JPH0160470B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to 2,4-diamino-6-[(2'-phenylimidazolyl)-ethyl]-s-triazine, which is a new substance useful as a polyepoxy curing agent, its production method, and polyepoxy curing using the same. This is related to drugs. The present inventors have been conducting research on the synthesis of various 2,4-diamino-6-[(imidazolyl)-ethyl]-s-triazines, and have already developed a synthesis method in which cyanethyl imidazole and dicyandiamide are subjected to an addition reaction. proposed (Special Public Interest Act 1977)
Publication No. 36391). This synthetic method is very useful, and by applying this synthetic method, the 2,4-diamino-6-[(2'-phenylimidazolyl)-ethyl]
Attempts to synthesize -s-triazine (hereinafter abbreviated as PA) virtually failed with extremely low yields of less than 10%, so PA was not included in the invention for the previously proposed synthesis method. After that, he secretly continued his research. As a result, the present inventors discovered that 2-vinyl-4,6-diamino-S-triazine and 2-vinyl-4,6-diamino-S-triazine
Addition reaction with phenylimidazole produces PA
The present invention was completed based on the discovery that PA can be obtained in good yield and that this PA is extremely useful as a curing agent or curing accelerator for polyepoxy compounds. That is, the PA of the present invention has the following structural formula: It is a new substance represented by , and has the following physical properties. Melting point: 212-213℃ (methanol). basic. water,
Slightly soluble in methanol, ethanol and acetone.
Soluble in acetic acid. TLC (silica G, ethanol):
Rf0.45-0.50 (BTB color development) ν ^KBr _Cn-1 : 3480, 3330, 3140, 1640 (second absorption),
1545 (first absorption), 1445 (third absorption), 1410,
1368, 1315, 1275, 1238, 1120, 1070, 1010,
938, 915, 842, 805, 760, 715, 695 NMR (CF ₃ COOH): δ7.5-7.9, m, 11H (phenyl group proton 5H, imidazole 4.5-position proton 2H, amino group proton 4H), 4.84, t, 2H
(Methylene proton); 3.35, t, 2H (methylene proton) Mass: m/e281 (M ⁺ ), 171 (M ⁺ -triazine ring), 157, 144, 143, 138 (M ⁺ -imidazole ring), 104, 77,... The PA of the present invention can be easily produced in good yield by the following production method. That is, the structural formula 2-vinyl-4,6-diamino-S-
Triazine (hereinafter abbreviated as VT) and 2-phenylimidazole (hereinafter abbreviated as 2PZ) are heated briefly in the presence of a solvent or in the absence of a solvent to cause an addition reaction. In this case, the molar ratio of 2PZ and VT is set to 0.5 to 3.0, and the heating temperature is set to 80 to 3.0.
The temperature is preferably in the range of 150°C, and if necessary, a VT polymerization inhibitor may be added. Incidentally, the reaction time is within 5 hours. VT, which is a starting material, can be synthesized by various methods, such as the method of reacting biguanide with acrylic acid chloride [CG Overberger et al.: JACS, 80 ,
988 (1958)], Method for Reacting Dicyandiamide and β-dimethylamino-propionitrile [Hoechst: Fr.
Di{4′,6′-diamino-s-triazinyl-
(2')}-Method of heating cyclobutane to 320°C under reduced pressure [Asahi Kasei: Japanese Patent Publication No. 46-35068], heating 2-β-methoxyethyl-4,6-diamino-s-triazine at 350°C in a nitrogen stream How to heat [Suddeutsche Kalkstickstoff Werke AG:
Ger. Offen. 2, 135, 881 (1973)]. In addition, the polymerization inhibitors include sodium sulfide, potassium sulfide, hydroquinone, copper sulfate, β
-Naphthylamine, etc. can be used, and among them, sodium sulfide (nonahydrate) is particularly preferred. still,
When the reaction is carried out in the presence of a solvent, water or the like is used as the solvent. PA obtained by the above manufacturing method is extremely useful as a curing agent for polyepoxy compounds.
When mixed with epoxy resin, it has a long pot life and does not harden easily at room temperature, but when heated to an appropriate temperature, it hardens quickly, resulting in a cured epoxy resin with good heat resistance. In this case, it is desirable that the amount of PA blended is 5 to 20 parts per 100 parts (parts by weight, the same applies hereinafter) of the polyepoxy compound, and the heating temperature is 90 to 20 parts.
It is desirable to set the temperature to 180℃, especially around 150℃. If necessary, it is preferable to adjust the viscosity by adding a small amount of an appropriate viscosity modifier and defoaming by reducing the pressure after mixing. Furthermore, the PA of the present invention is extremely effective as a curing accelerator when mixed with epoxy curing agent dicyandiamide, etc.
It is necessary that the amount of PA blended is at least 1 part per 100 parts of the polyepoxy compound. Next, a more specific explanation will be given with reference to examples. Example 1 VT0.1 mol (13.7 g) and 2PZ 0.22 mol (31.7 g)
and sodium sulfide nonahydrate 0.005 mol (1.4
The system consisting of g) was stirred and heated at 140°C for 2 hours (the system became a homogeneous phase), then allowed to cool, the precipitated crystals were collected by filtration, and recrystallized once with methanol.
(mp202-204°C) 0.073 mol (20.6 g) was obtained.
The yield of PA based on VT was 73% (weight %, same hereinafter). Example 2 A system consisting of 0.1 mol (13.7 g) of VT and 0.15 mol of 2PZ was stirred and heated at 140°C for 3 hours (the system became a homogeneous phase).
After that, it was left to cool, the precipitated crystals were collected by filtration, and methanol was reconsolidated to obtain the target product PA (mp200-203℃), 0.073
Mol (20.5g) was obtained. The yield of PA to VT is
It was 73%. Example 3 VT0.13 mol (17.8 g), 2PZ 0.1 mol (14.4 g),
A system consisting of 0.002 mol (0.6 g) of sodium sulfide nonahydrate and 15 ml of water was heated under reflux for 4 hours, then cooled, and the precipitated crystals were collected by filtration. The filtered crystals were subjected to Soxhlet extraction and reconsolidation to obtain the target substance PA (m.
P.212-213°C) 0.058 mol (16.3 g) was obtained. VT
The yield of PA was 58%. When the physical properties of the PAs obtained in Examples 1 to 3 above were measured, the above-mentioned measurement results were obtained. Example 4 5, 10, and 15 parts of PA and 2 parts of Erosil #300 (viscosity modifier, manufactured by Nippon Aerosil Co., Ltd.) were mixed with 100 parts of Epicote #828 (epoxy compound manufactured by Yuka Ciel Epoxy Co., Ltd.). Prepare three types of mixtures A, B, and C, and mill each with a 3-roll mill to 5 μm.
After pulverizing and kneading the following,
The mixture was stirred for a minute to defoam. The curing conditions for these mixtures A, B, and C and the physical properties of the cured products were as shown in Table 1 below.

