Inhibitor-containing acid cleaning compositions and processes
AssigneeAmchem Products, Inc.
InventorsJames D. Anderson, Sandra K. Seigle
Life of this patent
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Abstract
Acid cleaning compositions containing an inhibitor for cleaning metal surfaces, processes for cleaning metal surfaces therewith, and concentrates useful in forming the acid cleaning compositions. The present acid cleaning compositions contain an acid, a Mannich base, a thiourea, an alkyl trimethyl ammonium halide and/or an alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanol, and a nonionic surfactant which is a condensate of poly(oxyethylene) and poly(oxypropylene) groups.
Claims26
An aqueous acidic cleaning solution for cleaning acid soluble, water-insoluble deposits from metal surfaces comprising:
- (a) from about 5 to about 200 g/l of at least one metal cleaning acid;
- (b) from about 0.01 to about 9.5 g/l of at least one Mannich base;
- (c) from about 0.006 to about 5.8 g/l of at least one thiourea compound;
- (d) from about 0.008 to about 7.5 g/l of at least one surfactant which is a condensate of poly(oxyethylene) and poly(oxypropylene) groups;
- and
- (e) at least one of a surfactant selected from the group consisting of alkyl trimethyl ammonium halides and alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanols, said alkyl trimethyl ammonium halides being present in an amount from about 0.004 to about 4.1 g/l and said alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanols being present in an amount from about 0.002 to about 0.8 g/l, with the proviso that when the metal cleaning acid is other than glycolic acid, formic acid or a mixture of glycolic acid and formic acid, an alkyl trimethyl ammonium halide must be present.
A concentrated composition useful as an additive to form an aqueous acid metal cleaning bath comprising:
- (a) from about 0.006 to about 5.8 parts by weight of at least one thiourea compound;
- (b) from about 0.01 to about 9.5 parts by weight of at least one Mannich base;
- (c) from about 0.008 to about 7.5 parts by weight of at least one surfactant which is a condensate of poly(oxyethylene) and poly(oxypropylene) groups;
- and
- (d) from about 0.004 to about 4.1 parts by weight of
- (d) from about 0.004 to about 4.1 parts by weight of at least one alkyl trimethyl ammonium halide and/or from about 0.002 to about 0.8 parts by weight of an alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanol;
- and
- wherein the thiourea compound is present in at least about 100 g/l.
A process for cleaning a metal surface containing acid soluble, water-insoluble deposits thereon comprising contacting said metal surface with an aqueous acid cleaning solution comprising:
- (a) from about 5 to about 200 g/l of at least one metal cleaning acid;
- (b) from about 0.01 to about 9.5 g/l of at least one Mannich base;
- (c) from about 0.006 to about 5.8 g/l of at least one thiourea compound;
- (d) from about 0.008 to about 7.5 g/l of at least one surfactant which is a condensate of poly(oxyethylene) and poly(oxypropylene) groups;
- and
- (e) at least one of a surfactant selected from the group consisting of alkyl trimethyl ammonium halides and alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanols, said alkyl trimethyl ammonium halides being present in an amount from about 0.004 to about 4.1 g/l and said alkyl (C.sub.8 -C.sub.9) phenoxypolyethoxy ethanols being present in an amount from about 0.002 to about 0.8 g/l, with the proviso that when the metal cleaning acid is other than glycolic acid, formic acid or a mixture of glycolic acid and formic acid, an alkyl trimethyl ammonium halide must be present.
Dependencies are inferred from the claim text.