| abstract |
The invention relates to build-up agents which comprise a condensation product among an aldehyde, a phenol compound and an aromatic carboxylic acid, hydroxy-substituted on the aromatic nucleus. The products are particularly effective in reducing or suppressing the build-up formation in the polymerization of vinyl chloride or vinyl acetate, other copolymerizable substances being optionally present. Further objects of the invention are compositions containing the above agents, their use as build-up agents, methods for their preparation and the products obtained therefrom, the polymerization processes carried out in reactors whose inner walls are coated with these agents and the polymers obtained from these processes. |