Method to form an aqueous dispersion of an ionomer

摘要

Disclosed is a method for forming an aqueous dispersion of an ionomer composition comprising mixing a solid ionomer composition with water heated to a temperature from about 80 to about 90° C., the solid ionomer composition comprising an ethylene acid copolymer comprising 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., wherein about 50% to about 70% of the total carboxylic acid groups of the copolymer are neutralized to carboxylic acid salts comprising sodium cations.

主权项

1. A method for producing an aqueous dispersion comprising an ionomer composition, the method comprising
(a) providing a solid ionomer composition comprising a parent acid copolymer that comprises copolymerized units of ethylene, 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 (MFR) 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 sodium cations; (b) mixing the solid ionomer composition with water heated to a temperature from about 80 to about 90° C. under low shear conditions to provide a heated aqueous ionomer dispersion; and (c) optionally cooling the heated aqueous ionomer dispersion to a temperature of about 20 to 30° C., wherein the ionomer remains dispersed in the liquid phase.