Application Classes

The granulation of the applicable class of Amm Picrate shall be as specified in Table 2... 

The traditional use of dyes is in the coloration of textiles, a topic covered in considerable depth in Chapters 7 and 8. Dyes are almost invariably applied to the textile materials from an aqueous medium, so that they are generally required to dissolve in water. Frequently, as is the case for example with acid dyes, direct dyes, cationic dyes and reactive dyes, they dissolve completely and very readily in water. This is not true, however, of every application class of textile dye. Disperse dyes for polyester fibres, for example, are only sparingly soluble in water and are applied as a fine aqueous dispersion. Vat dyes, an important application class of dyes for cellulosic fibres, are completely insoluble materials but they are converted by a chemical reduction process into a water-soluble form that may then be applied to the fibre. There is also a wide range of non-textile applications of dyes, many of which have emerged in recent years as a result of developments in the electronic and reprographic... 

In Chapters 3-6, the commercially important chemical classes of dyes and pigments are discussed in terms of their essential structural features and the principles of their synthesis. The reader will encounter further examples of these individual chemical classes of colorants throughout Chapters 7 10 which, as a complement to the content of the earlier chapters, deal with the chemistry of their application. Chapters 7, 8 and 10 are concerned essentially with the application of dyes, whereas Chapter 9 is devoted to pigments. The distinction between these two types of colorants has been made previously in Chapter 2. Dyes are used in the coloration of a wide range of substrates, including paper, leather and plastics, but by far their most important outlet is on textiles. Textile materials are used in a wide variety of products, including clothing of all types, curtains, upholstery and carpets. This chapter deals with the chemical principles of the main application classes of dyes that may be applied to textile fibres, except for reactive dyes, which are dealt with exclusively in Chapter 8. 

The ability of transition metal ions, and especially chromium (as Cr3+), to form very stable metal complexes may be used to produce dyeings on protein fibres with superior fastness properties, especially towards washing and light. The chemistry of transition metal complex formation with azo dyes is discussed in some detail in Chapter 3. There are two application classes of dyes in which this feature is utilised, mordant dyes and premetallised dyes, which differ significantly in application technology but involve similar chemistry. 

Mixing applications, classes of, 26 670t Mixing methods, for kinetic measurements, 24 611-614... 

Application Class of imprinted compound Template Refer- ences... 

Hormone Application Class of cattle Response (%) Effect days... 

The nomenclature given for these componnds is a nniversally recognised system for the naming of dyestuffs devised by the Society of Dyers and Colourists as part of their Colour Index (Cl). The Cl Generic Name is made up of the application class, the hne and a nnmber. Acid dyes are nsed on wool and polyamide, direct dyes on cel-lulosic fibres, paper and leather, disperse dyes on polyester fibres, reactive dyes on cellnlosic fibres and basic dyes on polyacrylonitrile and paper. 

Portable fire extinguishers are classified according to applicability Class A for solid combustibles Class B for flammable liquids Class C for electrical fires that require a nonconducting agent and Class D for combustible metals. Water frequently is used for Class A extinguishers bicarbonates for Class B and Class BC carbon dioxide or Freon for Class C ammonium phosphate for Class ABC and powdered salt, sodium chloride, for Class D. 

The classification of dyes according to their usage is summarized in Table I. which is arranged according to the Colour Index (Cl) application classification. It shows the principal substrates, the methods of application, and the representative chemical types for each application class. 

The Colour Index assigns Cl generic names to commercial dyes. This Cl name is defined as a classification name and serial number which when allocated lo a commercial product allows that product to be uniquely Identified within any Colour Index Application Class." This enables the particular commercial products to be classified along with other products whose essential colorant has the same chemical constitution. 

Chemically, the triarylmethane dyes are monomethine dyes with three terminal aryl systems of wind] one or more arc substituted with primary, secondary, or tertiary amino groups or hydroxyl groups in the para position to the methine carbon atom. Additional substituents such as carboxyl, sulfonic acid, halogen, alkyl, and alkoxy groups may be present on the aromatic rings. The number, nature, and position of these substituents determine both the hue or color of the dye and the application class to which the dye belongs. 

The C.I. (Colour Index) name for a dye is derived from the application class to which the dye belongs, the color or hue of the dye and a sequential number, e.g., C.I. Acid Yellow 3, C.I. Acid Red 266, C.I. Basic Blue 41, and C.I. Vat Black 7. A five digit C.I. (Constitution) number is assigned to a dye when its chemical structure has been disclosed by the manufacturer. The following example illustrates these points ... 

It is possible to classify dyes by using the Color Index that classifies dyes according to a dual system. An assigned number defines the chemical class and a generic name identifies the usage of application. However, it is convenient to use the application classification used by the U.S. International Trade Commission for application classes ... 

Physical processing Application classes Chemical process... 

Since 1973, the U.S. International Trade Commission has reported the manufacture and sales of dyes by application class only. In 1972, the last year for which statistics are available by chemical class, 3900 metric tons of triarylmethane dyes were manufactured, which represents approximately 4% of total dyestuff production in the United States. At that time, there were 185 triarylmethane dyes Us ted in the Colour Index. From the latter half of the 1970s through the 1980s, annual dye production in the United States, including triarylmethane dyes, changed very litde. In 1981, methyl violet, with an annual production of 725 t, was the only triarylmethane dye for which production statistics were available. Some triarylmethane dyes were imported, eg, malachite green (163 t in 1981), methyl violet (40 t), new fuchsine (30 t), and other dyes totalling less than 15 t. 

Under the Mater-Bi trademark, Novamont produces different classes of starch-based biodegradable materials and blends of starch with synthetic polymers. Each class is available in several grades to meet the needs of specific applications. Classes include grades for film and sheet extrusion, injection moulding and foams. 

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