Interpolymer latex compositions and process

Claim 1

AN AQUOUD LATEX OF A WTER-INSOLUBLE COPOLYMER PRODUCT OF TWO-STAGTE AQUEOUS DISPERSION COPOLYMERIZATION OF A PLURALITY OF POLYMERIZABLE ALPHA MONO-OLEFINICALLYUNSATURATED MONOMERS CONSISTING ESSENTIALLY OF (A) ACRYLONITRILE, (B) AT LEAST ONE NEUTRAL ESTER OF AN ALPHA MONOOLEFINICALLY-UNSATURATED CARBOXYLIC ACID WITH A MONIHY DRIC ALCOHOL FREE OF POLYMERIZABLE CARBON-TO-CARBON UNSATURATION, AND BEING COMPOSED OF CARBON, HYDROGEN AND OXYGEN ATOMS, AND (C) AT LEAST ONE ALPHA MONO-OLEFINICALLY-UNSATURATED CARBOXYLIC ACID HAVING ONE TO TWO CARBOXYL MOIETIES PER MOLECULE IN A PROPORTION SUFFICIENT TO PROVIDE AN ACID NUMBER IN THE RANGE OF 15 TO 80 BASED ON THE TOTAL MONOMER COMPOSITION, WHICH COMONOMER COMPOSITION IS MADE UP OF AN INITIAL MONOMER CHARGE (A), WHICH IS AT LEAST TERNARY IN COMPOSITION, AND A SECOND COMONOMER CHARGE (B), WHICH IS AT LEAST BINARY IN COMPOSITION, SAID COMONOMERS (A) AND (B) BEING PRESENT IN BOTH SAID MONOMER CHARGES (A) AND (B) AND SAID CARBOXYLIC ACID MONOMER (C) BEING PRESENT IN SAID MONOMER CHARGE (A) SUFFICIENT TO PROVIDE AN ACID NUMBER IN THE RANGE OF 15-80, THE RELATIVE PROPORTIONS BY WEIGHT OF THE RESPECTIVE COMONOMERS (A) AND (B) IS SAID COMONOMER CHARGES (A) AND (B) EACH RANGING FROM 0.8 TO 1.2 TIMES THE RESPECTIVE RELATIVE PROPORTIONS OF (A) AND (B) IN THE TOTAL COMONOMER COMPOSITION, THE RELATIVE PROPORTION OF (C) IN SAID CHARGE (B) BEING NO GREATER THAN ABOUT 2 TIMES THE PROPORTION OF (C) IN SAID MONOMER CHARGE (A) ON A CARBOXYL BASIS, THE WEIGHT RATIO OF SAID SECOND CHARGE (B) BEING FROM 0.67 TO 1.5 PARTS PER PART OF SAID FIRST CHARGE (A), MONOMER CONVERSION OF SAID CHARGE (A) BEING AT LEAST 85% COMPLETE PRIOR TO CHARGING SAID MONOMER CHARGE (B), THEREAFTER MONOMER CONVERSION BEING AT LEAST 95% COMPLETE BASED ON THE TOTAL COMONOMER COMPOSITION, SAID TWO-STAGE COPOLYMERIZATON BEING CONDUCTED WITH A FREE RADICAL-GENERATING VINYL POLYMERIZATION INITIATOR IN BOTH STAGES OF THE COPOLYMERIZATION.