CS246327B1 - a method for preparing multi-epoxy epoxy resins - Google Patents

Abstract

Oceleni řeseui is the suppression of the formation of undesirable byproducts and hence the higher yield of the main silage in the production of multi-functional epoxy resins and the base of polyglycidyl compounds derived from aromatic polyominines with at least two aromatic cycles linked by a methylene bridge. The preparation of these resins involves, in the first phase, the addition of epichlorohydrin or its derivatives to the aromatic monoate and ultimately the dehydrochlorination of chlorohydrins by the action of the cleavage, wherein the chlorohydrides formed by the addition of said servants in the first stage are subjected to acid-catalyzed condensation with formaldehyde and parc-formaldehyde to form poly-N, N-chlorochlorines of aromatic polysmines, which are ultimately dehydrochlorinated by the aforementioned known method.

Description

246327

The present invention relates to a novel process for the preparation of polyfunctional epoxy resins based on polyglycidyl compounds derived from aromatic poles, amines with at least two aromatic cycles linked by a methylene bridge. The multifunctional epoxy resins represent a new generation of epoxy resins with properties unacceptable when using conventional epoxide types such as 2,2-bis (4-hydroxyethyl) propane or phenolic or epoxy resins. cresol novolak. The hardened materials retain excellent mechanical properties even under extreme conditions, i.e. high temperatures and humidity, and are also resistant to chemicals.

Therefore, they are mainly used as carbon fiber-based prolaminates. These materials serve as a substitute for the metal parts of the aircraft, in aerospace, and the like, by which substantial weight savings are achieved. Furthermore, these resins are used for laminating for very demanding applications in the electrical industry. In addition, their high functionality in preserving the aromatic character is also conducive to use as hardeners for liquid carbohydrates in the preparation of technical rubbers. In practice, the most widespread type of multifunctional epoxy resins is N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenyl methane. These resins are cured with conventional hardeners used to cure conventional types of epoxy resins, but usually hardeners are used that provide masses of high Tg values such as, e.g. -nylmethane, 4,4'-di, aminodiphenylsulfone, di-andiamide, ionic hardeners, urea derivatives, and the like. the Tg of the epoxy resin based on 4,4 ' -diaminodiphenyl sulfone-based N, N, N ', N ' -dietraglycidyl-4,4 ' -diaminodiphenylmethane (Dy-nes PJ, Kaelble DH: Physiochemical a-nalysis of graphite epoxy composite systems.In: Tsal SW: Composite Materials, Phila delphie 1979, p. 566). N, N, N ', N ' -tetra, < RTI ID = 0.0 > lycidyl, < / RTI > 1-4,4 ' -dianiodiphenylmethane is commonly prepared by the addition of 4,4 ' sodium hydroxide. The reaction product contains as a major component the above tetraglycidyl compound in an amount of 70 to 80% by weight. and, as an admixture, higher molecular weight fractions formed by dimerization or trimerization of the main component, as well as the polar substance containing chlorohydric groups remaining after imperfect dehydrogenation and glycol groups formed by hydrolysis of the epoxy groups. The high content of polar impurities leads to a spontaneous decrease in the content of epoxy groups in the product and affects negatively its storage stability and even the properties of the final cured masses, in particular the elevated temperatures and humidity. Therefore, to achieve the optimum properties of these resins and cured materials on their basis, a prerequisite for a better mastering of their synthesis process. Almost all of the processes used to synthesize multi-functional aromatic diamine based epoxy resins by the aromatic cycles linked by a methylene bridge utilize the corresponding aromatic diamine as the starting material. The synthesis of the sweat consists of two parts, the addition of amine hydrogen to epichlorohydrin and the following dehydrochlorination of the chlorohydrin groups, usually by hydroxides. The synthesis can be carried out either directly, in a mixture of aromatic, diamine and e-pichlorohydrin, or in an organic solvent-like aromatic hydrocarbon, ketone or alcohols environment (U.S. Pat. No. 2,951,82, U.S. Pat. 859 936, Japanese Patent No. 8,413,722, U.S. Patent No. 2,884,406). In some processes, the addition and / or dehydrochlorination is carried out under the catalysis of various compounds. E.g. by pal. pat. No. 109,867, the reaction is carried out in the presence of a catalyst composed of triethylenedianiine and triethylamine, according to European Patent Application No. 7,066,064. pat. No. 76,584, the addition is catalyzed by trifluoromethanesulfonic acid and hydrochloride benzyltriethylammonium chloride according to jap. pat. No. 33,198,475, de-hydrochlorination is carried out in the presence of a quaternary ammonium transfer catalyst. The preparation of pure 4,4'-diamino diphenylmethane or substituted derivatives thereof is relatively costly, both economically and economically. The known processes are based on the condensation of aniline or its substituted derivatives with formaldehyde under acid catalysis, generally with hydrochloric acid. In addition to the 4,4'-derivative, there are also 2,2'- and 2,4'-isomers and tri-, tri-, a- and higher polymers. The product is usually refined by distillation under reduced pressure. According to AO USSR No. 379 594, the reaction mixture is subjected to epi-chlorohydrin followed by dehydrochoration of the chlorohydrin groups directly after the condensation of aniline with formaldehyde without isolating 4,4'-diaininoidiphenylmethane. In this way, the production of the resin becomes cheaper, but the resulting product has a high content of higher molecular weight particles and thus a higher viscosity and lower functionality than pure diamine products. Reducing functionality results in reduced Tg values and the resulting decrease in the mechanical properties of the cured resin at elevated temperatures, thereby suppressing the main advantages of epoxy resins of this type as well as curedlimot on their basis.

