NO147938B - BOX WITH LID AND COVER - Google Patents

Description

New curing agents for polyepoxys.

Methods have previously been described for curing epoxy resins in which adducts are used as curing agents.

ter of epoxy resins and polyvalent amines (German specification document no. 1 006 152). According to German Patent Application No. 1 041 688, adducts of 1 mol of a monoepoxyd with an epoxy end group, and more than 2 mol of an aromatic polyamine are used for curing polyepoxides with an epoxy equivalence above 1. The subject of German Patent Application No. 1 117 871 is a method for curing polyepoxides with adducts of epoxides and di- or tri-(aminomethyl)-benzene, such as e.g. m-xylylenediamine.

The adduct of poly-amino-amides or poly-amino-imidazolines and polyepoxides has not previously been known, as it has obviously not been forthcoming or no advantage has been seen in using such adducts as curing agents for polyepoxides.

There has obviously been a prejudice against transferring the long-known method for the production of adducts of epoxy resins with an excess of amino curing agent to the production of adducts based on polyaminoamides or polyaminoimidazolines, since the polyaminoamides and polyaminoimidazolines, in contrast to the above-mentioned amino compounds, are higher molecular compounds and partly have a rather high viscosity. It would therefore seem inappropriate to increase this viscosity further by adduct formation. In connection with polyamines, the adduct formation was incidentally carried out to reduce the volatility and eliminate the toxicity of these substances. In connection with the polyaminoamides and polyaminoimidazoles, however, such a cause was in no way present as these compounds are neither volatile nor toxic.

In the present invention, disposal

fes the above-mentioned prejudice, as adducts have been found which have proven to be particularly advantageous curing agents for polyepoxys.

The characteristic main feature of the curing agents according to the invention is that they contain adducts of polyepoxides with an excess of polyamino-amides and/or polyaminoimidazolines.

According to the invention, particularly valuable adducts are obtained from poly-amino-amides and/or poly-amino-imidazolines which are based on saturated and/or unsaturated monovalent naturally occurring fatty acids;

on epoxidized unsaturated naturally occurring fatty acids; on polymers, especially dimers, and copolymerized fatty acids; on dicarboxylic acids obtained by carboxylation of unsaturated, monovalent, naturally occurring fatty acids; or on such polycarboxylic acids which can be obtained by addition of di- or tricarboxylic acids by their derivatives

ter, especially maleic anhydride, to naturally occurring, unsaturated fatty acids.

The curing agents according to the invention

are soluble in the usual solvents

clay for varnishes and are, when they are in a solid state, fusible. They can be applied to

many ways. For coating agents or laminating materials which are free of or poor in solvents, as well as for such water-dispersed substances, the curing agents are used in a liquid state, while those in solvent-containing coating agents are preferably used in a solid state. Solid curing agents according to the invention can also be used in powder form and in combination with solid powdery polyepoxy as lamination materials and adhesives. Such mixtures are storage-resistant and are processed using heat.

The poly-amino-amides and poly-amino-imidazolines used in the adducts according to the invention are in and of themselves known compounds which are produced by condensation of the acid components with an excess of polyalkylene polyamines, in particular polyethylene polyamines.

Acids suitable for the embodiment of the invention include, e.g. in consideration: palmitic acid, stearic acid, oleic acid, blaedic acid, linoleic acid, linolenic acid, ricinic acid, elaostearic acid or mixtures of such acids. The epoxidized fatty acids can be produced in a manner known per se from the corresponding unsaturated fatty acids, among which mention is made in particular of epoxidized oleic acid. The usable polymeric fatty acids can be prepared from mono- or polyunsaturated naturally occurring fatty acids by thermal or catalytic polymerization or by copolymerization in the presence of polymerizable compounds such as styrene or homologues, cyclopentadiene and other compounds. The carboxylation of unsaturated fatty acids is likewise known in and of itself and leads, when oleic acid is used, to a dicarboxylic acid with 19 carbon atoms in the molecule. As further polycarboxylic acids, those which can be produced by addition of di- or tricarboxylic acids or derivatives thereof, particularly maleic anhydride, to unsaturated fatty acids, particularly oleic acid, are taken into consideration.

Compounds which contain more than one epoxide group in the molecule and which can be cured with poly-amino-amides or poly-amino-imidazolines come into consideration as polyepoxides. Mention can be made here of the known polyglycidyl ethers of aromatic and aliphatic, multivalent hydroxyl compounds such as, for example resorcinol, pyrocatechol, hydroquinone, bisphenol A, dioxydiphenyl, dioxydiphenyl sulfone, dioxydiphenyl sulfide, as well as glycerol, penta-erythritol, mannitol, sorbitol and trimethylolpropane. Particularly suitable are polyepoxides produced by condensation of diphenylpropane and epichlorohydrin, as well as polyepoxides based on phenol-formaldehyde condensates and epichlorohydrin. Substances which are likewise suitable are a large number of known polyepoxyd compounds which are produced by epoxidation of aliphatic and/or cycloaliphatic polyolefins.

