Paint and Coating Terminology

Volume Solids

Solid ingredients as a percentage of total ingredients. The volume of pigment plus binder divided by the total volume, expressed as a percent. High-volume solids mean a thicker dry film with improved durability.

Binder

Solid ingredients in a coating that hold the pigment particles in suspension and attach them to the substrate. Consists of resins (e.g., oils, alkyd, latex). The nature and amount of binder determine many of the paint's performance properties--washability, toughness, adhesion, color retention, etc.

Liquid Driers

Solution of soluble driers in organic solvents.

Source Reduction

Steps taken to reduce waste generation and toxicity at the source through more effective utilization of raw materials and reformulation.

Monomer

Substance composed of low molecular weight molecules capable of reacting with like or unlike molecules to form a polymer.

Polymer

Substance, the molecules of which consist of one or more structural units repeated any number of times; vinyl resins are examples of true polymers.

Resin

Synthetic or natural material used as the binder in coatings. Can be translucent or transparent, solid or semi-solid. Examples: acrylic, alkyd, copal ester, epoxy, polyurethane, polyvinyl chloride, silicone.

Alkyd

Synthetic resin modified with oil. Coating that contains alkyd resins in the binder.

Fire Resistance

The ability of a coating to withstand fire or to protect the substrate to which it is applied from fire damage.

Adhesion

The ability of dry paint to attach to and remain fixed on the surface without blistering, flaking, cracking or being removed by tape.

Color Retention

The ability of paint to keep its original color. Major threats to color retention are exposure to ultraviolet radiation and abrasion by weather or repeated cleaning.

Volatility

The defining quality of a liquid that evaporates quickly when exposed to air.

Post-Consumer Paint Management

The following steps are recommended for dealing with post-consumer (leftover) paint: 1. Purchase the correct amount of paint 2. Store paint properly 3. Use leftover paint 4. Reuse (donate) or recycle 5. Dispose of paint properly (a last resort)

Propellant

The gas used to expel materials from aerosol containers.

Polymerization

The interlocking of molecules by chemical reaction to produce very large molecules. The process of making plastics and plastic-based resins.

Gloss

The luster or shininess of paints and coatings. Different types of gloss are frequently arbitrarily differentiated, such as sheen, distinctness-of-image gloss, etc. Trade practice recognizes the following gloss levels, in increasing order of gloss:flat (or matte)-- practically free from sheen, even when viewed from oblique angles (usually less than 15 on 60-degree meter); eggshell-- usually 20-35 on 60-degree meter; semi-gloss--usually 35-70 on 60-degree meter; full-gloss--smooth and almost mirror-like surface when viewed from all angles, usually above 70 on 60-degree meter.

Solids

The part of the coating that remains on a surface after the vehicle has evaporated. The dried paint film. Also called Nonvolatile.

Nonvolatile

The portion of a coating left after the solvent evaporates; sometimes called the solids content.

Cure, Curing

The process whereby a liquid coating becomes a hard film.

Viscosity

The property of a fluid whereby it tends to resist relative motion within itself.

Coalescent Aid

The small amount of solvent contained in latex coatings. Not a true solvent since it does not actually dissolve the latex resins, the coalescent aid helps the latex resins flow together, aiding in film formation.

Earth Pigments

Those pigments that are obtained from the earth, including barytes, ocher, chalk and graphite.

Driers

Various compounds added to coatings to speed the drying.

Titanium Dioxide

White pigment in virtually all white paints. Prime hiding pigment in most paints.

Cohesion

A bonding together of a single substance to itself. Internal adhesion.

Paint Remover

A chemical that softens old paint or varnish and permits it to be easily scraped off. Also called "stripper."

Paint

A coating including resin, a solvent, additives, pigments and, in some products, a diluent. Paints are generally opaque, and commonly represent the portion of the industry known as "architectural coatings."

Shellac

A coating made from purified lac dissolved in alcohol, often bleached white.

Fire Retardant

A coating which will (1) reduce flame spread, (2) resist ignition when exposed to high temperature or (3) insulate the substrate and delay damage to the substrate.

Gloss Meter

A device for measuring the light reflectance of coatings. Different brands with the same description (such as semi-gloss or flat) may have quite different ratings on the gloss meter.

Lacquer

A fast-drying usually clear coating that is highly flammable and dries by solvent evaporation only. Can be reconstituted after drying by adding solvent. Historical Note: The word lacquer is derived from the word lac, which describes the secretions of the lac beetle. This insect, found mainly in Asia, deposits its secretions on branches of trees and this crop is later harvested. The resin developed by the insects, in its original state, contains a red dye. This dye is separated from the resin by boiling in water. Next the residue resin, known as seed lac, is melted, strained, cooled and flaked and then becomes shellac.