These drawbacks are overcome by the prolonged inventive method of the preparation of 246367 multi-epoxy epoxy resins based on glycidyl compounds derived from aromatic polyamines having at least two aromatic cycles linked by a methenylene bridge by addition of epichlorohydrin or its derivatives to the amino group of aromatic monoamines. the first phase and dehydration of the product by alkali treatment in the early stage of preparation. The essence of the invention lies in it. wherein the chlorohydrins formed by the determination of epichiarohydrin or its derivatives of the amino group of the aromatic monoamines are first subjected to acid-catalyzed condensation with formaldehyde and / or paraformaldehyde in moles at 40 DEG-130 DEG C., optionally in the presence of organic solvents. 1: 0.3 to 1: 1 ratio. to form poly-N, N-bischlorohydrins of aromatic polyainines, which are ultimately dehydrochlorinated in a known manner.

The technological process of the present invention avoids the formation of higher molecular weight by-products of the structural formula " 1 "

CH, -m. and.

Since NH 3 since at least one hydrogen atom of the amino group has already been substituted by aromatic roonoamine prior to condensation with the formaldehyde, and thus the formation of the "NH-NH" linkages between the aromatic cycles is prevented or hindered; the monoamines, in particular, may be compounds of the group consisting of aniline and its derivatives with a free radical, e.g. o- or m-chloroaniline, o- or duidine, o- or m-anisidine, 2,5 or 2,6 -disubstituted aniline derivatives, optionally other types of aromatic mono-amines. The condensation of the N-mono- and / or NN-bipchlorohydrin of the aromatic monoamine with formaldehyde is carried out under acidic conditions, catalysed by inorganic and organic acids, e.g. hydrochloric acid. trichloroacetic, trifluoroacetic, alkyl- or aryl-sulfonic acids and the like.

The chosen ratio of the amine formaldehyde content can be adjusted in the final product by the content of NN-dlglycidyl derivative of the aromatic monoamine, which acts as a reactive diluent and reduces the viscosity of the multi-functional resin. The presence of this substance in the product can be of particular importance when used as a laminating resin in electrical engineering. Example 1

186.2 g of aniline, 36 g of science Ή 412 g of 99% epichlorohydrin are introduced into a 2.51 flask equipped with a stirrer, a thermometer, a reflux condenser and a separating funnel. The reaction mixture is heated to 80 ° C with stirring and the temperature is initially maintained at this temperature for 8 hours by cooling and then heating. Thereafter, the reaction mixture is cooled to 40 DEG C., 40 g of 36% hydrochloric acid are added and 90 g of a 37% strength aqueous solution of formaldehyde is added uniformly over 30 minutes. The temperature is maintained at that value for 2 hours and then increased to 80 degrees Celsius for 3 hours. After this time, the reaction mixture was cooled to 50 ° C, 400 g of methyl isobutyl ketone and 32 g of 50% aqueous sodium hydroxide solution were added to neutralize the hydrochloric acid. At the same temperature, 480 g of 50% aqueous sodium hydroxide solution was added uniformly over 1 hour and the reaction temperature was maintained for a further 9 hours. 500 g of water are then added to dissolve the sodium chloride and stirred for 5 minutes. After 30 minutes of separation, the lower aqueous layers are drained. The reaction product is then washed three times with 150 g of 5% aqueous sodium chloride solution for 5 minutes each time and after 30 minutes of separation, the bottom aqueous phase is again drained. Water and methyl isobutyl ketone are distilled off under reduced pressure of 5-10 mbar and 140 DEG C. The product is freed from the salt by filtration at the same temperature. 396 g epoxy resin epoxy resin content of 0.8 epox is obtained. eq / g and viscosity 400 Pa. s at 25 ° C. The content of the main component determined by gel permeation chromatography is 83% by weight, the content of N, N-di-glycidylaniline is less than 1% by weight. P ř 1 to 1 from 2

The procedure is as in Example 1, except that after addition of aniline to epi-chlorohydrin, only 50 g of 37% formaldehyde solution is condensed, and the preparation is completed as described in Example 1. 394 g of epoxy-containing resin 0.82 epox. eq / g and viscosity 100 Pa. s / 25 ° C. The content of the main ingredient is 45% by weight, the content of N, N-diglycidylaniline is 38% by weight. Example 3

To a 2.51 flask of Example 1 is added 214.2 g of o-toluidine, 36 g of water and 412 g of 99% epichlorohydrin. The reaction mixture is heated to 90 ° C and maintained at this temperature.

