Composition of Paints

There are basically four ingredients in paints.

Binder
Pigment
Solvent
Additives

The functions of the above ingredients are explained below.

Binders:  The function of a binder is to bind all the pigments together into a homogeneous film. The binder is basically a resin. The binder is also called 'vehicle'. Resins are non volatile. Examples include epoxy esters, chlorinated rubbers, acrylics, linylsy urethanes, etc.

Pigments:  Basically a pigment provides a decorative color and it protects the binders from the destructive effect of the sun rays on the binders. Examples: iron oxide (red), titanium dioxide (white), chrome yellow (yellow), lampblack (black).

Solvents:  The function of a solvent is to convert a solid binder into a homogeneous working fluid as many of the binders would be unworkable unless converted to liquid. Examples include aliphatic hydrocarbons, aromatic hydrocarbons, esters and alcohols.

Additives:  These are auxiliary products added to improve the technical properties of paints. Examples:

• Film formation promotes like glycol ethers, glycol ether esters, etc.

• Wetting agents which assist in wetting of the pigment by the binders (one to one contact) and prevents flacullates of the pigment)

• Catalysts are added to accelerate the process of drying. For example, manganese, zinc, barium salts and zirconium compounds.

• Plasticizers improve flexibility of fibre (esters of dicarboxylic acid) by biological agents (biocides and fungicides).