Basic dye is a stain that is cationic (+ve charged) and so will react with material that is (-ve) negatively charged. This dye is usually synthetic, that act as bases, and which are actually aniline dyes. Their color base is not water soluble but can be made so by converting the base into a salt. The basic dyes, while possessing great tinctorial strength and brightness, are not generally light-fast.
At the chemical level, basic dyes are typically cationic or positively charged. Basic dyes display cationic functional groups like -NR3+ or =NR2+. Since basic dye is a stain that is cationic or positively charged and it is the reason that it reacts well with material that is anionic or negatively charged.
Basic dyes consists of amino groups, or alkylamino groups, as their auxochromes. Synthetic dye that was discovered by Perkin incidentally was a basic dye. Few examples of basic dyes are the following, methylene blue, crystal violet, basic fuchsin safranin, etc. An example of a basic dye that has amino groups as their auxochrome is pararosanilin or basic red 9 (according to the strict color index system of classification) example of alkylamino groups is methylene blue or basic blue 9. Basic Blue 9 is a very popular dye that has vast use. Table given below provides more information about Basic Blue 9:
C I name
Basic blue 9, Solvent blue 8
C I number
A basic chemical structure of Basic Blue 9
Advantages of Basic Dyes
High Tinctorial strength
Wide shade range
Shows good brightness
Includes some of the most brilliant synthetic dyes
Limitations of Basic Dye
High acid content
Poor shade stability
Very poor light fastness
Modified Basic DyeModified basic dyes have similar chemistry, as of basic dyes. These only show a bit longer molecular structures than the typical conventional basic dyes, thus resulting in significantly improved properties.