Corrosion causes huge global cost
Corrosion generates immense costs throughout the world and poses a real problem for bridges, machines, and buildings, whether of metal, concrete, glass, or plastic; in all of these materials it is a serious problem. As long as eight years ago, DECHEMA, the Society for Chemical Engineering and Biotechnology, estimated annual global losses due to corrosion at an astounding 1.8 billion euros. However according to DECHEMA appropriate protective measures could save 25 to 30 percent of these costs, amounting to between 450 and 540 billion euros every year.
ALTERNATIVE AND SUSTAINABLE METHODS
Reducing VOC is a main requirement from the market, and in many countries there are also legislations restricting the use of VOC in coatings. The treatment with chromium (VI) is already prohibited in some application areas because chromate (CrVI) has been identified as a human carcinogen. Also other established surface processes like phosphate pre-treatment are under discussion, since aggressive media and chemicals with high environmental impact are used. Corrosion protection systems containing organic solvents are discussed as environmentally harmful and should be replaced by water-borne systems. In some cases there are alternatives available and promising candidates are water-borne silane systems. They are used as binder or component in corrosion protection formulations and are considered as forward-looking solutions.
Dynasylan® SIVO 140 for two pack zinc dust paints
The innovative water-borne silane formulations based on Dynasylan® SIVO 140 are designed for a better compatibility with additives and fillers. Such formulations can be applied with a different film thickness at the substrate. The curing time depends on the formulation (type and amount of fillers and additives used) and the applied wet film thickness.
The advantages of Dynasylan® SIVO 140 can be summarized as follows:
- Almost zero VOC
- Low temperature curing
- Low or higher film thicknesses are possible
- Improved heat resistance compared to organic binders
Dynasylan® SIVO 160 for blank corrosion protection of aluminum alloys and HDG steel
In some cases it is necessary to protect the blank aluminum surface against corrosion, which can happen in the presence of e.g. chloride. Water-borne silane systems based on Dynasylan® SIVO 160 can be used in such applications. Very thin layers in the range of 100 – 200 nm can prevent the corrosion of aluminum. In contrast to the current solutions employed in this area, the binder contains neither heavy metals nor fluorides, which are highly objectionable from an environmental viewpoint.
The benefits of Dynasylan® SIVO 160 at a glance:
- Almost VOC-free
- Excellent wetting effect
- High reactivity with aluminum surface
- Organofunctional group can react with subsequent topcoat
- High crosslinking density preventing water and chloride penetration