RU2735284C1 - Method of producing hardeners of epoxy resins - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of curing agents for epoxy resins. Described is a method of producing curing agents of epoxy resins, involving an operation of reacting an epoxide component with a molar excess of di- or polyamine, in which the epoxy component used is mono- and olefin dioxides, including cycloaliphatic or aliphatic-cycloaliphatic diepoxides or mixtures thereof (A) in a combination with compounds containing a triazine cycle (B) in ratio A:B from 95:5 to 40:60, and in the process of obtaining hardeners in a reactor first, liquid or fused di- or polyamine - aliphatic, aromatic, alkylene aromatic or cycloaliphatic, and then adding an epoxide component thereto, wherein the amine component is taken in 5–25-fold molar excess with respect to the epoxy component, after which tertiary amine is added in amount of 0.1–5 pts. wt. by 100 pts. wt. of reaction mass of amine and epoxy components and then mixed at temperature from 20 °C to 160 °C for 15 to 200 minutes.

EFFECT: technical result is high strength properties at high temperatures, as well as improved dielectric properties and high arc resistance.

1 cl, 2 tbl, 7 ex

Description

The invention relates to the field of obtaining hardeners for epoxy resins and their derivatives.

Known hardeners for epoxy resins obtained by reacting aliphatic amines with propylene oxide.

(See Handbook on plastics edited by V.M.Kataev, 2nd edition, M., Chemistry, 1975, T2).

The hardeners described in the handbook provide an improvement in the technological properties of epoxy compositions, but at the same time lead to a decrease in the deformational heat resistance of the cured polymers.

The closest prototype of the claimed invention is a method for producing epoxy resin hardeners, including the operation of interaction of various di- and polyamines with cycloaliphatic or aliphatic-cycloaliphatic dioxides, followed by the introduction of acrylate and amino alcohol into the composition (Patent RU 2.507.226 C2 dated December 28, 2011).

The known method makes it possible to obtain epoxy polymers with improved dielectric properties at temperatures up to + 200 ° C, which are preserved after exposure to hot superheated water and an increased Martens heat resistance index - up to 220 ° C. The disadvantages of this method are relatively low elastic and strength indicators at temperatures from +150 to 250 ° C, as well as insufficiently high values of the tangent of the dielectric loss angle and dielectric constant (E), which characterize the radio transparency of the materials obtained, as well as their preservation after exposure to solar radiation.

The disadvantages of this method is the relatively low strength characteristics of cured epoxy polymers at a temperature of 150-200 ° C.

The purpose of the proposed method is to obtain hardeners that provide the production of epoxy polymers with increased strength indicators in the temperature range from + 150 ° C to 200 ° C, improved radio transparency, that is, with improved values of the dielectric loss tangent and dielectric constant, as well as increased arc resistance.

This goal is achieved by the fact that when obtaining a hardener product of the interaction of aliphatic, aromatic, cycloaliphatic or alkylene aromatic di-, or polyamines with mono-, olefin dioxides, including cyclo-aliphatic or aliphatic-cycloaliphatic diepoxides or mixtures thereof (A), in the composition of the latter, compounds containing the triazine cycle (B) are preliminarily introduced at a ratio A: B from 95: 5 to 40:60, and in the process of obtaining the hardener, the amine component is first introduced into the reactor, and then the epoxy component (A + B) from calculating the molar excess of the amine over the epoxy component by 5-25 times, after which the tertiary amine is introduced in an amount of 0.1 ÷ 5 wt. h per 100 wt. h of the reaction mass and then the composition is stirred at a temperature of 20 ° C to 160 ° C for 15 to 200 minutes.

This is confirmed by examples.

Example 1.

In a reactor equipped with heating-cooling and a high-speed stirrer 1500 rpm, load 1000 wt. including meta-phenylenediamine in a molten state (Tm. + 63 ° C), then a pre-prepared mixture of cyclic ether dioxide based on tetrahydrobenzaldehyde (industrial grade resin UP-632) component A with triglycidyl cyanurate (industrial grade resin) is added to it within 15 minutes EC) - component B, in the ratio A: B = 65:35, the content of epoxy groups in the mixture is 32% in the amount of 330 wt. including, thus providing a 15-fold molar excess of meta-phenylenediamine in relation to the epoxy component. To the mixture heated to + 80 ° C, 3.325 wt. h of tertiary amine-triethanolaminotitanate (based on 0.25 wt. h per 100 wt. h of the reaction mixture) and stirred for 110 minutes.

The hardener thus obtained is cooled to ambient temperature and poured into metal containers.

The conditions for obtaining the hardener according to examples 2-5 are shown in table 1, and the properties of the polymers in table 2.

The properties of the hardener and polymers cured by it based on epoxy resin - vinylcyclohexene dioxide are shown in Table 2.

As can be seen from table 2, the claimed method for producing epoxy resin hardeners allows obtaining hardeners that are not inferior in technological properties to the prototype, but provides a significant increase in the strength characteristics of cured epoxy resins in the temperature range + 150 ÷ 200 ° C, an increase in arc resistance by 2 ÷ 3 times, and also the improvement of the indices of the tangent of the angle of dielectric losses and the permittivity, which characterize the radio transparency of the composite products obtained on their basis, for example, radio-transparent shelters, radars.

Claims (1)

A method of obtaining hardeners for epoxy resins, including the operation of interaction of an epoxy component with a molar excess of di- or polyamine, characterized in that olefin mono- and dioxides are used as the epoxy component, including cycloaliphatic or aliphatic-cycloaliphatic diepoxides or mixtures thereof (A) in combination with compounds containing the triazine cycle (B) in the ratio A: B from 95: 5 to 40:60, and in the process of obtaining hardeners, liquid or molten di- or polyamine is first introduced into the reactor - aliphatic, aromatic, alkylene aromatic or cycloaliphatic, and then to an epoxy component is added to it, and the amine component is taken in a 5 ÷ 25-fold molar excess with respect to the epoxy component, after which a tertiary amine is introduced in an amount of 0.1 ÷ 5 wt. hours per 100 wt. including the reaction mass of the amine and epoxy components and then it is stirred at a temperature of 20 ° C to 160 ° C for 15 to 200 minutes.