GB452950A - Processes for the production of thixotropic preparations containing copper oxychloride and the products obtained thereby - Google Patents

Abstract

Copper oxychloride preparations for use as fungicides are obtained in a thixotropic condition, so that while normally solid or semi solid they may be converted to the liquid condition by mechanical vibration, by kneading together, in a Werner-Pfleiderer or similar machine, copper oyxchloride containing from 20 to 58 per cent of water and a protective colloid in such proportions that the mixture contains at least 600 gms. of copper oxychloride per litre. Suitable protective colloids are sulphite cellulose liquor, molasses and dextrin. A washed precipitate of copper oxychloride is partly freed from water by pressure, centrifuging or evaporation and then is kneaded with sulphite lye or other protective colloid with or without the addition of a little calcium carbonate to eliminate traces of soluble copper. Part of the colloid may be added to the oxychloride precipitate before treatment to remove excess water. The precipitate is preferably freshly prepared, but dry oxychloride may be used in conjunction with the required quantity of water. The preparations are diluted with water when used. Reference is made to known preparations in which (1) a powder of copper oxychloride and a protective colloid is prepared, (2) a cream is made from a concentrated solution of copper chloride and calcium hydrate, and (3) a fresh copper oxychloride precipitate is stirred with a considerable quantity p of protective colloid and water to form a stiff paste.