COATINGSCOATINGS

PAINT vs COATINGPAINT vs COATINGdrying oils and/or drying oils and/or natural resins natural resins

oxidation/evaporation oxidation/evaporation to form a weather to form a weather resistant film resistant film

continues to oxidize continues to oxidize and breaking down.and breaking down.

synthetic resin or synthetic resin or inorganic silicate inorganic silicate polymer. polymer.

resistant to harsh resistant to harsh environmentsenvironments

superior performance superior performance (adhesion, toughness, (adhesion, toughness, and resistance to and resistance to chemicals, UV, etc.) chemicals, UV, etc.)

1.1. Solvent (volatile)Solvent (volatile)2.2. Resin/Binder (nonvolatile)Resin/Binder (nonvolatile)3.3. Pigments (nonvolatile)Pigments (nonvolatile)

Basic Basic IngredientsIngredients

SolventsSolvents

Dissolve film formerDissolve film former Reduce viscosity for ease of application Reduce viscosity for ease of application Control rate of cureControl rate of cure Low molecular weight organic chemicalsLow molecular weight organic chemicals

Examples include aliphatic, aromatic, and Examples include aliphatic, aromatic, and chlorinated hydrocarbons; alcohols; ketones; chlorinated hydrocarbons; alcohols; ketones; esters; glycol ethers; and water.esters; glycol ethers; and water.

Resin (binder)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 CoatingsOrganic Coatings

The resin is a carbon based polymer The resin is a carbon based polymer

(urethanes, epoxies, alkyds, acrylics, etc)(urethanes, epoxies, alkyds, acrylics, etc)

R C C

R

R

R

R

R

Inorganic CoatingsInorganic Coatings

The resin is not a carbon based polymerThe resin is not a carbon based polymer

Most utilize some type of silicate binderMost utilize some type of silicate binder

Si

O

O

O

O Si

O

O

Zn

ZnZn

Zn

O

Type of Curing in Type of Curing in Modern Coating ResinsModern Coating Resins

Solvent evaporationSolvent evaporation OxidationOxidation Chemical reactionChemical reaction Catalyzed film formerCatalyzed film former ThermoplasticThermoplastic ThermosetThermoset Emulsion - water basedEmulsion - water based

PigmentPigment1. Decorate, color, and hide1. Decorate, color, and hide

2. Protect2. Protect BarrierBarrier GalvanicGalvanic InhibitiveInhibitive

3. Provide consistency3. Provide consistency

4. Provide film thickness4. Provide film thickness

5. Control vehicle penetration into substrate5. Control vehicle penetration into substrate

Types of Pigmented Types of Pigmented PaintPaint

AdditivesAdditives Anti-fungusAnti-fungus Anti-skinningAnti-skinning PlasticizersPlasticizers LevelersLevelers Thixotropic agentsThixotropic agents AcceleratorsAccelerators StabilizersStabilizers

Life Expectancy of CoatingsLife Expectancy of Coatings

design of bridgedesign of bridge suitability of coating to suitability of coating to

bridge typebridge type environmentenvironment quality of paintquality of paint surface preparationsurface preparation applicationapplication thicknessthickness

Coatings ReviewCoatings Review

1.1. What are the 3 components of paint?What are the 3 components of paint?

2.2. What are 3 type of protection they What are 3 type of protection they provide? provide?