JPS6142928B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thermosetting resin composition.
More specifically, the present invention relates to a thermosetting resin composition that provides a cured resin product with excellent heat resistance and excellent mechanical and electrical properties. The thermosetting resin composition of the present invention is particularly useful as an electrically insulating material, and can be used in a wide range of applications such as impregnating resins, casting resins, and laminating resins. Epoxy resins are used in combination with various curing agents and are applied in a wide range of fields. However, although cured epoxy resins exhibit excellent properties under normal conditions, they do not have sufficient properties at high temperatures, and their properties change significantly over time due to heat, so they cannot withstand long-term use at high temperatures, and are classified as F. Seed (155℃)
is the limit. The present inventors have eliminated the above-mentioned drawbacks and have achieved heat resistance [H
As a result of extensive research in order to provide a thermosetting resin composition that has excellent heat resistance (180°C) and also has excellent mechanical and electrical properties, we have completed the present invention. . That is, in the present invention, 30% or more of the number of epoxy groups in the epoxy compound has the general formula (1): (In the formula, R and R' are hydrogen atoms or methyl groups.) A polyfunctional cyanate ester compound The invention relates to a thermosetting resin composition characterized by containing 1.2 to 6.0 equivalents of As with the cured resin compositions, the properties of the obtained cured resin deteriorate significantly over time due to heat, and the properties at high temperatures are not sufficient, so it cannot withstand long-term use at high temperatures. is eliminated, has excellent heat resistance, and is classified as H class (180
It has the extremely remarkable effect of producing a cured resin material that belongs to the heat resistance category of 30.degree. C.) and has excellent mechanical and electrical properties. In the thermosetting resin composition of the present invention, m-
Isopropenyl phenyl glycidyl ethers produce polymers by polymerization of isopropenyl groups in the presence of heat and acidic substances, while the glycidyl groups of m-isopropenyl phenyl glycidyl ethers form cyanic acid of polyfunctional cyanate ester compounds. Reacts with ester groups to form oxazoline rings. Furthermore, the cyanate ester group itself trimerizes to form an s-triazine ring. By carrying out the above three reactions in parallel, a cured resin product having excellent heat resistance, mechanical properties and electrical properties is obtained. m-isopropenyl phenyl glycidyl ethers have an extremely low viscosity at room temperature and provide thermosetting resin compositions with good workability such as impregnation and casting. , it provides a cured resin product that is completely different from that using a monofunctional epoxide diluent, and provides a cured resin product that has excellent heat resistance, mechanical properties, and electrical properties. The m-isopropenyl phenyl glycidyl ethers used in the present invention include those in the above general formula in which R and R' are a hydrogen atom or a methyl group, and specifically, m-isopropenyl phenyl Glycidyl ether (R:
H, R':H), m-isopropenylphenyl methyl glycidyl ether (R: _CH3 , R':H). Examples of the polyfunctional cyanate ester compound used in the present invention include 1,4-dicyanatobenzene, 1,3-dicyanatobenzene, 2,2-bis(4-cyanatophenyl)propane, 4-dicyanatobenzene, and 4-dicyanatobenzene.
Examples include 4'-dicyanatobiphenyl, 4,4'-dicyanatodiphenyl ether, and 4,4'-dicyanatobenzophenone. The blending amount of the polyfunctional cyanate ester compound is an epoxy compound in which 30% or more of the epoxy groups in the epoxy compound are methyl groups from m-isopropenylphenyl glycidyl ethers represented by the above general formula. 1.2 to 6.0 equivalents are employed per equivalent.
When the amount of polyfunctional cyanate ester compound compounded is less than 1.2 equivalents per equivalent of the epoxy compound, the heat resistance of the cured resin obtained is insufficient, and when it is more than 6.0 equivalent, the cured resin obtained is Although it has good heat resistance, it becomes hard and brittle and has poor mechanical properties, both of which are unfavorable. The resulting thermosetting resin composition is usually heat-polymerized at 50 to 300°C in the presence of a curing catalyst such as amines, Lewis acids, imidazoles, etc., to obtain a cured resin having excellent properties. Specific examples of epoxy compounds other than m-isopropenyl phenyl glycidyl ethers in the epoxy compounds used in the present invention include common epoxy resins such as bisphenol A type epoxy resins, novolak type epoxy resins, and glycidyl ether type epoxy resins. Examples include resin. In addition to the above catalyst, the thermosetting resin composition of the present invention contains a reactive diluent such as phenyl glycidyl ether, cresyl glycidyl ether, butane-1,4-diglycidyl ether, neopentyl diglycidyl ether, etc. If necessary, it is also possible to add fillers and reinforcing agents such as silica, alumina, magnesium hydroxide, mica, glass cloth, aromatic polyamide paper, Tetron paper, Tetron film, and polyimide film. be. The thermosetting resin composition of the present invention is widely used in other applications such as impregnating resins, casting resins, and laminating resins for electrical equipment, and has excellent heat resistance, mechanical properties, and electrical properties. It provides a cured resin with excellent physical properties and is extremely useful industrially. Next, the thermosetting resin composition of the present invention will be specifically explained with reference to Examples and Comparative Examples. Example 1 As shown in Table 1, m-isopropenyl phenyl glycidyl ether (epoxy equivalent: 200)
