INTRODUCTION TO PAINT.
Paint is any liquid, liquefiable or mastic composition that after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color or provide texture to objects.
Paint can also be defined as a liquid, paste or powder products which when applied to a substrate, dries to form a thin layer and serves for informative, decorative or protective purposes. Paints are made and purchased in many colors and in different types or forms depending on the required surface finish or design. Emulsion paint
HISTORY OF PAINT
The first form of paint appeared about 30,000 years ago when cavemen used underdeveloped paints to illustrate murals of their lives on the walls of their cave homes. These paints were mainly made of substances found naturally such as earth pigments and iron oxides. The Chinese then revolutionized the creation and use of paint during ancient times, accompanied by the Egyptians who created the first binder from ground blue glass in 3,000BC. The Egyptians considered coloured paint as sacred and were designated as having magical and healing properties.
Before the Industrial Revolution of the 1800s made paint commercially available to individuals, artists needed to make paint fresh each day before commencing their work. Types, techniques, colors and styles of painting available to individuals change over time due to what materials are available, what the latest trends are, and the properties of the different types of paint.
COMPOSITION OF PAINTS.
A paint is formulated as a mixture of four ingredients:
BINDERS OF PAINT.
Binder is the main ingredient of paints. Binders are polymers (resins) forming a continuous film on the substrate surface. Binders are responsible for good adhesion of the coating to the substrate. The binder holds the pigment particles distributed throughout the coating.
Common binders used in paint include
- Alkyd resins
- Acrylic resins
- Epoxy resins
SOLVENTS OF PAINTS.
Solvent (water or organic solvent) is a medium where the binder, pigment and additives are dispersed in molecular form (true solutions) or as colloidal dispersions (emulsions). Solvents (thinners) are also used for modification of the paint viscosity required for the application methods. Other important properties are the ability to dissolve the paint ingredients and toxicity.
The common solvent used as the carrier in paint is water.
PIGMENTS OF PAINTS.
Pigment is a solid substance dispersed throughout the coating to impart it a color, opacity (hide the substrate surface). Pigments change the paint appearance and also increase hardness and decrease ductility. Pigments may be natural, synthetic, inorganic or organic. Fillers and extenders are also referred to pigments. Fillers and extenders are non-expensive commonly natural inorganic materials added to the paint in order to increase its volume, to increase the paint film thickness, to impart toughness or abrasion resistance to coating.
Pigments commonly used in paints include titanium dioxide, iron oxide (yellow and red). Example of fillers and extenders include kaolin clay and calcium carbonate.
ADDITIVES FOR PAINTS.
Additives are small amounts of substance used in modifying the paint properties. Examples of additives include
- Coalescing agents
USES OF PAINTS.
We apply paint for: