RoHS Compliant, Non-Chrome Passivation of Galvanized …

1 Grace Chang, Charles Kerobo,MirjamHerrlich-Loos, Helmut WittelerProduct Development Surface FinishingRoHSCompliant, Non-Chrome PassivationofGalvanized Steel with LugalvanTMPassivationProductsLugalvanTMP assivation Application Post-Treatment LugalvanTMApplicationSkin-passingDrying< 50 CZincPlatingSteelCoil LugalvanTMPassivationhas been developed for spray + squeegee operation .. works on chemcoaters as wellTraditional Technology basedon Cr(VI) Formation of a Cr(III)-Zn(II)Oxlayer Self-repairing by Cr(VI) incorporationConversion layerCr(VI)-dopedZincCr(VI)Cr(VI) in electric appliances, July 2006, EU in cars, July 2007, be New Working Concept: PassivationLayer from is dipped into acidic aqueous dissolves in the acidic forms a metal salt with the polycarboxylate acting as of polycarboxylate allows self Layer FormationFormation of a uniform film 123 Reaction of the passivationwith adhering ZnO/ZnCO3 Untreated zinc.

2 Structure originating from adhering ZnO/ZnCO3 LugalvanTMPassivation Organic conversion layer No heavy metals No fluoride VOC- free , no organic solvents Aqueous solution Excellent corrosion protection Self-repairing Proprietary BASF technologyLugalvanTMPassivation Application On Zinc, HDG or EG steel Squeegee rollers or coil coating application Drying Dries without heating Drying up to 180 C possible Proven on production line with PMT 40 C / 3 sec Coating weight < g/m2 Hydrophilic surface Compatible with organic coatingsLugalvanTMPassivation Function ZincZn-depletedLugalvanTMPassivationZinc -richSteelLugalvanTMPassivation Morphology ZnZn-richZn-depleted10 m Top view.

3 Surface has been scratched after exposition to salt spray Scanning electron microscopy with integrated EDXSelf-repair of LugalvanTMPassivationdeformationzincZn-r ichZn-depletedcontact with waterrepairSelf-repair of and after scratch in a polymeric passivationlayer before ..2 mSelf-repair of LugalvanTMPassivation-X-Cut Test (after 24 h salt spray test) -Commercial Cr(III) and FluorideBasedPassivationLugalvanTMPassiv ationLugalvanTMPassivation Benefits to Steel Makers9 Heavy metal free product: RoHScompliant and well positioned to meet future regulatory restrictions Reduced health hazards compared to Chromium based products Eliminate chromium-based waste disposal9No handling and exposure issues with hydrofluoric acid9 Improves equipment durability.

4 Minimized corrosion on production equipment9 Enhanced corrosion performance Superiorcorrosion protection in salt spray test, 48 to 96 h Excellent appearance achieved in trials Target reduction in number of claims and returnsLugalvanTMPassivation Benefits to Steel Companies sCustomers9 RoHSCompliant High Performing Non-Chrome ChemTreat9 Reliable supply of high quality steel: 9 Paintability Direct Powder Coating Complete Removal for High End Paint lines9 Sufficient Resistivity9 Positive feedback regarding formability and weldabilityLugalvanTMPassivation High Performance Conversion Coating One step No heavy metals, no fluoride No rinsing, no toxic waste No VOC Self repair Excellent corrosion protection Excellent lacquer adhesio