The polyepoxys mentioned above as examples can be used both for the curable combinations with the adducts according to the invention and for the production of these adducts themselves. For both purposes, the same or different polyepoxys can be used.

When producing the adducts according to the invention, the quantity ratios between the polyepoxides on the one hand and the poly-amino-amides and/or the poly-amino-imidazolines on the other hand can vary within a large range. However, the quantity ratio is preferably between 1/4 and 1/12 epoxy equivalent per amine equivalent. As the amine components must always be used in excess, the adducts do not contain free epoxide groups.

The production of the adducts can take place by mixing the pure components, solutions of these or melts of these. When mixing the pure components, one must ensure a good distribution of these, e.g. during stirring and possibly for the dissipation of heat. When preparing the adducts from solutions, it is advantageous to use heating to accelerate the reaction.

For solvent-free laminating agents or coating agents, liquid combinations are taken into account which, due to their viscosity, allow processing using normal methods, possibly after the addition of viscosity-lowering agents, agents that speed up the reaction and agents that make the substances more fluid.

For the production of dispersions, combinations are used which, after evaporation of water, ensure that the film floats, these are especially the liquid combinations. The preparation of the dispersions takes place in a manner known per se by dispersing resin and curing agent separately, after which the obtained dispersions are mixed. However, it is particularly advantageous to first mix the two components and then to disperse the mixture.

Solid adducts according to the invention which can be pulverized are particularly suitable for processing by sintering in fluidized beds, in powder sprayers, electrostatic powder sprayers, flame sprayers and in the form of adhesives which are active in a hot state. Such methods are described in German patent documents no. 972 650 and 933 019, as well as in German explanatory documents no. 1 005 413 and 1 127 257.

The special advantages of adducts according to the invention in comparison with the pure poly-amino-amides or poly-amino-imidazolines when used as curing agents for polyepoxides are the avoidance of surface disturbances such as residual stickiness and lubricating surface layers. When used in solvent-free coatings as well as in coatings from dispersions, the dispersibility of the adducts is an advantage that is not achieved when using poly-amino-amides and poly-amino-imidazolines. By working up adducts in the solid state together with solid polyepoxides from solutions, significantly better film qualities are obtained and, e.g. considerably shortened drying times and curing times, a better course of reaction, better mechanical properties of the cured film in comparison with the results obtained when using pure poly-amino-amides or poly-amino-imidazolines. With the help of the new solid adducts according to the invention, it has also become possible for the first time to use poly-amino-amides and poly-amino-imidazolines together with solid polyepoxides as sintering powders, as well as to make use of the advantageous properties of poly-amino-amides and poly-amino-imidazolines by application of solid coating agents.

In the following, some embodiments of the invention are described as examples.

Example 1.

24 parts by weight of a polyepoxyd (epoxy value 0.52) of bisphenol A and epichlorohydrin modified with butyl glycidyl ether are mixed with 10 parts by weight of phenol which has been melted by heating, after which 7 parts by weight of triethanolamine are added to the mixture. 100 parts by weight of a poly-amino-imidazoline (amine number 375) from dimer fatty acid and triethylenetetramine are stirred into the mixture thus obtained. This initiates the formation of adduct and is then stirred and cooled to avoid overheating.

As soon as the temperature after the end of the reaction has dropped, one adds, suitably at approx. 50° C, 10 parts of a butylated urea resin that goes on the market under the name "Plastopal EBS". This substance is used as a means to improve fluidity. The final product is 151 parts by weight of a storage-resistant hardener mixture.

This product can be mixed with 186 parts by weight of the above-mentioned polyepoxyd, which results in an immediately ready-to-use solvent-free varnish.

Coatings obtained with this material prove to be free from defects and after 24 hours of curing at 20° C and 65% relative humidity give a hard, shiny, non-sticky and non-greasy surface.

Example 2.

