| Résumé : |
Model coatings with known composition were assessed for liquid water permeability both as single coat systems and combined as primers and topcoats to form regularly used coating systems - in total 38 different systems. The water permeability of the coatings, expressed as water absorption value, was measured by a method similar to the method that now is proposed as a European standard for the assessment of liquid water permeability. During artificial weathering, the samples were measured for a water absorption value, thus showing the change in water permeability as a function of weathering. The study has shown that an excess of surfactants in the alkyd emulsions has a negative effect on the coating's ability to exclude water from the test samples. A waterborne acrylic paint based on a dispersion of larger particle size (0.4 µm) showed a poor ability to exclude water compared to a similar paint based on smaller dispersion particles (0.1 µm). The alkyd emulsion paints, as single coats, showed high water absorption values compared to solventborne paints and acrylic paints. |
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Influence of coating system composition on moisture dynamic performance of coated wood in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 75, N° 938 (03/2003)
