GB420533A - Manufacture of metal salts of polymeric carboxylic acids and the production of shaped articles therefrom - Google Patents

Abstract

Metal salts of polymeric carboxylic acids are produced by reacting an aqueous solution of the free acid with a salt-forming compound of the metal, or by producing double decomposition between an alkali salt of the polymeric carboxylic acid and a salt of the metal. The metals used include magnesium. The polymeric carboxylic acids are produced by polymerization of a polymerizable carboxylic acid, such as acrylic acid, vinyl acetic acid or methyl acrylic acid. If the salts produced are insoluble in water, they are washed and may be dissolved in a feebly alkaline solution, for example, of alkali or alkali carbonate or of a nitrogenous base, for example, ammonia or triethanolamine. If soluble, they may be precipitated by an alcohol such as methanol or ethyl alcohol. The solutions are colloidal and shaped articles such as films, fibres or plates may be cast therefrom. The solid metal salts, preferably finely divided, and if desired in admixture with softening agents such as triethanolamine or polyethylene oxide, may be moulded under heat and pressure. The compounds may be heated in a shaped or unshaped condition with access of air to a feeble red heat until organic matter is burnt off, whereby there remains a loose porous mass of metallic oxides. The Specification as open to inspection under Sect. 91 comprises also the subject-matter of Specification 420,589. This subject-matter of does not appear in the Specification as accepted.ALSO:Metal salts of polymeric carboxylic acids are produced by reacting an aqueous solution of the free acid with a salt-forming compound of the metal, or by producing double decomposition between an alkali salt of the polymeric carboxylic acid and a salt of the metal. The metals used are those of the magnesium group, the aluminium group, the iron group, the antimony group, the tin group and copper, silver and gold, the term 'group' referring to the sub-groups of the periodic system. The polymeric carboxylic acids are produced by polymerization of a polymerizable carboxylic acid, such as acrylic acid, vinyl acetic acid or methyl acrylic acid. If the salts produced are insoluble in water, they are washed and may be dissolved in a feebly alkaline solution, for example, of alkali or alkali carbonate or of a nitrogenous base, for example, ammonia or triethanolamine. If soluble, they may be precipitated by an alcohol such as methanol or ethyl alcohol. The solutions are colloidal, and shaped articles such as films, fibres or plates may be cast therefrom. The solid metal salts, preferably finely divided, and if desired in admixture with softening agents such as triethanolamine or polyethylene oxide, may be moulded under heat and pressure. Examples relate to the production of silver polyacrylate films for photographic purposes, clear films of mercury polyacrylate, brown films of ferric polyacrylate films or threads of thallium polyacrylate and nickel polyacrylate, and films of zinc polyvinylacetate and cobalt polymethylacrylate. Mercury and bismuth compounds are applicable for medical purposes, films of the substances being used as poultices, silver, lead, uranium and nickel compounds for photographic purposes, e.g. for the manufacture of light filters, lead and thallium compounds for screening effects in X-ray technics, and iron compounds for electrotechnical purposes, for instance, for conducting layers as in condensers and Leyden jars. The compounds may be heated in a shaped or unshaped condition with access of air to a feeble red heat until organic matter is burnt off, whereby there remains a loose porous mass of metallic oxides, or in the case of noble metals, of metal. The Specification as open to inspection under Sect. 91 comprises also the subject-matter of Specification 420,589. This subject-matter does not appear in the Specification as accepted.ALSO:A loose porous mass of a noble metal is obtained by heating the metal salt of a polymeric carboxylic acid, for example, silver polyacrylate, either in an unshaped condition or in the form of films, fibres or plates, with access of air to a feeble red heat until organic matter is burnt off.