Process for preparing acrylic polymers in the presence of a radical initiator and a polymeric suspending agent

A process for the polymerization of acrylic monomers in aqueous suspension in the presence of a radical initiator soluble in the monomers and of a polymeric suspending agent selected from:

• a) the homopolymers of a compound of formula:
• wherein:
• R1 is H or CH3;
• R2 and R3, equal or different, are H or C1-C8 alkyls;
• M is an alkaline or alkaline-earth metal or ammonium;
• and
• A is NH, O, or NCH3;
• b) the copolymers of said compound of formula I including no more than 40% by weight acrylic monomers, wherein the polymerization aqueous phase is wholly formed by mother waters obtained from a previous polymerization process after the separation of the acrylic polymer, said mother waters containing an organic phase comprising said suspending agent and products obtained during the polymerization, said polymerization aqueous phase containing at least 0.01% by weight and up to about 1% by weight of said suspending agent and from 0.05% to 1.5% by weight of said organic phase determined on the dry residue at 160° C. of the mother waters.