Paint and coating contain various components like:
- Pigments to transmit colour and opacity
- Blinders or polymer, also known as resin, it forms a matrix to hold the pigment in place.
- The Extender is the larger pigment particles use to strengthen the film as well as improve adhesion and save the binders.
- Solvent (or thinner) is an organic solvent. Further, its use is in reducing the viscosity of the paint for smooth application.
- Additives are in use to change the properties of liquid paints as well as dry film.
Depending on the types of Paint and Coating and intended use, additives include:
- Dispersants are in use to separate and stabilize pigment particles
- Silicones are used to improve weather resistance
- Thixotropic agents are used to giving paints a jelly-like consistency that breaks down to a liquid when stirred or when a brush is dipped into it
- Driers – to accelerate drying time
- Anti-settling agents are in use for preventing pigment settling.
- Bactericides are in use to preserve water-based paints in the can
- Fungicides and algaecides used to protect exterior paint films against disfigurement from molds, algae, and lichen.
Formulation of paints are according to their proposed use – primer, undercoat, special finishes (matt, gloss, heat resistance, anti-corrosion, abrasion resistance). The break down of pigment powder is into individual particles. They are coated and dispersed in the binder (resin) – known as ‘wetting out’. Moreover, the addition of solvents gives the required consistency. In addition, each batch of ingredients is thoroughly mix in large, stirring containers with the require additives.