COATINGS

PAINT vs COATING synthetic resin or inorganic silicate polymer. resistant to harsh environments superior performance (adhesion, toughness, and resistance to chemicals, UV, etc.) drying oils and/or natural resins oxidation/evaporation to form a weather resistant film continues to oxidize and breaking down.

Basic Ingredients Solvent (volatile) Resin/Binder (nonvolatile) Pigments (nonvolatile)

Solvents Dissolve film former Reduce viscosity for ease of application Control rate of cure Low molecular weight organic chemicals Examples include aliphatic, aromatic, and chlorinated hydrocarbons; alcohols; ketones; esters; glycol ethers; and water.

Resin (binder) Principal ingredient Holds paint together and to the substrate Establishes chemical and physical properties Defines coatings generic type A "Vehicle" that turns to a "Solid" (nonvolatile)

Organic Coatings The resin is a carbon based polymer (urethanes, epoxies, alkyds, acrylics, etc) R R R C C R R R

Inorganic Coatings The resin is not a carbon based polymer Most utilize some type of silicate binder Zn Zn O O O Si O Si O O O Zn Zn

Type of Curing in Modern Coating Resins Solvent evaporation Oxidation Chemical reaction Catalyzed film former Thermoplastic Thermoset Emulsion - water based

Pigment 1. Decorate, color, and hide 2. Protect 3. Provide consistency Barrier Galvanic Inhibitive 3. Provide consistency 4. Provide film thickness 5. Control vehicle penetration into substrate

Types of Pigmented Paint

Additives Anti-fungus Anti-skinning Plasticizers Levelers Thixotropic agents Accelerators Stabilizers

Life Expectancy of Coatings design of bridge suitability of coating to bridge type environment quality of paint surface preparation application thickness

Coatings Review What are the 3 components of paint? What are 3 type of protection they provide?