New polymeric materials

Methyl methacrylate-methacrylhydroxamic acid copolymers may be prepared by polymerization in bulk or, preferably, in aqueous emulsion in the presence of catalysts, e.g. ammonium, sodium and potassium persulphates, hydrogen peroxide and redox catalysts such as ammonium persulphate and sodium metabisulphite, and dispersing agents, e.g. sodium salt of sulphated sperm oil alcohols, Turkey Red Oil, soaps, long chain sulphates and sulphonates, and ethylene oxide condensates. The methacrylhydroxamic acid may be formed in situ by reacting methyl methacrylate with hydroxylamine hydrochloride as described in Specifications 852,100 and 852,176. Pigments, synthetic resins, protective colloids, casein and tanning agents, e.g. those of vegetable origin and basic salts of chromium or zirconium, may be added and the polymer dispersions used for filling leather. Specification 887,175 also is referred to.