European Coatings Tech Files The Mission: A single book covering the practical and scientific basics underpinning the strategic formulation of modern paint and coatings systems – from physicochemical concepts to the recipes themselves. This book explains and elaborates in some depth on the key principles of coatings formulation. Indispens- Bodo Müller | Ulrich Poth able for formulators. Coatings Formulation The Audience: Trainees, students and newcomers to the profes- sion who are seeking to acquire a solid grounding in coatings formulation, along with experienced formulators wishing to 2nd Revised Edition deepen, extend or refresh their knowledge. A knowledge of chemistry and basic knowledge of binders, pigments and addi- tives are required. B The Value: Coatings formulation explained step by step. The Uo book opens with a look at the composition of coatings, placing ld r Rückenstärke bei special emphasis on the base binder in each type. Advice on ico hM 180 Seiten 18 mm specific formulations is then given before formulation guidelines Pü are analysed. Throughout, the focus is on coatings formulation ol l and how to arrive at the final recipe. A special feature of the ther Bei 288 Seiten 25 MM book is its detailed index, which allows the reader to conduct • | A U targeted searches for specific aspects of coatings formulation. ulr ti oc mh oP to it vh e · C C o o a a t it ni n g g s s F oF o r mr m u u l al ta it oi no n ISBN 978-3-86630-872-5 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network Cover: Dr. Iwona Löhrke Bibliographische Information der Deutschen Bibliothek Die Deutsche Bibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über http://dnb.ddb.de abrufbar. Bodo Müller, Ulrich Poth Coatings Formulation: An International Textbook, 2nd Revised Edition Hanover: Vincentz Network, 2011 EuropEan Coatings tECh filEs ISBN ISBN 978-3-86630-891-6 © 2011 Vincentz Network GmbH & Co. KG, Hanover Vincentz Network, P.O. Box 6247, 30062 Hanover, Germany This work is copyrighted, including the individual contributions and figures. Any usage outside the strict limits of copyright law without the consent of the publisher is prohibited and punishable by law. This especially pertains to reproduction, translation, microfilming and the storage and processing in electronic systems. The information on formulations is based on testing performed to the best of our knowledge. The appearance of commercial names, product designations and trade names in this book should not be taken as an indication that these can be used at will by anybody. They are often registered names which can only be used under certain conditions. Please ask for our book catalogue Vincentz Network, Plathnerstr. 4c, 30175 Hanover, Germany T +49 511 9910-033, F +49 511 9910-029 [email protected], www.european-coatings.com Layout: Vincentz Network, Hanover, Germany Printed by Quensen Druck + Verlag GmbH &Co. KG, Hildesheim, Germany ISBN ISBN 978-3-86630-891-6 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network EuropEan Coatings tECh filEs Bodo Müller | Ulrich Poth Coatings Formulation An international textbook 2nd revised edition Bodo Müller, Ulrich Poth: Coatings Formulation © Copyright 2011 by Vincentz Network, Hanover, Germany ISBN: 978-3-86630-891-6 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network Natural products for sustainability Decorative Coatings Industrial Coatings & Inks Omyacarb®, Omyabrite®& Omyafl ow® Omyacoat® & Calcigloss® Omyabond® & Omyacarb® Omyapearl™, Inducarb® & Carolith® Sealants & Adhesives Plasters & Joint Fillers Innovative. Reliable. Sustainable. Omya offers a broad portfolio of calcium carbonate and distribution products together with extensive technical support – worldwide. One single contact to our global distribu- tion network is enough to purchase our products and our partners‘ material. Profi t from our sustainable solutions for virtually any of your applications. We strive for continuous innovation, anticipating your needs of tomorrow. Omya International AG | P.O. Box 335 | 4665 Oftringen | Switzerland | www.omya.com omya.com This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network Preface The authors were not surprised by the success of the first edition, as there had been no comparable reference book on the market that provided detailed explanations of recipes and formulations. Although guide formulations abound, meaningful and informed selections accompanied by notes and evaluations are in short supply. The authors have therefore gladly taken on the task of revising and updating the first edition. To this end, they have replaced outdated guide formulations, eliminated errors and added several new figures. Developing paint recipes or paint formulations is an important part of paint and coatings technology. Unfortunately, paint recipes are listed in very few publications because they are closely guarded secrets of the paint and coatings industry. While starting formulations are available from the manufacturers of raw materials, they cannot be used for a textbook without careful selection and revision beforehand. This book will teach paint formulation in two steps. Each chapter will first describe the chemical composition of and, especially, the binders for the type of paint presented. This will then be followed by formulation advice and an analysis of existing recipes (e.g. starting formulations). This analysis consists in calculating the important characteristic values of coatings, such as the pigment/binder ratio, pigment volume concentration and, as neces- sary, the hardener addition level. Finally, examples of how to develop a real-life paint for- mulation are provided in the case of the most important types of coatings. All calculations based on recipes and formulations are worked through step by step and