Patent ID: 9079982
Filing Date: 2015-07-14
Classification: C08F,C08L

Abstract:
1. A process for producing high impact polystyrene in serially arranged reactors, comprising: feeding at least one vinyl aromatic monomer, an elastomer, and a free radical initiator to a first linear plug flow reactor to form a reaction mixture; polymerizing the reaction mixture in the first linear flow reactor to a point below the point at which phase inversion occurs to produce a first polymerization mixture; feeding the first polymerization mixture from the first linear flow reactor to a second linear flow reactor; polymerizing the first polymerization mixture in the second linear plug flow reactor to at least a phase inversion point of the mixture to produce a second polymerization mixture, wherein the second linear flow reactor is a horizontally oriented plug flow reactor that is equipped with an agitator; and feeding the second polymerization mixture from the second linear flow reactor to at least two serially arranged post-inversion reactors for post-inversion polymerization of the second polymerization mixture, wherein each post-inversion reactor is a linear plug flow reactor; wherein a product stream leaving the post-inversion reactors has an ESCR value at an oven temperature of 65° C. of at least 10% toughness retained with less than 10 wt % rubber content.