or head office use has low viscosity, good workability, no voids after curing, and strong mechanical strength at high temperatures. Conventionally, research into heat-resistant insulating materials has progressed mainly in the field of solvent-based phenols for enameled wires and laminated materials, and excellent materials such as polyamide-imide, silicone, and polydiphenyl ether have been developed. Since these materials are generally solid, they require a solvent when used as pheno. When using solvent-based phenos, the solvent evaporates during curing and tends to leave a large amount of voids, so compared to solvent-free varnishes,
It has disadvantages such as poor heat dissipation, low voltage resistance, low adhesive strength, poor moisture resistance, and large thermal deterioration. For this reason, as an insulating phenol for electrical equipment, it is a solvent-free type that does not contain solvents.
Moreover, as the curing reaction progresses, it becomes very important that the material be of an addition polymerization type (non-condensation polymerization type) that does not generate volatile matter.

Currently, epoxy resin is widely used as a solvent-free phenol with relatively excellent heat resistance due to its low viscosity and good workability, but no matter what combination is used, the maximum operating temperature of epoxy resin is 180C. This is the limit. Solvent-free silico/pheno is attracting attention due to its good thermal stability, but
Its uses are limited because its mechanical strength at high temperatures is weak and its solvent resistance is poor.

On the other hand, the heat resistance of the bismaleimide polymer obtained by the reaction of amine and maleic anhydride is not only due to the contribution of imide groups, but also due to the formation of volatile components because the above polymerization reaction is an addition reaction. It is attracting attention because there is no such thing. However, since the bismaleimide radical polymer a has a high crosslinking density, heat shrinkage during curing is also severe, and the resin produced by the curing reaction is mechanically brittle and impractical. Therefore, it has been proposed that monopolymerization be performed with bismaleimide and diamine. This polymer has excellent physical and chemical heat resistance and electrical properties, but its resin composition has a very high melting point or glass transition point. Solvent-free waxes and varnishes cannot be used as solvent-free phenols because they require a poise of less than 1-0 poise during impregnation and a long pot life.

In order to make casting possible without a solvent, a method has been proposed in which monomaleimide, bismaleimide, etc. are mixed to raise the Kl and melting point near room temperature (%Kokusho 48-32187
). However, this method still has the disadvantage that the viscosity is not lowered sufficiently and the heat resistance is also lowered.

A method of adding liquid epoxy to lower the viscosity has also been proposed. However, this method generally tends to cause precipitation at around room temperature, making it difficult to use as a one-solvent wax, and has the disadvantage that the heat resistance of the cured product is significantly lower than that of a product without epoxy.

In addition, mixtures with polycarboxylic acid allyl esters such as diallyl phthalate, triallyl trimellitate, and triallyl in cyanurate have also been proposed (Japanese Patent Publication No. 1983-1999).
13676). However, this method also tends to precipitate at around room temperature, making it difficult to use as a solvent-free phenol.In addition, the copolymerizability of allyl groups and bismaleimide groups is poor, resulting in cured products that are brittle and prone to cracking. The disadvantage is that it also reduces performance.

On the other hand, recently, polyhydric phenol or aminophenol has attracted attention as a curing agent for bismaleimide. This polymer of polyhydric phenol or aminophenol and bismaleimide has excellent physical and chemical heat resistance and electrical properties.

However, these resin compositions are either solid with a high melting point or glass transition point, or are very viscous liquids, so raising the temperature to lower the viscosity shortens the pot life, making it difficult to use as a solvent-free phenol. was there.

[Purpose of the invention]

The purpose of the present invention was made in view of the above points, and
By including (a) polyfunctional maleimide, Φ) polyhydric phenol and/or aminophenol, (C) polyhydric carboxylic acid allyl ester, and optionally (d) polymerization catalyst, the group becomes extremely well compatible. The object of the present invention is to provide a thermosetting resin composition which has low viscosity, excellent curability, and can exhibit excellent heat resistance due to heat curing reaction.

[Summary of the invention]

Based on the above findings, the present invention provides a thermosetting heat-resistant resin composition and its prepolymer that has excellent heat resistance and is suitable for use as an electrical insulating material in impregnation, casting, lamination, molding, adhesion, etc. That is.

