2 сентября, 2015 
Malyar Industrial protective coatings cover heavy duty, maintenance and marine systems including coatings for structural steel, ships, tanks, off shore installations, mining, oil and gas pipelines and refineries.
In the case of topcoats, the two pack acrylic polyurethane almost invariably uses aliphatic isocyanates because of their excellent appearance characteristics and long term durability. The carbon carbon backbone and urethane linkage also impart excellent resistance to chemicals, fuels and environmental conditions.
The acrylic topcoat is normally applied over an epoxy primer or an inorganic/organic zinc rich primer, which maximises the anti-corrosion characteristics of the complete system.
The type of OH functional acrylic polymer selected will be dependent on the level of resistance required, hardness/flexibility, ease of application and aesthetic requirements.
The second component in the two pack is a polymeric multi functional isocyanate. The isocyanate group is extremely hydrogen acquisitive and will therefore abstract hydrogen from the hydroxy functional acrylic resin, forming a urethane link in the process. The multi functionality of the isocyanate ensures the formation of a network structure. Reactions take place at ambient temperatures or can be forced along at slightly above ambient temperatures, e. g. 60°C for 20 minutes as a typical cure cycle.
Acrylic resins are particularly popular as partners with isocyanates for several reasons. The obvious alternatives are polyesters and alkyds. It is quite possible to formulate a paint with an alkyd or polyester resin in combination with an isocyanate which will have comparable film properties — durability, toughness, chemical resistance, but the predominant choice in the industrial market is acrylic.
Acrylic polymers are, by their nature, higher molecular weight, ‘bigger’ molecules than their polyester equivalents. This means that during the cure process, less crosslinking is required to achieve a final coating with the desired properties. This in turn means that less isocyanate co-reactant is required, resulting in a cheaper formulation as the isocyanate resin is usually more expensive than either the acrylic or polyester.
A further big advantage of acrylic polyurethane paints is that when the solvent has evaporated, the paint film is lacquer dry. In an ambient cure industrial paint finishing situation, the acrylic polyurethane appears to have cured before the crosslinking reaction is complete. A comparable polyester polyurethane would still be too soft to handle, thus extending the painting time. Rapid handling time on an industrial production line is important.
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