Paint & Coatings Industry - March 2008 - (Page 40)

Reaching Strict VOC Requirements with Outstanding Durability Table 2 | Silicone epoxy formulations. Figure 8 | Color change on South Florida exposure on Aluminum. 3 Component A Silicone Silicone Silicone I II Amine SILRES® SY 231 Aliphatic epoxy Silicone defoamer Additol XL 121 Acid functional acrylic Titanium dioxide Disperse to a Hegman >7 (4000 rpm, dispermat) Acid functional acrylic Acetone Mix thoroughly Subtotal 69.8 0.0 0.9 0.2 250.0 248.2 69.8 0 0.9 0.2 250 248.2 0 405.1 0.9 3.1 0 366 Panels washed Color Change (Delta E) 2 1 0 0 1 Commercial Urethane (white) Silicone epoxy II/Acrylic (gray) Silicone amine/epoxy (white)* 2 3 Silicone epoxy I/Acrylic (gray) Silicone epoxy I/Acrylic (white) 4 328.5 0.0 897.6 328.5 0 897.6 0 122.5 897.6 Time (Years) Component B SILRES® HP 1000 SILRES® HP 1250 SILRES® HP 2000 Subtotal Total (Component A+B) Silicone content of paint by wt. Silicone content on solids by wt. 87.74 0 0 87.7 985.3 16% 19% 0 203.5 0 203.5 1101.1 25% 29% 0 0 449.5 449.5 1347.1 33% 37% Figure 9 | Gloss change on South Florida exposure on steel. 100 90 80 70 60 50 40 30 20 10 0 1 Commercial Urethane Silicone epoxy II/Acrylic Panels washed 2 Silicone epoxy I/Acrylic Epoxy/Acrylic (Non-Iso) 3 Time (Years) Figure 10 | Color change on South Florida exposure on steel. 3 2 1 Panels washed 0 0 1 2 3 Commercial Urethane Silicone epoxy II/Acrylic Silicone epoxy I/Acrylic Epoxy/Acrylic (Non-Iso) Time (Years) 40 MARCH 2008 | W W W . P C I M A G . C O M ural sunlight (Figures 9 and 10). The non-iso system had excellent performance in QUV but dropped significantly after 1-2 years exposure in South Florida. The other variables not measured by QUV are the effect of dirt pickup, abrasion due to blowing particulate, colder climates and wind driven rain. The exposure panels were prepared from the same paints to minimize variability when comparing QUV verses Florida exposures. The silicone epoxy I and silicone epoxy II performed better than urethane and non-iso systems. The silicone epoxy (Figure 11) used in the silicone epoxy I/acrylic formulation is used as the crosslinker for the acid-functional acrylic, which is approximately 16% by weight based on total formulation (Table 2). The silicone epoxy II had a lower functionality and, therefore, the coating formulation (silicone epoxy II/acrylic) contained much higher silicone content (25%). The commercial urethane had a gloss of 26 versus the silicone epoxy I formulation having 38-39 and the silicone II having 66 measured at a 60° angle. The silicone epoxy II had less than 53% change in color (delta E 1.28) compared to the urethane (delta E of 2.42) after 4 years. Increasing the silicone content of the addition curing technology will further increase the performance as it relates to gloss and color retention. If gloss and color were the only predictors for exterior durability, the silicone epoxy II system would last 2.5 times longer than the urethane technology and the silicone epoxy I would last ~30% longer. Color Change (Delta E) Gloss (60 deg.) http://WWW.PCIMAG.COM

Table of Contents Feed for the Digital Edition of Paint & Coatings Industry - March 2008

Viewpoint Industry News Calendar of Events Company News Mergers and Acquisitions Names in the News Marketplace Quarterly Stock Watch Reaching Strict VOC Requirements With Outstanding Durability for Industrial Maintenance and Marine Coatings A Unique Fungicide for Wood-Filled Plastic deSigns of the Times: Slacking Off! From Rocks to Nanos Shear-Free Dispersion Process Fluorinated Oxetane Oligomers as Versatile Intermediates for Polymer Modification The Effects of TPO Composition on Adhesion and Proposed Chemical Mechanism Supplier Showcase Color Management Materials Watch Products Classifieds Advertiser Index

Paint & Coatings Industry - March 2008

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