Lambourne / Strivens Paint and Surface Coatings

Theory and Practice
2. Auflage 1999
ISBN: 978-1-85573-700-6
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 800 Seiten

Reihe: Woodhead Publishing Series in Metals and Surface Engineering

This second edition of an established and well received book has been carefully revised, in many instances by the original authors, and enlarged by the addition of two completely new chapters. These deal with the use of computers in the paint industry and with the increasingly important subject of health and safety. The chapter on pigments has also been re-written by an author new to this edition.It was the editor's intention in the first edition to provide science graduates entering the paint industry with a bridge between academia and the applied science and technology of paints. The great strength and appeal of this book remains that it deals with the technology of paints and surface coatings while also providing a basic understanding of the chemistry and physics of coatings. - Extensive revision of first edition - New chapter on computers and modelling - New chapter on health and safety

Autoren/Hrsg.

Lambourne, R.

Strivens, T A

Inhaltsverzeichnis

1;Front Cover;1
2;Paint and Surface Coatings: Theory and Practice;2
3;Copyright Page;3
4;Table of Contents;4
5;List of contributors;11
6;Preface to first edition;12
7;Preface to second edition;14
8;Chapter 1. Paint composition and applications — a general introduction;16
8.1;1.1 A short history of paint;16
8.2;1.2 Paint or surface coating?;18
8.3;1.3 The components of paint;20
8.4;1.4 Paint making;31
8.5;1.5 Methods of application;32
8.6;1.6 Paint markets;33
9;Chapter 2. Organic film formers;34
9.1;2.1 Introduction;34
9.2;2.2 Natural polymers;38
9.3;2.3 Oils and fatty acids;39
9.4;2.4 Oleoresinous media;45
9.5;2.5 Alkyd resins;46
9.6;2.6 Polyester resins;55
9.7;2.7 Acrylic polymers;59
9.8;2.8 Emulsion and dispersion polymers;69
9.9;2.9 Non-aqueous dispersion polymerization;75
9.10;2.10 Amino resins;77
9.11;2.11 Phenol formaldehyde resins;81
9.12;2.12 Epoxy resins;82
9.13;2.13 Isocyanates;85
9.14;2.14 Silicone resins;89
9.15;2.15 Vinyl resins;90
9.16;2.16 Water-borne systems;91
9.17;2.17 Resins for electrodeposition;95
9.18;2.18 High solids coatings;97
9.19;2.19 Radiation-curing polymers;99
9.20;2.20 Powder-coating compositions;100
9.21;2.21 Resin manufacture;101
9.22;Bibliography;102
9.23;References;102
10;Chapter 3. Pigments for paint;106
10.1;3.1 Introduction;106
10.2;3.2 Definition;106
10.3;3.3 Required qualities of pigments;107
10.4;3.4 Pigment classification;120
10.5;3.5 Pigment nomenclature;123
10.6;3.6 Further types of pigments and terms used;124
10.7;3.7 Particulate nature of pigments and the dispersion process;129
10.8;3.8 Manufacture of pigments;134
10.9;3.9 Toxicity and the environment;139
10.10;3.10 Choosing pigments;140
10.11;3.11 Physical forms of pigment;142
10.12;3.12 Notes on families of pigments;144
10.13;References;180
11;Chapter 4. Solvents, thinners, and diluents;181
11.1;4.1 Introduction;181
11.2;4.2 The market for solvents in the paint industry;182
11.3;4.3 Solvent power or solvency;183
11.4;4.4 Solvent effects on viscosity;193
11.5;4.5 Evaporation of solvents from coatings;194
11.6;4.6 Flashpoint;195
11.7;4.7 Toxicity and environmental pollution;196
11.8;Acknowledgement;198
11.9;References;198
12;Chapter 5. Additives for paint;200
12.1;5.1 Introduction;200
12.2;5.2 Anti-corrosive pigment enhancers;201