80 parts by weight of poly-amino-imidazoline as used in example 1 are mixed with 19.8 parts by weight of a polyepoxyd likewise as used in example 1. One waits for the reaction to subside, after which 3.0 parts by weight of glacial acetic acid are added while stirring. To the material thus obtained is added 8 parts by weight of the urea resin used in example 1, 2 parts by weight of ethylene glycol-monomethylether (hereinafter referred to as "ethylglycol"), 10 parts by weight of a mixture of aromatic hydrocarbons sold under the name "Shellsol A" and 10 parts by weight n-butanol. You get a stable, storage-resistant, dispersible curing agent with incorporated fluidity-improving agents. 46 parts of this curing agent are mixed with 54 parts of an unmodified polyepoxy obtained from bis-phenol A and epichlorohydrin. 300 parts by weight of water are added to the mixture and, under medium-rapid stirring, a stable, aqueous dispersion is formed, whose shelf life ("Topfzeit") is approx. 24 hours.

A coating produced using this two-component dispersion and cured at room temperature shows a clear, shiny and hard surface which is not greasy or tacky.

Example 3.

160 parts by weight of poly-amino-imidazoline as used in example 1 are mixed with 252 parts by weight of a 50% solution of a solid polyepoxyd (made from bisphenol A and epichlorohydrin) with an epoxy value of 0.2 in a mixture of xylene and methylisobutyl ketone (weight ratio 1:1) and 200 parts by weight of a mixture of xylene and ethylene glycol (4:1). The mixture is boiled for 1 hour under reflux or left to stand for 8 days, whereby the adduct is formed.

By adding 233.5 parts by weight of a 50% solution of the above-mentioned polyepoxyd, a solvent-containing varnish with a serviceability period ("Topfzeit") of 1-2 days is formed.

Cover made with this varnish, with a layer thickness of approx. 30 (x is not sticky after standing for 2 hours at 20° C and reaches its final hardness after 2-3 days.

The lacquer's hardness according to Buchholz is 95 and its "Erichsen-Tiefung" is 9.5 to 10.5 mm.

Example 4.

The procedure is as indicated in example 1, with the exception that instead of 100 parts by weight of polyaminoimidazoline, 100 parts by weight of a polyaminoamide of dimer fatty acid and a mixture of triethylenetetramine and tetraethylenepentamine are used.

You get 151 parts by weight of a storage-resistant hardener mixture which can be mixed with 168 parts by weight of polyepoxyd, as indicated in example 1, whereby you get a solvent-free varnish. Coatings applied with this varnish show very good properties and after 24 hours at 20°C and 85% relative humidity have a hard and smooth surface whose gloss can be further improved by washing with water.

Example 5.

The procedure is as indicated in example 2, but instead of poly-amino-imidazoline, 80 parts by weight of a poly-amino-amide of dimer fatty acid and a mixture of triethylenetetramine and tetraethylenepentamine are used.

Example 6.

220 parts by weight of a 60% solution of a polyaminoamide of dimer fatty acid and triethylenetetramine in a mixture of xylene and ethyl glycol (weight ratio 4:1) are added 287 parts by weight of the same solvent mixture and 98.8 parts by weight of a 50% .'s solution of a solid polyepoxyd (made from bisphenol A and epichlorohydrin) with an epoxy value of 0.2, in a mixture of xylene and methylisobutyl ketone (weight ratio 1:1). The mixture is boiled for 1 hour under reflux or left to stand for 8 days.

100 parts by weight of the thus obtained solution of curing agent are mixed with 63.5 parts by weight of a 50% polyepoxy solution as indicated above. You get a lacquer solution with a usable period ("Topfzeit") of 1-2 days.

After standing at 20°C, coatings made with this solution are not sticky after 1-2 hours and reach final hardness after 2-3 days.

Example 7.

35 parts by weight of a polyaminoamide of tall oil fatty acid and tetraethylenepentamine are added to 65 parts by weight of a 50 percent solution of a polyepoxyd (made from bisphenol A and epichlorohydrin) with an epoxy value of 0.2, in xylene and methylisobutyl ketone

(1:1) and 200 parts by weight of a mixture of

xylene and ethyl glycol (4:1). The resulting mixture is boiled for 1 hour under reflux cooling. A ready-to-use varnish is obtained from 100 parts by weight of the adduct thus obtained and 197.5 parts by weight of the above-mentioned 50% polyepoxy dopp solution.

Example 8.

35 parts by weight of a poly-amino-imidazoline from tall oil fatty acid and triethylenetetramine, 65 parts by weight of a 50% solution of a polyepoxyd made from bis-phenol A and epichlorohydrin and with an epoxy value of 0.2 in a mixture of xylene and methylisobutyl ketone (1:1), as well as 85 parts by weight of a mixture of xylene and ethyl glycol (4:1) are boiled for 1 hour under reflux cooling. When one gets to 100 parts by weight of it

add 197.5 parts by weight of the above-mentioned polyepoxy solution to the adduct obtained in this way, a ready-to-use varnish is obtained.

