Styrene suspension polymerization system for spheres

Claim 1

A batch useful for the suspension polymerization of a styrene-monomer, which batch comprises (A) an aqueous phase which is the aqueous suspension vehicle which consists essentially of (a) water and dissolved therein (b) a water-soluble suspending agent inert to reaction with the styrene-monomer, which is at least one of (i) a hydroxyethylcellulose having a viscosity within the range of one whose 2% by weight, on dry basis, aqueous solution at 20° C. has a Hoopler viscosity of from 6175 to 7600 centipoises (ii) a hydroxyethylcellulose whose whole such 5% aqueous solution at 20° C. has a Hoopler viscosity of from 120 to 160 centipoises, (iii) carboxymethylcellulose, (iv) polyacrylic acid, (v) polymethacrylic acid, (vi) the sodium or ammonium salt of any of the carboxylic acid substances (iii), (iv), and (v), and (vii) polyvinyl alcohol; said suspending agent being present in said suspension vehicle in a concentration above that which will allow the produced styrene-polymer to agglomerate under the polymerization conditions and below about 0.4 weight percent, and (c) from about 0.01 to about 0.5 percent of a water-soluble organic solvent for said suspending agent, which solvent is selected from the group consisting of formic acid, dimethylformamide, dimethylacetamide, tetrahydrofuran, ethylenediamine, diethylenetriamine, 2-bromopyridine, and 3-cyanopyridine; and (B) an organic phase composed of a styrene-monomer having dissolved therein a styrene-monomer polymerization effective amount of a styrene-monomer polymerization free radical-providing catalyst; said suspending agent being present in the range of from about 0.2 to about 1 pound thereof for each about 50 pounds of the styrene-monomer, and said styrene-monomer is present in the range of from about 1 pound thereof for each from about 6 to about 7 pounds of water.