RU2065436C1 - Hardening agent for epoxy resins - Google Patents

Abstract

FIELD: production of hardener for epoxy resin. SUBSTANCE: desired product is prepared by interaction of N,N-bis(2-)cyclohexylydeneamino(ethyl)ethylene-1,2-diamine and phenylor tolyl glycidal ether at their molar ratio 1:1. The process is carried out at 80 C. EFFECT: improves quality of desired product.

Description

 The invention relates to the field of production of amine hardeners for epoxy compositions used for coatings with high physical, mechanical and anticorrosive properties.

 Amine hardeners are known aliphatic amines, polyamines and others with a wide variety of structures and properties, as well as their modifications (see, for example, Lee H. Neville K. Epoxy Resin Reference Guide. M. Energy, 1973).

 Such compounds are not very easy to handle, have an unpleasant odor, are volatile and toxic. Compositions based on them with epoxy resins have low (1-5 hours) viability and insufficient resistance to some aggressive environments. In addition, such hardeners do not make it possible to obtain coatings with high performance in high relative humidity conditions: the films are sticky, dull, with a loss of chemical resistance.

с кремнийорганическим диоксидом формулы:

при их молярном соотношении 1:0,5, с содержанием активного азота в отвердителе 6,9%
Отвердитель получают взаимодействием кетимина с кремнийорганическим диоксидом при 50-80^oС до полного исчезновения эпоксидных групп (см. авторское свидетельство СССР N 1803411, кл. С 08 G 59/40, опубл. 1993).Closest to the invention in terms of the chemical structure of the components for synthesis according to the principle of preparation and use in the composition, is the product of the interaction of ketimine based on diethylenetetramine and cyclohexane-bis- (2-cyclohexylideneamino) ethyl) amine with the formula:

with organosilicon dioxide of the formula:

at a molar ratio of 1: 0.5, with an active nitrogen content of 6.9% in the hardener
The hardener is obtained by reacting ketimine with organosilicon dioxide at 50-80 ^° C until the epoxy groups completely disappear (see USSR author's certificate N 1803411, class 08 G 59/40, publ. 1993).

The known hardener is used in a composition with a low molecular weight diane resin ED-20 and glycidyl ethers of higher isomeric carboxylic acids C _9> -C ₁₉ in the following combination of binder components, parts by weight:
Epoxy resin ED-20 100
Glycidyl esters of higher isomeric carboxylic acids C ₉ -C ₁₉ 15-25
Hardener 30-110
The disadvantages of the above hardener are the high gelation rate of the hardener under the influence of air moisture, which necessitates the storage of the hardener in a hermetically sealed (paraffinized) container, as well as the low activity of the hardener in the composition of epoxy compositions at low (up to 45 ^o C) temperatures.

The essence of the invention is to obtain an amine hardener for epoxy compositions, forming coatings with high and stable performance when cured in conditions of high (up to 100%) relative humidity and low temperatures (up to -5 ^o C, more environmentally friendly due to the high dry residue having increased stability during storage and providing high viability of the mixture ready for saturation with the epoxy component.

либо

Отвердитель получают взаимодействием N,N'-бис[2-(циклогексилденамино)этил]-этилен-1,2-диамина и фенил- или толилглицидилового эфира при их мольном соотношении, равном 1:1, и температуре 80^oС.To achieve this, an amine hardener 1,10-dicyclohexyl-4- (2-hydroxy-3 phenoxypropyl) -1,4,7,10 tetraazodecadiene or 1,10-dicyclohexyl-4- (2-hydroxy-3 toloxypropyl) -1 , 4.7,10 tetraazodecadiene of the following formula, respectively:

or

The hardener is prepared by reacting N, N'-bis [2- (cyclohexyldenamino) ethyl] ethylene-1,2-diamine and phenyl or tolyl glycidyl ether at a molar ratio of 1: 1 and a temperature of 80 ^° C.

The process is conducted as follows. Phenyl glycidyl or tolyl glycidyl ether is slowly added (added dropwise) to the melt of ketimine at 80 ^{° C.} and the reaction mixture is stirred vigorously. Upon completion of the instillation of the entire amount of phenylglycidyl or tolylglycidyl ether, the reaction mixture is aged for 8-10 hours at a temperature of 80 ^° C with constant stirring until the reaction is complete, as judged by the complete decrease in the epoxy groups.

