Polymerization process with anti-scaling agents

A process for the preparation of an anti-scaling coating on the walls of a polymerization vessel using aromatic hydroxy compounds reacted with sodium hydroxymethanesulphinate, characterized in that said anti-scaling coating:

• is obtained by first reacting sodium hydroxymethanesulphinate with 1-naphthol in a basic environment with the pH value 11-13 to prevent the evolution of the reaction into stable condensate forms;
• the liquid mixture resulting is maintained in absence of oxygen and then
• adding to said liquid mixture, polyvinyl alcohol's having a degree of hydrolysis higher than 99% OH and the molecular weight between 70,000 and 90,000 and finally:
• to apply this mixture to the internal walls of said polymerization vessel, maintained at about 85.degree. C., by means of mixing and injection with aqueous vapour with a pressure of about 10 Kg./cm2.