In the present invention, the polyfunctional maleimide contains at least a group represented by the following formula I: 1 1 (wherein D represents a divalent group containing a carbon-carbon double bond) in one molecule. 2
It is a maleimide containing For example, N,N'-ethylene dimaleimide, N,N'-hexamethylene bismaleimide, N,N'-dodecamethylene bismaleimide, N
, N', -m-xylylene bismaleimide, N, N'
-p-xylylene bismaleimide, N,N'-1,3-
Bismethylene diclohexane bismaleimide, N, N'
-1,4-bismethylenecyclohexane bismaleimide, N,N'-2,4-)rylenebismaleimide, N,N
'-2,6-) rylene bismaleimide, N, N'-3,
3'-diphenylmethane bismaleimide, N, N'
a, 4/-diphenylmethane bismaleimide, 3.3'
-Diphenylsulfone bismaleimide, 4.4'
-diphenylsulfone bismaleimide, N, N'-4,
4'-diphenyl sulfide bismaleimide, N, N'
-1)-benzophenone bismaleimide, N, N'-
diphenylethane bismaleimide, N,N'-diphenylether bismaleimide, N,N'-(methylene-ditetrahydrophenyl)bismaleimide, N,N'-
(3-ethyl)4.4'-diphenylmethane bismaleimide, N,N'-(3,3'-dimethyl)4.4'-
diphenylmethane bismaleimide, N, N'-(3,
'3'-diethyl)diphenylmethane bismaleimi)"
, N, N'-(3゜3'-dichloro)-4,4'-
Diphenylmethane bismaleimide, N,N'-)lysine bismaleimide, N,N'-isophorone bismaleimide, N.

N'-p, p-diphenyldimethylsilyl pismaleimide) e, N, N'-benzophenone bismaleimide, N
, N'-diphenylmethane), N,
N'-naphthalene bismaleimide, NTN'-1)-phenylene bismaleimide)", N, N'-m-phenylene bismaleimide)", N, N'-4°4' = (1,
1-diphenyl-cyclohexane)-bismaleimide,
N,N'-3,5-(1,2゜4-triazole)bismaleimide, N,N'-pyridine-2,6-diylbismaleimide, NIN'-5-me)xy-1,3-phenylene Bismaleimide, 1,2-bis(2-maleimidoethoxy)-ethane, 1,3-bis(3-maleimidopropoxy)propane, N, N'-4,4'-diphenylmethane-bis-dimethylmaleimide, N.

N'-hexamethylene-bis-dimethylmaleimide,
N,N'-4,4'-(diphenyl ether)-bis-dimethylmaleimide, N,N'-4,4'-diphenylsulfone-bisdimethylmaleimide, N,N' of 4,4'-diamino-triphenylphosphate In addition to bifunctional maleimide compounds represented by -bismaleimide, N,N'-bismaleimide of 4,4'-diamino-triphenylthiophosphate, etc., reaction products of aniline and formalin (polyamine compounds), 3 ,4.4'
- Triaminodiphenylmethane, polyfunctional maleimide compound obtained by reaction of triaminophenol with maleic anhydride, reaction of tris-(4,aminophenyl)phosphate or tris(4,aminophenyl)thiophosphate with maleic anhydride A trifunctional maleimide compound obtained in the above is a typical example of a polyvalent maleimide compound particularly suitable for the composition of the present invention. It is also a particularly effective method in the present invention to use one or more of these polyvalent maleimide compounds as a mixture.

