Contents
Preface ix
CHAPTER 1 Classification and general properties of colorants 1
1.1 Introduction 1
1.2 Development of colorant classification systems 2
1.3 Colour Index classification 4
1.4 Chemical classes of colorants 5
1.5 Colour and chemical structure 14
1.6 Application ranges of dyes and pigments 18
1.7 Colorants and the environment 33
References 42
CHAPTER 2 Organic and inorganic pigments; solvent dyes 45
2.1 Pigments 45
2.2 Dyes converted into pigments 48
2.3 Azo pigments 53
2.4 Phthalocyanine pigments 67
2.5 Quinacridone pigments 71
2.6 Isoindolinone pigments 73
2.7 Dioxazine pigments 73
2.8 Diketopyrrolopyrrole pigments 73
2.9 Fluorescent pigments 74
2.10 Inorganic pigments 75
2.11 How pigments act as colorants 82
2.12 Solvent dyes 86
2.13 Conclusion 86
References 87
Bibliography 88
CHAPTER 3 Dye structure and application properties 89
3.1 Dye characteristics and chemical structure 89
3.2 Dyeability of fibres in relation to dye structure 116
3.3 Application properties and chemical structure 134
References 176
CHAPTER 4 Chemistry of azo colorants 180
4.1 Introduction 180
4.2 Mechanism of diazotisation and coupling 180
4.3 Diazo components and diazotisation methods 182
4.4 Preparation and use of coupling components 186
4.5 Structure of azo dyes 193
4.6 Preparation and importance of naphthalene intermediates 196
4.7 Schematic representation of coupling 204
4.8 Sulphonated azo dyes 204
4.9 Unsulponated monoazo dyes 211
4.10 Basic azo dyes 218
4.11 Azoic diazo and coupling components 220
4.12 Stabilised diazonium salts and azoic compositions 223
4.13 Azo pigments produced by final coupling 225
4.14 Implications of new technology in diazotisation and coupling 227
References 228
CHAPTER 5 Chemistry and properties of metal-complex and mordant dyes 231
5.1 Introduction 231
5.2 Fundamental concepts 233
5.3 Electronic structure of transition-metal ions 235
5.4 Structural characteristics necessary for complex formation 240
5.5 Preparation of metal-complex colorants 248
5.6 Isomerism in metal-complex dyes 260
5.7 Stability of metal-complex dyes 261
5.8 Chromium-related problems in the mordant dyeing of wool 268
References 277
CHAPTER 6 Chemistry of anthraquinonoid, polycyclic and miscellaneous
colorants 280
6.1 Anthraquinone acid, disperse, basic and reactive dyes 280
6.2 Polycyclic vat dyes 294
6.3 Indigoid and thioindigoid dyes 316
6.4 Sulphur and thiazole dyes 321
6.5 Diarylmethane and triarylmethane dyes 327
6.6 Miscellaneous colorants 344
References 353
CHAPTER 7 Chemistry of reactive dyes 356
7.1 Introduction 356
7.2 Reactive systems 358
7.3 Monofunctional systems 361
7.4 Bifunctional systems 385
7.5 Chromogens in reactive dyes 400
7.6 Stability of dye–fibre bonds 410
7.7 Reactive dyes on wool 415
7.8 Reactive dyes on silk 420
7.9 Reactive dyes on nylon 424
7.10 Novel reactive dyeing processes 426
References 440
Preface to Volume 1
This Second Edition of a textbook first published in 1990 forms part of a series on colour and coloration technology initiated by the Textbooks Committee of the Society of Dyers and Colourists under the aegis of the Dyers’ Company Publications Trust Management Committee, which administers the trust fund generously provided by the Worshipful Company of Dyers.
The initial objective of this series of books has been to establish a coherent body of explanatory information on the principles and application technology of relevance for students preparing to take the Associateship examinations of the Society. This particular book has been directed specifically to the subject areas covered by Section A of Paper B: the organic chemistry and application of dyes and pigments and of the auxiliaries used with them in textile coloration processes. However, many qualified chemists and colourists interested in the properties of colorants and their auxiliaries have found the First Edition useful as a work of reference. For several reasons it has been convenient to divide the material into two separate volumes: 1. Colorants, 2. Auxiliaries. Although fluorescent brighteners share some features in common with colorants, they have been treated as auxiliary products in this book.
This first volume of the book is concentrated on the chemical characteristics of dyes and pigments, with emphasis on attempts to interpret their colouring and fastness properties in terms of the essential structural features of colorant molecules. This Second Edition has been extensively updated and greater attention has also been given to factors associated with the potential impact of colorants and their metabolites on the environment. All chapters have been affected by these changes, but the concluding chapter on reactive dyes contains more new material than the others. Rationalisation of the global dyemaking industry during the 1990s means that many of the traditional commercial names of dyes and pigments have disappeared. For this reason Part 2 of the Colorants Index has been eliminated and colorants have been specified almost always by their CI Generic Names. The fundamental value of the unique Colour Index International to colorant makers and users is recognised worldwide.
Chapters 4 and 7 in the First Edition were written by Vivian Stead and Chapter 5 by Frank Jones. Sadly, Frank died in 1989 and Vivian in 1996, but my co-authors and myself would like to record our tribute for the major contributions to this volume by our former friends and colleagues. We have tried to preserve their original style intact during the necessary updating process. Our grateful thanks are due to John Holmes and Catherine Whitehouse for their patient copy editing and to the publications staff of the Society, especially Carol Davies, who have prepared all the material in this new edition for publication.
JOHN SHORE