DE2117099A1 - Epoxy curing agents - by reacting (cycloaliphatic) branched diamine with (meth)acrylic aid deriv - Google Patents

Abstract

Amino acid derivatives are prepd. by reacting aliphatic and/or cycloaliphatic diamines of formula (I) directly or in the form of their amides with alpha,beta-unsatd. carbonyl cpds. of formula II. (where R is a divalent aliphatic or cycloaliphatic 4-38C gp. with a branched chain; R' is H, alkyl or aryl; X is HO-alkyl-O-, aryl-O-, H2N-, alkyl-HN-, aryl-HN-, (alkyl)2-N-; (aryl)2-N, or group III). Gives uncrosslinked products in relatively short reaction times. These pdts. are used for crosslinking 1,2-epoxide cpds. The pdts. have a good colour, low viscosity and good solubility and compatibility with the epoxide cpds.

Description

Amino acid derivatives The present invention is a Process for the production of special amino acid derivatives.

It is known that α, p-unsaturated carbonyl compounds with primary and secondary monoamines) i.e. amines, the still active N-bonded Possess hydrogen, react (Marsch, M. 63, 230; Howton, J. org. Chem. 10, (1945) 278; Hromatka, Siles M. 78, (1948) 129).

It is also known that diamines (and polyamines) with α, ß-unsaturated React carbonyl compounds with addition to the activated C-C double bond. So react Poylalkylenpolyamines, such as z .13. Diethylenetriamine, tetraethylene pentamine with d, ß-unsaturated carbonyl compounds, such as acrylic and substituted acrylic acid esters and amides to form viscous, dark-colored products with a high content of amine hydrogen.

Because of their dark color, high viscosity and limited Such products have only a low range of compatibility and solubility Importance as an epoxy hardener.

Furthermore, those from such aminoamides and polyepoxide compounds show produced films have poor flow and do not completely wet the substrate. The amine compounds tend to exude on the surface of the film, resulting in the Gives film a greasy, cloudy appearance.

In the condensation of acrylic acid esters with unbranched aliphatic Diamines are easily crosslinked polyamides.

According to a known method, the reaction is therefore avoided of crosslinking carried out at temperatures below + 300C. It is also described that in the reaction of di'-alpine with acrylic acid derivatives at temperatures above 75 ° C crosslinking takes place. The reaction is therefore preferably carried out at temperatures performed around ° C. The reaction proceeds very slowly under these conditions. There will be times between 8 h and several. Days specified.

It has now surprisingly been found that uncrosslinked products can also be obtained at higher temperatures in a shorter reaction time by carrying out the process for the preparation of amino acid derivatives by condensation of diamines with 7> -unsaturated carbonyl compounds so that branched aliphatic and / or cycloaliphatic compounds are used as the diamine component Diamines of the formula in which R can be a divalent branched aliphatic or cycloaliphatic radical with 4-38 carbon atoms and R 'can be hydrogen and an alkyl or aryl radical, with α, ß-unsaturated carbonyl compounds of the general formula in which X means HO-, alkyl-O-, aryl-O-, H2N-, alkyl-HN-, aryl-HN-, (alkyl-) 2N-, (aryl-) 2N- and Can have the rest. Those branched aliphatic diamines which contain at least one carbon-bonded C1-C5 alkyl radical are preferred. Among the cycloaliphatic diamines, preference is given to those which have one or more carbon-bonded C1-C3-alkyl radicals. A particularly preferred cycloaliphatic diamine is 1-amino-3-animomethyl-3,5,5-trimethylcyclohexane.

Suitable diamines in the context of the present invention are both the branched aliphatic diamines as well as the cycloaliphatic diamines 4 -38 carbon atoms, which in turn can be unsubstituted and alkyl-substituted. In the case of the branched aliphatic diamines, preference is given to those having -20 carbon atoms and / or additionally have 1-carbon-bonded C1-C5-alkyl radicals in the chain wear. In the case of cycloaliphatic diamines, too, those 6-20 are preferred Have carbon atoms and also have one or more carbon-bonded C1-C3-alkyl radicals to have. Examples of branched aliphatic diamines include: 3,6-diethyloctanediamine- (1,8), 2,5-diethylhexanediamine- (1,6), 4,4-dimethylheptanediamine- (1,7), 2,2-dimethylpentanediamine- (1,5), 2-methyl-4-ethyloctanediamine- (1,8), 1,4,4-trimethylheptanediamine- (1,7), 2,4,4-trimethylhexanediamine- (1,6), 2,2,4-trimethylhexanediamine- (1,6) buw. the 1: 1 Isomer mixture and the diamines, which by hydrogenation of the dinitrile by Dimerization of unsaturated fatty acids, e.g. 13. Linoleic acid, available dicarboxylic acids can be produced u.

