Patent ID: 6471880
Filing Date: 2002-10-29
Classification: C03C

Abstract:
Process for etching glass objects by chemical treatment, comprising:(a) at least one stage of etching by chemical treatment of the glass objects, and (b) at least one stage of rinsing the etched objects of stage (a) with an aqueous solution of one or more alkali metal or alkaline earth metal cation salts, wherein the chemical etching solution employed in stage (a) is obtained by mixing: between 0.1 kg and 5 kg of a composition comprising: from 20% to 99% by weight of potassium bifluoride; from 1% to 80% by weight of at least one water-soluble divalent or trivalent cation salt selected from divalent and trivalent cation salts; and optionally one or more of the following compounds: up to 15% by weight of ammonium bifluoride, sodium bifluoride in a proportion by weight of less than or equal to that of potassium bifluoride, with the proviso that, when the composition comprises both ammonium bifluoride and sodium bifluoride, the total amount of these two bifluorides does not exceed that of potassium bifluoride, from 5% to 60% by weight of at least one water-insoluble filler chosen from inorganic and organic products which are stable in an acidic medium, or from 0.2% to 6% by weight of one or more surface-active agents which are stable in an acidic medium; per liter of water or per liter of an aqueous solution of one or more inorganic or organic acids, with the proviso that the inorganic acid optionally present in the aqueous solution before mixing with the composition is not hydrofluoric acid, preferably per liter of aqueous hydrochloric acid solution.