Example 9.

A mixture of 80 parts by weight of a poly-aminoimidazoline of dimer fatty acid and triethylenetetramine, 12 parts by weight of an aliphatic polyglycidyl ether (traded under the name "Epoxin 162"), 2 parts by weight ethyl glycol, 10 parts by weight of a mixture of aromatic hydrocarbons (traded in the trade under the name "Shellsol A"), 10 parts by weight of n-butanol and 8 parts by weight of a butylated urea resin (traded under the name "Plastopal EBS") are kept under constant stirring in boiling until gel formation occurs. 200 parts by weight of a mixture of xylene and ethyl glycol (4:1) are then added while stirring. This makes the mass liquid again.

To prepare a ready-to-use varnish, 75.6 parts by weight of a 50% solution of a polyepoxyd made from bisphenol A and epichlorohydrin and with an epoxy value of 0.2 in xylene and methylisobutyl ketone are added to 29.4 parts by weight of the solution obtained (1:1).

Example 10.

25 parts by weight of a poly-amino-amide of an oleic acid maleic anhydride adduct and triethylenetetramine are dissolved in 25 parts by weight of a mixture of xylene and ethyl glycol (4:1). To the solution obtained is added 6.6 parts by weight of a 50 percent solution of a polyepoxyd made from bisphenol A and epichlorohydrin and with an epoxy value of 0.2 in xylene and methylisobutyl ketone (1:1), as well as 38.4 parts by weight of a mixture of xylene and ethyl glycol (4:1). The resulting mixture is boiled for 1 hour under reflux cooling. 50 parts by weight of the solution of the adduct thus obtained is added to 65.6 parts by weight of a 50% solution of the above-mentioned polyepoxyd, whereby a ready-to-use varnish is obtained.

Example 11.

35 parts by weight of a polyamino-amide of epoxidized oleic acid and tetraethylenepentamine, 65 parts by weight of a 50% solution of a polyepoxyd produced from bis-phenol A and epichlorohydrin and with an epoxy value of 0.2 in xylene and methylisobutyl ketone (1:1), as well as 85 parts by weight of a mixture of xylene and ethyl glycol (4:1) are heated to boiling temperature for 1 hour under reflux cooling. 100 parts by weight of the thus obtained solution of the adduct are added to 197.5 parts by weight of the 50% polyepoxy solution specified above.

Example 12.

105 parts by weight of a poly-amino-imidazoline of dimer fatty acid and triethylenetetramine and 39 parts by weight of a 50 percent solution of a polyepoxyd made from phenol-formaldehyde condensate and epichlorohydrin (which is marketed by the company Dow under the designation DEN 438) in a mixture of xylene and methylisobutyl ketone (1:1), as well as 150 parts by weight of a mixture of xylene and ethylglycol (4:1) and 20 parts by weight of propanol are reacted for 1 hour at boiling temperature. 50 parts by weight of the obtained solution are added to 161 parts by weight of a 50% solution of a polyepoxyd based on bisphenol A and epichlorohydrin and with an epoxy value of 0.2 in xylene/methylisobutyl ketone (1:1). You get a ready-to-use clear varnish.

Example 13.

160 parts by weight of a poly-amino-amide of epoxidized oleic acid and tetraethylenepent-

amine, 38 parts by weight of the diepoxide of cyclohexylmethylcyclohexenecarboxylate (traded under the name "Unox 201"), 4 parts by weight of ethyl glycol, 20 parts by weight of a

mixture of aromatic hydrocarbons (traded under the name "Shellsol A") and 20 parts by weight of n-butanol is reacted for 3'/2 hours at boiling temperature. 16 parts by weight of a butylated urea resin are then added

(marketed under the name "Plastopal EBS") and stirred into the mixture. 45 parts by weight of it is herewith".

Example 14.

50 parts by weight of a poly-amino-imide-isoline of a CIH-dicarboxylic acid which can be <t>rested by the carboxylation of oleic acid, and ;tetraethylenepentamine, 15 parts by weight of a polyepoxyd which is modified with butyl-^lycidyl ether and is made from bisphenol °i. and epichlorohydrin, 6 parts by weight of the butylated urea resin specified above, 1 part ethyl glycol, 7 parts by weight of the mixture of aromatic lydrocarbons specified above and 6 parts by weight of n-butanol coke for 1 hour under reflux. For the preparation of ready-to-use, solvent-poor coating agents, 50 parts by weight of the adduct obtained in this way are mixed with 79.5 parts by weight of the

>modified polyepoxyd specified above.

Example 15.

