DISPERSION STABILIZER FOR SUSPENSION POLYMERIZATION OF VINYL COMPOUND TO SATISFY HIGH PERFORMANCE OF THE STABILIZER AND METHOD FOR PRODUCING THE SAME

摘要

PURPOSE: Provided are a dispersion stabilizer comprising vinyl alcohol based polymer for suspension polymerization of vinyl compound to satisfy high performance of the stabilizer and a process for production of the same. CONSTITUTION: The dispersion stabilizer comprises vinyl alcohol based polymer(A) from another vinyl alcohol polymer(B) having 0.3 to 0.6 of block character of residual acetate group and 60 mol% or more of saponification value. The process for production of the dispersion stabilizer comprises heat-treatment of the vinyl alcohol polymer(B) under atmosphere less than 8000ppm of oxygen content at 90 to 180 deg.C for 0.5 to 20 hours. Vinyl alcohol polymer(A') contained in the stabilizer exhibits a ratio of light-absorption(a) at 280nm to light-absorption(b) at 320nm represented by £(b)/(a)| more than 0.7, light-transmission rate of 80% at 500nm and 30 deg.C, and YI(Yellow Index) less than 40.