should therefore be intelligible to beginners, as well. The skills acquired in dealing with these recipes can also be employed in other applications, such as adhesives and sealants. This book focuses on the paint formulation itself, and how to arrive at it. Of the many various paint and coating systems available, the selection provided in this textbook features the most important types. The formulations have been developed mostly from starting formulations or patent examples and cannot be used to produce paints without further ado. Patent restrictions or registered trade marks (™ or ®) are not mentioned expli- citly. Furthermore, it should be noted that product and trade names may change as a result of mergers and acquisitions. Nonetheless, most of the raw materials described herein or their equivalents should be available worldwide. This textbook seeks to familiarize laboratory assistants, engineers and chemists with the practice of formulating paints. It presupposes a basic knowledge of chemistry, binders, pigments and additives. It will also serve as a reference work for all readers interested in paints and coatings. Our thanks to Dr. Jürgen Kraut for kindly providing scanning electron micrographs for use herein, and to Ray Brown for polishing the text. Esslingen and Münster, Germany in February 2011 Bodo Müller Ulrich Poth [email protected] [email protected] Bodo Müller, Ulrich Poth: Coatings Formulation © Copyright 2011 by Vincentz Network, Hanover, Germany ISBN: 978-3-86630-891-6 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network Exclusion of liability It should be noted that this book reflect the authors’ personal views, based upon their own knowledge. This does not absolve readers of the responsibility of performing their own tests with respect to the uses and applications of various processes or products described herein, and/or of obtaining additional advices regarding the same. Any liability of the authors is excluded to the extent permitted by law, subject to all legal interpretations. POWDER COATING The Plasmec TRR model is the most successfully system for the Premixing and metallic Blending used by the principal producers of Powder coatings worldwide. PLAS MEC s.r.l. - Plastic Technology Via Europa, 79 - 21015 LONATE POZTZhOisL isO a ( VdAed) i-c IaTtAeLdY s i-n gTelel.- u+s3e9r .c0o3p3y1 o.3f0 a1n6 e4b8o (or.ka.. ) - [email protected] - www.plasmec.it Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network Contents 7 Contents Part I Basics 1 Introduction ........................................................................................ 17 1.1 Preliminary remarks .............................................................................................. 17 1.2 Comments on environmental protection ............................................................ 17 1.3 Paints and coatings as high-tech products ........................................................ 19 1.4 Definitions ................................................................................................................. 20 1.5 Coatings ..................................................................................................................... 21 1.5.1 Solidification of paints ............................................................................................ 21 1.5.2 Phase boundaries in coatings ............................................................................... 24 1.6 Adhesion .................................................................................................................... 25 1.6.1 Wetting of substrates .............................................................................................. 25 1.6.2 Adhesion forces and mechanisms ........................................................................ 29 1.6.3 Adhesion promoters/adhesion-promoting layers .............................................. 34 1.6.3.1 Silane adhesion promoters ..................................................................................... 34 1.6.3.2 Thin polymeric adhesive layers ............................................................................ 35 1.6.4 Corrosion inhibitors, anticorrosive pigments, corrosion protection additives 36 1.7 References.................................................................................................................. 39 2 Pigment dispersions ........................................................................... 40 POWDER COATING 2.1 Fundamentals of disperse systems ...................................................................... 40 2.2 Stabilization of dispersions .................................................................................... 43 2.2.1 Electrostatic stabilization ....................................................................................... 45 The Plasmec TRR model is the most successfully system for the Premixing 2.2.2 Steric stabilization ................................................................................................... 47 and metallic Blending used by the principal producers of 2.3 Wetting and dispersing agents ............................................................................. 48 2.3.1 Dispersing agents .................................................................................................... 48 Powder coatings worldwide. 2.3.2 W etting agents (surfactants) ................................................................................. 52 2.4 Wetting of pigments ................................................................................................ 57 2.5 References.................................................................................................................. 59 3 Paint formulation ................................................................................ 