Polyhydric phenols (optionally mixtures of species-type phenols) in the present invention include mononuclear phenols such as hydroquinone, oxyhydroquinone, pyrogallol, phloroglucin, pyrocatechol and resorcin, as well as polynuclear phenols. This type of polynuclear phenol has, for example, the following formula: It is a compound represented by O or 1). Compounds corresponding to I above include bis-(p-hydroxyphenyl)-furopane, bis-(p-hydroxyphenyl)-methane, bis-(p-hydroxyphenyl)
-sulfone, bis-(p-hydroxyphenyl)-sulfoxide, bis-(p-hydroxyphenyl)-sulfite, bis-(p-hydroxyphenyl)-ether, and 4,4'-dihydroxy-diphenyl. Moreover, not only the p-position but also the ○-position can be used. or,
Polynuclear phenols in which part of the nucleus is substituted with halogen atoms can also be used. For example, tetrabromobisphenol A may be mentioned. Furthermore, polynuclear polyphenols such as 1,4-dihydroxynaphthalene can also be used. Moreover, novolak resin can also be used as the polyhydric phenol.

The amine phenol in the present invention includes p-aminophenol, O-amine phenol, 2-methyl-4-
Examples include amine group-substituted phenols such as aminophenol, N-methyl-m-aminephenol, and N-methyl-p-aminophenol. Also included are amine cresol, aminoxylenol containing various substituent isomers, aminochlorophenol, aminobromophenol, aminocatechol, amylsorcin, aminobis(hydroxyphenyl)propane, aminooxybenzoic acid, and the like. Furthermore, reaction products of phenols, aniline, and formalin may also be used. A mixture of two or more of the above-mentioned polyhydric phenols and amine phenols may also be used.

The allyl ester of polycarboxylic acid in the present invention is preferably an allyl ester of aromatic polycarboxylic acid or cyanuric acid, and examples thereof include triallyl trimellitate,
diallyl terephthalate, diallyl inphthalate, p
, p'-diaryloxycarbonyl diphenyl ether,
Examples include m, p-sialyloxycarbonyl diphenyl ether, 0°p'-diallyloxycarbonyl diphenyl ether, m, m'-diallyloxycarbonyl diphenyl ether, triallyl 7-anurate, triallyl in cyanurate, and the like. Many of these carboxylic acid allyl esters can be used in combination. Among these, triallyl in cyanurate is preferred from the viewpoint of heat resistance.

The composition ratio of polyfunctional maleimide and polyhydric phenol and/or aminophenol is 1 equivalent of the former and 0 equivalent of the latter.
．． It can be selected within the range of 1 to 1.0 equivalents, preferably 0.2 to 0.8 equivalents. If the amount of the latter is small, it tends to become brittle. On the other hand, if the amount of the latter is more than 1.0 equivalent, phenolic hydroxyl groups remain and polymerization of allyl groups tends to be inhibited, resulting in a decrease in thermotropy. Also,
The amount of polyhydric carboxylic acid allyl ester to be blended is not particularly limited to the total amount of polyfunctional maleimide, polyhydric phenol and/or amine phenol, but it is 10 parts to 300 parts, preferably 20 parts to 200 parts. It is preferable to mix them in the following proportions. When the amount of polyvalent carboxylic acid allyl ester is small, the viscosity tends to increase, and when it is large, the viscosity decreases, but conversely, the heat resistance tends to decrease.

Although the resin composition of the present invention can be sufficiently cured without a catalyst,
If it is desired to further promote the reaction, a free radical catalyst or an ionic catalyst is effective. The catalyst is present in an amount of 0.1 to 10% by weight, preferably 0.1% by weight, based on the total amount of reaction components.
K is present in the reaction mixture at a concentration of from 5 to 50%. Free radical catalysts are known organic peroxides and hydroperoxides and azobisbutyronitrile.

Ionic catalysts include tertiary, secondary and primary amines, quaternary ammonium compounds, and alkali metal compounds. A mixture of these catalysts may be used. Examples of amine catalysts include triethylamine, tributylamine, triamylamine, diethylamine, benzylamine, tetramethyldiaminodiphenylmethane, N,N-di-isobutylaminoacetonitrile, heterocyclic bases such as quinoline, N-methylpyrrolidine, Examples include imidazole, benzimidazole and their congeners, and mercaptobenzothiazole, benzyltrimethylammonium hydroxide, benzyltrimethylammonium methoxide, sodium methylate, and the like.

