Accession Number : AD0692595

Title :   ANTI-FOULING PAINTS. I. THEORETICAL APPROACH TO LEACHING OF SOLUBLE PIGMENTS FROM INSOLUBLE PAINT VEHICLES,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Marson,F.

Report Date : 10 SEP 1968

Pagination or Media Count : 7

Abstract : A theoretical approach to the problem of how contact leaching anti-fouling paints work is discussed; a possible mechanism is selected and applied to an idealised model of a paint film. A precise mathematical treatment is then attempted of the relationship between the leaching rate, the physical properties, and if applicable the chemical properties of the envisaged paint film and its environment. A mechanism previously proposed has been examined by this method. An equation is derived for an idealised paint film relating the leaching rate to the physical properties of the paint film and the leachate. It is assumed that the rate of solution of a soluble pigment from an insoluble vehicle is dependent only on the physical properties of the paint film and the diffusion of the solvated pigment through the exhausted matrix and the diffusion layer of leachate in direct contact with the surface of the paint. An equation is derived for an idealised paint film which relates the leaching rate to some physical properties of the paint film and of the leachate. The equation is shown to predict qualitatively the effect of most variables known to affect the leaching of contact leaching paints. Some evidence is given to support the quantitative prediction of the relationship between the pigment volume content and the initial leaching rate, the effect of dissolved pigment in solution on the leaching rate, the increase in leaching rate for a given temperature increase, and the effect of velocity of flow past the surface of the paint film. This method of approach would appear to be applicable to mechanisms and models bearing a closer resemblance to practical anti-fouling paints. (Author)

Descriptors :   (*ANTIFOULING COATINGS, SOLUBILITY), PAINTS, DIFFUSION, OXIDES, COPPER COMPOUNDS, SURFACE PROPERTIES, AUSTRALIA

Subject Categories : Coatings, Colorants and Finishes

Distribution Statement : APPROVED FOR PUBLIC RELEASE