RU2207349C2 - Method of preparing cold-hardening epoxide resin hardeners - Google Patents

Abstract

FIELD: polymer materials. SUBSTANCE: cold-hardening epoxide resin hardeners useful in epoxide compounds intended for anticorrosive protection are prepared by mixing aromatic and aliphatic di- and polyamines with salicylic acid additive. Preliminarily, aromatic di- or polyamine is brought into reaction with salicylic acid dissolved in product of esterification of o-phthalic acid with hydroxyl- containing compound selected from group including butyl, isononyl, and benzyl alcohols by stirring components in reactor at 50-90 C for 6 to 40 min at ratio aromatic di- or polyamine/salicylic acid/hydroxyl-containing compound between 98:1:1 and 10:20:70. In another reactor, aliphatic di- or polyamine is brought into reaction with the same components by stirring mixture at 30-55 C for 3 to 25 min at ratio aliphatic di- or polyamine/salicylic acid/hydroxyl-containing compound between 96:2:2 and 4:16:80. Preliminarily prepared products based on aromatic and aliphatic amines are then combined and stirred at 15-60 C for 3 to 20 min at ratio from 95:5 to 5:95. EFFECT: enabled preparation of hardeners stable upon long storage and suitable for manufacturing high-strength polymers with elevated heat resistance. 3 tbl

Description

 The invention relates to a method for producing hardeners of cold cured epoxy resins using aromatic amines and can be used in the production of hardeners used in epoxy compounds intended for corrosion protection, as bulk floors in construction, for impregnation of reinforcing fillers in contact molding of products and other purposes .

 A known method of producing hardeners of cold cured epoxy resins by mixing an aromatic amine with cresol and salicylic acid or a liquid mixture of 3 aromatic amines with salicylic acid (see V. A. Lapitsky, A. A. Kritsuk, "Physical and mechanical properties of epoxy polymers and fiberglass ", Kiev:" Naukova Dumka ", 1986, p.26-27).

 The specified method allows to obtain hardeners that provide during cold curing higher strength characteristics and deformation heat resistance of epoxy polymers compared to those obtained using aliphatic amines as hardeners.

The disadvantage of this method is the low viability of the hardeners themselves (1 ÷ 2 hours at 20 ^o C), which does not allow them to be prepared in advance and delivered as a commercial product, that is, when working with such hardeners, they must be prepared in small portions and immediately used. In addition, the known method involves the use of toxic components - cresol and meta-phenylenediamine, which cause toxic effects on working personnel, and pollutes the environment. Cured polymers, although they exceed those in terms of strength and heat resistance, cured by aliphatic amines, have insufficient wear resistance and vibration resistance. The disadvantage of these hardeners is also the dark color of the cured epoxy polymers.

 A method for producing hardeners is also described, as a stage in the preparation of cold cured epoxy compositions, which consists in mixing an aromatic amine, an aliphatic amine, cresol and salicylic acid (see USSR author's certificate 807622 with priority of February 27, 1978 on application 2583142 - prototype).

 Obtained by the specified method hardeners provide improved wear resistance and vibration resistance of cold-cured polymers, but are not without the above drawbacks.

The aim of the present invention is a method for producing hardeners of cold-cured epoxy resins, stable during long-term storage, providing curing starting from -10 ^o C, and obtaining high-strength polymers with high heat resistance, allowing the possibility of dyeing almost any color with the introduction of dyes and pigments .

This goal is achieved by first obtaining the product of the interaction of aromatic di- or polyamine (A) with salicylic acid (B) dissolved in the esterification product of orthophthalic acid with a hydroxyl-containing compound (C) selected from the group consisting of methyl, ethyl, octyl, butyl , isononyl, benzyl alcohol by mixing the components in the reactor at a temperature of 50 ÷ 90 ^o C for 6 ÷ 40 min in the ratio A: B: C in wt.h from 98: 1: 1 to 10:20:70, in another reactor pre-receive product interact Ia aliphatic di- or polyamine (F) with the same components by mixing them at a temperature of 30 ÷ 55 ^o C for 3 ÷ 25 min at a ratio T: B: B parts from 96: 2: 2 to 4:16:80, after which the obtained reaction products based on aromatic and aliphatic di or polyamines are mixed at a temperature of 15 ÷ 60 ^o C for 3 ÷ 20 min in a ratio of 95: 5 to 5: 95.

 The above is confirmed by examples.

 Example 1

In the reactor, equipped with heating-cooling and stirrer, load 54 wt. including aromatic diamine -4,4'diaminodiphenylmethane (A), 10 parts by weight of salicylic acid (B), dissolved in 36 parts by weight of the product of the esterification of orthophthalic acid, a mixture of n-butyl and benzyl alcohols in butylbenzyl phthalate (C), with a ratio of components A: B: C = 54: 10: 36, the temperature in the reactor is raised with a constantly working stirrer, and after reaching a temperature of 70 ^o C the mixture they are kept under stirring for 12 minutes, while the temperature, due to the exothermicity of the reaction, begins to rise and therefore, cooling is turned on and the temperature is maintained at 70 ^{° C. for} another 11 minutes (i.e., the total time is 23 minutes). The resulting product is cooled to 36 ^o C. In another reactor, similarly carry out the mixing of ethylenediamine - 50 wt.h. with 9 parts by weight salicylic acid, also dissolved in 42 parts by weight benzyl butylphthal. The process of obtaining the reaction product is exothermic, therefore, after reaching a temperature of 36 ^{° C.} after 2 minutes, cooling is turned on and, while maintaining a temperature of 42 ^{° C.} , it is stirred for another 12 minutes. After that, the product is cooled to 20 ^o C.

Next, both products of the reaction of -4,4'diaminodiphenylmethane and ethylenediamine with salicylic acid in benzylbutylphthalate are mixed in a ratio of 50:50 for 12 min at a temperature of 38 ^o C. The hardener thus obtained is packaged in a metal container and stored in storage conditions.

 Examples 2-14 are carried out analogously to example 1. The parameters of their implementation are given in table. 1. The properties of the hardeners in examples 1-14 in comparison with the analogue and prototype and the most common hardeners of cold cured epoxy resins - polyethylene polyamine (PEPA) and ethylene diaminophenol-formaldehyde condensate - AF2 are given in table. 1 and 2.

 Hardeners obtained by the claimed method have indisputable advantages compared to the known ones and have received good reviews from both foreign and domestic consumers. They are stable during storage and transportation, non-volatile, non-toxic, cure epoxy resins even in moderate frosts, providing higher strength properties and heat resistance.

Claims (1)

A method of obtaining hardeners of cold cured epoxy resins, including the operations of mixing aromatic and aliphatic di or polyamines and introducing salicylic acid, characterized in that the product of the interaction of aromatic di or polyamine (A) with salicylic acid (B) dissolved in the esterification product is preliminarily obtained orthophthalic acid with a hydroxyl-containing compound (B) selected from the group including butyl, isononyl, benzyl alcohol, by mixing the components in the reactor at ture 50 ÷ 90 ^o C for 6 ÷ 40 minutes in a ratio of A: B: B weight. hours from 98: 1: 1 to 10:20:70, in another reactor, the product of the interaction of an aliphatic di- or polyamine (G) with the same components is preliminarily obtained by mixing them at a temperature of 30 ÷ 55 ^o C for 3 ÷ 25 min in the ratio G: B: C in parts by weight from 96: 2: 2 to 4:16:80, after which the resulting reaction products based on aromatic and aliphatic di or polyamines are mixed at a temperature of 15 ÷ 60 ^o C for 3 ÷ 20 min in a ratio of from 95: 5 to 5: 95.

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