Pigments added to coating formulations to provide an appealing look, besides coloring the coating. For this purpose, aluminum pigments and mica based pearlescent pigments of platelet shape are widely used. There is a special aesthetical expectation from basecoat applications containing metalic or pearlescent (or micaceous) pigments: the flip-flop property. This coating property, formed by parallel allignment of aluminum or pearlescent platelets to the surface, leads to a mirror-like appearance when looked from the front, and to a dark color appearance when looked from a very low angle. Transparency of the film formed by binders enhances the flip-flop effect.

Certain mechanic tests applied to determine the elasticity of dry coating film. Elasticity measurement tests (deep-cupping, bending, impact) are also used to measure toughness.

Natural or synthetic polymer that can be elongated to at least double its length at room temperature and can recover to its original length after removal of force. Vulcanized rubber usually demonstrates elastomeric behaviour.

See Conductivity

In coatings industry, conductivity is frequently used to state the electrical conductivity of wet coating or dry coating film. 1) It is important that electrical conductivity of a solventborne wet coating is convenient for electrostatic spraying application. 2) If a dry coating film is conductive enough, it enables application of another layer of coating by electrostatic spraying or electrophoresis.
 

Term generally used in coatings industry to describe the electrical resistivity of wet paints. In order for the wet paint to be sprayed by electrostatic methods, it has to reach to the cathodic surface with the effect of electrical attraction forces. For this purpose, electrical resistance of the we paint should be below a certain value. In other words, the wet paint has to be sufficiently conductive. See Also Conductivity

In coatings industry, conductivity is frequently used to state the electrical conductivity of wet coating or dry coating film. 1) It is important that electrical conductivity of a solventborne wet coating is convenient for electrostatic spraying application. 2) If a dry coating film is conductive enough, it enables application of another layer of coating by electrostatic spraying or electrophoresis.
 

Coating of an object with paint particles after dipping into an emulsion paint bath as an electrode and applying external current.

Coatings, on generally steel based surfaces, obtained by connecting the surface to an electrolysis circuit as the cathode leading to formation of a thin zinc layer on the surface. Electrogalvanic coatings provide corrosion resistance to the steel based surface with the help of the thin zinc layer.

Process of migration of electrically charged emulsified particles to the oppositely charged electrode and deposition on the electrode under an electrical current. If the material migration under the influence of the electric field occurs by movement of (+) charged particles to cathode, the process is called cataphoresis. Similarly, if (-) charged particles move towards the anode, the process is called anaphoresis.

Through these applications, powder coating fluidized by mixing with air is sprayed using a powder gun with an orifice. A high voltage of 40-100 kV connected to a negative electrode at the orifice ionizes air molecules. This cloud of ions is called “corona”. Powder particles pick-up anions when passing through the corona and become negatively charged. Since the object to be coated has become anode because of grounding it attracts particles to its surface. Particles are neutralized when they reach the surface. Loose powder coating film, turns to a tough, durable, continuous, film with good adhesion after baking.

Spray coatings performed by negatively charging the paint or surrounding the sprayed paint with ionized air (:corona) and connecting the application surface to the circuit as the positively charged electrode. Electrostatic spray coating is used for both wet and powder coatings because of the minimum transfer loss as a result of the movement of particles directly to the surface with the electrical attraction forces.

System formed by suspension of a liquid in another immiscible liquid as droplets larger than a colloidal state.

Waterborne emulsion paints

Paints in which waterborne emulsion polymers are used as binders.

Waterborne emulsion polymers

Waterborne emulsion polymers are suspensions of small polymer droplets which are stabilized by emulsifiers in water. If the polymerization occurs in the droplets formed by raw materials, the emulsion is called “primary emulsion”. If the solution of a solventborne polymer is emulsified in water, than it is called “secondary emulsion”.