12.3;5.3 Antifoams;201
12.4;5.4 Antisettling agents;202
12.5;5.5 Antiskinning agents;203
12.6;5.6 Can-corrosion inhibitors;203
12.7;5.7 Dehydrators/antigassing additives;204
12.8;5.8 Dispersion aids;204
12.9;5.9 Driers;205
12.10;5.10 Electrical properties;207
12.11;5.11 Flash corrosion inhibitors;207
12.12;5.12 Floating and flooding additives;207
12.13;5.13 In-can preservatives;208
12.14;5.14 In-film preservatives;209
12.15;5.15 Insecticidal additives;209
12.16;5.16 Optical whiteners;210
12.17;5.17 Reodorants;210
12.18;5.18 Ultraviolet absorbers;210
12.19;5.19 Additive suppliers;211
13;Chapter 6. The physical chemistry of dispersion;213
13.1;6.1 Introduction;213
13.2;6.2 Immersion and wetting of the pigment;214
13.3;6.3 Deagglomeration (mechanical breakdown of agglomerates);218
13.4;6.4 Dispersion — colloid stabilization;220
13.5;6.5 Steric (or polymer) stabilization;234
13.6;6.6 Depletion flocculation and stabilization;239
13.7;6.7 Adsorption;242
13.8;6.8 Rate of flocculation;249
13.9;References;255
14;Chapter 7. Particle size and size measurement;258
14.1;7.1 Introduction;258
14.2;7.2 Definitions;258
14.3;7.3 Sampling;267
14.4;7.4 Methods of particle sizing;272
14.5;7.5 The best method?;295
14.6;References;298
15;Chapter 8. The industrial paint-making process;301
15.1;8.1 Introduction;301
15.2;8.2 The use of dispersants;301
15.3;8.3 Methods of optimizing millbases for dispersion;303
15.4;8.4 The instrumental formulating technique;305
15.5;8.5 Methods of dispersion and machinery;324
15.6;8.6 Mixing;340
15.7;8.7 Control techniques;342
15.8;Acknowledgements;344
15.9;References;344
16;Chapter 9. Coatings for buildings;345
16.1;9.1 Introduction;345
16.2;9.2 Formulating considerations and constraints;346
16.3;9.3 Pigment–binder–solvent relationships;350
16.4;9.4 The nature of paint binder;365
16.5;9.5 Colour delivery;374
16.6;9.6 Meeting the needs of the substrate;380
16.7;9.7 Masonry and cementitious substrates;398
16.8;9.8 Metallic substrates;413
16.9;9.9 Plastic as a substrate;421
16.10;References;421
17;Chapter 10. Automotive paints;426
17.1;10.1 Introduction;426
17.2;10.2 Pretreatment;430
17.3;10.3 Priming;434
17.4;10.4 Surfacers;446
17.5;10.5 Anti-chip coatings;453
17.6;10.6 Inverted or reverse process;453
17.7;10.7 Automotive topcoats;455
17.8;10.8 In-factory repairs;472
17.9;10.9 Painting of plastic body components;474
17.10;10.10 Spray application;476
17.11;10.11 Stoving procedures;487
17.12;10.12 Performance/testing;492
17.13;10.13 Future developments;498
17.14;Acknowledgements;505
17.15;Bibliography;506
18;Chapter 11. Automotive refinish paints;507
18.1;11.1 Introduction;507
18.2;11.2 Topcoat systems;509
18.3;11.3 Colour;512
18.4;11.4 Future developments;515
18.5;Bibliography;516
19;Chapter 12. General industrial paints;517
19.1;12.1 Introduction;517
19.2;12.2 Factors governing the selection of industrial painting processes;518
19.3;12.3 Industrial application and curing methods;524
19.4;12.4 Finishing materials and processes in selected industrial painting operations;532
19.5;12.5 Developments and trends in general industrial finishing;541
19.6;References;543
20;Chapter 13. The painting of ships;544
20.1;13.1 Introduction;544
20.2;13.2 Corrosion;545
20.3;13.3 Surface preparation;548
20.4;13.4 Blast primers;549
20.5;13.5 Paint systems for ships;549
20.6;13.6 The painting of off-shore structures;562
20.7;References;564
21;Chapter 14. An introduction to rheology;565
21.1;14.1 Introduction;565