где

Пример А. К расплаву кетимина в количестве 30,6 г (0,1 моль) при температуре 80^oС прикапывают при интенсивном перемешивании толилглицидиловый эфир в количестве 14,6 г (0,1 моль) в течение 10-15 минут, затем производят выдержку реакционной массы при той же температуре и непрерывном перемешивании в течение 8-10 часов до полной убыли эпоксидных групп. Получают 44,9 г отвердителя (выход 99%). Отвердитель охлаждают, фильтруют и сливают в емкость. Полученный продукт имеет внешний вид вязкой смолообразной жидкости от светло-желтого до коричневого цвета, без механических включений. Содержание массовой доли молекулярного азота составляет 12,4-15,5% вязкость 10 Па•с, среднечисловая молекулярная масса 450.The modification reaction scheme can be represented as follows:

Where

Example A. To a melt of ketimine in an amount of 30.6 g (0.1 mol) at a temperature of 80 ^{° C.,} toluene glycidyl ether in an amount of 14.6 g (0.1 mol) is added dropwise with vigorous stirring for 10-15 minutes, then produced exposure of the reaction mass at the same temperature and continuous stirring for 8-10 hours until the epoxy groups are completely reduced. 44.9 g of hardener are obtained (99% yield). The hardener is cooled, filtered and poured into a container. The resulting product has the appearance of a viscous gummy liquid from light yellow to brown in color, without mechanical impurities. The content of the mass fraction of molecular nitrogen is 12.4-15.5% viscosity of 10 Pa • s, the number average molecular weight of 450.

Example B. To a melt of ketimine in an amount of 30.6 g (0.1 mol) at 80 ^{° C.} with continuous stirring, 13.0 g (0.1 mol) of phenyl glycidyl ether are added dropwise over 10-15 minutes, then the reaction mixture is kept at the same temperature and continuous stirring for 8-10 hours until the epoxy groups are completely reduced. 42.9 g (98% yield) of curing agent are obtained, which are cooled, filtered and poured into a storage tank. The product has the appearance of a viscous liquid from yellow to light brown in color without mechanical impurities. The content of the mass fraction of molecular nitrogen is 12.4-15.5%, the viscosity is 21 Pa • s, and the number average molecular weight is 470.

 For curing, the hardener is introduced in an amount of 0.75 to 1.15 equivalent to 1 equivalent of a diane resin, which can be used as low molecular weight diane resins ED-20 (molar mass 400, 22% epoxy content GOST 105972-76); ED-16 (mol. Mass 600, the content of epoxy groups 18% GOST 10597-76); E-40 (mol. Mass 700-800, the content of epoxy groups 13-15% OST 6-10-416-77), etc.

 The properties of the coatings obtained by curing epoxy dianes by the aforementioned hardener can be illustrated by the following examples, in wt.

Example 1
Epoxy resin ED-20 68.0
Hardener of Example A 27.2
Ethyl Cellosolve 4.8
A hardener, previously mixed with ethyl cellosolve, is introduced into the epoxy resin, the mixture is thoroughly mixed and applied onto the substrate with a brush.

Example 2
Epoxy resin ED-20 61.2
Hardener of Example A 33.0
Ethyl cellosolve 5.8
Preparation and application are similar to example 1.

Example 3
Epoxy resin ED-20 64.39
Hardener according to example B 30.27
Ethyl Cellosolve 5.34
Preparation and application are similar to example 1.

Example 4
Epoxy resin ED-16 67.3
Hardener of Example A 28.4
Ethyl Cellosolve 5.1
Preparation and application are similar to example 1.

Example 5
Epoxy resin E-40 68.0
Hardener of Example A 27.3
Ethyl Cellosolve 5.6
Preparation and application are similar to example 1.

 The properties of hardeners, compositions and coatings based on them are presented in the table.

 Hardener storage time, months prototype 0.5; Example A 3.0; Example B 3.0

Curing conditions for coatings: temperature 20 ^o C; humidity up to 100% curing time 5 days.

 As can be seen from the research results, the hardener according to the invention allows to obtain, upon curing, compositions with epoxy resin coatings that are significantly superior in their properties to coatings obtained when used as a hardener according to the prototype. TTT1

Claims (1)

Hardener for epoxy resins, which is the product of the interaction of N, N'-bis- [2- (cyclohexylideneamino) ethyl] ethylene-1,2-diamine and phenyl or tolyl glycidyl ether in their molar ratio of 1: 1, and at temperature 80 ^o C.

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