Constituents of paint:
1. Pigments
2. Vehicle or medium (drying oil)
3. Thinners
4. Driers
5. Fillers
6. Plasticizers
Functions of various constituents:
Pigments:
i) Provides opacity and desired colour to the paint film.
ii) Gives pleasing (aesthetical) look to the paint.
iii) Gives protection to the paint by reflecting U.V.light.
iv) Provide resistance to the paint film against abrasion or wear and weather.
Vehicle or medium (drying oil) :
i) It is a film forming constituent of paint.
ii) It provides a durability and water proof-ness to the film.
iii) It provides toughness to the film.
iv) It provides adhesion to the film.
Thinners:
i) They hold pigments in paint.
ii) They dissolve film forming materials.
iii) They reduce the viscosity of paint.
iv) They help drying of paint.
v) They increase the elasticity of paint film.
Driers :
i) They improve the drying quality of paint.
ii) They act as oxygen carrier catalyst.
iii) They accelerate the drying of paint film by oxidation, polymerization & evaporation.
Fillers or Extenders :
i) They reduce the cost of paint.
ii) They provide durability to the film.
iii) They reduce the cracking of the paint film.
iv) They increase the random arrangement of pigmented particles
v) They help to fill the voids in the film.
vi) They act as carrier for the pigment colour.