Pigments have entered into every aspect of our life and made it very colorful and bright. Since the time they were naturally discovered to today’s times when they are synthetically produced in laboratories, pigments have come a long way in terms of their use and application. Today, we find that pigments have wound their way into several hundreds of applications ranging from plastics, inks, paints, textiles, soaps and detergents and many more.

Pigments in Paint

Pigments have formed the basis of all paints. Though they have been used for long, it was only in the nineteenth century that they came to be commonly used for innumerable applications. Today, paints are used to give a decorative touch to several items as well as act as industrial coatings in factories. Adding a dash of color besides protecting the surfaces on which it is applied; paints have become highly indispensable in today’s times. The basic constituents of paints are:

• Pigments
• Binder
• Solvent
• Extender
• Additives

Additives like silicones, dispersants, bactericides, fungicides and pesticides are included in paints as they lend additional protecting and stabilizing properties. Pigments for paint perform several functions, the main being lending an aesthetic effect like opacity or color. However, there are certain pigments known as ‘extenders’ that play a vital role in enhancing the paint film’s properties such as hardness, gloss and reinforcement. Some pigments are mainly used for their protective properties such as corrosion protection, fire retardance or enhance the substrate’s weather ability.

Pigments for Inks

Pigments have been used in preparing inks since ancient times. The ink formulations in modern times, however,  are much more complex than in earlier days. In addition to pigments, they include several ingredients like pH modifiers, polymeric resins to give binding properties, humectants to prevent premature drying, antifoaming agents to control foam efficiency, biocides to prevent bacterial and fungal growth and thickeners to regulate the consistency of ink. Most of today’s inks are printing inks where pigments are the source of imparting color. Pigments used pigments for inks could be either organic or inorganic. However, the growing awareness of the increased toxicity levels in the inorganic pigments have led to their replacement with organic pigments which contain reduced levels of toxicity and provide better light fastness. Some inorganic materials like clay are used as extenders which help to enhance the properties of ink besides reducing the pigment cost.

Solvent Dyes

Solvent dyes are used on a wide scale for dyeing plastics, with PVC being categorically colored by the use of these dyes. The process of dyeing is undertaken in a solution due to the non-polarity of the molecules of solvent dyes. This type of dye is very versatile and is being used in a number of applications. Coloring of all hydrocarbon and non-polar based materials is done through these dyes. They are therefore used for coloring wax and candles, cosmetics, wood stain, varnishes, spirit, leather-spray finishing of undyed as well as dyed leather; the list is almost endless.

Whatever be the colorant; whether a pigment or a dye, it has lived up to the expectations in every application it has been used.