115.2 parts of acrylic acid, 28.8 parts of acrylamide, 2.3 parts of a 9 mole ethylene oxide condensate of nonylphenol acrylate (a water soluble derivative), 220 parts of water, 65 parts 32% aqueous ammonia, 0.4 parts of Tetralon B (trade mark), 0.04 parts of AZDN and 0.04 parts of methylene bis-acrylamide were mixed to form an aqueous phase. A non-aqueous liquid phase was formed of 15 parts Span 80, 42 parts of a 30% w/w solution of a 1:2 molar copolymer of cetostearyl methacrylate:methacrylic acid in SBP11, 117 parts of Pale Oil 150 and 149 parts of SBP11. The aqueous phase was homogenised into the oil phase, deoxygenated and polymerised using 0.043 parts of sodium metabisulphite and 0.043 parts of tertiary butyl hydroperoxide. The resulting inverse dispersion of hydrated polymer gel was dehydrated by distillation under reduced pressure to a final pressure of 10 mm of mercury at a temperature of 95° C.
