<I>EASTMAN</I> PIA (Purified Isophthalic Acid) 1,3-Benzenedicarboxylic Acid 121-91-5 Eastman Chemical Company Solvent Alkyd Resins Polyester Coatings Automotive OEM Coil Coating General Industrial /Maintenance Powder coating Transportation >> Aerospace Industry Eastman PIA (Purified Isophthalic Acid) is the industry standard diacid component in high-quality alkyds and polyester resins for industrial coatings and unsaturated polyesters for fiberglass-reinforced plastics applications. Polyester resins containing PIA exhibit excellent outdoor weathering relative to those containing phthalic anhydride and terephthalic acid. The excellent hardness and high glass transition temperature imparted by PIA leads to improved chemical, stain, humidity, and corrosion resistance required in coatings for industrial maintenance, automotive, aerospace, general metal and coil coating applications. Powder coatings formulated with PIA are used in exterior applications such as patio furniture, lawn mowers, vending machines, and automotive parts. One of the largest applications for Eastman PIA is in unsaturated polyester resins for high-quality gel coats. The hardness, stain and detergent resistance characteristics of PIA are ideal for polyester solid-surface countertops that are an inexpensive alternative to acrylics. It has excellent thermal stability for low resin color, high heat distortion temperature, outstanding hardness, excellent weathering, outstanding boiling water and stain resistance, superior corrosion and stain resistance. It is used in high molecular weight thermoplastic polymer (PET) modifier, polyester-melamine baking enamels, unsaturated polyester resins for high-performance gel coats, polyester polyols for polyurethane coatings, super-weatherable powder coatings and waterborne polyester resins with good hydrolytic stability. Purified isophthalic acid. Used in coatings for industrial maintenance, automotive, aerospace, powder coatings, general metal and coil coating applications. Offers very good hardness and weathering. Provides very good boiling water and stain resistance. Exhibits superior corrosion and stain resistance.