Anticorrosive Coatings Joerg Sander 1 Introduction 1.1 Why corrosion-protective coatings 1.2 Literature 2 Corrosion protection coatings 2.1 Principles of function 2.1.1 Electrochemistry of corrosion inhibition 2.1.2 Metal oxide formation 2.1.3 Cathodic protection 2.1.4 Passivation and conversion coating 2.2 Design of organic coating systems 2.2.1 Diffusion barrier features humidity uptake and electrolyte permeation 2.2.2 Active pigments 2.3 Function of individual coating layers 2.4 Literature 3 Surface preparation 3.1 Industrial cleaning 3.1.1 Importance of cleaning process 3.1.2 Contaminants 3.1.3 Surface energy and tension 3.2 Mechanical cleaning 3.3 Chemical cleaning 3.3.1 Plasma and corona processes 3.3.2 Solvent cleaning 3.3.3 Chemistry of aqueous cleaners 3.3.3.1 Mechanism: alkalinity, saponification and metal dissolution 3.3.3.2 Ingredients of aqueous cleaners 3.3.3.2.1 General considerations 3.3.3.2.2 Surfactants 3.3.4 Physics of aqueous cleaning, bath life and rinsing 3.4 Literature 4 Organic coating materials 4.1 Ingredients of organic coating materials 4.2 Resins 4.2.1 Alkyd resins 4.2.1.1 Alkyd resins manufacturing process 4.2.1.2 Decay of alkyd resins 4.2.1.3 Composition of alkyd resins 4.2.1.4 Curing of alkyd resins 4.2.2 Chlorinated rubber 4.2.3 Polyvinyl chloride 4.2.4 Epoxy resins 4.2.4.1 Raw materials for epoxy resins 4.2.4.2 Manufacturing process for epoxy resins 4.2.4.3 Cross-linking of the epoxy resins 4.2.5 Epoxy esters 4.2.6 Acrylic resins
4.2.6.1 Manufacturing of acrylic resins 4.2.6.2 Thermoplastic and thermosetting acrylic resins 4.2.7 Polyurethanes 4.2.7.1 Reactivity of isocyanate group 4.2.7.2 Waterborne polyurethanes 4.2.7.3 Isocyanate free polyurethanes 4.2.8 Polyaspartics 4.2.8.1 Polyurea systems 4.2.8.2 Polyaspartic systems 4.2.9.1 Nomenclature of the silicon chemistry 4.2.9.2 Manufacturing of alkyl silicates 4.2.9.3 Reactions of alkyl silicates 4.2.10 Polysiloxanes 4.2.10.1 Reactions of siloxanes 4.2.10.2 Manufacturing of siloxanes 4.3 Pigments Introduction 4.3.1 Corrosion protection pigments 4.3.1.1 Lead and chromate pigments 4.3.1.1.1 Lead pigments 4.3.1.1.2 Chromate pigments 4.3.1.2 Phosphate based pigments 4.3.1.2.1. Zinc phosphate 4.3.1.2.2 Modified orthophosphates 4.3.1.2.3 Modified polyphosphates 4.3.1.3 Inorganic/organic synergies 4.3.1.4 Wide spectrum anticorrosives 4.3.1.5 Phosphites and phosphides 4.3.1.5.1 Zinc hydroxyphosphite 4.3.1.5.2 Iron phosphide 4.3.1.6 Borates 4.3.1.6.1 Barium metaborate 4.3.1.6.2 Zinc borate 4.3.1.6.3 Calcium borosilicate 4.3.1.7 Molybdates 4.3.1.8 Ion-exchange pigments 4.3.1.9 Zinc cyanamide 4.3.1.10 Hybrid anticorrosive inhibitors 4.3.2 Barrier pigments 4.3.2.1 Micaceous iron oxide 4.3.2.2 Aluminium flakes 4.3.2.3 Zinc flakes 4.3.3 Sacrificial pigments 4.3.3.1 Zinc dust 4.3.3.2 Magnesium 4.3.4 Colouring agent 4.3.4.1 White pigment, titanium dioxide 4.3.4.2 Red pigments 4.3.4.3 Yellow pigments 4.3.4.4 Green pigments 4.3.4.5 Blue pigments 4.3.4.6 Black pigments 4.4 Extender pigments 4.4.1 Carbonates 4.4.2 Sulphates
