Phosphonate-Free, Aqueous Pickling Compositions and Their Use
AssigneeChemetall GmbH
InventorsAnna Verena MOHR, Marcell SIX, Nawel Souad KHELFALLAH
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Abstract
Disclosed herein is a phosphonate-free, aqueous pickling composition having a pH value at 55° C. in the range from 5 to 9, and containing at least one copolymer, which is water-soluble or water-dispersible and selected from the group consisting of polyvinylpyrrolidones; the content of water being in the range from 95.0 wt.-% to 99.9 wt.-% based on the total weight of the composition. Further disclosed herein is a concentrate to produce such compositions, a pickling method for pickling metallic substrates making use of the compositions, a coating method for coating metallic substrates including the pickling method and a method of using the compositions for pickling metallic substrates.
Claims16
A phosphonate-free, aqueous pickling composition having a pH value at 55° C. in the range from 5 to 9, and containing at least one copolymer, which is water-soluble or water-dispersible and selected from the group consisting of polyvinylpyrrolidones;
- the content of water being in the range from 95.0 wt.-% to 99.9 wt.-% based on the total weight of the composition, wherein the polyvinylpyrrolidone is a random polymer polymerized from a mixture of vinyl pyrrolidone and vinyl acetate and optionally a further monoethylenically unsaturated monomer, wherein the molar ratio of vinyl acetate to vinyl pyrrolidone is from 30:70 to 70:30.
Dependencies are inferred from the claim text.