Lugalvan® EDC from BASF is a transparent, cathodic electrodeposition coating with very high scratch resistance. This new transparent product for sealing metal surfaces differs from conventional electrodeposition coatings in that it is not pigmented, which makes it more versatile. Lugalvan® EDC forms a crystal-clear layer that protects metal from corrosion and prevents it from tarnishing. Because it is applied by electrophoretic deposition, this new product is particularly suited to the demands of electroplating companies. The main practical advantage of Lugalvan® EDC is that it consists of only one-component, which makes it easier to use than the conventional two-component on today’s market.
“In the past, chromate conversion coatings have regularly been applied to zinc-plated parts and fittings to protect them from corrosion. This is no longer possible, because the EU Directive 2002/95/EC on the restriction of the use of certain hazardous substances in electrical and electronic equipment that came into force on 1 July 2006 EU and the EU Directive 2000/53/EC on end-of-life vehicles that comes into force on 15 July 2007 prohibit the use of certain heavy metal compounds, including chromate”, explained Dr. Helmut Witteler, head of product development for metal surface treatment at BASF. The idea of coating metal parts instead of treating them with chromate is neither new nor particularly effective. “Conventional coatings protect metal surfaces well, but their coverage of sharp edges is insufficient and these remain virtually unprotected. Small parts with a complicated shape are particularly prone to corrosion”, said Dr. Witteler. The solution here is to use a cathodic electrodeposition coating, which is applied by means of a process that is similar to electroplating. The metal part to be coated is dipped in a tank containing Lugalvan® EDC and attached to the cathode. An electrical current is then applied, which causes a thin layer of polymer to be deposited on the substrate. The polymer layer forms a film of uniform thickness, even in nooks and crannies. The process automatically comes to a halt when the layer reaches a certain thickness, and the result is a very even coating applied to the whole surface of the substrate.
Cathodic electrodeposition coatings have been in use for a long time as base coats in automotive and appliances manufacturing. “The idea of using a cathodic electrodeposition coating as a transparent top coat, and not just as a base coat, is relatively new” said Dr. Frank Dietsche, who is responsible for the development and application technology of Lugalvan® coatings at BASF. Lugalvan® EDC offers much more than preventing corrosion on functional metal components. For instance, it can also be used to prevent tarnishing on decorative brass fittings. “In this particular application, the coating has to do more than merely preventing corrosion, because the surface of the metal has to appear as if it has just been freshly polished and it has to be resistant to scratching as well as resistant to tarnishing”, said Dr. Dietsche. Typical examples are brass door handles and furniture fittings made from brass. These products no longer have to be polished in everyday use. Lugalvan® EDC is superior to conventional transparent coatings in this application, because cathodic electrodeposition coatings have very high resistance to abrasion.
Lugalvan® EDC contributes to sustainability and protecting the environment, because this new product makes it possible to prolong the working life of metal parts without having to resort to corrosion protection methods that employ heavy metals. Lugalvan® EDC is a very useful addition to the range of surface treatment products supplied by BASF. Lugalvan® is a well known brand in the surface treatment industry for products that are used in zinc plating and finishing processes.