FAST-CURING EPOXY SYSTEMS

Abstract

The present invention provides a composition comprising a) at least one epoxy resin, b) at least one cyclic amine of the formula (I)

##STR00001## in which R.sup.1 to R.sup.4 is H or an organic radical and

X(Y.sup.1).sub.m-(A.sup.1).sub.n-(Y.sup.2).sub.o-(A.sup.2).sub.p-(Y.sup.3).sub.q-(A.sup.3).sub.r-(Y.sup.4).sub.s, (II) where, independently of one another, m, n, o, p, q, r and s=0 or 1, A.sup.1, A.sup.2, A.sup.3=alkylene or alkenylene radical and Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4=NR.sup.5, PR.sup.5, O or S, where R.sup.5 independently=organic radical, where any two organic radicals selected from R.sup.1 to R.sup.5 and any radicals present in the alkylene and/or alkenylene radicals A.sup.1, A.sup.2, A.sup.3 may also form one or more further rings, with the proviso that at least one of the radicals selected from R.sup.1 to R.sup.5 present and any radicals present in the alkylene and/or alkenylene radicals A.sup.1, A.sup.2, A.sup.3 is substituted by at least one NHR.sup.6 or NH.sub.2 group, where R.sup.6=organic radical, and c) at least one salt of a very strong Brnsted acid with a counterion selected from metal ions, metal-containing ions, phosphonium ions and unsubstituted ammonium ions, and to processes for production thereof and use thereof.

Claims

1. A composition comprising an epoxy resin, a cyclic amine of the formula (I) ##STR00004## in which R.sup.1 to R.sup.4 is H or an organic radical and
X(Y.sup.1).sub.m-(A.sup.1).sub.n-(Y.sup.2).sub.o-(A.sup.2).sub.p-(Y.sup.3).sub.q-(A.sup.3).sub.r-(Y.sup.4).sub.s, (II) where, independently of one another, m, n, o, p, q, r and s=0 or 1, A.sup.1, A.sup.2, A.sup.3=alkylene or alkenylene radical and Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4NR.sup.5, PR.sup.5, O or S, where R.sup.5 independently=organic radical, where any two organic radicals selected from R.sup.1 to R.sup.5 and any radicals present in the alkylene and/or alkenylene radicals A.sup.1, A.sup.2, A.sup.3 may also form one or more further rings, wherein at least one of the radicals selected from R.sup.1 to R.sup.5 present and any radicals present in the alkylene and/or alkenylene radicals A.sup.1, A.sup.2, A.sup.3 is substituted by at least one NHR.sup.6 or NH.sub.2 group, where R.sup.6=organic radical, and c) a salt of a very strong Brnsted acid with a counterion selected from metal ions, metal-containing ions, phosphonium ions and unsubstituted ammonium ions.

2. The composition according to claim 1, wherein the ratio of the epoxy groups in the epoxy resin to the sum total of all NH groups in all amines is 0.5:1 to 1.5:1,

3. The composition according to claim 1, wherein the epoxy resin is a polyepoxide based on bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, 4,4-methylenebis[N,N-bis(2,3-epoxypropyl)aniline], hexanediol diglycidyl ether, butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, propane-1,2,3-triol triglycidyl ether, pentaerythritol tetraglycidyl ether and diglycidyl hexahydrophthalate.

4. The composition according to claim 1, wherein at least one of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 radicals in formula (I)=H.

5. The composition according to claim 1, wherein A.sup.1, A.sup.2 and A.sup.3 independently have the formula (III))
(CR.sup.7R.sup.8).sub.x(CR.sup.9CR.sup.10).sub.y(CR.sup.11R.sup.12).sub.z(III) in which, independently of one another, R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11 and R.sup.12H or organic radical and 1x+y+z7.

6. The composition according to claim 1, wherein X in formula (II) has a chain length of 2 to 15 atoms.

7. The composition according to claim 1, wherein X has the formula (IIa)
X(CR.sup.7R.sup.8).sub.x(Y).sub.o(CR.sup.11R.sup.12).sub.z(IIa) with x and z=0, 1, 2, 3, 4, 5, 6 or 7, o=0 or 1, 2x+o+z15 R.sup.7, R.sup.8, R.sup.11, R.sup.12H or organic radical and YNR.sup.5, PR.sup.5, O or S, where R.sup.5=organic radical.

8. The composition according to claim 7, wherein x=1, 2, 3 or 4, o=0 or 1 and z=0, 1 or 2.

9. The composition according to claim 1, wherein the cyclic amine of the formula (I) is a triazinane or triazepane.

10. The composition according to claim 1, wherein the cyclic amine of the formula (I) is selected from the group consisting of 1-(2-aminoethyl)piperazine, 1-(3-aminopropyl)piperazine, 1-imidazolidinoethanamine, imidazolidino-N-propanamine, -methyl-1-piperazinethanamine, 2,6-dimethyl-1-piperazinoethanamine, 2-amino-1-(piperazin-1-ypethanone, 4-(2-aminoethyl)piperidine, 3-(2-aminoethyl)piperidine and 2-(2-aminoethyl)piperidine.

11. The composition according to claim 1, wherein the salt of an acid is an alkaline earth metal salt, lithium salt, aluminium salt, bismuth salt, zinc salt, europium salt, tetraphenylstibonium salt, phosphonium salt or unsubstituted ammonium salt.

12. The composition according to claim 1, wherein it also includes d) amines not covered by the formula (I) and/or e) further auxiliaries or additives.

13. The composition according to claim 12, wherein the amines d) not covered by the formula (I) are selected from the group consisting of aliphatic amines, oxyalkylenepoly amines cycloaliphatic amines, araliphatic amines, aromatic amines adduct hardeners, polyamidoamine hardeners Mannich base hardeners and Mannich bases.