It is also effective to modify the present resin composition depending on the intended use of the insulating material. Examples include modification with epoxy resins and various curing agents, modification with vinyl monomers such as styrene and methyl methacrylate, modification with synthetic rubbers such as polybutadiene and polychloroprene, modification with unsaturated polyesters, modification with diallyl phthalate and triallyl phthalate prepolymers, and modification with fatty acids. group amines, aromatic amines,
Modification with amines such as allylamine, furan compounds,
It is also possible to modify with a phenol resin or to add and blend an inorganic photonic agent.

[Examples of the invention] Comparative Examples 1 to 6, Examples 1 to 9 Bisphenol A, 4.4'-, soumaleimide diphenylmethane (BMI) and triallyl isocyanurate (TAIC) were mixed in the composition ratios shown in Table 1. The mixture was heated to 130C in an oil bath to completely dissolve it. This thing,
When left to cool, in all cases except Comparative Example 6, the temperature ranged from room temperature to 1
Precipitation occurred in the 00C range, and it was found that this state was unsuitable as a solvent-free phenol.

After complete dissolution, the mixture was further kept at 130C for about 25 minutes to obtain a prepolymer. This prepolymer no longer formed a precipitate upon cooling. The viscosity of this prepolymer at 120C was measured using a B-type viscometer, and the results are shown in Table 1.

In addition, the pot life when the prepolymer was stored at 120C was measured and is also listed in Table 1.

Note that the pot life was defined as the number of days for the viscosity to reach 5 times the initial value.

Next, after degassing the prepolymer under reduced pressure, it was poured into a mold, heated to 120C for 5 hours, and heated to 150C for 15 hours.
3 hours at 200C, 3 hours at 230C, and 250C
The mixture was heated at t:' for 12 hours.

After cooling, the molds were removed, and reddish brown resin plates were obtained except for Comparative Example 6. Note that Comparative Example 6 did not harden. In addition, 5 g of dicumyl peroxide was added to the composition of Comparative Example 6, and 12 (Ic15h+150C/150C/15h+200U/
It did not harden even after heating for 3 hours + 230C/3 hours + 250C/12 hours.

Next, the glass transition temperature Tg and heat resistance of the obtained resin plate were examined and are shown in Table 1. In addition, the heat resistance is 15X25
A resin plate of size X2 was placed in a 295C air circulation type air constant temperature bath, taken out at predetermined time intervals, and its weight was measured, and the time was defined as the time until the weight loss on heating reached 10 weight.

As can be seen from Table 1, Examples 1 to 9 are Comparative Examples 1'-
Compared to No. 5, there is less decrease in glass transition temperature and heat resistance, it has sufficient heat resistance of C rice, it can be impregnated into coils at 120 C with less than 10 poise, and it has a longer pot life.

Example 10 The mechanical properties and electrical properties of the cured product obtained in Example 2 were measured at the initial stage and after deterioration for 10 days at 290C. As a result, as shown in Table 2, it exhibited very excellent mechanical and electrical properties at room temperature and at a high temperature of 250C.

Table 2 Examples 11-21 BMI 70 g, Bisphenol A 30 g and TAI
067g was mixed and heated to 130C in an oil bath to completely dissolve, and then kept at that temperature for 25 minutes to obtain a prepolymer. The prepolymer was cooled to 120C and the catalyst in the proportions shown in Table 3 was added.

When the viscosity of this product was measured at 120C, it was found to be 1 poise. Pour this prepolymer into a mold, 12 (115h+15 (1/15h+20(
Heating was performed for 1/3 hour + 230C/3 hours to obtain a reddish brown transparent resin plate. When the glass transition temperature (physical heat resistance) and heat resistance (chemical) of this resin plate were measured, the third
As shown in the table, the catalyst-added system showed good heat resistance even at low temperature curing.

Examples 26 to 28 BMI, polyhydric phenol and/or amine phenol, and TAIC were mixed in the proportions shown in Table 4, and the viscosity, glass transition temperature, and heat resistance were measured in exactly the same manner as in Example 4. As a result, as shown in Table 4, all showed good results.

Claims (1)

[Claims] 1. A thermosetting resin composition containing at least a polyfunctional maleimide, a polyvalent phenol and/or an amine phenol, and a polyvalent carboxylic acid allyl ester.