List the three main constituents of paint and give functions of each.
Paints are formed by using various ingredients which are listed below. Each ingredients is mixed for a particular function.
1) Drying oils /medium/ vehicle.
Constituent - Drying oils or vehicle
Examples - Linseed oil, soya bean oil, dehydrated castor oil, neem oil, fish oil, etc.
Functions - They help pigments to be held on surface. They provide dried film by oxidation or polymerization. They provide durable water resistant film of paint.
Constituent - Pigments
Examples - White pigments: White lead, ZnO, Titanium oxide, Coloured pigments Red lead, Fe2O3, chrome red, etc.
Functions - Provide opacity, colour strength, and protection. Provide resistance against abrasion. Minimize shrinkage and cracking caused on drying.
Constituent - Thinners
Examples - Turpentine, spirits, benzene, naphtha, xylol, kerosene, methylated naphthalene etc.
Functions - Adjust viscosity of formulation. Help in drying of the paint. Suspend the pigments and dissolve film forming material.
Constituent - Driers
Examples - Oxygen carrying catalyst, Linoleates of Co, Mn, Zn, etc
Functions - Improve drying process. Act as catalyst in drying process.