Method for preparing aqueous dispersions of ethylene copolymers

Claim 1

A PROCESS FOR PREPARING DISPERSIONS OF ETHYLENE COPOLYMERS WHICH COMPRISES DISSOLVING A COPOLYMER OF MONOMERS COMPRISING AT LEAST 65 PERCENT BY WEIGHT ETHYLENE AND AN A,B-ETHYLENICALLY UNSATURATED CARBOXYLIC ACID HAVING FROM 3 TO 8 CARBON ATOMS, THE ACID BEING PRESENT IN AMOUNT OF AT LEAST 8 PERCENT BY WEIGHT WHEN ONLY ETHYLENE AND ACID ARE PRESENT IN THE COPOLYMER AND WHEN ANY OTHER MONOMER POLYMERIZED THEREIN IS A NON-POLAR MONOMER, THE ACID BEING PRESENT IN AMOUNT OF AT LEAST 5 PERCENT BY WEIGHT WHEN ANOTHER POLAR MONOMER IS POLYMERIZED IN THE COPOLYMER, IN A SUBSTANTIALLY WATERMISCIBLE ORGANIC SOLVENT WHICH HAS A BOILING POINT BELOW 100*C. OR FORMS AN AZEOTROPIC MIXTURE WITH WATER HAVING A BOILING POINT BELOW 100*C., DISPERSING THE POLYMER SOLUTION IN AN AQUEOUS LIQUID SYSTEM CONTAINING AN AMOUNT OF AN ALKALINE COMPOUD SUFFICIENT TO NEUTRALIZE AT LEAST 10 PERCENT OF THE CARBOXYLIC ACID UNITS PRESENT IN THE COPOLYMER AND SIMULTANEOUSLY VOLATIZING A MAJOR PORTION OF THE SOLVENT AS THE POLYMER SOLUTION IS ADMIXED WITH THE AQUEOUS SYSTEM AND THEREBY FORMING A DISPERSION OF THE POLYMER IN THE AQUEOUS LIQUID SYSTEM.