20.0 g (0.1 equivalent), 72.0 g (0.5 equivalent) of 2,2-bis(4-cyanatophenyl)propane as a polyfunctional cyanate ester compound, 0.04 g of zinc octylate and 2-methyl-4- as a curing catalyst. A thermosetting resin composition was prepared by blending 0.04 g of ethymidazole. The obtained thermosetting resin composition was heat-cured at 120°C for 5 hours and then at 180°C for 16 hours to obtain a cured resin. In the infrared absorption spectrum of this cured resin, the absorption near 2250 cm ^-1 due to the cyanate ester group and the absorption near 910 cm ^-1 due to the epoxy group disappear, and the absorption due to the s-triazine ring disappears.
Absorption around 1580 cm ^-1 and absorption around 1750 cm ^-1 due to the oxazole ring were observed, and it was confirmed that this was the desired cured resin product. Various properties (bending strength, dielectric loss tangent (tan δ) properties, volume resistivity, heat distortion temperature, heating weight loss rate) of the resulting cured resin were measured. The measurement results are shown in Table 1. The bending strength, dielectric loss tangent characteristics, and volume resistivity were measured in accordance with JIS C 2105, and the heat distortion temperature was measured in accordance with the TMA method.
In addition, the heating weight loss rate was determined by placing the measurement sample in a 240℃ oven.
It was left to stand for 500 hours, and the weight loss was calculated. Examples 2 to 5 Thermosetting resin compositions were prepared using the ingredients and amounts shown in Table 1. The obtained thermosetting resin compositions were heated and cured at 130°C for 5 hours, at 150°C for 8 hours, and then at 200°C for 16 hours to obtain cured resins. In the infrared absorption spectrum of these cured resins, the absorption near 2250 cm ^-1 due to the cyanate ester group and the absorption near 910 cm ^-1 due to the epoxy group disappear, and the absorption near 1580 cm ^-1 due to the s-triazine ring disappears. Absorption and absorption around 1750 cm ^-1 due to the oxazole ring were observed, and both were confirmed to be the desired cured resin product. Various properties of the resulting cured resin are shown in Example 1.
Each was measured in the same manner. The measurement results are shown in Table 1. Comparative Example 1 A thermosetting resin composition was prepared using the ingredients and amounts shown in Table 1. The obtained thermosetting resin composition was heat-cured at 150°C for 15 hours to obtain a cured resin. Various properties of the resulting cured resin are shown in Example 1.
Each was measured in the same manner. The measurement results are shown in Table 1. Comparative Examples 2 to 4 Thermosetting resin compositions were prepared using the ingredients and amounts shown in Table 1. The obtained thermosetting resin composition was heat cured at 120°C for 5 hours and at 180°C for 16 hours to obtain a cured resin,
Various properties of the cured resin product were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 5 As shown in Table 1, a thermosetting resin composition was prepared by blending 100 g of m-isopropenyl phenyl glycidyl ether, 68 g of methyl nadic anhydride, and 1 g of benzyldimethylamine. The obtained thermosetting resin composition was heated at 80°C for 2 hours.
The resin was then thermally cured at 120° C. for 2 hours and then at 180° C. for 3 hours to obtain a cured resin, and the properties of the cured resin were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 6 KU-6573 (2.2-screw (4
- A varnish made of a prepolymer derived from (cyanatophenyl) propane using methyl ethyl ketone as a solvent to a solid concentration of 70% by weight. 0.2 g of zinc octylate, 0.1 g of catechol and 0.02 g of triethylenetetramine are mixed with 100 g of varnish) and heated. A curable resin composition was prepared. The obtained thermosetting resin composition was thermally cured at 180°C for 2 hours and then at 190°C for 2 hours to obtain a cured resin product, and various properties of the cured resin product were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 7 A thermosetting resin composition was prepared by blending 100 g of 2,2-bis(4-cyanatophenyl)propane, 50 g of styrene, and 1.5 g of benzyldimethylamine at 50°C. The obtained thermosetting resin composition was heated at 80°C for 4 hours.
Then, a cured resin was obtained by heat curing at 160° C. for 16 hours, and various properties of the cured resin were measured in the same manner as in Example 1. The results are shown in Table 1.

【table】

[Table] From Table 1, the thermosetting resin composition of the present invention is
It is clear that a cured resin product with excellent heat resistance, mechanical properties, and electrical properties can be obtained compared to the thermosetting resin composition obtained in the comparative example.

Claims (1)

[Claims] 1. 30% of the number of epoxy groups in the epoxy compound
The above is the general formula (1): (In the formula, R and R' are hydrogen atoms or methyl groups.) A polyfunctional cyanate ester compound A thermosetting resin composition comprising 1.2 to 6.0 equivalents of