Examples of cycloaliphatic diamines are: 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4-diamonodicyclohexyl methane, 2,2-bis (4-aminocyclohexyl) propane. 1-Amino-3-aminomethyl-3,5,5-trimethylcyclohexane (often abbreviated to IPD), 1-amino-3-aminomethyl-3,5-dimethyl-5-ethylcyclohexane i.a. Mixtures of the abovementioned compounds can also be used.

Suitable α, S ß-unsaturated carbonyl compounds of the above general formula are for example: acrylic acid, acrylic anhydride, acrylic acid methyl ester, Acrylic acid n-butyl ester, acrylic acid 2-ethylhexyl ester, acrylic acid n-octyl ester, Acrylic acid N-methylamide, methacrylic acid methyl ester, methacrylic acid n-butyl ester, Phenyl methacrylate, phenyl cinnamate and others. Mixtures can also be used.

The new compounds according to the present invention can by Reaction of the described diamines with the «, p saturated carbonyl compounds in a molar ratio of 2.0-0.5: 1, preferably 1.9-0.75: 1.

However, molar ratios deviating therefrom are also possible.

In these cases, the excess of one or the other component removed.

The implementation of the diamines with the α, ß-unsaturated carbonyl compounds is expediently carried out in the temperature range of 0-300 ° C. The reaction however, it can also be done in two stages by initially implementing the range of O - 20 0C carried out and then at temperatures rising up to 3000C is accomplished.

The products of the invention can be produced by simply Mixing the two components together, if necessary in the presence of solvents - whereby the reaction begins immediately with development of heat. With the diamines according to the present Invention can reduce the reaction time by heating to temperatures up to the boiling point of the reaction mixture and closer to 1 hour and less. Also at At relatively high reaction temperatures around 200-250 ° C. there was no crosslinking observed.

Further details of this process can be found in the examples A particular advantage of the process according to the invention is that the reaction can also be carried out without the use of a solvent or dispersant can, which is of great importance in the case of direct further use.

The products produced according to the invention are characterized by high Reactivity towards a number of reactants.

They have a practically linear structure.

The products produced according to the invention can be used to produce mg of polyadducts based on epoxy compounds are used by known methods will and do not have the undesirable disadvantageous properties of the o. Amino amide masses.

Particularly interesting are the liquid products that result from sales of the two starting products amine to carbonyl derivative in a molar ratio of 2.0-0.75: 1 can be obtained. Their mixtures with liquid 1,2-epoxy compounds are of low viscosity u: d can therefore be used as casting resins. The cold or warm hardened ones Moldings are characterized by their colorlessness and high transparency, in particular when the aminoamide contains acrylic acid or methacrylic acid as a building block.

With decreasing molar ratio of diamine to carbonyl compounds the viscosity increases. The higher viscosity products according to the invention are suitable excellent for the production of storage-stable epoxy-hardener combinations in the B stage, which are also completely colorless.

Is used to manufacture the products according to the present Invention branched alkylenediamines with 4 - 38 carbon atoms, which have at least two or Carry several C1 to C5 groups bonded to C, e.g. B. dimethylhexamethylenediamine, This gives you "epoxy resin hardeners" with high reactivity and compatibility. the Epoxy adducts produced with these hardeners are distinguished by their brightness and high impact strength.

These advantages are particularly outstanding in the case of the basic Products of the acrylic acid derivatives used according to the invention observed, to their Production of aliphatic diamines with at least three C1 to C3 alkyl groups and a total of not more than 20 carbon atoms, such as B. 2,4,4- and / or 2,2,4-trimethylhexamethylenediamine, be used. The epoxy adducts of these products are characterized by both their high impact strength as well as high notched impact strength. The adducts remain colorless even after heat curing and show very good adhesion to steel.

By incorporating cyclic diamines with 1 or more C1 to C3 alkyl groups in an appropriate molar ratio, e.g. B. 2,4-diamino-1-isopropylcyclolexane, If one obtains a basic product, epoxy adducts are exceptionally hard without being brittle about it.

These have to be post-cured at a higher temperature. At temperatures below 50 ° C the adducts harden only to the extent that they are hardened at 180 ° C Adducts show no discoloration. Such basic ones are thermally particularly stable Products of the acid derivatives, for their preparation cyclic diamines with at least three alkyl groups attached to carbon atoms can be used.