4.4.3 Silicas 4.4.4 Silicates 4.4.4.1 Talc 4.4.4.2 Kaolin 4.4.4.3 Wollastonite 4.4.4.4 Mica 4.5 Other additives 4.6 Solvents 4.7 Raw materials for powder coatings 4.8 Literature 5 Film formation 5.1 Physical drying 5.2 Chemical curing 5.2.1 Thermal cross-linking: chemistry, mechanism, imparted properties 5.2.2 Radiation curing 5.2.2.1 Chemical principles and intrinsic properties 5.2.2.2 Applications 5.2.2.3 Equipment 5.3 Literature 6 Mechanism of protection and properties of organic coatings 6.1 Measurement of physical properties and influence 6.2 Dry film thickness 6.3 Adhesiveness 6.3.1 Role of adhesion and factors of influence 6.3.2 Measurement of adhesion and elasticity 6.3.2.1 Industrial methods 6.3.2.2 Laboratory methods 6.4 Permeation through organic coatings 6.5 Corrosion protective performance 6.5.1 Titanium and zirconium fluoro complex based pretreatments 6.5.2 Weldable corrosion protection primer for automotive sheet 6.5.3 Thermally curing 2-in-1 primer-pretreatment 6.5.4 Chromous based pretreatments chromiting 6.5.5 Active pigments, ion exchangers and scavengers 6.5.6 UV-curable primer-pretreatment 6.6 Degradation and ageing 6.6.1 Weathering 6.6.2 Electrochemical degradation 6.6.2.1 Cathodic disbonding: oxygen reduction 6.6.2.2 Anodic disbonding: filiform corrosion 6.7 Literature 7 Testing of organic coatings 7.1 Performance testing 7.2 Accelerated corrosion tests 7.2.1 Overview 7.2.2 Constant climate tests 7.2.2.1 Salt spray 7.2.2.2 Constant climate, humidity 7.2.2.3 Filiform corrosion 7.2.2.4 Condensation 7.2.2.5 Boiling, water soak
7.2.3 Cyclic climate tests 7.2.3.1 Cyclic humidity 7.2.3.2 Prohesion 7.2.3.3 VDA test 7.2.3.4 UV test, weathering 7.3 Electrochemical testing 7.3.1. General remarks 7.3.2. Electrochemical potential 7.3.2.1 Standard potential 7.3.2.2 Cyclovoltammetry 7.3.3 Electrochemical impedance spectroscopy 7.3.4. Electrochemical techniques with high spatial resolution 7.3.4.1 Scanning vibrating electrode 7.3.4.2 Height-regulated Scanning Kelvin Probe 7.3.4.2.1 General technique 7.3.4.2.2 Blister test 7.4 Outdoor exposure tests 7.5 Literature 8 Chemical conversion treatment 8.1 Substrates 8.2 Chemicals for pretreatment 8.2.1 General remarks 8.2.2 Alkaline passivation 8.2.3 Phosphating 8.2.3.1 Iron phosphating 8.2.3.2 Zinc phosphating 8.2.4 Chromating 8.2.5 Anodising of aluminium 8.2.6 Chromiting 8.2.7 Chromium-free pretreatment 8.2.7.1 Titanium and zirconium fluoro-complex technology 8.2.7.2 Other chromium-free pretreatments 8.2.8 Hybrid pretreatment coatings 8.2.8.1 Silane/siloxane coatings 8.2.8.2 Combined thermal processes for primer-pretreatment 8.2.9 Surface preparation of other substrates copper alloys, white metal, magnesium, stainless steel 8.2.10 Environmental considerations 8.3 Application of pretreatments 8.3.1 Immersion and Spray Treatment 8.3.2 Pretreatment application for coil: spray/squeeze, spray-cell, roll-coating 8.4 Literat 9 Organic coatings for maintenance 9.1 Surface tolerant coatings 9.1.1 General considerations 9.1.2 Surface tolerant coating materials 9.2 Organic coatings on residual rust and old coatings 9.3 Literature 10 New corrosion protection concepts 10.1 Thin films
10.1.1 Self-assembling monolayers 10.1.2 Conducting polymers 10.1.3 Biopolymers 10.2 Nanomaterials 10.2.1 Nanocomposites 10.2.2 Sol-gel derived ceramic and hybrid coatings 10.3 Self-healing coatings 10.3.1 Self-repairing polymer films 10.3.2 Inhibitor release 10.4 Conclusions 10.5 Literature 11 Standards and guidelines 11.1 General information 11.2 General norms 11.2.1 Norms on mechanical testing of organically coated metallic work pieces 11.2.2 Norms on corrosion testing of organically coated metallic work pieces 11.3 Selected European legislation on environmental protection 11.4 Literature Authors Index