Method of preparation of a water based epoxy curing agent

1. A curing agent in dispersion form for water based epoxy resins, obtained by a method of preparation of a water based epoxy resin curing agent in dispersion form, which water based curing agent is formed by combining an active amine-hydrogen containing amine-functional dispersion (A) with an active amine-hydrogen containing amine-functional water based curing agent (B) in solution or emulsion form;

wherein said active amine-hydrogen containing amine-functional dispersion (A) comprises a reaction product of:

a) a polyamine compound having at least three active amine-hydrogen, and

b) an aqueous epoxy resin dispersion having an epoxy solids equivalent weight of equal to or greater than 150 g/eq;

wherein said active amine-hydrogen containing amine-functional water based curing agent (B): has an amphiphilic structure and a solids hydrogen equivalent weight of 50-500 g/eq; is capable of emulsifying a liquid epoxy resin to produce a stable emulsion; and is capable of yielding coating preparations of high gloss; and

wherein the curing agent in dispersion form, at 5500 solids, has a viscosity less than 500 mPa's at 20° C.

2. The curing agent in dispersion form for water based epoxy resins according to claim 1 , wherein the polyamine (a) is a polyether containing polyamine selected from polyether containing polyamines having a number average molecular weight of 150 to 2000, that contain at least 3 active amine-hydrogens, at least 2 amino groups, and from 6 to 150 carbon atoms, and comprise 2 to 6 carbon atoms between the ether groups.

3. The curing agent in dispersion form for water based epoxy resins according to claim 2 , wherein the epoxy resin dispersion (b) is a pre-dispersed solid epoxy resin dispersion of an optionally modified bisphenol A diglycidyl ether having an average epoxy functionality of up to 2 and an epoxy solids equivalent weight in the range 400 to 700 g/eq.

4. Composition, obtained from curing modified or unmodified, liquid or pre-dispersed solid epoxy resins with a curing agent in dispersion form for water based epoxy resins according to claim 2 .

5. The curing agent in dispersion form for water based epoxy resins according to claim 1 , wherein the epoxy resin dispersion (b) is a pre-dispersed solid epoxy resin dispersion of an optionally modified bisphenol A diglycidyl ether having an average epoxy functionality of up to 2 and an epoxy solids equivalent weight in the range of 400 to 700 g/eq.

6. Composition, obtained from curing modified or unmodified, liquid or pre-dispersed solid epoxy resins with a curing agent in dispersion form for water based epoxy resins according to claim 5 .

7. The curing agent in dispersion form for water based epoxy resins according to claim 1 , wherein the active amine-hydrogen containing amine-functional curing agent (B) is an optionally modified adduct of a polyamine compound and an epoxy compound, said adduct having terminal amino groups.

8. Composition, obtained from curing modified or unmodified, liquid or pre-dispersed solid epoxy resins with a curing agent in dispersion form for water based epoxy resins according to claim 7 .

9. A method of curing modified or unmodified liquid or pre-dispersed epoxy resins which comprises combining a curing agent in dispersion form according to claim 1 with a modified or unmodified liquid or pre-dispersed epoxy resin in a two component water based epoxy system.

10. Composition, obtained from curing modified or unmodified, liquid or pre-dispersed solid epoxy resins with a curing agent in dispersion form for water based epoxy resins according to claim 1 .

11. The composition of claim 10 in form of a primer, sealer, paint, filler, coating, covering, trowelling or self leveling composition, adhesive or modifier for cements and mortars.