Nanofiller-containing epoxy resins and stable aqueous dispersions thereof

1. A water-dispersible composition comprising a mixture of:

(a) a nanofiller-containing epoxy resin; and

(b) at least one low temperature nonionic surfactant; wherein the concentration of the low temperature nonionic surfactant comprises from about 10 wt % to about 25 wt % based on the nanofiller-containing epoxy resin; and wherein the molecular weight of the low temperature nonionic surfactant comprises from about 1000 Daltons to about 7000 Daltons.

2. The composition of claim 1 including at least one anionic surfactant.

3. The composition of claim 1 including at least one high temperature nonionic surfactant.

4. The composition of claim 1 wherein the nanofiller-containing epoxy resin comprises (i) a bisphenol A or bisphenol F based epoxy resin with a maximum molecular weight of about 3000 Daltons, and (ii) a nanofiller selected from the group consisting essentially of silicon dioxide, graphene, clay or carbon black with a maximum volume average particle size of about 100 nm.

5. The composition of claim 2 wherein the anionic surfactant comprises a sulfosuccinate, a phophateester, an alkylethersulfate or mixtures thereof.

6. The composition of claim 2 wherein the concentration of the anionic surfactant comprises from about 1 wt % to about 6 wt %.

7. The composition of claim 3 wherein the high temperature nonionic surfactant comprises a polyoxyethylenepolyoxypropylene block copolymer with a molecular weight of about 15,000 Daltons.

8. The composition of claim 3 wherein the concentration of the high temperature nonionic surfactant comprises from about 6 wt % to about 18 wt %.

9. The composition of claim 1 wherein the nanofiller in the nanofiller-containing epoxy resin comprises a nanofiller selected from the group comprising spherical nanofillers, plate-shaped nanofillers, and needle-shaped nanofillers; and wherein the epoxy resin in the nanofiller-containing epoxy resin comprises a diglycidyl ether of bisphenol A or a diglycidyl ether of bisphenol F.

10. The composition of claim 1 wherein the volume average particle size of the nanofiller particles in the nanofiller-containing epoxy resin is less than about 0.2 microns.

11. A stable aqueous dispersion composition comprising

(I) a water phase; and

(II) a water-dispersible composition of claim 1 .

12. A process for preparing a water-dispersible composition comprising mixing:

(a) a nanofiller-containing epoxy resin; and

(b) at least one low temperature nonionic surfactant; wherein the concentration of the low temperature nonionic surfactant comprises from about 10 wt % to about 25 wt % based on the epoxy resin containing the nanofiller; and wherein the molecular weight of the low temperature nonionic surfactant comprises from about 1000 Daltons to about 7000 Daltons.

13. A process for preparing a stable aqueous dispersion composition comprising mixing:

(I) a water phase; and

(II) a water-dispersible composition of claim 1 .

14. The process of any one of claim 12 , including at least one anionic surfactant.

15. The process of any one of claims 13 , including at least one high temperature nonionic surfactant.

16. A process of preparing a stable aqueous dispersion of a nanofiller-containing epoxy resin comprising the steps of:

(a) continuously merging into a disperser, and in the presence of an emulsifying and stabilizing amount of a surfactant mixture, a flowing stream of water flowing at a rate r 1 , and a flowing stream comprising a nanofiller-containing epoxy resin flowing at a rate r 2 ;

(b) mixing the streams of step (a) with a sufficient amount of shear to form a high internal phase ratio emulsion; and

(c) diluting the high internal phase ratio emulsion with water to form a stable aqueous dispersion; wherein the surfactant includes a low temperature nonionic surfactant and optionally an anionic surfactant or optionally a high temperature nonionic surfactant; wherein the low temperature nonionic surfactant is characterized by having a molecular weight of not less than about 1,000 Daltons and not more than about 7,000 Daltons; and where r2:r1 is in such a range such that the volume average particle size of the dispersion is not greater than about 2 microns.