Diffusionsverhalten von IPBC in wasserbasierten Beschichtungssystemen auf Holzfassaden

Abstract

Zusammenfassung Wasserbasierte Beschichtungssysteme auf Holzbauteilen sind einem verstärkten Befall durch Schimmel-und Bläuepilze ausgesetzt. Durch einen gezielten Einsatz von Bioziden ist es möglich, einen Befall auf und unter der Beschichtung zu kontrollieren. Jodpropinyl-N-butylcarbamat (IPBC) ist eines der wichtigsten Biozide für den Filmschutz von wasserbasierten Systemen in Europa. In der vorliegenden Arbeit wurde das Diffusionsverhalten von IPBC untersucht. Dabei wurde festgestellt, dass eine Diffusion des IPBC aus der Grundierung in die Deckschicht erfolgt. Die Verteilung des Wirkstoffes in der Deckschicht ist relativ gleichmässig. Die Eindringung in das Holzsubstrat (Fichte) ist mit 250 µm sehr gering und die nachgewiesene Wirkstoffmenge in diesem Bereich variiert deutlich. Das Diffusionsverhalten von IPBC ist an einen Wasserdampfstrom und ein notwendiges Konzentrationsgefälle in der Beschichtung gekoppelt. Durch Bewitterungsversuche wurde nachgewiesen, dass bereits nach dreimonatiger Bewitterung nur noch 30% IPBC in der Deckschicht nachgewiesen werden konnten. Diffusion behavior of IPBC in water based coatings on wooden facades Abstract Water based coating systems for wood are more prone to infection and colonization by mould and blue stain

Penetration of 3-iodo-2-propynyl butylcarbamate (IPBC) in coniferous wood pre-treated with Physisporinus vitreus

“…For practical purposes, it is advisable to use concentrations of approximately 0.7% IPBC in the primer to reach the required quality standards. 2 The results of the biological investigations show a number of interesting phenomena. In sapwood specimens of Scots pine, pre-treatment with P. vitreus resulted in an increase in blue-stain intensity.…”

“…Studies have also revealed that after 3 months exposure to natural weathering the total amount of IPBC in the paint is reduced by approximately 70% by leaching. 2 In general, water-based formulations penetrate poorly into Norway spruce because aspiration of the bordered pits results in low permeability. Recently, pre-treatment of wood with the white-rot fungus Physisporinus vitreus was proposed to increase permeability.…”

“…Recent studies indicate that effective protection against microbial colonization of the wood or the topcoat is only possible with the use of biocides. [1][2][3] Environmental legislation in North America and the European Union is driving the move to water-based coatings and away from solvent-based products. Although solvent-based preservatives penetrate wood more easily, water-based acrylic and hybrid systems are widely used and wellestablished wood protection products.…”

Functionalization of halloysite nanotubes by enlargement and layer-by-layer assembly for controlled release of the fungicide iodopropynyl butylcarbamate

“…However, IPBC is not chemically bonded to the bamboo during service process, which may be leached out from treated bamboo in many cases, resulting in short-term anti-fungal purposes and be toxic to ecosystem. 3,[10][11][12] It has been reported that IPBC only slightly penetrates wood with a inhomogeneous distribution and the amount of IPBC is reduced by approximately 70% by leaching aer 3 months exposure to natural weathering. 3 Thus, it is important to develop a delivery methodology to gain control over the release prole of the IPBC, as well as reducing the total amount of active agent needed in bamboo protection applications and minimizing the cumulative release to the environment.…”

“…3,[10][11][12] It has been reported that IPBC only slightly penetrates wood with a inhomogeneous distribution and the amount of IPBC is reduced by approximately 70% by leaching aer 3 months exposure to natural weathering. 3 Thus, it is important to develop a delivery methodology to gain control over the release prole of the IPBC, as well as reducing the total amount of active agent needed in bamboo protection applications and minimizing the cumulative release to the environment. 13 Many inhibitor encapsulation systems for reducing the release rate of IPBC have been studied, such as porous silica, polymer microcapsules, sol-gel nanoparticles and other methods.…”