During obtaining of wooden materials, if the cutting direction is perpendicular to the grain direction of wood, it is called end cutting. See Also Edge Cutting

Edge cutting

During obtaining of wooden materials, if the cutting direction is parallel to the grain direction of wood, it is called edge cutting. See Also End cutting

Compound obtained by starting from chlorination of propylene and used in production of epoxy resins and epichlorohydrin rubber.
Chemical name: Chloromethyloxirane
Chemical formula: 
Boiling point: 116°C

See Oxirane groups

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OsmosisThink of two fluids with the same chemical composition but differing in concentration which are separated by a semi-permeable membrane. This membrane permits passage of small size solvent molecules but not the large solute molecules. Movement of solvent molecules from an area of low solute concentration to an area of high solute concentration is called “osmosis”. During osmosis, movement of solvent molecules leads to an increase in mass followed by an increase in pressure. The equilibrium in osmosis is reached when concentration difference (driving force of osmosis) and pressure difference which acts against it balance each other.

 

Organic coating resins obtained by reaction of Bisphenol A based epoxy resins with fatty acids; solvent or water thinning versions can be produced. Air drying or oven drying epoxy resins can be synthesized depending on the fatty acid type used.

Resins carrying two or more extra epoxy groups at the ends of their polymer chains. The most widely used type is produced by reaction of epichlorohydrine (chloromethyl oxirane) and bisphenol A (diphenylolpropane). Liquid or solid epoxy resins can be produced depending on the length of the polymer chain. For organic coatings, epoxy resins are reacted with polyamides, polyaminoamides, isocyanate compounds, amino resins and ketimines. Epoxy resins are used in production of organic coatings with superior adhesion, chemical resistance and corrosion resistance.

Epoxy based coatings in which ketimine compounds are used as hardeners. Typical epoxy-amine crosslinking reaction occurs as a result of decomposition of ketimine to amine and ketone in the presence of water or moisture. See Also Moisture curing coatings

Resins with isocyanate functionality react with moisture in the air to form polyurea. The coatings produced form these resins are called “moisture curing coatings”. Epoxy-ketimine based 2K coatings are also called moisture curing coatings because amine produced from the reaction  of ketimine with water, forms a cross-linked network.
 

Two component coatings having one epoxy resin based and one polyamide resin based component.

See Deep cupping

Test performed by pushing a knob with a constant speed against the back side of a coated panel causing deformation. During the test, also called Erichsen deformation test, knob is stopped when the first sign of crack formation is observed, deformation depth is measured in mm and this value is defined as deep cupping resistance.

 

Organic compounds formed by condensation reaction of organic acids and alcohols.

Ethanol, just like methanol, is not a strong solvent for most of the polymers. However, blending with aromatics causes a strong solvent effect.
Chemical name: Ethyl alcohol
Chemical formula: 
Boiling point: 78,3°C; evaporation number relative to ether: 8,3; specific gravity: 0,789; refractive index: 1,3614; flash point: 12°C

2-(2-ethoxy) ethoxy ethanol

See Ethyl diglycol

Methanol / Methyl Alcohol

Due to the lack of good solvency in most organic polymers, its use in paint industry is rare.
Chemical name: Methyl alcohol
Chemical formula: 
Boiling point: 64,7°C; Evaporation number based on the ether: 6,3; Specific gravity: 0,792; Refractive index: 1,3287; Flash point: 11°C

Cyclohexanedimethylol (CHDM)

Polyol that is used in exterior-use industrial coating polyesters which require high water and UV resistance.
Chemical name: 1,4-cyclohexane dimethylol, 1,4-dimethylcyclohexane
Chemical formula: 

Melting point: 35°C

Type of ester that is a strong solvent for a wide range of polymers including many cellulose derived resins, polyvinyl acetate and polyesters.
Chemical name: Acetic acid ethyl ester
Chemical formula: 

Boiling point: 77,2°C; evaporation number relative to ether: 2,9, specific gravity: 0,901; refractive index: 1,3725; flash point: –4°C

Water soluble cellulose ether resins obtained by reaction of cellulose with ethanol. They are used as binders in water-borne architectural coatings and as thickeners.

