CIDEPINT   05376
CENTRO DE INVESTIGACIONES EN TECNOLOGIA DE PINTURAS
Unidad Ejecutora - UE
artículos
Título:
Lanthanum-exchanged zeolite and clay as anticorrosive pigments for galvanized steel
Autor/es:
S. ROSELLI; N. BELLOTTI; C. DEYÁ; M. REVUELTA; B. DEL AMO; R. ROMAGNOLI
Revista:
JOURNAL OF RARE EARTHS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2014 vol. 32 p. 352 - 359
ISSN:
1002-0721
Resumen:
A wide variety of inhibitive pigments is now being offered as possible alternatives to chromate and lead compounds for painted metals protection. Unfortunately, the most wide spread of these substitute pigments, zinc phosphate, has, at present, raised some environmental concern because phosphate causes the eutrophication of water courses and zinc itself is toxic. The aim of this research was to study the anticorrosive performance of a mixture consisting of zinc phosphate, modified zeolite and clay (bentonite) in order to diminish phosphate content in paints. The zeolite and the clay were exchanged with La(III) ions, as inorganic green inhibitor. In the first step, the anticorrosion protection by La(III) ions in solution was assessed by electrochemical tests. In the second step, an epoxy-polyamide paint formulated with the pigment mixture applied on galvanized panels was studied by salt spray test and electrochemical noise measurements (ENM). The results showed that it was possible to replace part of the zinc phosphate content in the paint with the exchanged zeolite and the clay.