Adding Value to Industrial Coatings by Using Epoxy Functional Silicone Resins
Coatings used on petrochemical manufacturing facilities, oil-drilling platforms and above-water marine applications generally face exposure to corrosive environments from water and/or harsh chemicals, as well as intense radiation exposure from sunlight. Standard coatings last approximately 7 years for topside (above-water applications), and 3 years for applications that have continuous exposure to water (splash zone). Coating failure can be attributed to either cracking due to temperature variations and exposure to water, abrasion, pinholes during drying, or delamination of the film due to over application or high film build.
Coatings designed for the marine market have typically been formulated with an aromatic epoxy blended with mono or difunctional reactive diluents, silicone alkyds, aliphatic urethanes, and condensation-curable polysiloxane systems. Coatings utilizing the latter two chemistries have increased UV resistance and chemical resistance, however, there is still a problem with cracking in thicker films, and in some cases they do not meet the ever-changing VOC regulations. However, the use of silicone resins with epoxy functionality in conjunction with acid-functional acrylics increase resistance to cracking and improve UV resistance without sacrificing VOC.