Influencia del tipo de fibra de refuerzo y del material formador de película en pinturas de terminación aplicadas sobre fondos anticorrosivos basados en zinc metálico

PEREYRA, ANDREA M.; ALFIERI, PAULA; GIUDICE, CARLOS. A

Fortaleza, Brasil

Congreso; Abraco Intercorr 2010. 30º Congresso Brasileiro de Corrosão; 2010

Abraco, Asociación Brasileña de Corrosión

The zinc-based coatings have better efficiency against metal corrosion in relation to other coatings types. However, these need in some cases a top coat either to confer the system a good finish or to give adequate protection against the aggressive action of the environment; in other cases, the top coat is also applied to confer to the film an increased surface hardness (transport industry, agricultural machinery, etc.). In this study, three systems with regard to film-forming material were selected; in all cases, the same tripigmented zinc-based metallic laminar epoxy-polyamide primer was used. For the finishing layer a pure acrylic resin, a vinyl and an alkyd resins were selected as binders; various fibrous reinforcement were used in the formulation of finishing coatings with hybrid structures to confer high stress and modulus of elasticity to the film (graphite, silicon nitride, glass or quartz). The results indicated that the hybrid structures with semiconductor fibers in their composition showed high dissolution of metallic zinc since those fibers would act as cathodes in galvanic cell; besides, in the case of susceptible binder to basic hydrolysis by the action of hydroxyl ions formed on semiconductor fiber, they had a degradation of their structure and the consequent loss of film properties.