Coating Terms

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Aluminum pigments are used to create a metallic effect on painted surfaces. They are composed of pure aluminum platelets of 10-30 micrometers diameter and of 0,1-0,9 micrometer thickness. See Effect pigments
Functional pigments added to the paint formulation in order to improve the corrosion resistance of the paint. Most widely used anticorrosive pigments are: chromates, phosphate, phosphosilicate and borosilicate salts, having controlled water solubilities and inactivating the metal surfaces; zinc powder, cathodically protecting the coated metal surfaces; and micaceous iron oxide (MIO or MIOX), having a plate-like structure and acting as a water barrier for metal surfaces.
Natural or synthetic oxides of iron are considered to be the oldest and the most widely used pigments. Oxides of the Fe2O3 structure are red, Fe2O3xH2O structure are yellow, Fe3O4 structure are black, and different mixtures of FeO and Fe2O3 are used as brown pigments.
Flourescent pigments, after absorbing the UV spectral part of the light, return the UV light energy in the form of a blue visible light together with some heat energy. Therefore, flourescent pigments emit more visible light than they are exposed to.
Phosphorescent pigments, following absorption of the UV spectral part of the light, return some of the energy as heat energy; after a time lag they emit the rest of the energy in the form of a blue visible light. Therefore, phosphorescent pigments continue to emit a blue light also after removal of the light source.
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.
Inorganic based pigments, most of which are formed by metal oxides, metal oxide mixtures and carbon black. Almost all inorganic pigments used today are obtained synthetically.
Pigment volume concentration at which all the binder in a coating formulation is used up to wet the pigments and to fill up the pigment pores, leaving no free binder.
Group of pigments synthesized from basic organic molecules and possessing the ability to enhance the aesthetics in paint industry by virtue of their wide range of colors.
Pigments are finely ground, organic solvent and water insoluble chemical substances that impart color, various visual effects and in some cases corrosion resistance to paint. Two main differences between pigments and dyestuffs are pigments are insoluble in both organic solvents and water and pigments have better exterior durability than dyestuffs.
The percentage ratio of the volume of total pigment (and extender) to the volume of total nonvolatile material present in paint formulation.

Chemical groups present in dispersion additives to ease the attachment to the surfaces of polar pigments. Pigment affinic groups comprise carboxylic acid, amine, isocyanate and their derivatives.
Paint semi-product which has a higher pigment content and generally a higher viscosity then the finished paint.
Although pigments and extenders are produced as primary particles, they form aggregates and agglomerates when they are in touch with each other in bulk phase. In dispersion stage, these pigment clusters are tried to break down to primary particles. If dispersed pigments are not stable, they form loosely combined units called flocculates. Since, the distinction between these three terms might not be clear, for a better understanding a schematic representation is given below.



See Also Aggregate, Agglomerate, Flocculate
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.
The ratio by weight of pigment content to solid binder content in paint formulation. See Also Solid binder content
Pigments produced by coating TiO2 or some other oxides at varying thickness from 120 nm to 160 nm on the mica flakes of 100–500 nm (0,1–0,5 µm) thick. Nacreous pigments are perceived in different colors and sheen depending upon the viewing angle. Mica based nacreous pigments impart color to the coating by light interference caused by mica flakes of the same thickness with the wavelengths in visible light spectrum (100–500 nm). See Also Effect pigments
In this paint production approach, a resin with a high compatibility range is selected as main dispersion resin and different pigments are dispersed separately to a certain grain size using this resin. Color matching is performed using this pigment pastes and letdown is done by adding remaining ingredients after a proper calculation. The main advantages of this approach are, better optimization of capacity of production equipment (especially the mills) and storage areas in addition to reduced production times. It is achieved by producing common pigment pastes, which can be used in various product groups owing to the compatible resin used. The drawback of this approach is the difficulties in sensitive color matching because of highly concentrated pigment pastes in addition to the possibility of decrease in color strength, gloss as well as haze and formation of particles due to pigment flocculation during storage.