Release of biocides from hydrophobic facade coatings

Release of biocides from hydrophobic fa ade coatings: encapsulated vs. non-capsulated biocide systems. Due to driving rain biocidal active substances, which prevent or delay the overgrow of fa ades with algae and fungi, can be leached out of the facade coatings. For the past 10 years encapsulated active substances are increasingly used. During a one year field trial the leaching of the substances Terbutryn (2-Methylthio-4-tert-butylamino-1,3,5triazine), Diuron (DCMU, 3-(3,4-dichlorophenyl)-1,1-dimethylurea), IPBC (3-Iodoprop-2-ynyl-N-butylcarbamate), OIT (2-n-Octyl-isothiazolin- 3-one) and DCOIT (4, 5-Di-chloro-2-n-octyl-isothiazolin-3one) have been investigated in capsulated and non-capsulated form. It shows that a well adjusted rate of encapsulation of the active substances could significantly reduce the release (up to 85 % in case of Diuron) from highly hydrophobic fa ade coatings.