Excor Korrosionsforschung Gmbh

Frank Fassbender

Gerhard Hahn

Georg Reinhard

Peter Neitzel

Bianka Leitner

Gregor Wowsnick

Substance combinations are disclosed which include urea, at least one chitosan biopolymer having a degree of deacetylation of from 70% to 95%, and at least one dicarboxylic acid in aqueous solution. The substance combinations are useful as primers for the pretreating substrate surfaces, in particular flat or sheet-form, non-metallic substrates, which are provided as carrier materials for vapor phase corrosion inhibitors, to enable subsequent fixing to those substrate surfaces of vapor phase corrosion inhibitors from an aqueous or aqueous-alcoholic solution containing them. Certain embodiments of the substance combination include 0.1-2% by weight chitosan biopolymer, 10-25% by weight urea, and 0.5-2.5% by weight of a dicarboxylic acid, completely dissolved in deionized water. Yet a further, related aspect of the invention relates to a carrier material for vapor phase corrosion inhibitors, wherein the vapor phase corrosion inhibitors are fixed to a substrate surface pretreated with the substance combination.

Compositions and methods for pretreating substrates for the subsequent fixing of vapor phase corrosion inhibitors

Disclosed are combinations of substances for stimulus-dependent release of vapor phase corrosion inhibitors including: (1) a matrix; (2) at least one symmetrical or asymmetrical carboxylic acid anhydride of at least one first carboxylic acid, (3) at least one salt of at least one second, highly volatile corrosion-inhibiting carboxylic acid, wherein (2) is a non-volatile anhydride or an anhydride with low volatility with a vapor pressure of preferably lower than 1&#xd7;10Pa at 25&#xb0; C. The combination is effective to release the first carboxylic acid(s) by hydrolysis of the anhydride and release the second carboxylic acid(s) of (3) from its salt by proton transfer from first carboxylic acid(s), so that the second carboxylic acid(s) is/are present as a corrosion inhibitor in the vapor phase. Also disclosed are methods for producing and using the combinations for corrosion protection of conventional industrially used metals, in, e.g., packing, storage and transport processes.

Compositions and methods for releasing vapor phase corrosion inhibitors

The invention relates to corrosion-inhibiting substance combinations capable of evaporation or sublimation, containing at least: (1) substituted 1,4-benzoquinone, (2) aromatic or alicyclic substituted carbamate, (3) polysubstituted phenol, and (4) monosubstituted pyrimidine. These combinations preferably include 1-30 mass % of component (1), 5-40 mass % of component (2), 2-20 mass % of component (3), and 0.5-10 mass % of component (4), each relating to the total quantity of the substance combination. The components can be provided mixed together or dispersed in water, or also pre-mixed in solubilizer that can be mixed with mineral oils and synthetic oils, preferably an arylalkylether alcohol such as, e.g., phenoxyethanol. Such substance combinations can be used as vapor phase corrosion inhibitors in packaging or during storage in closed spaces for protecting common commodity metals such as iron, chrome, nickel, aluminum, copper and their alloys as well as galvanized steels, against atmospheric corrosion.

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Dresden, Germany

Frank Fassbender