摘要 |
A metal article is coated with a thick liquid film of a corrosion inhibiting, substantially anhydrous composition having a pH in the range from 6 but less than 8, containing less than 10 wt % of an ester of a vegetable oil and less than 2 wt % of a known corrosion inhibitor ("CI") which is required to be at least partially soluble in a solvent which is driven off. The resulting solvent-free ester has a high concentration of CI and coats the surface of a metal part with a thin, essentially invisible, protective oily film which is less than 15 mum thick containing from 10 to 50 wt % of the CI homogeneously dispersed in the film. Depending upon the choice of CI in the protective oily film it may function only as a contact corrosion inhibitor ("CCI"), or the film-coated metal article may function as a vapor corrosion inhibitor ("VCI"), effective VCI over a period from about 4 weeks to 1 year. Such a metal article functions as a VCI, and the article is also protected by the film as a CCI. Whether the article functions as a VCI or the protective oily film functions as a CCI, or both, the CI in the oily film unexpectedly resists depletion in a Water Fog Test over a period of a week.
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