Imperial Chemical Industries Limited

Zeneca Limted

Frederick Campbell

John D Schofield

Alan S Baker

Peter Kingsley Davies

John M Geary

A surfactant comprising a carboxylic acid ester or amide carrying a terminal strong acid group selected from carboxymethyl, sulphate, sulphonate, phosphate and phosphonate, suitable for stabilising dispersions of solids in organic liquids and oil/water emulsions, processes for the preparation of the surfactant and dispersions and emulsions containing the surfactant. A preferred species of the surfactant is a poly(hydroxyalkanecarboxylic acid) having the strong acid group attached, either directly or through a linking group, to a terminal hydroxy or carboxylic acid group.

Surfactant and dispersible or emulsifiable compositions employing

Surfactant products of poly(hydroxyalkanecarboxylic acid) phosphate

A composition comprising a finely-divided non-magnetic solid and a dispersant comprising a poly(C.sub.2-4 -alkyleneimine) carrying at least two mono- or poly-(carbonyl-C.sub.1-7 -alkyleneoxy) groups, a dispersion of the composition in an organic medium and a dispersant comprising a poly(C.sub.2-4 -alkyleneimine) carrying at least two carbonyl- C.sub.1-7 -alkyleneoxy groups.

Composition

A dispersion of finely divided particles of a magnetic material in an organic liquid containing a dispersant comprising an amine carrying a poly(carbonylalkyleneoxy) chain (PCAO chain) in which the alkylene groups contain up to 8 carbon atoms, or an acid-salt thereof. The dispersion is useful for the preparation of magnetic recording media such as video, audio and computer recording tapes and discs. Certain of the dispersants are novel, especially a polyethyleneimine carrying at least two PCAO chains.

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Failsworth, United Kingdom

Frederick Campbell