14. The composition as claimed in claim 1, wherein the composition includes components a) to e) in the following percentages by weight, based on the total mass of the composition: a) epoxy resin from 30-95% b) cyclic amine from 1-50% c) salt of the very strong Brnsted acid from 0.001-5% d) further amine from 0-48% and e) further auxiliaries or additives from 0-48%.

15. The composition according to claim 12, wherein the percentage by weight of the amines b) based on the total mass of the amines b) and d) is at least 10% by weight.

16. The process for producing a composition according to claim 1, wherein the epoxy resin a), the cyclic amine b) and the salt of a Brnsted acid c) are mixed with one another.

17. A composite comprising the composition according to claim 1.

18. A casting resin comprising the composition according to claim 1.

19. A coating composition comprising the composition according to claim 1.

20. An adhesive comprising the composition according to claim 1.

Description

EXAMPLE 1

[0108] To demonstrate the particular reactivity of the catalysts claimed, model experiments are first compared with one another. For this purpose, 0.025 mol (3.75 g) of 1,2-epoxy-3-phenoxypropane is added to a mixture of 22.68 g of toluene (solvent) and 2.08 g of tetradecane (internal standard). To this are added 0.025 mol (2.13 g) of piperidine, and 0.06 g of the particular catalyst. Immediately after the mixing, a GC is taken and the content of 1,2-epoxy-3-phenoxypropane is compared with the content of tetradecane. After 4 h at room temperature, by means of GC analysis, the residual content of 1,2-epoxy-3-phenoxypropane (EP) is ascertained (calibrated by the internal tetradecane standard). This gives the following results:

[0109] Comparison of the Catalysts

TABLE-US-00002 % EP % EP after Catalyst in the 0 sample 4 hours at RT 1* No catalyst 97 93 2* Dibutyltin dilaurate 99 93 3* Diazabicyclononane (DBN) 97 95 4* Diazabicycloundecane (DBU) 96 93 5* Diazabicyclooctane (DABCO) 94 93 6* Zinc acetylacetonate 94 90 7* Tetrabutylammonium 91 87 tribromide 8* Bismuth neodecanoate 91 88 9* Titanium tetrabutoxide 95 94 10* Salicylic acid 93 90 11* Phenol 97 85 12 Calcium triflate 90 0 13 Bismuth triflate 90 57 14 Sodium triflate 96 52 15 Europium triflate 85 16 16 Barium triflate 96 37 17 Aluminium triflate 98 53 18 Lithium triflate 90 28 19 Lithium perchlorate 73 9 20 Barium perchlorate 85 26 21 Zinc perchlorate 96 46 22 Ammonium 86 43 hexafluorophosphate 23 Calcium perchlorate 98 49 24 Samarium iodide 98 37 25 Potassium 97 36 hexafluorophosphate 26 Lithium hexafluorophosphate 78 9 27 Zinc triflate 98 44 28 Copper triflate 93 48 29 Samarium triflate 84 32 30 Magnesium triflate 94 41 31 Indium triflate 89 39 32 Nickel triflate 100 56 33 Iron triflate 93 39 34 Manganese triflate 93 44 35 Tin triflate 96 42 36 Terbium triflate 90 41 37 Cadmium perchlorate 98 64 38 Iron perchlorate 97 52 39 Manganese perchlorate 98 59 40 Indium perchlorate 99 59 *Non-inventive comparative experiments

EXAMPLE 2

[0110] To demonstrate the particular reactivity of the amines claimed, model experiments are first compared with one another. For this purpose, 0.025 mol (3.75 g) of 1,2-epoxy-3-phenoxypropane is added to a mixture of 22.68 g of toluene (solvent) and 2.08 g of tetradecane (internal standard). To this are added 0.025 NH equivalent of an amine and 0.06 g of calcium triflate. Immediately after the mixing, a GC is taken and the content of 1,2-epoxy-3-phenoxypropane is compared with the content of tetradecane. After 4 h at room temperature, by means of GC analysis, the residual content of 1,2-epoxy-3-phenoxypropane (EP) is ascertained (calibrated by the internal tetradecane standard). This gives the following results:

TABLE-US-00003 % EP in the 0 % EP after % EP after Amine sample 4 hours at RT 4 hours at 5 C. 1* Butylamine 92 52 73 2* Methylpropylamine 92 46 91 3* Ethanolamine 91 63 80 4 Piperidine 93 0 32 *Non-inventive comparative experiments

[0111] It is clearly apparent from the model experiments that the compositions claimed are much more reactive than conventional systems.

COMPARATIVE EXAMPLE 3a

[0112] 100 parts aminoethylpiperazine (AEP, Aldrich) are intimately mixed with 446 parts Epikote 828 (epoxy equivalent 190, Hexion) and a DSC is taken immediately thereafter.

COMPARATIVE EXAMPLE 3b

[0113] 0.5 part calcium triflate (Aldrich) is dissolved in 100 parts aminoethylpiperazine (AEP, Aldrich) and this mixture is intimately mixed with 446 parts Epikote 828 (epoxy equivalent 190, Hexion) and a DSC is taken immediately thereafter.

TABLE-US-00004 Recipe No. 3a* 3b DSC analysis immediate Exothermic peak C. 97 74 Onset C. 61 32 Exothermic heat flow J/g 500 456 Tg max. C. 121 122 *Non-inventive comparative experiments

[0114] In the inventive experiment, the exothermic peak is 23 C. lower, and the onset of this exothermic peak is 29 C. lower. The reactive composition according to the invention is thus much more reactive.