TECHNICAL SEMINAR ON PAINT Presentation.ppt (Size: 2.05 MB / Downloads: 391)
TECHNICAL SEMINAR ON PAINT
Classification of paint , its properties and general raw materials used in manufacture of paints.
R.V College of Engineering
The US Federal Highway Administration released a study, entitled Corrosion Costs and Preventive
Strategies in the United States, in 2002 on the direct costs associated with metallic corrosion in
nearly every U.S. industry sector. The study showed that for 1998 the total annual estimated direct
cost of corrosion in the U.S. was approximately $276 billion (approximately 3.1% of the US gross
domestic product). FHWA Report Number:FHWA-RD-01-156. The NACE International website has a summary
slideshow of the report findings. Jones1 writes that electrochemical corrosion causes between $8
billion and $128 billion in economic damage per year in the United States alone, degrading
structures, machines, and containers.
Methods of corrosion prevention:
WHAT IS PAINT?
Paint is a stable fluid suspension of finely divided pigment particles.
Paint is a mixture of finely dispersed pigment in resin media which, when applied on a substrate it
forms a hard film, which is both protective & decorative in nature.
Properties Of Paint
When paint is applied to the surface of a metal, wooden article or building, it not only gives
decorative and aesthetic look but also protects the material from weathering, corrosion, etc.
It also prevents the surface from Algae or fungal attacks.
Classification of Paints
Water soluble paints (generally used in construction sector).
Solvent soluble paints (generally used on metallic surface)
Solvent free paint (used exclusively for metallic surface also called as Powder Paint)
Water-soluble paints are mixed with water for application viscosity. Water used as solvent, is eco
-friendly and the surface dries fast to go for second coat application.
I) Cement Paint (For Exterior Purpose).
II) Distemper (For Interior Wall Finish).
III) Emulsion Paint (Interior Wall Finish).
IV) High performance water soluble metal paints are available, which are costlier and not popular in
the local market.
Solvent-based paints are thin able in solvents, selection of solvent-based paints are based on
Solvent-based paints are classified as follows:
I) Alkyd Resin based paints
II) Acrylic Resin based PU paints
III) Polyester Resin based Paints
IV) Epoxy Resin based Paints
V) Special paints based on modified resins
RAW MATERIALS USED IN THE MANUFACTURE OF PAINTS
RESIN / BINDER :
Resins are organic compounds made by Polymerization of oils (both vegetable & petroleum products).
Resins are film formers in which micronised pigment particles are evenly dispersed forming a fluid
Resins are the Heart of Paint.
They are also called as binders,mediums, vehicles.
A Substance capable of dissolving a solute to form a uniformly dispersed mixture i.e. Solution.
Solvents are used in paints for the purpose of flow and leveling.
Eg :Water (in case of water solb paints), organic solvents like xylene,toluene etc.
Colored particles in paints is called as pigments.
Pigments are suspended in resin media to give the required coloration.
Pigments are mainly classified as organic & inorganic pigments.
Eg: Azo pigments, Anthraquinon, Pthalocyanin in case of organic pigments.
Titanium Dioxide, Chrome pigments etc in case of inorganic pigments.
Extenders are optically inert and colorless material used in combination with pigments to increase
color effect and thereby reduce the cost of paint production.
Extenders by themselves are transparent material.
Eg: Calcite, China Clay, Barytese etc.
Additives are certain chemical agents added in order to enhance certain required properties of
They are used in very small quantity but contribute significantly to the property of paint.
The following classes of additives are commonly used.
1. Wetting and dispersing agent
2. Anti skinning agent
3. Anti settling agent
5. Flow control and leveling agent
6. Preservatives and fungicides. etc
Driers are chemical agents which helps in absorbing atmospheric oxygen and oxidizes the paint film
as a result of which the film hardens.
Eg: Napthenic acid, Octoic acid derivatives etc are the driers widely used in paint industry.
Driers are classified as primary and secondary driers.
Eg: Cobalt, lead, manganese (primary driers).
calcium, Barium, Zinc soaps (secondary driers).