GB769799A - Improvements in or relating to articles treated so as to have microbicidal properties - Google Patents

Abstract

In a method of treating an article to render it antiseptic the article is first contacted with an aqueous solution comprising a water-soluble silver salt, e.g. silver nitrate and a first water-soluble salt of another metal, e.g. magnesium nitrate the cation of which is capable of forming a sparingly water-soluble salt with the anion of at least one other water-soluble salt, e.g. with a third salt; subsequently contacting the thus treated article with a second aqueous solution containing a second water-soluble salt, the anion of which is the anion of a sparingly soluble water salt and a third water-soluble salt, e.g. sodium phosphate, the anion of which forms a sparingly water-soluble compound with the metal cation of the first water-soluble salt, and a water-soluble basic nitrogen compound, e.g. ammonia or an amine, whereby a sparingly water-soluble silver salt and a sparingly water-soluble metal compound are formed, the metal compound functioning as an effective stabilizer of the silver salt against the effect of light normally tending to discolour the silver salt. When the articles are to have fungicidal in addition to germicidal properties a co-precipitation of calcium undecylenate is effected by treating the article with a solution of a water-soluble calcium salt, e.f. calcium chloride and then with a solution of the ammonium, sodium or other water-soluble salt of undecylenic acid, or vice versa, these treatments being carried out either prior to or subsequent to the treatment with the first and second solutions, or preferably a water-soluble calcium salt, e.g. calcium nitrate is incorporated with the first solution along with the water-soluble silver silver salt and the water-soluble undecylenate, e.g. ammonium undecylenate, in the second solution with the second and third water-soluble salts.