Amide

A functional group which can act as an epoxy resin curing agent.

Butadiene

A gas which is chemically combined with styrene to create a resin used in latex binders, styrene-butadiene.

Creosote

A liquid coating made from coal tar once used as a wood preservative. It has been banned for consumer use because of potential health risks.

Diluent

A liquid used in coatings to reduce the consistency and make a coating flow more easily. The water in latex coatings is a diluent. A diluent may also be called a "Reducer," "Thinner," "Reducing Agent" or "Reducing Solvent."

Inert

A material that will not react chemically with other ingredients.

Chroma

A measurement of color. The degree of saturation of a hue. A color at its full intensity has maximum chroma.

Intumescence

A mechanism whereby fire-retardant paints protect the substrates to which they are applied. An intumescent paint puffs up when exposed to high temperatures, forming an insulating, protective layer over the substrate.

Lead

A metal, previously used as a pigment in paints. Discontinued in the early 1950s by industry consensus standard, and banned by the Consumer Products Safety Commission in 1978 because of its toxicity.

Emulsion

A mixture of solids suspended in a liquid.

Oleoresin

A natural plant product that contains oil and resins. Turpentine is an example.

Oil Paint

A paint that contains drying oil, oil varnish or oil-modified resin as the film-forming ingredient. The term is commonly and incorrectly used to refer to any paint soluble by organic solvents.

Coating

A paint, varnish, lacquer or other finish used to create a protective and/or decorative layer. Generally used to refer to paints and coatings applied in an industrial setting as part of the original equipment manufacturer's (OEM) process.

Naphtha

A petroleum distillate used mostly by professionals (as opposed to do-it- yourself painters) for cleanup and to thin solvent-based coatings. A volatile organic compound (see VOC).

Aerosol

A product that uses compressed gas to spray the coating from its container. Historical Note: Aerosol paint products have not contained chlorofluorocarbons--CFCs--since 1978.

Silicone

A resin used in the binders of coatings. Also used as an additive to provide specific properties, e.g., defoamer.Paints containing silicone are very slick and resist dirt, graffiti and bacterial growth, and are stable in high heat.

In-place Management

A series of steps used as an alternative to lead-based paint removal. Improves condition of intact lead-based paint to reduce and/or eliminate hazards without total removal.

Flat

A surface that scatters or absorbs the light falling on it so as to be substantially free from gloss or sheen (0-15 gloss on a 60-degree gloss meter).

Acrylic

A synthetic resin used in high-performance water-based coatings. A coating in which the binder contains acrylic resins.

Polyvinyl Chloride

A synthetic resin used in the binders of coatings. Tends to discolor under exposure to ultraviolet radiation. Commonly called "vinyl."

Clear Coating

A transparent protective and/or decorative film; generally the final coat of sealer applied to automotive finishes.

Corrosion Inhibitive

A type of metal paint or primer that prevents rust by preventing moisture from reaching the metal. Zinc phosphate, barium metaborate and strontium chromate (all pigments) are common ingredients in corrosion-inhibitive coatings. These pigments absorb any moisture that enters the paint film.

Lithopone

A white pigment of barium sulfate and zinc sulfide. Historical Note: Lithopone was once a primary substitute for lead carbonate or "white lead" pigments; it has been largely replaced by titanium dioxide.

Film Build

Amount of thickness produced in an application. Millimeters (mils) of dry film per mils of applied wet film.

Urethane

An important resin in the coatings industry. A true urethane coating is a two-component product that cures when an isocyanate (the catalyst) prompts a chemical reaction that unites the components.

Drying Oil

An oil that when exposed to air will dry to a solid through chemical reaction with air: linseed oil, tung oil, perilla, fish oil, soybean oil.

Solvent

Any liquid which can dissolve a resin. Generally refers to the liquid portion of paints and coatings that evaporates as the coating dries.

Substrate

Any surface to which a coating is applied.

Forced Dry

Baking the paint between room temperature and 150� F to speed the drying process.

Enamel

Broad classification of paints that dry to a hard, usually glossy finish. Most equipment-coating enamels require baking. Enamels for walls do not.

Oxidation

Chemical reaction upon exposure to oxygen. Some coatings cure by oxidation, when oxygen enters the liquid coating and cross-links the resin molecules. This film-forming method is also called "Air Cure" and "Air Dry." (Oxidation also causes rust on bare metals.)

Emulsion Paint

Coating in which resins are suspended in water, then flow together with the aid of an emulsifier. Example: latex paint.