The use of 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane is particularly advantageous (IPD) or its isomers. Mixtures of these basic compounds with 1,2-epoxy compounds with more than one epoxy group in the molecule remain at 80 0C long enough thermoplastic and harden at 150 ° C with sufficient speed. At temperatures around 180 - 200 ° C. hardening takes place within a few seconds.

These basic products can therefore be used for the production of storage-stable Epoxy resin adduct molding compounds and sintering powder can be used.

The processing of the amino acid derivatives prepared according to the invention with 1,2-epoxy compounds with more than one gpoxy group in the molecule takes place according to known method and is explained in the examples. Others can do the same known hardeners, such as. B. polyamines, polyamidoamines and / or polyamides, such as curing accelerators can also be used.

From the large number of epoxy compounds that have more than one 1,2-epoxy group contained in the molecule and which according to the invention to moldings and coatings with the nitrogen-containing products obtained according to the invention can be reacted, may be mentioned: The epoxides of polyunsaturated hydrocarbons (vinylcyclohexane, Dicyclopentadiene, cyclohexadiene, cyclododecadiene, cyclododecatriene, isoprene, 1, 5-hexadiene, butadiene, polybutadiene, Divinylbenzenes and the like), Epoxy ethers of polyhydric alcohols (ethylene, propylene and butylene glycols, polyglycols, Thioc3.iglycols, glycerine, pentaecrythritol, sorbitol, polyvinyl alcohol, polyallyl alcohol etc.), epoxy ethers of polyhydric phenols (resorcinol, hydroquinone, bis (4-hydroxyphenyl) methane, Bis- (4-hydroxy-3-methylphenyl) -methane, bis- (4-hydroxy-3,5-dichlorophenyl) -methane, Bis (4-hydroxy-3,5-dibromophenyl) methane, bis (4-hydroxy-3,5-difluorophenyl) methane, 1,1-bis- (4-hydroxyphenyl) -ethane, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (4-hydroxy-3-methyl-phenyl) -propane, 2,2-bis- (4-hydroxy-3-chlorophellyl) -proparl, 2,2-bis- (4-hydroxy-3,5-dichlorophenyl) -propane, Bis- (4-hydroxyphenyl) -phenylmethane, bis- (4-hydroxyphenyl) -diphenylmethane, bis- (4-hydroxyphenyl) -4'-methylphenylmethane, 1,1-bis- (4-hydroxyphenyl) -2,2,2-trichloroethane, bis- (4-hydroxyphenyl) - (4-chlorophenyl) methane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, bis- (4-hydroxyphenyl) -cyclohexylmethane, 4,4 ' -Dihydroxydiphenyl, 2 * 2 '-dihydroxydiphenyl, 4,4'-dihydroxydiphenylsulfone as well their hydroxyethyl ether, phenol-formaldehyde condensation products, such as phenol alcohols, Phenolaldehyde resins, etc.), S- and N-containing epoxides (N, N'-diglycidylaniline, N, Ii'-dimethyldiglycidyl-4,4'-diaminodiphenylmethane) and also epoxides, which are prepared from polyunsaturated carboxylic acids by customary processes or monounsaturated carboxylic acid esters of unsaturated alcohols have been, glycidyl esters, polyglycidyl esters obtained by polymerization or interpolymerization can be obtained from glycidyl esters of unsaturated acids or other acidic acids Compounds (cyanuric acid, diglycidyl sulfide, cyclic trimethylene trisulfone or whose derivatives, among other things, are available. As well as the pure epoxies above Mixtures of these as well as mixtures with monoepoxides can be used, if appropriate in the presence of solvents or plasticizers, implemented according to the present process will. For example, the following monoepoxides can be mixed with the aforementioned Epoxy compounds are used: epoxidized monounsaturated hydrocarbons (Butylene, cyclohexene, styrene oxide, etc.), halogen-containing epoxides such as epichlorohydrin, Epoxy ether is a valuable alcohol (methyl, ethyl, butyl, 2-ethylhexyl, dodecyl alcohol i.a.), epoxy ethers of monohydric phenols (phenol, cresol and others in ortho- or Para substituted Phenols), glycidyl esters unsaturated Carboxylic acids, epoxidized esters of unsaturated alcohols or unsaturated carboxylic acids as well as the acetals of glycidaldehyde.

