Aqueous alkaline cleaning composition.

摘要

An alkaline composition and method of cleaning aluminium surfaces is disclosed which avoids discoloring or tarnishing of the metal surface. The composition comprises a mixture of alkali metal metasilicate and a compound chosen from the group consisting of sodium carbonate, potassium carbonate, lithium carbonate, potassium orthophosphate and sodium orthophosphate and mixtures thereof, wherein the metasilicate salt is present in an effective amount up to about 3% by weight of the composition and wherein the pH ranges above about 12.0.