Isocryl EP-550

Isocryl EP-550 is the original matting hardener of the Isocryl line that now includes EP-550, EP-560 and EP-570. Isocryl EP-550 can be formulated with low viscosity, linear, carboxyl-functional polyesters having acid values 30-35 to generate low-gloss, weatherable, TGIC-free powder coating systems. A typical binder consists of 75 parts polyester and 25 parts Isocryl EP-550. Mechanical properties and chemical resistance are enhanced with the use of Estron’s specialty additive ESCAT 22 in the formulation, which is generally used at one-tenth the amount of the Isocryl EP-550.

As with any raw material, laboratory evaluation is required for each formulation to determine the best processing method and the optimum concentration of the binder components. In addition to matte finishes with Isocryl EP-550, mid-gloss powder coatings are possible with some formulation adjustments such as using two polyesters of differing viscosities, or by addition of a co-reactant such as Estron’s GMA-300. The ability to adjust the 60° gloss from 5 to 50% is a key attribute of Isocryl EP-550. Additional formulating tips and application data for Isocryl EP-550 are provided in the Technical Briefs #1, #2, and #3.