Epoxy liquid curing agent compositions

1. A liquid curing agent composition comprising:

at least 50% by weight of at least one polyamine; and

0.2% to 10% by weight of dicyandiamide,

wherein:

the polyamine comprises a mixture of at least one major polyamine and at least one minor polyamine;

the at least one major polyamine is at least 80% by weight of the total polyamine;

the at least one minor polyamine is less than 20% by weight of the total polyamine;

the at least one major polyamine comprises at least one of polyamides and amidoamines;

the at least one minor polyamine comprises at least one member selected from the group consisting of aliphatic polyamines, polyetheramines, and cycloaliphatic polyamines;

the ratio of the at least one minor polyamine to the dicyandiamide is sufficiently high so as to solubilize the dicyandiamide to an optically clear fluid;

the ratio of the at least one minor polyamine to the at least one major polyamine is sufficiently low so as not to adversely affect the curing properties of the liquid curing agent relative to the at least one major polyamine; and

the composition is effective to cure an epoxy component comprising at least one multi-functional epoxy resin when the ratio of the equivalent of the reactive amine hydrogen in the liquid curing agent composition to the equivalent of epoxide present in the epoxy component is 0.7 to 1.3.

2. The liquid curing agent composition of claim 1 comprising 0.2% to 5% by weight of dicyandiamide.

3. The liquid curing agent composition of claim 1 wherein the amidoamine comprises the reaction product of tall oil fatty acid and tetraethylenepentamine, and the polyamide comprises the reaction product of tall oil fatty acid, at least one dimer acid, and tetraethylenepentamine.

4. The liquid curing agent composition of claim 1 wherein the at least one minor polyamine comprises at least one member selected from the group consisting of diethylenetriamine (DETA), triethylenetetramine (TETA), N-3-aminopropyl ethylenediamine (N3), N,N′-bis(3-aminopropyl) ethylenediamine (N4), N,N,N′-tris(3-aminopropyl) ethylenediamine (N5), and 3,3,5-trimethyl-1,6-hexanediamine; 1,2-diaminocyclohexane, 4,4′-di(aminocyclohexyl)methane, isophorone diamine (IPDA), norbornane diamines, 1, 3-bis(aminomethyl)cyclohexane, and 1-cyclohexylamino-3-aminopropane; m-xylylenediamine (mXDA), p-xylylenediamine, di(aminoethyl)benzene, tri(aminoethyl)benzene, triethylene glycol diamine, poly(ethylene glycol-block-propylene glycol) bis(2-amino-2-methyl) ether, tri(2-amino-2-methylethyl) trimethylolpropane ether, bis(3-aminopropyl) polypropylene glycol ether, bis(3-aminopropyl) diethyleneglycol ether, bis(2-amino-2-methylethyl) diethylene glycol ether, poly(ethylene oxide) methyl (3-aminopropyl) ether, bis(3-aminopropyl)polytetrahydrofuran; heterocyclic polyamines of N-aminoethylpiperazine (NAEP), piperazine, 4,4′-trimethylenedipiperidine, 1,4-bis(3-aminopropyl)piperazine, 2, 5-dimethylpiperazine, and 2,6-dimethylpiperazine; amidoamines of reaction product of tall oil fatty acid (TOFA) and tetraethylene pentamine (TEPA), epoxy modified amidoamine, polyamide of the reaction product of dimer acid, and tall oil fatty acid (TOFA) with tetraethylene pentamine (TEPA), and amine-epoxy adducts prepared by the reaction of an aliphatic amine, cycloaliphatic amine, heterocyclic, polyether amine, aromatic amine with an epoxy resin, or combination thereof.

5. The liquid curing agent composition of claim 1 , wherein the at least one major polyamine is at least 90% by weight of the total polyamine, and the at least one minor polyamine is less than 10% by weight of the total polyamine.

6. The liquid curing agent composition of claim 1 , wherein the at least one major polyamine comprises at least one member selected from the group consisting of diethylenetriamine (DETA), triethylenetetramine (TETA), 1,2-diaminocyclohexane, 4,4′-di(aminocyclohexyl)methane, isophorone diamine (IPDA), norbornane diamines, 1,3-bis(aminomethyl)cyclohexane, 1-cyclohexylamino-3-aminopropane, N-aminoethylpiperazine (NAEP), piperazine, 4,4′-trimethylenedipiperidine, and 1,4-bis(3-aminopropyl)piperazine, and the at least one minor polyamine comprises at least one member selected from the group consisting of diethylenetriamine (DETA), 1,2-diaminocyclohexane, bis(3-aminopropyl) diethylene glycol ether, bis(3-aminopropyl) ethylene glycol ether, bis(3-aminopropyl) polypropylene glycol ether, tri(1-amiono-1-methylethyl) trimethylolpropane ether, and triethylene glycol diamine.