80 parts by weight of a poly-amino-amide of tall oil fatty acid and tetraethylenepentamine, 20 parts by weight of a polyepoxyd modified with butyl glycidyl ether, made from bis-phenol and epichlorohydrin, 3 parts by weight of glacial acetic acid, 2 parts by weight of ethyl glycol and 10 parts by weight of the above-mentioned mixture of aromatic hydrocarbons and 10 parts by weight of n-butanol are reacted for 1 hour at boiling temperature. After cooling the mixture to 60 °C, 8 parts by weight of the butylated urea resin specified above are stirred into it.

A dispersion slack is obtained when 46 parts by weight of this product are dispersed together with 54 parts by weight of an unmodified polyepoxyd made from bisphenol A and epichlorohydrin in water.

Example 16. 20 parts by weight of the polyepoxyd modified with butyl glycidyl ether, made from bisphenol A and epichlorohydrin, 10 parts by weight phenol, 7 parts by weight triethanolamine and 100 parts by weight of a poly-amino-imidazoline of C]()-dicarboxylic acid and tetraethylenepentamine are heated for 1 hour to 100°C. After the mixture has cooled, 16 parts by weight of the butylated urea resin specified above are stirred into it. 20 parts by weight of the adduct thus obtained are added to 35.7 parts by weight of the above-mentioned polyepoxyd, modified with butyl glycidyl ether, whereby a coating agent is obtained which is free of solvents.

Example 17. 10 parts by weight of an aliphatic polyglycidyl ether (traded under the name "Epoxin 162"), 10 parts by weight of phenol, 7 parts by weight of triethanolamine and 100 parts by weight of a poly-amino-imidazoline of dimer fatty acid and triethylenetetramine are reacted for 1 hour at 100 °C. After cooling the mixture, 16 parts by weight of the butylated urea resin specified above are added there. A ready-to-use solvent-free coating agent is prepared from 143 parts by weight of this product and 140 parts by weight of the above-mentioned aliphatic polyglycidyl ether.

Example 18. 33 parts by weight of a polyepoxyd made from bisphenol A and epichlorohydrin and with an epoxy value of 0.2 are melted at 125°C whereupon, with vigorous stirring, it is mixed with 48 parts by weight of a polyamino-imidazoline of dimer fatty acid and triethylenetetramine. After 15 minutes at 125°C, the reaction is finished and the resin, which is liquid at this temperature, changes to a solid state on cooling and can then be ground. 20 parts by weight of this adduct in a finely ground state with 54 parts by weight of the above-mentioned finely ground polyepoxyd produced from bisphenol A and epichlorohydrin and with an epoxy value of 0.2 gives a ready-to-use sinter powder. When immersing an iron rod that has been heated to approx. 200°C in this sinter powder which is fluidized according to the usual fluidization technique for sintering and subsequent curing of the coating for y2 hours at 130°C, a smooth and hard coating is obtained that is resistant to chemicals and solvents.

Example 19.

Comparative experiments. 80 parts by weight of a polyaminoimide-isoline of dimer fatty acid and triethylenetriimine are mixed with stirring with 3 parts by weight of glacial acetic acid, 8 parts by weight of a urea resin (commercially known as "Plastopal EBS"), 10 parts by weight of ethyl-Lenglyeol-monomethylether and 10 parts by weight of n-butanol is mixed with stirring. 160 parts by weight of an unmodified polyepoxy made from bisphenol A and epichlorohydrin are added to the curing agent obtained in this way, while stirring. 300 parts by weight of water are added to the resulting mixture and a dispersion is formed while stirring at a moderate speed. The dispersion produced in this way is so unstable that it begins to break down immediately after production. After 2 hours, a complete separation into resin and water occurs. As a result of the poor stability of the dispersion produced in this way, it is not possible to produce technically usable laminates, coating agents or the like with it.

Claims (3)

1. Curing agent for polyepoxides, characterized in that they contain adducts of polyepoxides with an excess of poly-amino-amides and/or poly-amino-imidazolines. 2. Curing agents according to claim 1, characterized in that the poly-amino-amides and/or poly-amino-imidazolines are based on saturated and/or unsaturated, monovalent, naturally occurring fatty acids; on epoxidized unsaturated naturally occurring fatty acids; on polymeric, especially dimer or copolymerized fatty acids; on dicarboxylic acids obtained by carboxylation of unsaturated, monovalent, naturally occurring fatty acids; or on polycarboxylic acids which can be obtained by addition of di- or tricarboxylic acid or derivatives thereof, especially maleic anhydride, to naturally occurring unsaturated fatty acids. 3. Curing agents according to claim 1 or 2, characterized in that the adducts contain from 1/4 to 1/12 epoxy equivalent per equivalent amine compound.