21.2;14.2 History of viscosity measurements;566
21.3;14.3 Definitions;567
21.4;14.4 Methods of measurement;575
21.5;14.5 Interpretation of results;582
21.6;References;589
22;Chapter 15. The rheology of paints;590
22.1;15.1 Introduction;590
22.2;15.2 General considerations on paint rheology — paint application processes;590
22.3;15.3 Experimental methods for measuring paint rheology for application and flow-out after application;596
22.4;15.4 Paint rheology during manufacture and storage;608
22.5;References;610
23;Chapter 16. Mechanical properties of paints and coatings;613
23.1;16.1 Introduction;613
23.2;16.2 Viscoelastic properties of polymers;614
23.3;16.3 Ultimate mechanical properties of polymers;618
23.4;16.4 Experimental methods for determining mechanical properties of coatings;620
23.5;16.5 Discussion of experimental methods;626
23.6;16.6 Technological tests for mechanical properties;627
23.7;16.7 Acoustic emission;630
23.8;16.8 Recent developments;632
23.9;References;633
24;Chapter 17. Appearance qualities of paint — basic concepts;636
24.1;17.1 Introduction;636
24.2;17.2 Physics of reflection by paint/air interfaces;636
24.3;17.3 Light scattering and absorption by paint films;639
24.4;17.4 Colour of pigment mixtures and pigmented films;644
24.5;17.5 Changes in paint films;649
24.6;17.6 Fluorescence and phosphorescence;651
24.7;17.7 Colour appreciation;651
24.8;17.8 Further reading;654
24.9;References;655
25;Chapter 18. Specification and control of appearance;657
25.1;18.1 Gloss;657
25.2;18.2 Opacity of paint films;662
25.3;18.3 Specification and control of colour;667
25.4;18.4 Colour control in paint manufacture;672
25.5;Acknowledgements;672
25.6;References;672
26;Chapter 19. Durability testing;673
26.1;19.1 Introduction;673
26.2;19.2 Chemical resistance testing;676
26.3;19.3 Testing mechanical properties of paints;683
26.4;19.4 Accelerated weathering;690
26.5;19.5 Natural weathering;701
26.6;19.6 Suppliers of accelerated weathering test equipment;707
26.7;Acknowledgements;707
26.8;References;708
27;Chapter 20. Computers and modelling in paint and resin formulating;709
27.1;20.1 Introduction;709
27.2;20.2 Software in the laboratory;710
27.3;20.3 Information technology and knowledge-based systems;710
27.4;20.4 Modelling and mathematical techniques;711
27.5;20.5 Molecular modelling;715
27.6;20.6 Resin formulating and processes;716
27.7;20.7 Resin scale-up and manufacture;726
27.8;20.8 Polymer properties, curing, and network properties;727
27.9;20.9 Solvents and solubility properties;731
27.10;20.10 Paint formulation, manufacture, and use, and coating performance;733
27.11;20.11 Experimental analysis, design, and quality control;734
27.12;Bibliography;734
27.13;References;735
28;Chapter 21. Health and safety in the coatings industry;740
28.1;21.1 Introduction;740
28.2;21.2 Raw materials and intermediates;741
28.3;21.3 Occupational exposure;744
28.4;21.4 Provision of information;747
28.5;21.5 The approved supply list;747
28.6;21.6 Hazard details;753
28.7;21.7 Safety data sheets;754
28.8;21.8 Labelling of substances and preparations;755
28.9;21.9 Classification and labelling for transport (conveyance);760
28.10;21.10 Control of hazardous substances;765
28.11;21.11 New substances regulations;767
28.12;21.12 Food contact coatings;768
28.13;21.13 Major accident hazards;771
28.14;21.14 Environmental protection;774
28.15;21.15 Conclusions;776
28.16;References;777
29;Appendix 1: risk phrases;777
30;Appendix 2: safety phrases;779
31;Index;782

