METHOD FOR PREPARING STYRENE/ACRYLIC WATER-SOLUBLE RESIN BY CONTINUOUS BULK POLYMERIZATION

摘要

PURPOSE: A method for preparing a styrene/acrylic water-soluble resin having a small molecular weight, narrow molecular weight distribution, high acidity value and low volatile matter content by using a continuous bulk polymerization is provided. CONSTITUTION: A method comprises steps of: (i) continuously throwing a monomer, an initiator and 5-15 wt. parts of a mixed solvent of dipropylene glycol methyl ether and water regarding 100 wt. parts of the monomer in a reactor controlling the temperature by using an oil jacket and a cooling coil of the inside of the oil jacket; (ii) polymerizing the step (i) at a reaction temperature of 150-220°C and a retention time of 10-20 minutes; and (iii) transferring the polymer of step (i) to a falling strand type of devolatilizer and then operating the devolatilizer at a temperature of 180-210°C and under pressure of -500¯-750 millimeter Hg to remove volatile dust from the polymer.