7. The composition of claim 1 , wherein the ratio of the equivalent of the reactive amine hydrogen in the liquid curing agent composition to the equivalent of epoxide present in the epoxy component is 0.7 to 1.0.

8. The composition of claim 1 , wherein the composition is cured at a temperature from 5° C. to 150° C.

9. The composition of claim 1 , further comprising a reinforcing fiber.

10. The composition of claim 9 , wherein the reinforcing fiber comprises at least one member selected from the group consisting of woven or non-crimp fabrics, nonwoven webs or mats, fiber stands, staple fiber formed of continuous or discontinuous fiber and combinations thereof.

11. The composition of claim 9 , wherein the reinforcing fiber comprises at least one member selected from the group consisting of fiberglass, carbon fiber, carbon nanotubes nano composite fibers, polyaramide fibers, poly(p-phenylene benzobisoxazole) fiber, ultrahigh molecular weight polyethylene fibers, high and low density polyethylene fibers, polypropylene fibers, nylon fibers, cellulose fibers, natural fibers, biodegradable fibers and combinations thereof.

12. The composition of claim 1 , wherein the epoxy component comprises a member selected from the group consisting of glycidyl ethers of polyhydric phenols.

13. The composition of claim 1 , wherein the epoxy component comprises a member selected from the group consisting of 2,2-bis-(4-hydroxyphenyl)-propane and bis-(4-hydroxyphenyl)-methane.

14. The resin composition of claim 1 , wherein the epoxy component comprises a cycloaliphatic epoxide.

15. The liquid curing agent composition of claim 1 wherein the liquid curing agent is substantially free of aliphatic, cycloaliphatic, aromatic and heterocyclic polyamines.

16. The liquid curing agent composition of claim 1 wherein the at least one major polyamine comprises di(aminocyclohexyl)methane and the at least one minor polyamine comprises at least one polyether amine.

17. The liquid curing agent composition of claim 1 wherein the solubility of dicyandiamide is greater in the at least one minor polyamine than in the at least one major polyamine.

18. A liquid curing agent composition comprising:

at least 50% by weight of at least one polyamine;

0.2% to 10% by weight of dicyandiamide, and

a reinforcing fiber,

wherein:

the polyamine comprises a mixture of at least one major polyamine and at least one minor polyamine;

the at least one major polyamine is at least 80% by weight of the total polyamine;

the at least one minor polyamine is less than 20% by weight of the total polyamine;

the at least one major polyamine comprises at least one cycloaliphatic polyamine;

the ratio of the at least one minor polyamine to the dicyandiamide is sufficiently high so as to solubilize the dicyandiamide to an optically clear fluid; and

the ratio of the at least one minor polyamine to the at least one major polyamine is sufficiently low so as not to adversely affect the curing properties of the liquid curing agent relative to the at least one major polyamine.

19. A liquid curing agent composition comprising:

at least 50% by weight of at least one polyamine;

0.2% to 10% by weight of dicyandiamide, and

a reinforcing fiber,

wherein:

the polyamine comprises a mixture of at least one major polyamine and at least one minor polyamine;

the at least one major polyamine is at least 80% by weight of the total polyamine;

the at least one minor polyamine is less than 20% by weight of the total polyamine;

the at least one major polyamine comprises at least one of polyamides and amidoamines;

the at least one minor polyamine comprises at least one member selected from the group consisting of aliphatic polyamines, polyetheramines, and cycloaliphatic polyamines;

the ratio of the at least one minor polyamine to the dicyandiamide is sufficiently high so as to solubilize the dicyandiamide to an optically clear fluid; and

the ratio of the at least one minor polyamine to the at least one major polyamine is sufficiently low so as not to adversely affect the curing properties of the liquid curing agent relative to the at least one major polyamine.

20. The liquid curing agent composition of claim 1 wherein the composition is effective to cure an epoxy component comprising at least one multi-functional epoxy resin when the ratio of the equivalent of the reactive amine hydrogen in the liquid curing agent composition to the equivalent of epoxide present in the epoxy component is 0.7 to 1.3.