PURPOSE: To obtain a constant-size polymer for coating by subjecting an-acrylic monomer to aq. suspension polymn. under specified conditions in the presence of a monomer-soluble free-radical initiator and a specific polymeric suspending agent.

CONSTITUTION: This acrylic polymer is prepd. by subjecting (A) an acrylic monomer (e.g. methyl acrylate) to aq. suspension polymn. in the presence of (B) a free-radical initiator which is soluble in monomer A and (C) a polymeric suspending agent which is selected from among homopolymers of monomers of the formula [wherein R1 is H or CH3; R2 and R3 are each H or 1-8C alkyl; M is an alkali or alkaline earth metal or ammonium; and A is NH, O, or NCH3] and copolymers of the monomers of the formula and up to 40 wt.% acrylic monomers. The above polymn. is characterized in that the polymn. aq. phase is wholly or partly formed by the mother waters obtd. after the separation of the acrylic polymer, so as to have a polymerizable suspension contg. 0.01-1 wt.% said suspensding agent and 0.05-5 wt.% other products.