Vapor phase corrosion inhibitor-dessiccant material

Abstract

A vapor phase corrosion inhibitor-desiccant formulation comprising silica gel granules coated with a finely divided anhydrous molybdate selected from the group consisting of anhydrous sodium molybdate, anhydrous ammonium dimolybdate, and anhydrous amine molybdates having the structural formula: ##STR1## wherein R.sub.1 is an aliphatic hydrocarbon having up to 7 carbon atoms, and wherein R.sub.2 is either hydrogen or an aliphatic hydrocarbon having up to 7 carbon atoms with these anhydrous molybdates being provided in admixture with sodium nitrite and benzotriazole. The composite formulations of the present invention have been found to be particularly desirable as a vapor phase corrosion inhibitor when in contact with the environs of metals susceptible to corrosion including, for example, iron, aluminum, copper, and alloys such as alloys of iron, copper, and the like. The vapor phase corrosion inhibitors appear to exhibit improved properties when utilized as a powdered coating upon granular silica gel. In a preferred embodiment, the amine-molybdate compounds are those amine-molybdates derived from dicyclohexylamine, 2-ethylhexylamine, and cyclohexylamine. When incorporated as a powdered coating upon silica gel granules, the amine-molybdates have vapor pressures which contribute to enhanced protection against corrosion, as well as a continued or ongoing availability of that protection. When provided in admixture with sodium nitrite and benzotriazole, these composite materials find particular applicability for extrusion with polyolefin films such as polyethylene and polypropylene, and with such films being capable of forming laminates with metallized second film layers.