Abstract: A process of coating or encapsulating an inorganic powder is described in which the powder, preferably a pigment, is dispersed in an aqueous medium and an ethylenically unsaturated monomer is polymerized in the presence of the powder and while subjecting the reaction mixture to ultrasonic vibrations. The monomer is present in an amount not exceeding 200% by weight of the powder and preferably is an acrylate or methacrylate.The powder has a cationic charge on its surface which can be generated by treatment of the surface with, preferably an aluminium salt.

Abstract: A scale inhibiting composition comprises the combination of (a) a copolymer of an alkene, preferably a branched chain alkene, and an unsaturated dicarboxylic acid or anhydride, in acidic or neutralized form, and (b) an organic polyphosphonic acid or salt.A preferred composition contains the sodium salt of a copolymer of isobutene and maleic anhydride and 1-hydroxyethyl-1,1-diphosphonic acid.The compositions may be used in secondary or tertiary oil recovery, desalination of sea water and the softening of boiler feed water.