60 3.1 Ratio of binder to solid particles ........................................................................... 61 3.1.1 Pigment/binder ratio and pigment volume concentration ............................. 61 3.1.2 Oil adsorption value................................................................................................. 63 3.2 Influence of pigments on the properties of coatings ....................................... 65 3.3 Development of paint formulations ........................................................................ 66 3.4 Multi-coat systems ................................................................................................... 70 3.5 References.................................................................................................................. 72 Bodo Müller, Ulrich Poth: Coatings Formulation © Copyright 2011 by Vincentz Network, Hanover, Germany ISBN: 978-3-86630-891-6 PLAS MEC s.r.l. - Plastic Technology Via Europa, 79 - 21015 LONATE POZZOLO (VA) - ITALY - Tel. +39.0331.301648 (r.a.) - [email protected] - www.plasmec.it This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network 8 Contents Part II Solvent-borne paints 1 Paints that form films at ambient temperature ................................ 75 1.1 Physically drying paints ........................................................................................ 75 1.1.1 Paints based on cellulose nitrate .......................................................................... 76 1.1.1.1 Structure and properties of cellulose nitrate..................................................... 76 1.1.1.2 Combination partners for cellulose nitrate ........................................................ 78 1.1.1.3 Applications of cellulose nitrate paints ............................................................... 80 1.1.2 Physically drying paints based on acrylic resins ............................................ 82 1.1.3 Paints based on rubber modifications ................................................................. 82 1.1.3.1 Structure and properties of rubber modifications ............................................ 82 1.1.3.2 Applications of rubber modifications .................................................................. 83 1.2 Oxidative-cure paints ............................................................................................. 85 1.2.1 Oxidative-cure reactions ........................................................................................ 85 1.2.2 Binders for oxidative curing .................................................................................. 87 1.2.3 Siccatives and anti-skinning additives ............................................................... 89 1.2.4 Oil varnishes ............................................................................................................. 91 1.2.5 Alkyd resin paints ................................................................................................... 91 1.2.6 Paints based on epoxy ester resins ...................................................................... 96 1.3 Two-component systems......................................................................................... 98 1.3.1 Two-component polyurethane paints .................................................................. 98 1.3.1.1 Reactions of isocyanates ......................................................................................... 98 1.3.1.2 Isocyanate crosslinkers (hardeners for two-component polyurethanes) .... 99 1.3.1.3 Hydroxyl resins for two-component polyurethane systems .......................... 103 1.3.1.4 Catalysts and accelerators for two-component polyurethane paints ........... 106 1.3.1.5 Development of formulations for two-component polyurethane paints ...... 106 1.3.2 Two-components epoxy paints .............................................................................. 112 1.3.2.1 Base component: epoxy resins .............................................................................. 112 1.3.2.2 Hardeners: polyamines and derivatives ............................................................. 114 1.3.2.3 Formulation of two-components epoxy paints .................................................. 118 1.4 References.................................................................................................................. 123 2 Stoving enamels .................................................................................. 125 2.1 Definitions ................................................................................................................. 125 2.2 Stoving enamels based on amino resins ............................................................ 125 2.2.1 Chemical structure of amino resins .................................................................... 125 2.2.2 Types and properties of amino resins ................................................................. 127 2.2.3 Combination partners for amino resins .............................................................. 131 2.2.3.1 Alkyd resins .............................................................................................................. 131 2.2.3.3 Saturated polyester .................................................................................................. 133 2.2.3.3 Acrylic resins crosslinked by amino resins ...................................................... 134 2.2.3.4 Comparison of alkyd resins, polyesters and acrylic resins in stoving enamels 134 2.2.4 Crosslinking reactions ............................................................................................ 135 2.2.5 Catalysis of crosslinking reactions ...................................................................... 