The epoxy compounds mentioned, which according to the invention result in molded articles and coatings are convertible, fillers, dyes, Pigments, solvents or flexibilizers as well as curing accelerators before the Hardening can be added.

The moldings and coatings according to the invention can be produced possibly by adding accelerating substances from the group the monohydric or polyhydric phenols, especially the aminophenols, the monohydric or polyhydric Alcohols or by compounds such as mercapto compounds, thioethers, dithioethers or compounds with nitrogen-carbon-sulfur groups or sulfoxide groups be shortened. Also suitable are salts of hydrofluoric acid, if appropriate in the form of complex compounds.

Among complex compounds of salts of hydrofluoric acid, the can be used according to the invention, complex compounds of these with inorganic or organic components understood. Such compounds are e.g. E.g .: NH4SCN, NaSCN, KSCN, Mg (SCN) 2, Ca (SCN) 2, Zn (SCN) 2, Mn (SCN) 2, pyridine HSCN, chiolin HSCN, Aniline HSCN, o- and p-toluidine #HSCN, guanidine # HSCN, Cd (SCN) 2 # 4 NH3, Zn (SCN) 2 # 2 N2H4, Mn (SCN) 2 # N2H4, 2 KSCN # [(CH2) 6N4], Zn (SCN) 2 # (pyridine) 4, Mn (C5H5N) 2 # (SCN) 2, NaSCN # (C3H6O) and [(NH2) 2CS] 3 # KSCN.

The amount of accelerator added can be, depending on the reactivity the amine or epoxy components, can be varied within a wide range. In the Amounts of accelerator in the range from 0.05 to 10 percent by weight are generally preferred 0.5 to 5 percent by weight, based on the epoxy, used, but can sometimes smaller or larger additives can also be particularly advantageous the Curing accelerators can also add epoxy and amine or amide as a solid substance to the mixture, in the form of a dispersion or in solution in one of the reactants or can also be added in a solvent which does not affect the reaction.

The curing of the moldings and coatings according to the present invention is preferably branched when using amino acid derivatives on the basis aliphatic diamines carried out at room temperature. With those on the basis Cycloaliphatic diamines are preferably cured above 60.degree However, from case to case, especially with a high filler content, temperatures can also be used can be used up to 200 ° C.

To improve the mechanical properties, the low Temperatures hardened moldings or coatings also a post-hardening at higher To be subjected to temperature.

The amount of the amino acid derivative added is usually so too dimensioned that per epoxy group one hydrogen atom bonded to a nitrogen is available. However, it can sometimes be advantageous to have an excess or a shortfall to use hardeners.

The amino acid derivatives are also valuable modifiers for the synthesis of polyamides. They can also be used as intermediates for numerous syntheses of industrial products, e.g. B. modified emulsifiers, thermoplastic processable Polyimides and the like can be used.

The present invention is illustrated by the following examples: Example 1: In a reaction flask equipped with a stirrer, reflux condenser and thermometer was equipped, 100 parts by weight of acrylic acid ethyl ester and 633 parts by weight a 1: 1 isomer mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamine given. The batch was heated to 90 ° C. and held at this temperature for about 7 students. The alcohol formed in the reaction and the excess diamine were then distilled off. The basic amide obtained contained 11.3% basic nitrogen; the H-aktiv-Äquivalentgewi cht was 74 34 parts by weight of that prepared in this way Polyamides were mixed with 66 parts by weight of a diglycidyl ether of 2,2-bis (4-hydroxyphenyl) propane (Dian), the epoxy value of which was 0.52.

The mixture was then put into molds for the production of standard small rods poured. After curing for 2 hours at 80 ° C., the notched impact strength was 16 cm kp / cm 2 measured.

Example 2: 300 parts by weight of methyl methacrylate and 780 parts by weight 2,2-Dimethylpentamethylenediamine were combined and after the spontaneous Heating heated to 1400C for a further 2 hours.

The alcohol formed was then distilled off. The reaction product contains 12.8% basic nitrogen; the H-active equivalent weight was 65.5.

31.3 parts by weight of the polyamide thus produced were 68.7 Parts by weight of the diglycidyl ether of Example 1 mixed. The mix was again in forms for standard small rods poured. After hardening for 2 hours a notched impact strength of 8.5 kpcm / cm2 was found at 80 ° C .; without notch there was no breakage of the samples.

Example 3: 300 parts by weight of ethyl acetate and 569 parts by weight a 1: 1 monomer mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamine mixed together at room temperature. The reaction mixture warmed up from to to 80 ° C. The reaction was through 30 min. Heating to 220 ° C finished.