【table】

[Table] Example 5 Polyepoxy compound (product name: Epicote 828,
100 parts of Yuka Ciel Epoxy Co., Ltd., 1 part of the PA of the present invention, 10 parts of dicyandiamide (manufactured by Nippon Carbide Co., Ltd.) as a hardening agent, and a viscosity modifier (trade name:
Three parts of Aerosil #300 (manufactured by Nippon Aerosil Co., Ltd.) were added, and the mixture was crushed through a three-roll machine to a size of 5 μm or less, mixed, and evaluated as a printing material. The results are shown in Table 2 below. Reference Example A printing material was evaluated in the same manner as in Example 5, except that the amount of PA blended was 0.6 parts. The results are also listed in Table 2 below.

【table】

[Table] From Tables 1 and 2, it is clear that the mixture of the PA of the present invention mixed with polyepoxy has excellent storage stability, and the heat-cured product has excellent physical properties. It turns out that PA is extremely excellent as an epoxy curing agent and curing accelerator.

Claims (1)

[Claims] 1. Structural formula 2,4-diamino-6-[(2'-phenylimidazolyl)-ethyl]-s-triazine represented by 2 Structural formula 2-vinyl-4,6-diamino-s-
Structural formula characterized by addition reaction of triazine and 2-phenylimidazole A method for producing 2,4-diamino-6-[(2'-phenylimidazolyl)-ethyl]-s-triazine shown by 3 Structural formula A polyepoxy curing method characterized by blending 2,4-diamino-6-[(2'-phenylimidazolyl)-ethyl]-s-triazine represented by the formula into a polyepoxy compound and heating the mixture.