Leseproben

2 Organic film formers
J. Bentley 2.1 Introduction
The first chapter has indicated the major types of surface-coating resins used, and this chapter will describe their chemistry in more detail, including their preparation. In this introductory section an outline is presented of the theory of polymer formation and curing; the mechanism specific to each type of resin is then covered more fully in the subsequent sections of the chapter. The classes of resins available and the factors that decide the choice of resin for a particular use are also indicated. The properties and uses of each type of resin, again, are detailed more fully in the later relevant sections. A number of terms are used interchangeably to describe the film-forming component of paint, as will already be apparent. ‘Film former’, ‘vehicle’, or ‘binder’ relates to the evident fact that this component carries and then binds any particulate components together, and that this provides the continuous film-forming portion of the coating. Resin or varnish are older terms relating to the previous more prevalent use of natural resins in solution or ‘dissolved’ in oils as the film former; they date from the time when the chemistry and composition of these components were far less well understood. Nowadays, with our better knowledge of the materials used, along with the wide application of the sophisticated polymers used also in the plastics and adhesives industries but tailored to our own use, it is strictly more correct to refer to this component as the polymeric film-forming component. The interchangeable use of old and new nomenclature is also found in the manufacture of film formers where ‘kettle’ refers to the polymerization reactor, and ‘churn’ to the thinning tank normally part of the manufacturing plant. Film-forming polymers may or may not be made in the presence of solvent; however, since the polymers in solvent-free form generally range from highly viscous liquids to hard brittle solids, they are practically always handled in storage and in the paint-making process in solution (or in dispersion) with significant quantities of solvent or diluent included (and here the terms solvent and diluent include the full range of organic solvents and water). The exceptions are where unsaturated monomers and liquid oligomeric materials are used in place of solvent as diluents in high solids finishes. Solid resins are also used alone for the specialized application of powder coatings. Many polymers used will be in true solution, with solvent being the other component. However, in other cases, either for reasons connected with the polymer preparation or with its final use, the polymer will exist in the form of a fine-particle dispersion in non-solvent (diluent); this is true for aqueous emulsions, non-aqueous dispersions, and for the emulsified materials used in electrodeposition and other water-borne applications. In some cases the system may be mixed solution/dispersion, for example a solution containing micellar polymer dispersion, micro-emulsion or microgel. A particular striking consequence of whether the polymer is dissolved or dispersed is the viscosity; dispersions are invariably more fluid at comparable solids contents than solutions. Most significantly while solution viscosity increases as molecular weight rises, the viscosity of emulsions or dispersions is independent of molecular weight. For any given polymer in solution or dispersion, viscosity will broadly increase as the solids increases (though water-borne solutions often exhibit unusual behaviour); the viscosity will decrease if the temperature rises. As with any utility product, the paint user is concerned mostly with the ability of the material to provide final protective and decorative effects; he or she has little regards for composition, except in so far as it guides him or her to the ability of the material to satisfy those needs. Table 1.1 in Chapter 1 has listed the function of paint components and Table 2.1 shows the contribution that the three major components — resin, pigment, and solvent — make to the most important properties of a typical gloss paint. Informed readers will see limitations in the above, but it is primarily intended to highlight the broader binder/solvent contributions. Table 2.1 Contribution of major paint components to final paint properties Application ajor Minor Major Cure rate Major None Significant Cost Major Major Minor Mechanical properties Major Minor — Durability Major Major — Colour Minor Major — Generally all polymer types can provide a spectrum of compositions covering a span of properties at varying cost, and so given user criteria may be satisfied by selection from a number of resin types. The principal final choice for the user, whose application and cure conditions will probably have been determined by scale and now possibly environmental considerations, ultimately would appear to concern balancing performance and cost; true cost includes the total of paint cost, labour and equipment cost, and energy for cure. The industry is constantly striving for higher performance and novel products. Factors influencing system design may well include a need to guarantee performance in such diverse applications as decorative maintenance paints and in automobile and coated coil products, and to apply total quality management concepts as enacted in the ISO 9002 standards required of suppliers. Other forces that increasingly apply are legislation to control usage and pollution, availability and cost of energy supplies, and periodic abundance or shortage of natural and oil-based materials. Most recent developments are the carrying out of life-cycle assessments (LCAs) on paints in connection with eco-labelling studies, along with needs to apply environmental management systems (EMSs) in manufacture [1, 2]. LCA carries through to ultimate disposal including consideration of recycling of paint, paint waste, and packaging. Eco-labelling is now a major issue and can drive the choice of all components of the paint system; compliant coatings are those fully meeting both legislation and voluntary agreements. These issues present many challenges to the resin formulator [3, 4]. The choice and amount of solvent or diluent used will be constrained by hazard and eco-labelling and then will depend on the nature of the polymer and the method of application; the quantity of solvent (solids) and final viscosity will then depend on the latter. The method of application generally imposes constraints regarding solvent boiling point and evaporation rate, for example, to ensure good spray or brush application. If the polymer can be prepared in the presence of little or no solvent, the solvent required by the method of paint application has little practical significance to the resin chemist, i.e. an alkyd or polyester may easily be thinned at end point with high or low boiling solvent. However, for an acrylic resin it is usually necessary to use a solvent or solvent blend of low chain transfer properties; the boiling point must be such that the reaction mixture can be refluxed to remove heat of polymerization and such that an initiator system is available at that temperature capable of efficient conversion of monomer to polymer. The enduring market trend is in reducing quantities of all organic solvent (particularly hydrocarbon solvent) used and in an increase in the use of water as a major part of the solvent/diluent system. The mechanical properties of any given polymer ‘improve’ as molecular weight increases up to a value at which no change is seen with a further increase. In contrast the viscosity of the solution of a polymer continues to increase with molecular weight without a break. This imposes the constraint in designing a surface-coating system that if the polymer is to be made for optimum application and final properties, then molecular weight needs careful specification and control. Furthermore, since for many polymer systems the molecular weight necessary for good mechanical properties and durability will be high, considerable amounts of solvent will be needed to obtain good application properties, if the polymer is to be applied in solution at that molecular weight. The kind of system this describes is a lacquer, drying by solvent evaporation alone to leave a film of the polymer with useful properties, with no subsequent change of molecular weight or further reaction occurring. Practically this system, initially used with varnishes such as Shellac and French polish, continues with plasticized nitrocellulose and with thermoplastic acrylic lacquer systems used in automotive refinishing systems. The simplest way of avoiding the molecular weight/viscosity conflict is the use of dispersion rather than solution systems. Examples are the decorative aqueous emulsions now made in high volume, the dispersed polymer used in water-borne systems, non-aqueous dispersion (NAD) systems, and organosols. The use of dispersions can also allow the use of cheaper, less polluting diluents, and was particularly useful when the Californian Rule 66 legislation controlling the VOC (volatile organic content) of factory exhaust...