Stable latex of an interpolymer of a conjugated diene, an unsaturated nitrile, and an alpha-unsaturated acrylic acid, and method of preparation

Claim 1

IN THE PREPARATION OF LATEX THAT FORMS A READILYSTRETCHED, STRONG ELASTIC FILM FROM MONOMERIC MATERIAL COMPRISING A MAJOR PORTION OF A CONJUGATED DIENE HAVING FOUR TO SIX CARBON ATOMS, A LESSER PORTION OF A LOWER MOLECULAR WEIGHT OLEFINICALLY UNSATURATED NITRILE AND A MINOR PORTION OF AN ALPHA-UNSATURATED ACRYLIC ACID HAVING THREE TO FIVE CARBON ATOMS, THE STEPS WHICH COMPRISE POLYMERIZING SAID MONOMERIC MATERIAL EMULSIFIED IN AN ACIDIC AQUEOUS SYSTEM WITH AN EMULSIFIER SELECTED FROM THE GROUP CONSISTING OF ANIONIC AND NON-IONIC EMULSIFIERS AND IN THE PRESENCE OF, BASED ON 100 PARTS BY WEIGHT OF TOTAL MONOMERIC MATERIAL, BETWEEN 0.025 AND 0.075 PART BY WEIGHT OF POTASSIUM PERSULFATE AND AN AMOUNT OF A MERCAPTAN MODIFIER EQUIVALENT TO ABOUT 0.1 TO 2 PARTS BY WEIGHT OF PRIMARY DODECYL MERCAPTAN, NEUTRALIZING THE POLYMER EMULSION SO FORMED WITH A VOLATILE MONOVALENT BASE AND COMPOUNDING THE NEUTRALIZED EMULSION WITH AN INSOLUBLE BASIC OXIDE OF A POLYVALENT METAL.