SU495335A1 - Epoxy composition - Google Patents

Description

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This invention relates to epoxy compositions used in casting and impregnating compositions with reduced toxicity and good processing properties.

A known epoxy composition containing maleic anhydride as a hardener and styrene as an active diluent. A disadvantage of the known composition is its increased toxicity, due to the fact that in order to avoid precipitation of maleic anhydride in the sediment, the preparation of the composition is carried out at elevated temperature (50-70 ° C). Due to this, an increased concentration of harmful vapors of styrene and maleic anhydride is created in the environment.

In order to reduce the toxicity of the composition in the process of preparation, improve its technological properties and improve the mechanical properties of the finished material, the proposed composition contains vinylsuccinimide as an active diluent and maleic anhydride as a hardener. Equimolecular amounts of these components combine at normal temperature to produce a liquid eutectic mixture from two crystalline substances. The latter has the following properties: viscosity

(20 ° С) 3.8 сП, т. Пл. 5 ° С; density (20С) 1.26 g / cm; refractive index 1.4960.

Volatility of its vapors is much lower, ps. M in the case of a mixture of maleic anhydride with styrene: for example, the first one after holding at 120 ° C for 5 h loses 4% in weight, the last -14%. Low viscosity transparent eutectic mixture is combined at room temperature.

temperature with epoxy resin Dianova based U, 8-1.0 mol of eutectic mixture per 1 epoxy equivalent of resin.

The resulting composition is a clear liquid with a low viscosity.

(100-700 cSt at 20 ° C), which provides for pouring molds with; single-burned configuration without heating. Curing of the composition is carried out in a stepped mode, keeping it at 100-160 ° C for 10-15 hours. To accelerate

curing and reducing the process temperature; tertiary amines and peroxide initiators can be introduced into the composition to ensure the copolymerization of maleic anhydride with vinylsuccinimide. After curing

receive transparent materials of dark brown color, possessing high physicomechanical properties.

Example 1. 100 wt. including epoxy resin ED-16 (epoxy equivalent 254) is mixed at 20 ° C with 88.0 weight. h, a eutectic mixture prepared by mixing at room temperature 38.7 weight. including maleic anhydride with 49.3 wt. including vinylsuccinimide. A low-viscous homogeneous mass is poured into molds and cured at first 5 hours at 120 ° С, then 5 hours at 140 ° С and, finally, 5 hours at 160 ° С.

Example 2. 100 weight. including epoxy resin ED-16 (epoxy equivalent of 254) is mixed with 70 weight. h. eutectic mixture,

(Prepared by mixing at room temperature 30.8 parts by weight of maleic acid hydride with 39.2 parts by weight of vinylsuccinimide. Low-grade homogeneous composition is poured into molds and cured according to the regime described in Example 1.

The physicomechanical properties of the cured compositions of the proposed and known compositions are given in the table.

Here, for comparison, similar indicators of a known composition containing 100 wt. including resin ED-16, 38.5 wt. including maleic antidrid and 41.0 wt. including styrene.

Claims (2)

Invention Formula I. Epoxy composition, used as casting and impregnating compositions, including epoxy resin, lmaleic anhydride and unsaturated active diluent, in order to reduce the toxicity of the composition in the process of preparation, improving its technological properties and improving the mechanical properties of the finished material, the composition as an active diluent contains vinylsucimimide in the following ratio of ingredients: 0.8-1 mol of maleic aagidride, 0.8-1 mol of vinylsucminimide per 1 epoxy equivalent epoxy resin. 2. Epoxy composition pop. 1, characterized in that maleic anhydride and vinylsuccinimide are introduced into the epoxy resin as a liquid eutectic mixture.