Emulsifier-free, aqueous microgel dispersion for use in paint, e.g. basecoats for cars, obtained by making a polyacrylate with hydroxyl, carboxyl and phosphonic acid groups and then crosslinking with melamine resin

摘要

An emulsifier-free, aqueous microgel dispersion which is obtained by making a polyacrylate with hydroxyl groups and carboxyl groups in presence of compounds with phosphonic acid groups and then crosslinking the mixture with an aminoplastic resin. An emulsifier-free, aqueous microgel dispersion (I), obtained by (a) making a polyacrylate (A) containing hydroxyl group(s) and carboxyl group(s) in presence of compound(s) with phosphonic acid groups (B), (b) crosslinking the resulting mixture with an aminoplastic resin (C) and (c) emulsion polymerisation of the mixture with monomer(s) (D) containing radically-polymerisable double bond(s) (Method M1). Independent claims are also included for (1) a similar microgel dispersion obtained by carrying out stages (a) and (b) without stage (c) (Method M2) (2) a microgel dispersion obtained by the above methods in which stage (a) involves copolymerisation of a monomer (i) with polymerisable double bond(s) (PDB) and OH group(s), a monomer (ii) with PDB and COOH group(s) and a monomer (iv) with PDB and phosphonic acid group(s) .