Method for pickling metallic surfaces by using alkoxylated alkynols

A process for pickling metallic surfaces comprising treating the metallic surface with an acidic aqueous formulation which comprises at least one acid, a pickling inhibitor and optionally further additives, wherein the aqueous formulation comprises at least the following components:

• (d) from 60 to 99.97% by weight of a mixture of water and at least one acid,
• (e) from 0.01 to 2% by weight of at least one alkyne alkoxylate of the formula
• HC≡C—CH2—O(—CH2—CHR1—O—)nH (I)
• or
• H(—O—CHR1—CH2—)n—O—CH2—C≡C—CH2—O(—CH2—CHR1—O—)nH, (II)
• where the radicals R1 in each case independently of one another are H or methyl and the indices n and n′, independently of one another, are from 1 to 10,
• (f) from 0.01 to 20% by weight of at least one surface-active substance, and
• (g) from 0.01 to 10% by weight of at least one water-soluble, at least bidentate, chelate-forming complexing agent comprising acidic groups and/or at least one water-soluble polymer comprising quatemized ammonium groups.

An acidic, aqueous composition for pickling metallic surfaces, which comprises at least one acid, a pickling inhibitor and optionally further additives, wherein the aqueous formulation comprises at least the following components:

• (a) from 60 to 99.97% by weight of a mixture of water and at least one acid,
• (b) from 0.01 to 2% by weight of at least one alkyne alkoxylate of the formula
• HC≡C—CH2—O(—CH2—CHR1—O—)nH (I)
• or
• H(—O—CHR1—CH2—)n—O—CH2—C≡C—CH2—O(—CH2—CHR1—O—)nH, (II)
• where the radicals R1 in each case independently of one another are H or methyl and the indices n and n′, independently of one another, are from 1 to 10,
• (c) from 0.01 to 20% by weight of at least one surface-active substance, and
• (d) from 0.01 to 10% by weight of at least one water-soluble, at least bidentate, chelate-forming complexing agent comprising acidic groups and/or at least one water-soluble polymer comprising quatemized ammonium groups.

A process for pickling metallic surfaces comprising treating the metallic surface with an acidic aqueous formulation which comprises at least one acid, a pickling inhibitor and optionally further additives, wherein the aqueous formulation comprises at least the following components:

• (h) from 60 to 99.97% by weight of a mixture of water and at least one acid,
• (i) from 0.01 to 2% by weight of at least one alkyne propoxylate of the formula
• HC≡C—CH2—O(—CH2—CH(CH3)—O—)nH (I)
• or
• H(—O—CH(CH3)—CH2—)n—O—CH2—C≡C—CH2—O(—CH2—CH(CH3)—O—)n′H, (II)
• where the indices n and n′ independently of one another are from 1 to 10,
• (j) from 0.01 to 10% by weight of at least one water-soluble, at least bidentate, chelate-forming complexing agent comprising acidic groups and/or at least one water-soluble polymer comprising quatemized ammonium groups.