Polyvinyl ester dispersions and method for making them

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF POLYVINYL ESTER DISPERSIONS CONTAINING PARTICLES OF A SUBSTANTIALLY UNIFORM SIZE, THE IMPROVEMENT WHICH COMPRISES ADJUSTING THIS SUBSTANTIALLY UNIFORM SIZE OF SAID PARTICLES WITHIN A RANGE OF 0.5 MICRON TO 15 MICRONS BY POLYMERIZING VINYL ESTERS IN THE PRESENCE OF A PROTECTIVE COLLOID, OF AN HYDROLYZABLE WHICH EFFECT THE DEGREE OF HYDROLYSIS OF THE HYDROLYZABLE EMULSIFIER, SAID SUBSTANTIALLY UNIFORM PARTICLE SIZE DECREASING WITHIN THE STATED RANGE IN THE PRESENCE OF INCREASING AMOUNTS OF BASIC BUFFER BETWEEN 0.025 PERCENT AND 5 PERCENT, AND INCREASING WITHIN THE STATED RANGE IN THE PRESENCE OF INCREASING AMOUNTS OF SEMI-ESTER BETWEEN 0.01 PERCENT AND 3 PERCENT, SAID PROTECTIVE COLLOID BEING HYDROXYETHYL CELLULOSE PRESENT IN AN AMOUNT OF 0.5 PERCENT TO 15 PERCENT, SAID HYDROLYZABLE EMULSIFIER BEING AN ALKALI METAL SALT OF MONOHYDROXY DIPHENYL PRESENT IN AN AMOUNT OF 0.025 TO 5 PERCENT, SAID BASIC BUFFER BEING AN ALKALI METAL SALT OF A WEAK ACID SELECTED FROM THE GROUP CONSISTING ESSENTIALLY OF PHOSPHORIC, BORIC, ACETIC, CITRIC, AND ADIPIC ACIDS, AND SAID SEMI-ESTER BEING A SEMI-ESTER OF AN UNSATURATED ALIPHATIC DICARBOXYLIC ACID OF 4-10 CARBON ATOMS AND AN ALCOHOL SELECTED FROM THE GROUP CONSISTING OF BENZYL ALCOHOL, CYCLOHEXANOL, METHYLCYCLOHEXANOL, AND ALIPHATIC ALCOHOLS HAVING 1-30 CARBON ATOMS, ALL PERCENTAGES BEING BY WEIGHT OF THE DISPERSION.