Cymel 683 n-Butylated melamine resin Cytec Amino Resins >> Urea based (incl. UF) n-Butanol N-BUTYLATED MELAMINE RESINS N-butylated resins in this category are very polymeric in nature. They differ in extent of methylolation, butylation and polymerization. In general, higher extents of methylolation and butylation result in more hydrophobic resins with lower viscosities, higher stability, slightly higher film flexibility, film gloss and adhesion but slower cure response. Higher extents of polymerization result in faster film property development but also in higher viscosities, and therefore higher VOCs. None of the resins in this category require the addition of a strong acid catalyst for adequate cure at 125-150°C. Usually, the acidity of the other resin components in the formulation results in sufficient catalysis. In addition to reacting with hydroxyl, carboxyl and amide functionalities on polymers, these resins self-condense readily. Their practical equivalent weight is typically 220-280 on a solids basis. High concentrations of the melamine resins in the formulation result in high film hardness and improved exterior durability but, possibly, lower film flexibility and lower adhesion properties. They, too, can be stabilized by adding amines and stabilizing alcohol to the formulation. CYMEL 683 Medium reactivity. Excellent compatibility. n-Butylated melamine resin. Possesses very polymeric nature. Does not require addition of a strong acid catalyst. Reacts with hydroxyl, carboxyl and amide functionalities on polymers. Provides high film hardness and improved exterior durability. Gives medium reactivity and very good compatibility.