137 2.2.6 Formulation of stoving enamels based on amino resins ................................. 139 2.3 Stoving enamels based on thermosetting phenolic resins (resols) .............. 145 2.4 Stoving enamels based on blocked polyisocyanates ........................................ 147 2.4.1 Structure and properties of blocked polyisocyanates ..................................... 147 2.4.2 Combination partners for blocked polyisocyanates ......................................... 150 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network 10 Contents 2.4.3 Comparison of blocked polyisocyanates and amino resins in stoving enamels 151 2.4.4 Formulation of stoving enamels based on blocked polyisocyanates ............ 152 2.5 Other solvent-borne stoving enamels .................................................................. 155 2.5.1 Self-crosslinking acrylic resins ............................................................................ 155 2.5.2 Self-crosslinking polyesters .................................................................................. 155 2.5.3 Reactions between epoxy groups and acid derivatives ................................... 156 A new generation of even more 2.5.4 Siloxanes in stoving enamels ................................................................................ 156 2.6 Fastness to re-coating ............................................................................................. 157 GREEN ULTRALUBE® wax additives 2.7 References.................................................................................................................. 159 HDPE wax based E-854 emulsion Part III Water-borne paints MD-2300/50 micro dispersion D-803 dispersion Comprising following key features like all ULTRALUBE® products: 1 Solubility and dispersibility of paint resins in water ....................... 163 VOC-free formaldehyde-free 1.1 Exceptional position of water as a paint solvent ............................................... 163 heavy-metal free and additional: 1.2 Distributions of polymers in water ...................................................................... 164 APEO-free amine-free 1.3 Dispersions and emulsions of paint resins and polymers .............................. 165 Used raw materials fulfi lling several legislative requirements 1.3.1 Primary dispersions ................................................................................................ 165 for food contact approval like: FDA 175.300, BfR XIV and XXXVI, Swiss Ordinance, plastics directive and much more. 1.3.2 Emulsions of liquid paint resins ........................................................................... 168 1.3.3 Secondary dispersions ............................................................................................ 169 1.3.3.1 Acrylate secondary dispersions ............................................................................ 169 keim additec surface GmbH Hugo-Wagener-Straße 9 55481 Kirchberg/Hunsrück Germany 1.3.3.2 Polyurethane secondary dispersions .................................................................. 169 Phone +49 (0) 6763/9333- 0 Fax +49 (0) 6763/9333- 30 [email protected] 1.4 Aqueous solutions of paint resins ........................................................................ 171 www.keim-additec.de 1.4.1 Water-solubility of paint resins ............................................................................ 171 1.4.2 Neutralizing agents ................................................................................................. 172 1.4.3 Cosolvents .................................................................................................................. 173 1.5 References.................................................................................................................. 175 2 Water-borne paints and coatings that dry/cure at ambient temperatures .............................................................................................. 176 2.1 Physically drying paints ........................................................................................ 176 Environmentally friendly SILCO additives 2.1.1 Film formation by primary dispersions .............................................................. 176 2.1.2 Latex gloss enamels ................................................................................................. 179 Example: Typical SILCO SPERSE dispersing additive 2.2 Façade coatings ....................................................................................................... 180 2.2.1 Latex paints ............................................................................................................... 181 fulfi lling european/international legislations (e.g. TSCA, REACH, RoHS) 2.2.2 Silicone resin paints ................................................................................................ 183 APEO-free 2.2.3 Silicate paints (two-components) ......................................................................... 185 zero-VOC content (<0,1%) 2.2.4 Latex silicate paints (one-component) ................................................................. 187 halogene-free 2.3 References.................................................................................................................. 189 heavy metal content <100 ppm (CONEG) silicone-free plasticizer-free 3 Water-borne paints that cure at ambient temperatures ................... 191 formaldehyde-free 3.1 Water-borne paints that cure oxidatively ........................................................... 191 Further SILCO specialty additives with similar 3.1.1 Water-borne paints based on alkyd resins ......................................................... 191 product profi le available. Please inquire. 