Marine Paint:

Coating specially designed for immersion in water and exposure to marine atmosphere. (See also Anti-fouling Paint)

Hardener

Curing agent for epoxies or fiberglass.

Film Thickness

Depth or thickness of the dry coating in millimeters.

Turpentine

Distilled pine oil, used as a cleaner, solvent or thinner for oil-based and alkyd coatings.

Linseed Oil

Drying oil made from the flax seed. Used as a solvent in many oil- based paints. "Boiled" linseed oil can be used to protect wood from water damage. Sometimes used as a furniture polish.

Epoxy

Extremely tough and durable synthetic resin used in some coatings. Epoxy coatings are extremely tough, durable and highly resistant to chemicals, abrasion, moisture and alcohol.

Primer

First complete coat of paint of a painting system applied to a surface. Such paints are designed to provide adequate adhesion to new surfaces or are formulated to meet the special requirements of the surfaces.

Chalking

Formation of a powder on the surface of a paint film caused by disintegration of the binder during weathering. Can be affected by the choice of pigment or binder.

Blistering

Formation of dome-shaped projections in paints or varnish films resulting from local loss of adhesion and liftingof the film from the underlying surface.

Latex-based Paint

General term used for water-based emulsion paints made with synthetic binders such as 100% acrylic, vinyl acrylic, terpolymer or styrene acrylic. A stable emulsion of polymers and pigment in water.

Eggshell

Gloss lying between semigloss and flat.

HEPA Vacuum

High-efficiency particulate air-filtered vacuum designed to remove lead- contaminated dust.

Material Safety Data Sheet (MSDS)

Information sheet that lists any hazardous substance that comprises one percent or more of the product's total volume. Also lists procedures to follow in the event of fire, explosion, leak or exposure to hazardous substance by inhalation, ingestion or contact with skin or eyes. Coatings manufacturers are required to provide retailers with an MSDS for every product they sell to the retailer. Sales clerks should make MSDSs available to retail customers.

Extender

Ingredients added to paint to increase coverage, reduce cost, achieve durability, alter appearance, control rheology and influence other desirable properties. Less expensive than prime hiding pigments such as titanium dioxide. Examples: barium sulphate, calcium carbonate, clay, gypsum, silica, talc. May also improve coating performance.

Pigment

Insoluble, finely ground materials that give paint its properties of color and hide. Titanium dioxide is the most important pigment used to provide hiding in paint. Other pigments include anatase titanium, barium metaborate, barium sulphate, burnt sienna, burnt umber, carbon black, China clay, chromium oxide, iron oxide, lead carbonate, strontium chromate, Tuscan red, zinc oxide, zinc phosphate and zinc sulfide.

Abatement

Involves either removal of the painted surface, covering the painted surface with an impermeable surface, or covering surface with heavy-duty coating (encapsulant).

White Lead

Lead carbonate. A poisonous basic salt Pb 3 (OH) 2 (CO 3 ) 2 that was formerly used as a white pigment in paints, that was a common cause of painter's colic, and that may cause lead poisoning especially in children who come in contact with or ingest paint from older surfaces which contain it

Boiled Oil

Linseed (sometimes soya) oil that was formerly heated for faster drying. Today, chemical agents are added to speed up the drying process.

Rosin

Natural resin obtained from living pine trees or from dead tree stumps and knots.

Dead Flat

No gloss or sheen.

Colorant

Non-fading in prolonged exposure to light.

Air Cure

One method by which liquid coatings cure to a dry film. Oxygen from the air enters the film and cross-links the resin molecules. Also called "Air Dry" and "Oxidizing."

Volatile Organic Compound

Organic chemicals and petrochemicals that emit vapors while evaporating. In paints, VOC generally refers to the solvent portion of the paint which, when it evaporates, results in the formation of paint film on the substrate to which it was applied.

Mineral Spirits

Paint thinner. Solvent distilled from petroleum.

Anti-fouling Paint

Paints formulated especially for boat decks and hulls, docks and other below-water-line surfaces and structures to prevent the growth of barnacles and other organisms on ships' bottoms.

Hazardous Air Pollutant (HAP)

Pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects.

Vehicle

Portion of a coating that includes all liquids and the binder. The vehicle and the pigment are the two basic components of paint.

Dry Colors

Powder-type colors to be mixed with water, alcohol or mineral spirits and resin to form a paint or stain.

Galvanizing

Process in which a thin coating of zinc is applied to iron or steel to prevent rust.

Natural Resins

Resins from trees, plants, fish and insects. Examples: damars, copals.