ES381255A1 - Improvements in a procedure to produce a synthetic reinforced rubber resin. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Improvements in a process for producing a synthetic reinforced rubber resin by polymerizing a mixture of vinyl aromatic monomers and vinyl cyanide contain from about 18 mole percent to about 57 mole percent of the vinyl cyanide monomer in an area of reaction containing an aqueous emulsion of from about 0.1 to about 1.25 parts by weight for each part of said monomer mixture of an ethylenically unsaturated rubber, a free radical initiator, and a mercaptan polymerization regulator, characterized by: (a) employing an inorganic peroxide as said free radical initiator; (b) employing as the said rubber a butadiene polymer containing up to about 50% by weight of combined styrene and having an average particle size of from about 0.2 to about 0.6 microns, a gel content of approximately 85%, and a benzene swelling index greater than about 15; (c) employing said mercaptan polymerization regulator in an amount of less than about 0.034 equivalents of mercaptene per kilogram of said rubber and monomers; (d) reacting an initial portion of about 20% to 80% of said monomers at a polymerization temperature of about 60ºC to 90ºC in the presence of an initial portion of said regulator of at least about 0.0035 equivalents of mercaptan per kilogram of said rubber and monomers in said reaction zone, and then introduce a further portion of said regulator in said reaction zone, sufficient to increase the total amount of said regulator introduced in said reaction zone by at least 25% and maintain a temperature of polymerization of about 60ºC to 90ºC until at least about 90% of said monomers have reacted. (Machine-translation by Google Translate, not legally binding)