Imperial Chemical Industries Limited

Andrew Frangou

Alan J Backhouse

Stephen J Thorne

William James Highcock

Deepak Gogna

James William Casper

Coating composition

The invention provides an aqueous coating composition which comprises a film forming polymer and a particulate metallic pigment characterized in that the composition contains as corrosion inhibition agent for the pigment a phosphatic material containing at least one acidic hydroxyl group or a salt thereof linked to a phosphorus atom and which has been obtained by the co-reaction of (i) an addition polymer carrying a functional hydroxyl group, (ii) a monohydric alcohol or phenol and (iii) a compound containing in the molecule the grouping: ##STR1## or a compound equivalent in structure to such a grouping. Preferably, where the reactant (i) and/or (ii) contains a material having a terminal alkyl group containing more than 6 carbon atoms such a material provides less than 25% by weight of the combined weights of the reactants (i) and (ii), since we have found that the presence of such long chain terminal groups impairs the inter coat adhesion between a base coat of the composition of the invention and a subsequently applied translucent top coat.

Coating compositions

The tendency of metallic pigments, especially of aluminum flake pigments, to react with the aqueous medium of a water-born paint composition with the generation of gaseous material is prevented or reduced by incorporating in the composition an agent containing in the molecule at least one P--OH group, or a salt derivative thereof, which is obtained by reacting a compound containing the grouping --O--PO(OH.sub.2) with one or more epoxide group-containing compounds at least one of which also contains at least one aromatic or alicyclic group.

Water-born coating compositions comprising metallic powder or flake

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Windlesham, United Kingdom

Andrew Frangou