Method to form an aqueous dispersion of an ionomer-polyolefin blend

1. A method to produce an aqueous dispersion comprising water and about 0.001 to about 50 weight % of a mixture of an ionomer and an ethylene ester copolymer, the method comprising

(1) providing a solid blend composition comprising

(a) about 75 to about 99.9 weight %, based on the combination of (a) and (b), of an ionomer composition comprising a parent acid copolymer consisting of copolymerized units of ethylene and about 18 to about 30 weight % of copolymerized units of acrylic acid or methacrylic acid, based on the total weight of the parent acid copolymer, the acid copolymer having a melt flow rate from about 200 to about 1000 g/10 min., measured according to ASTM D1238 at 190° C. with a 2160 g load, wherein about 50% to about 70% of the carboxylic acid groups of the copolymer, based on the total carboxylic acid content of the parent acid copolymer as calculated for the non-neutralized parent acid copolymer, are neutralized to carboxylic acid salts comprising potassium cations, sodium cations or combinations thereof; and

(b) about 0.1 to about 25 weight %, based on the combination of (a) and (b), of an ethylene ester copolymer consisting of copolymerized units of ethylene and about 10 to about 45 weight % of copolymerized units of an alpha, beta-ethylenically unsaturated carboxylic acid ester, based on the total weight of the ethylene ester copolymer;

(2) mixing the solid blend composition with water heated to a temperature from about 80 to about 100° C. to provide a heated aqueous blend dispersion; and

(3) optionally cooling the heated aqueous blend dispersion to a temperature of about 20 to 30° C., wherein the blend remains dispersed in the liquid phase.

2. The method of claim 1 wherein the mixture of polymers consists essentially of the ionomer and at least one ethylene ester copolymer.

3. The method of claim 1 comprising an ionomer wherein the cations of the carboxylate salts consist essentially of sodium cations.

4. The method of claim 1 comprising an ionomer wherein the cations of the carboxylate salts consist essentially of potassium cations.

5. The method of claim 1 wherein the acid copolymer has a MFR from about 250 to about 400 g/10 min.

6. The method of claim 1 wherein the alpha, beta-ethylenically unsaturated carboxylic acid ester comonomer is methyl acrylate, ethyl acrylate, isopropyl acrylate, or butyl acrylate.

7. The method of claim 1 wherein the alpha, beta-ethylenically unsaturated carboxylic acid ester comonomer is methyl acrylate.

8. The method of claim 1 wherein providing the solid blend composition comprising (a) and (b) comprises melt mixing.

9. The method of claim 1 wherein providing the solid blend composition comprising (a) and (b) comprises melt extrusion blending.