| 摘要 |
PURPOSE:To obtain the titled latex which is stable for a long period of time and has a desired particle shape and a desired particle specific gravity, by heating a specified styrene copolymer suspension under an alkaline condition and then under a neutral or acidic condition, and chlorinating it. CONSTITUTION:A suspension of copolymer particles is obtained by copolymerizing styrene with 0.0001-3wt% styrenesulfonate at 70-72 deg.C for 5-50hr with the aid of 0.01-1wt% persulfate as an initiator in the absence of any emulsifier in an aqueous solution containing 0.003-3wt% bivalent metal (hydr)oxide such as Mg(OH)2. This suspension is heated at 50-90 deg.C for 10-100hr under an alkaline condition of a pH of 7.5-12.5 and then heated at 60-80 deg.C for 10-50hr under a neutral or acidic condition. Subsequently, this suspension is chlorinated at 5- 65 deg.C for 10-500min to a final chlorine content of 5-40% to obtain the titled soap-free latex having a particle specific gravity of 1.10-1.60 and most suited for use in the microtiter method. |