The split off alcohol was distilled off. The reaction product, a colorless, highly viscous liquid, contained 80% basic nitrogen. That H-active equivalent weight was 130.

22 parts by weight of the polyamide thus produced and 78 parts by weight a Dian-based epoxy resin, the epoxy value of which was 0.22 dissolved in a mixture of equal parts of xylene and isopropanol. The solution was applied to deep-drawn sheets. The paint film obtained was dust-dry after 1 hour.

After curing for 24 hours at room temperature, the following values were measured: Layer thickness 30µ, Erichsen cupping 10 min, Buchhloz hardness 100, cross-cut characteristic value: 0 Example 4: 256 parts by weight of 1,4 diamino-2-methylcyclohexane and 72 parts by weight Acrylic acid were slowly heated together within four hours up to 2100C, The resulting water was distilled off. The reaction product turned water white Liquid. It contained 13.4% basic nitrogen. Its H-active equivalent weight was 62.4.

31.2 parts by weight of the basic amide produced and 95 parts by weight of the epoxy resin of Example 1 were mixed with 120 parts by weight of Toluene and isopropanol (1: 1) mixed. The solution was applied to deep-drawn sheets. After curing for 24 hours at room temperature, the Bucholz hardness of the paint films was 140

Example 5: 340 parts by weight of 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (also known as isophoronediamine) were used together with 100 parts by weight of methyl methacrylate Heated to 2000C for 2 h. The alcohol formed was then distilled off. The polyamide was colorless and contained 10.1% basic nitrogen. The H-active equivalent weight was 80.1.

14.9 parts by weight of the polyamide produced and 85.1 parts by weight Epoxy resin according to Example 3 were in a twin-cam extruder at 50 0C with Kneaded and extruded with a residence time of 5 minutes. The extruded product was Shelf life in the B-stage at normal temperature for at least 1/2 year. It hardened as a molding compound off within 10 minutes at 1600C. The moldings were colorless and transparent and selir hard.

Example 6: 170 parts by weight of 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (also known as isophoronediamine = IPD) were mixed with 100 parts by weight of methyl methacrylate Heated at 120-150 ° C for 2 h. About 3 parts by weight of methanol were distilled off. A vacuum was then applied in order to distill off any residual monomer that might still be present. The reaction product was colorless and contained 10.3% basic nitrogen. The H equivalent weight was 90.

27 parts by weight of the compound prepared and 150 parts by weight Epoxy resin according to Example 3 were in a twin screw extruder at 50 0G and Kneaded and extruded with a dwell time of 4 minutes. The extruded product was in the B-stage at normal temperature for at least 1/2 year. durable. It hardens as a molding compound or as sintering powder within 10 minutes at 1600C. The moldings and Coatings were colorless and very hard.

Example 7: 27 parts by weight of the basic prepared in Example 6 Amides and 40 parts by weight of epoxy resin according to Example 3 were melted together.

After cooling, the prepolymer obtained in this way was mixed with a further 110 Parts by weight of the same type of epoxy resin are mixed well and placed in a twin screw extruder kneaded at 50 ° C and a residence time of 4 minutes and extruded. The extruded Product hardened as a molding compound or as a sinter powder within 10 minutes at 1800C the end.

The moldings and coatings were colorless, glossy and very hard.

Claims (5)

P a t e n t a n s p r u c e 1. A process for the preparation of amino acid derivatives by condensation of diamines with c &, ß-unsaturated carbonyl compounds, characterized in that purple branched aliphatic and / or cycloaliphatic diamines of the formula below in which R is a divalent branched aliphatic or cycloaliphatic radical with 4-38 carbon atoms and R 'is hydrogen and an alkyl or aryl radical, with alpha;, ß-unsaturated carbonyl compounds of the general formula in which X means HO-, alkyl-on, aryl-O-, H2N-, alkyl-HN-, aryl-HN-, (alkyl -), N-, (aryl °) 2N- and Remainder owns. 2. The method according to claim 1, characterized in that the branched aliphatic diamine contains at least one carbon-bonded C1 - C5 alkyl radical. 3. The method according to claim 1, characterized in that the cycloaliphatic Diamine contains one or more carbon-bonded C1 - C3 - alkyl radicals. 4. The method according to claim 3, characterized in that the cycloaliphatic Diamine is 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane. 5. Process according to claims 1-4, characterized in that the diamine and the ß-unsaturated carbonyl compounds in a molar ratio of 2-0.5: 1, preferably 1.9-0.75: 1.