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, with the proviso that at least one of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 radicals H, 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, 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 strong Brnsted acid with a counterion selected from metal ions, metal-containing ions, phosphonium ions and unsubstituted ammonium ions, where 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, and to processes for production thereof and use thereof.

Claims

1. A composition comprising a) an epoxy resin, b) a cyclic amine of the formula (I) ##STR00004## in which R.sup.1 to R.sup.4 is H or an organic radical, wherein at least one of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 radicals H, 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 strong Brnsted acid with a counterion selected from metal ions, metal-containing ions, phosphonium ions and unsubstituted ammonium ions, where 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.

2. The composition according to claim 1, wherein the epoxy resin is a polyepoxide based on 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 or diglycidyl hexahy drophthalate.

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

4. The composition according to claim 2, 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.

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

6. 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.

7. The composition according to claim 6, wherein x=1, 2, 3 or 4, o=0 or 1 and z=0, 1 or 2.

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

9. 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-yl)ethanone, 4-(2-aminoethyl)piperidine, 3-(2-aminoethyl)piperidine and 2-(2-aminoethyl)piperidine.

10. The composition according to claim 1, wherein the salt of a strong acid is an alkaline earth metal, lithium, zirconium, phosphonium or unsubstituted ammonium salt.

11. 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.

12. The composition according to claim 11, wherein the amines d) not covered by the formula (I) are selected from the group consisting of aliphatic amines, oxyalkylenepolyamines cycloaliphatic amines, araliphatic amines, aromatic amines adduct hardeners, polyamidoamine hardeners Mannich base hardeners and Mannich bases.

13. 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 strong acid from 0.001-5% d) further amine from 0-48% and e) further auxiliaries or additives from 0-48%.

14. The composition according to claim 11, 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.

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

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

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

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

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

Description

EXAMPLE 1

[0113] 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:

TABLE-US-00002 Comparison of the catalysts % 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 nitrate 93 36 13 Magnesium bromide 91 28 14 Indium chloride 94 35 15 Bismuth chloride 94 43 16 Copper tetrafluoroborate 93 33 17 Calcium oxalate 94 38 18 Zirconium(IV) chloride 89 33 19 Lithium bromide 95 34 20 Magnesium nitrate 98 33 21 Calcium bromide 98 79 *Non-inventive comparative experiments

EXAMPLE 2

[0114] 12.2 g of bisphenol A diglycidyl ether (Epikote 828, Hexion), 2.8 g of aminoethylpiperazine (AEP, Aldrich) and 0.25 g of calcium nitrate (dissolved in 0.25 ml of ethanol, Accelerator 3130, Huntsman) were mixed well with one another and then subjected immediately to a DSC analysis (Mettler-Toledo, 10 K/min). An exothermic peak was measured with an onset of 47 C. and a maximum of 85 C.

COMPARATIVE EXAMPLE 3

[0115] 12.2 g of bisphenol A diglycidyl ether (Epikote 828, Hexion) and 2.8 g of aminoethylpiperazine (AEP, Aldrich) were mixed well with one another and then subjected immediately to a DSC analysis (Mettler-Toledo, 10 K/min). An exothermic peak was measured with an onset of 61 C. and a maximum of 97 C.