Abstract: Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.
Type:
Grant
Filed:
September 14, 2012
Date of Patent:
May 28, 2013
Assignee:
Ablemarle Corporation
Inventors:
Charles H. Kolich, John F. Balhoff, Douglas W. Luther, Robert C. Herndon, Ronny W. Lin, Bruce C. Peters, Arthur G. Mack, David A. Lee
Abstract: The present invention is directed to a process for the production of agglomerates of a blend of a sterically hindered phenol antioxidant and an acid neutralizer such that the agglomerates have a balanced hardness to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such agglomerates are achieved through the use of a processing aid consisting of an alcohol of the formula ROH wherein R is an alkyl group of 1 to 8 carbon atoms, either alone or having up to 80% by volume of a cosolvent selected from the group consisting of methylene chloride, chloroform, toluene, acetone, methylethylketone, xylene, cyclohexane, styrene, methylcyclohexane, and hexane. The cosolvent processing aid has at least 1 gram of antioxidant dissolved therein per 100 mL of solvent. The processing aids are used to form a paste of a mixture of antioxidant and an acid neutralizer. The resulting paste is then subjected to agglomeration and the resulting agglomerates are thereafter dried.