Patent GB-844683-A (GB)
Title: Process for the manufacture of water-insoluble salts of polyvalent metals
IPC: C08K5/098
Filed: 1956-07-16
Abstract: Water-insoluble salts of polyvalent metals are prepared by reacting a water-soluble salt of a polyvalent metal with an aqueous solution containing both an alkali metal silicate and an alkali metal salt of a fatty acid or hydroxy fatty acid containing at least 6 carbon atoms so as to effect a coprecipitation of the insoluble polyvalent metal silicate and the polyvalent metal salt of the fatty acid and produce a homogeneous suspension. Generally the dry solids content of the reaction liquid should not be more than 25% and preferably less than 25% calculated as polyvalent metal salt of silicic acid and organic acid.  The product may consist of polyvalent metal silicates, polyvalent metal salts of the fatty acid and mixed salts.  A high proportion of the latter is attained by slowly adding a highly dilute solution of alkali metal silicate and alkali metal carboxylate with stirring to the solution of the polyvalent metal salt, preferably by spraying.  The products may be recovered from the aqueous suspension, e.g. by filtration, centrifugation or drying. They may be incorporated in hydrophobic substances in dry or wet condition e.g. by adding hydrophobic substance to the aqueous suspension, or to one of the component solutions before mixing. The products are said to be of use as catalysts, builders for rubber, plastics, soap, and detergents, paint pigments and in liniment and lubricating campositions.ALSO:Water-insoluble salts of polyvalent metals, especially calcium, magnesium and aluminium, are prepared by reacting a water-soluble salt of a polyvalent metal with an aqueous solution containing both an alkali-metal silicate and an alkali-metal salt of a fatty acid or hydroxy fatty acid containing at least 6 carbon atoms so as to effect a coprecipitation of the insoluble polyvalent metal silicate and the polyvalent metal salt of the fatty acid and produce a homogeneous suspension.  Generally the dry solids content of the reaction liquid should not be more than 25% and preferably less than 25% calculated as polyvalent metal salt of silicic acid and organic acid.  The product may consist of polyvalent metal silicates, polyvalent metal salts of the fatty acid and mixed salts.  A high proportion of the latter is attained by slowly adding a highly dilute solution of alkali-metal silicate and alkali-metal carboxylate with stirring to the solution of the polyvalent metal salt, preferably by spraying.  The products may be recovered from the aqueous suspension, e.g. by filtration, centrifugation or drying.  They may be incorporated in hydrophobic substances in dry or wet condition, e.g. by adding hydrophobic substance to the aqueous suspension, or to one of the component solutions before mixing, and finally separating the hydrophobic and aqueous phases.  The products may be incorporated in soap and other detergent compositions as builders.  The suspensions in hydrophobic substances such as mineral oils, petrolatum, fatty oils and fats may be lubricating oil and grease compositions. Examples are given.ALSO:Liniment compositions comprise suspensions in hydrophobic substances such as mineral or fatty oils and fats of water-insoluble salts of polyvalent metals prepared by reacting a water-soluble salt of a polyvalent metal with an aqueous solution containing both an alkali metal silicate and an alkali metal salt of a fatty acid or hydroxy fatty acid containing at least 6 carbon atoms so as to effect a coprecipitation of the insoluble polyvalent metal silicate and the polyvalent metal salt of the fatty acid and produce a homogenous suspension.  Generally the dry solids content of the reaction liquid should not be more than 25% and preferably less than 25% calculated as polyvalent metal salt of silicic acid and organic acid.  The product may consist of polyvalent metal silicates, polyvalent metal salts of the fatty acid and mixed salts.  A high proportion of the latter is attained by slowly adding a highly dilute solution of alkali metal silicate and alkali metal carboxylate with stirring to the solution of the polyvalent metal salt, preferably by spraying.  The products may be recovered from the aqueous suspension, e.g. by filtration, centrifugation or drying.  They may be incorporated in hydrophobic substances in dry or wet condition e.g. by adding hydrophobic substance to the aqueous suspension, or to one of the component solutions before mixing.  Silver or mercury compounds are preferably present.