3.1.2 Hybrid systems ......................................................................................................... 194 3.2 Two-component, water-borne systems ................................................................ 196 3.2.1 Two-component, water-borne polyurethane paints ......................................... 196 silcona GmbH & Co. KG Am Buchenring 22 D-55442 Stromberg/Hunsrück Germany 3.2.2 Water-borne two-components epoxy paints ...................................................... 200 Phone + 49 (0) 6724/602245 Fax + 49 (0) 6724/602375 [email protected] 3.3 References.................................................................................................................. 206 www.silcona.de This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network 12 Contents 4 Water-borne stoving enamels ............................................................. 207 4.1 Guidelines for water-borne stoving enamels ..................................................... 207 4.2 Water-borne stoving enamels based on amino resins ..................................... 208 4.3 Water-borne stoving enamels based on thermosetting phenolic resins ..... 217 4.4 Electrodeposition paints ......................................................................................... 219 4.4.1 Electrodeposition processes .................................................................................. 219 4.4.2 Anionic deposition paints ...................................................................................... 222 4.4.3 Cationic electrodeposition paints ......................................................................... 224 4.5 References ................................................................................................................ 230 Part IV Solvent-free coatings 1 Two-components systems ................................................................... 235 1.1 Two-components polyurethane coatings ............................................................ 235 1.2 Two-components epoxy coatings .......................................................................... 237 1.3 Coatings based on unsaturated polyester resins .............................................. 239 1.4 References.................................................................................................................. 241 2 Radiation curing ................................................................................. 242 2.1 Definitions ................................................................................................................. 242 2.2 UV curing .................................................................................................................. 242 2.2.1 Principles of UV curing ......................................................................................... 242 2.2.2 UV coating process .................................................................................................. 243 2.2.3 UV initiators and sensitizers ................................................................................. 245 2.2.4 Resins for UV coatings ........................................................................................... 248 2.2.5 Reactive diluents for UV coatings ........................................................................ 251 2.2.6 Properties and application of UV coatings ......................................................... 252 2.2.7 Typical UV coatings ................................................................................................ 253 2.3 Electron beam curing.............................................................................................. 254 2.4 References.................................................................................................................. 255 3 Powder coatings .................................................................................. 256 3.1 Development of powder coatings .......................................................................... 256 3.2 Production of powder coating materials and general properties .................. 256 3.3 Application of powder coatings ............................................................................. 259 3.3.1 Fluid bed sintering .................................................................................................. 259 3.3.2 Electrostatic spray application .............................................................................. 260 3.4 Composition of powder coatings and special properties ................................. 261 3.4.1 Thermoplastic powder coatings ............................................................................ 261 3.4.2 Crosslinkable powder coatings ............................................................................. 262 3.4.2.1 Powder coatings from epoxy resins ..................................................................... 262 3.4.2.2 Epoxy resin/polyester hybrid systems ................................................................ 266 3.4.2.3 Polyester powder coatings ..................................................................................... 268 3.4.2.3.1 Polyesters containing carboxyl groups ............................................................... 268 3.4.2.3.2 Polyesters containing hydroxyl groups .............................................................. 270 3.4.2.4 Acrylic resin powder coatings .............................................................................. 272 3.4.2.4.1 Structure and production of acrylic resins for powder coatings ................... 272 This is a dedicated single-user copy of an ebook. Copyright laws apply; it is prohibited to copy or distribute the ebook or any part hereof. ©2012 Vincentz Network