| US 7,468,158 B2 | ||
| Corrosion inhibitor for protecting metallic materials in strongly alkaline medium | ||
| Lutz Heuer, Dormagen (Germany); Stylianos Savakis, Köln (Germany); Helmut Diekmann, Burscheid (Germany); and Eberhard Zirngiebl, Köln (Germany) | ||
| Assigned to LANXESS Deutschland GmbH, Leverkusen (Germany) | ||
| Filed on Jan. 23, 2003, as Appl. No. 10/349,756. | ||
| Claims priority of application No. 102 03 329 (DE), filed on Jan. 29, 2002. | ||
| Prior Publication US 2003/0152479 A1, Aug. 14, 2003 | ||
| Int. Cl. C23F 11/06 (2006.01) | ||
| U.S. Cl. 422—13 [422/7] | 2 Claims |
| 1. A method of protecting metallic materials in chlorate ion containing, sodium hydoxide solutions comprising: reducing the
corrosive effects of the chlorate ions contacting the metallic materials by adding a polyamine to the chlorate ion containing,
sodium hydroxide solution having a sodium hydroxide concentration of 5 to 95% by weight, and wherein the polyamine is selected
from the group consisting of the reaction products of dichloroethane with ammonia and/or amines, or from the group consisting
of the reaction products of ethylene oxide with ammonia or amines, or
wherein the polyamine has one of the formulae (II) and (III) below:
Hp—N(CH2—CH2)q—[NHr—(CH2—CH2)s]n—NHt (II),
NH2—CH2—CH2—CH2—[NHr—(CH2—CH2—CH2)s]n—NH2 (III),
where
n is 0 or an integer from 1 to 300,
p, q, s and t are each 1 or 2, and
r is 0 or 1,
where the sum of the substituents on a nitrogen is three or
an anion, additionally present to balance the charge when a nitrogen is bound to 4 substituents, or
wherein the polyamine has the formula (IV) below:
 where v is H or an aminoalkyl radical.
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