Claims (1)

246327 is 5 hours. Thereafter, the reaction mixture is cooled to 40 ° C, 33.3 g of 98% trichloroacetic acid are added over 40 minutes, 162 g of 37% aqueous formaldehyde solution are added. After the addition of formaldehyde is complete, the temperature is immediately increased to 90 ° C and keep for 6 hours. After this time, the reaction mixture was cooled to 50 ° C, 400 g of methyl isobutyl ketone and 16 g of 50% aqueous sodium hydroxide solution were added to neutralize the acid. Next, as in Example 1, 457 g of epoxy resin having an epoxy content of 0.7 epox are obtained. eq / g and viscose 350 Pa. s / 25 ° C. The content of the main component is 85% by weight, the content of N, N-diglycidyl-1-ol is less than 1% by weight. EXAMPLE 4 The procedure of Example 1 was followed except that after the addition of 50% aqueous sodium hydroxide solution to neutralize hydrochloric acid, 12.3 g of a 56% solution of clilorcholine chloride (Retacel) was added, then 480 g of 50% aqueous sodium hydroxide solution are added uniformly over 1 hour and the reaction temperature is maintained for a further 4 hours. Next, proceed as in Example 1. 395 g of epoxy resin having an epoxy content of 0.8 epox are obtained. eq / g and viscosity 380 Pa. . s / 25 ° C. The content of the main component is 83% by weight, the content of Ν, Ν-diglycidylaniline is less than 1% by weight. EXAMPLE 5 The procedure of Example 1 was followed except that for the condensation of β, β-bis-chlorohydrin of aniline, 36.3 g of 90% by weight of formaldehyde was used instead of the aqueous solution of formaldehyde. 399 g of an epoxy resin of qualitative parameters are obtained, as is the resin prepared according to Example 1. EXAMPLE 6 186.2 g of aniline, 36 g in a 2L flask equipped with a stirrer, a thermometer, a reflux condenser and a separating funnel are introduced. and 474 g of 99% (3-methylepichlorohydrin) and 200 g of toluene. The reaction mixture is stirred at room temperature. The process for the preparation of polyglycidyl-based multifunctional epoxy resins derived from aromatic polyamines with at least two aromatic cycles linked by a methylene bridge by the addition of epichlorohydrin or its derivatives to the amino group of aromatic monosmins in the first phase and dehydrochlorination of the product by the action of alkali in the final stage of preparation, characterized in that the chlorohydrins are heated to 89 ° C and the temperature is maintained at 8 hours. Then the reaction mixture is cooled to 50 ° C, 35 g of 36% hydrochloric acid and 20 g of 90% paraformaldehyde are added. The reaction mixture was heated to 70 ° C and this temperature was maintained for 2 hours. Thereafter, 41 g of 37% aqueous formaldehyde solution was added over 10 minutes and the temperature was maintained for 70 hours for a further 4 hours. After this time, the reaction mixture was cooled to 50 ° C, 200 g of toluene and 28 g of 50% aqueous sodium hydroxide solution were added to neutralize the hydrochloric acid. The next procedure is the same as in Example 1. 450 g of epoxy resin having an epoxide content of 0.65 epox are obtained. The content of the main component determined by gel permeation chromatography was 81% by weight. EXAMPLE 7 186.2 g of aniline, 200 g of methylisobutyl ketone, 18 g of water and 412 g of 99% ophyl orhydrin are introduced into a 2.51 flask equipped with a stirrer, a thermometer, a reflux condenser and a separating funnel. The reaction mixture is heated to 80 ° C with stirring and the temperature is maintained at this temperature for 8 hours. Thereafter, the reaction mixture was cooled to 40 ° C, 40 g of 36% hydrochloric acid was added and 85 g of 37% aqueous formaldehyde solution was evenly added over 30 minutes. The temperature is maintained at this value for 50 hours, then 32 g of 50% aqueous sodium hydroxide solution is added and the mixture is poured into a separatory funnel. After 30 minutes of separation, the bottom water is drained, the organic phase is cooled to 5 ° C and allowed to stand for 24 hours. . The 4,4'-diaminodiphenylmethane crystallized tetrachlorohydrin is filtered off with suction on a frit, washed with ethanol and dried at normal temperature. Then transfer to a flask, add 400 g of methylisobiityl ketone, heat to 50 ° C with stirring and dehydrochloride with 50% aqueous sodium hydroxide in the same manner as in Example 1. After washing and distilling off Solvents recover 400 400 epoxy resin content of epoxide groups 0.9 enox, eq./100 g and viscosity 100 Pa. s at 25 ° C. The main content determined by gel permeation chromatography is 92% by weight. EMBODIMED by the addition of epichlorohydrin or its derivatives to the amino group of aromatic monomers, the acid-catalyzed condensation with formaldehyde and / or paraformaldehyde in moles is first subjected to acidification at 40 to 130 ° C, optionally in the presence of organic solvents. 1: 0.3 to 1: 1 ratio of poly-N, N-bischlorohydrins of aromatic polyamines, which are finally dehydrochlorinated in a known manner. Savwografla, n. P., Závod 7, Most Price 2.40 KCs