Tail solvent of ether alcohol structure, used to retard drying of cellulose derived resins, epoxy resins, polyester resin based coating systems and water-borne coatings at low quantities such as 1-2 %.
Chemical name: Diethylene glycol mono ethyl ether; 2-(2-ethoxyethoxy)ethanol (also known by the commercial name Carbitol)
Chemical formula: 

Boiling point: 202°C; evaporation number relative to ether: ~1200, specific gravity: 0,990; refractive index: 1,4270; flash point: 90°C

Ethyl diglycol acetate

Tail solvent used to retard drying of cellulose derived resins, polyester resins and short oil alkyd based coating systems at low quantities such as 1-2 %.
Chemical name: Diethylene glycol mono ethyl ether acetate; 2-(2-ethoxyethoxy) ethyl acetate.
Chemical formula: 

Boiling point: 217°C; evaporation number relative to ether: >1200, specific gravity: 1,009; refractive index: 1,4213; flash point: 98°C

Tail solvent used to retard drying of cellulose derived resins, polyester resins and short oil alkyd based coating systems at low quantities such as 1-2 %.
Chemical name: Diethylene glycol mono ethyl ether acetate; 2-(2-ethoxyethoxy) ethyl acetate.
Chemical formula: 

Boiling point: 217°C; evaporation number relative to ether: >1200, specific gravity: 1,009; refractive index: 1,4213; flash point: 98°C

Group of coating binders that is obtained by reaction of silica with ethyl groups and that provides high corrosion resistance. Most widely used example is tetraethylorthosilicate monomer. They are used in production of zinc-rich waterborne primers.

Type of polyol that is obtained by hydration of ethylene oxide and is a petrochemical product. It is widely used in making of alkyd and polyester resins. Also widely used in closed circuit anti-freeze solutions.
Chemical name: Ethane-1,2-diol
Chemical formula: 

Boiling point: 197°C; specific gravity: 1,113; refractive index: 1,4310; flash point: 110°C

Monoethylene glycol See Ethylene glycol

Type of synthetic rubber. Tailor-made plastics with adjusted strength, flexibility and brittleness are obtained by preparation of alloys of ethylene propylenediene polymer and polypropylene (PP/EPDM) at various ratios. PP/EPDM alloys are most widely used for automotive bumpers.

“Evaporation number” is defined as the ratio of time spent to completely evaporate a certain amount of solvent at 20°C temperature and 65% relative humidity, to the time spent to completely evaporate the same amount of reference solvent under same conditions. Diethyl ether is widely used as the reference solvent in Europe. In America and Far East, the most widely used reference solvent is n-butyl acetate.

The coefficient indicating how fast a solvent or a solvent blend evaporates compared to a reference solvent. Diethyl ether and butyl acetate are widely used as referance solvents. See Also Evaporation number

“Evaporation number” is defined as the ratio of time spent to completely evaporate a certain amount of solvent at 20°C temperature and 65% relative humidity, to the time spent to completely evaporate the same amount of reference solvent under same conditions. Diethyl ether is widely used as the reference solvent in Europe. In America and Far East, the most widely used reference solvent is n-butyl acetate.
 

General name for micron-sized powder coating input materials, many of which are comprised of grinded natural minerals (baryte, calcite, talc, kaolin, mica) and some of which are obtained by synthetic methods (Blanc Fixe, lithopone). While main reason for using extenders is cost reduction, they can also be used to improve certain properties. For extenders used in pigmentless coatings, it is crucial that extenders are also colorless and have refractive indicis close to the binder’s refractive index in order for the transparent look not to be affected.

Dispersion of pigments and extenders

Breaking down of pigment flocculates which are combined as agglomerates or aggregates, in a binder and solvent medium. Dispersion of pigments and extenders is performed using high-speed dispersers and wet mills.

Silica extenders

Quartz powder which is obtained by grinding amorphous quartz is widely used in paint industry as matting additive. Furthermore, SiO2 based on diatomaceous earth is used for the same purpose. Moreover, pyrogenic silica obtained by burning of silicon tetrachloride (SiCl4) is used as rheology modifier in paints.