67 Transparent pigments
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Gerhard Pfaff
Abstract
Transparent pigments are characterized by very small particles with sizes in the range below 100 nm and large specific surface areas. Most of the technically relevant pigments consist of inorganic compounds. Transparent pigments are classified as nanomaterials. Nanosized primary particles do not or only slightly scatter visible light, which is the reason for their transparency. Pigmentation with these pigments leads to a transparent appearance of the application systems. There are colored and colorless transparent pigments. If colored pigments such as α-FeOOH, α-Fe2O3, and CoAl2O4 are used, the application medium takes on color while remaining transparent. Colorless transparent pigments are nearly invisible in the application system. Only in combination with effect pigments or conventional colored pigments, effects with a special appearance are possible, e.g., frost effects. There are two industrially relevant colorless transparent pigments, TiO2 and ZnO. Both pigments find their main applications as functional powders. They are characterized by strong UV absorption and are therefore applied as UV absorbers. As such, they are used for the protection of organic materials such as plastics and coatings. They are used in addition in a broad diversity of sun screen products where they protect human skin. The manufacture of transparent pigments takes place mostly using wet-chemical or gas-phase reactions.
Abstract
Transparent pigments are characterized by very small particles with sizes in the range below 100 nm and large specific surface areas. Most of the technically relevant pigments consist of inorganic compounds. Transparent pigments are classified as nanomaterials. Nanosized primary particles do not or only slightly scatter visible light, which is the reason for their transparency. Pigmentation with these pigments leads to a transparent appearance of the application systems. There are colored and colorless transparent pigments. If colored pigments such as α-FeOOH, α-Fe2O3, and CoAl2O4 are used, the application medium takes on color while remaining transparent. Colorless transparent pigments are nearly invisible in the application system. Only in combination with effect pigments or conventional colored pigments, effects with a special appearance are possible, e.g., frost effects. There are two industrially relevant colorless transparent pigments, TiO2 and ZnO. Both pigments find their main applications as functional powders. They are characterized by strong UV absorption and are therefore applied as UV absorbers. As such, they are used for the protection of organic materials such as plastics and coatings. They are used in addition in a broad diversity of sun screen products where they protect human skin. The manufacture of transparent pigments takes place mostly using wet-chemical or gas-phase reactions.
Chapters in this book
- Frontmatter I
- Preface V
- Contents VII
- List of contributors XV
- 45 Mixed metal oxide pigments 849
- 46 Monoazo (Monohydrazone) pigments based on acetoacetanilides 859
- 47 Monoazo (Monohydrazone) pigments based on benzimidazolones 871
- 48 Monoazo (Monohydrazone) pigments based on 2-naphthol and derivatives 885
- 49 Naphthopyran dyes 909
- 50 Organic pigments: general principles 925
- 51 Oxonitride pigments 955
- 52 Oxonol dyes 959
- 53 Perylene and perinone pigments 967
- 54 Photochromic dyes 979
- 55 Phthalocyanine blue pigments 1015
- 56 Phthalocyanine green pigments 1029
- 57 Phthalocyanine pigments: general principles 1035
- 58 Pigments: general aspects 1041
- 59 Polymethine dyes 1057
- 60 Quinacridone pigments 1071
- 61 Special effect pigments 1081
- 62 Spirooxazine dyes 1105
- 63 Spiropyran dyes 1125
- 64 Streptocyanine dyes 1153
- 65 Streptomerocyanine dyes 1165
- 66 Titanium dioxide pigments 1177
- 67 Transparent pigments 1195
- 68 Ultramarine pigments 1203
- 69 White pigments 1211
- 70 Zinc oxide pigments 1213
- 71 Zinc sulfide pigments 1219
- Index 1225
Chapters in this book
- Frontmatter I
- Preface V
- Contents VII
- List of contributors XV
- 45 Mixed metal oxide pigments 849
- 46 Monoazo (Monohydrazone) pigments based on acetoacetanilides 859
- 47 Monoazo (Monohydrazone) pigments based on benzimidazolones 871
- 48 Monoazo (Monohydrazone) pigments based on 2-naphthol and derivatives 885
- 49 Naphthopyran dyes 909
- 50 Organic pigments: general principles 925
- 51 Oxonitride pigments 955
- 52 Oxonol dyes 959
- 53 Perylene and perinone pigments 967
- 54 Photochromic dyes 979
- 55 Phthalocyanine blue pigments 1015
- 56 Phthalocyanine green pigments 1029
- 57 Phthalocyanine pigments: general principles 1035
- 58 Pigments: general aspects 1041
- 59 Polymethine dyes 1057
- 60 Quinacridone pigments 1071
- 61 Special effect pigments 1081
- 62 Spirooxazine dyes 1105
- 63 Spiropyran dyes 1125
- 64 Streptocyanine dyes 1153
- 65 Streptomerocyanine dyes 1165
- 66 Titanium dioxide pigments 1177
- 67 Transparent pigments 1195
- 68 Ultramarine pigments 1203
- 69 White pigments 1211
- 70 Zinc oxide pigments 1213
- 71 Zinc sulfide pigments 1219
- Index 1225
