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US 3,960,735 AGranted
Corrosion-inhibited polyphosphate compositions
AssigneeEarly California Industries, Inc.
InventorKathleen P. Lacey
Life of this patent
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Abstract
The tendency of polyphosphate liquids to corrode aluminum is inhibited by incorporating into the liquid a minor effective amount of an iron cyanide blue, either ferric ferrocyanide or ferrous ferricyanide.
Claims8
A composition consisting essentially of
- a. ammonium polyphosphate liquid, and
- b. an iron cyanide blue,
- said iron cyanide blue being present in a minor amount effective to substantially reduce the corrosiveness of said composition to aluminum to less than or equal to 1 mil per year as determined by the "Uniform Corrosion" test set forth in Section 4.3.4 of the "Interim Specification" 5100-00302a (June 1972), entitled "Specification for Retardant, Forest Fire, Liquid Chemical, Unthickened for Aircraft or Ground Application," issued by the United States Department of Agriculture, Forest Service.
A process for preparing an ammonium polyphosphate liquid having reduced tendency to corrode aluminum, comprising incorporating into said ammonium polyphosphate liquid compounds which react in situ to form a minor effective amount of an iron cyanide blue.
Dependencies are inferred from the claim text.