Curing agent for epoxy coatings
Compositions, methods, and coating composition using a curing agent are provided herein. In one embodiment, a curing agent for epoxy resins may be prepared using a formulation including: (a) an adduct of: (i) a diglycidyl ether of a bisphenol, and (ii) a first polyamine; (b) a second polyamine; and (c) water; wherein the composition has an amine hydrogen equivalent weight, based on solids, of less than or equal to 105.
1. A coating formulation comprising the reaction product of:
a curable epoxy resin; and
a curing agent comprising a composition of:
an adduct of:
a diglycidyl ether of a bisphenol having an epoxy equivalent weight from about 200 to about 300, and
a first polyamine;
a second polyamine different than the first polyamine; and
water;
wherein the composition is a solution and wherein the composition has an amine hydrogen equivalent weight, based on solids, of less than 105.
2. The coating formulation of claim 1 , wherein the curable epoxy resin is added in an amount from about 0.5 to about 2 epoxy equivalents per NH equivalent in the composition.
3. The coating formulation of claim 1 , wherein the curing agent comprises from 1 wt. % to 99 wt. % of the coating formulation.
4. The coating formulation of claim 1 , wherein the reaction product further comprises one or more components selected from the group consisting of acids, organic solvents, surfactants, fillers, defoamers, leveling agents, flow agents, wetting agents, cure rate accelerators, pigments, and combinations thereof.
5. The coating formulation of claim 4 , wherein the one or more components comprise less than or equal to 60 wt. % of the weight percent of the coating formulation.
6. The coating formulation of claim 1 , wherein the diglycidyl ether of the bisphenol has an epoxy equivalent weight from about 220 to about 285.
7. The coating formulation of claim 1 , wherein the diglycidyl ether of the bisphenol has an epoxy equivalent weight from about 235 to about 263.
8. The coating formulation of claim 1 , wherein the first polyamine has an amine hydrogen equivalent weight from about 7 to about 35.
9. The coating formulation of claim 8 , wherein the first polyamine has an amine hydrogen equivalent weight from about 13 to about 27.
10. The coating formulation of claim 1 , wherein the adduct has a weight average molecular weight less than or equal to 1150.
11. The coating formulation of claim 10 , wherein the adduct has a molecular weight from about 580 to about 1000.
12. The coating formulation of claim 1 , wherein the composition has an amine hydrogen equivalent weight, based on solids, from about 50 to about 98.
13. The coating formulation of claim 12 , wherein the composition has an amine hydrogen equivalent weight, based on solids, of about 87 to about 96.
14. The coating formulation of claim 1 , wherein the first polyamine is ethylene diamine and the second polyamine is a polyetheramine.
15. The coating formulation of claim 1 , wherein the adduct is formed using an excess of first polyamine to epoxy at a ratio of epoxy equivalents to NH2 equivalents from about 1:8 to about 1:40.
16. The coating formulation of claim 1 , wherein the composition comprises
from about 10 wt. % to about 90 wt. % of the adduct;
from about 10 wt. % to about 90 wt. % of the second polyamine; and
about 1 wt. % to about 50 wt. % of water, wherein the total wt. % is 100 wt. %.
17. The coating formulation of claim 1 , wherein the composition further comprises one or more components selected from the group consisting of acids, organic solvents, surfactants, fillers, defoamers, leveling agents, flow agents, wetting agents, cure rate accelerators, pigments, and combinations thereof.
18. The coating formulation of claim 1 , wherein the second polyamine has an amine hydrogen equivalent weight from about 40 to about 120.
19. The coating formulation of claim 1 , wherein the composition is free of surfactants, free of dispersing agents, or free of both.