Cymel 303 Hexamethoxymethylmelamine Cytec Crosslinking / Coupling / Curing Agents >> Amine Acrylic/Acrylate Resins Alkyd Resins Cellulosic Resins Epoxy Resins Polyester Polyurethane Coatings >> Solvent-Free/ High-Solids Coatings >> Waterborne Automotive refinishing Coil Coating Isobutanol CYMEL 303 crosslinking agent is a commercial grade of hexamethoxymethylmelamine supplied in liquid form at >98% non-volatile. It is a versatile crosslinking agent for a wide range of polymeric materials, both organosoluble and water borne. The polymeric materials should contain either hydroxyl, carboxyl or amide groups and would include alkyds, polyesters, acrylic, epoxy, urethane, and cellulosics. ADVANTAGES Solvent-free Wide compatibility and solubility Excellent stability Excellent hardness-film flexibility Fast catalyzed cure response Economical APPLICATION AREAS High solids finishes Water borne finishes Coil coatings Automotive finishes Container coatings General metals finishes Inks SOLUBILITY CHARACTERISTICS CYMEL 303 resin is soluble in most commonly used organic solvents, e.g., aromatic hydrocarbons, alcohols, esters, and ketone solvents. Solubility in water is limited; however, CYMEL 303 resin, when blended with most other water-reducible resins, tolerates dilution in water. REACTIVITY AND CATALYSIS Because of its high extent of alkylation, the reaction of CYMEL 303 resin with hydroxyl, carboxyl and amide funtionalities on other polymers is typically catalyzed by the presence of a strong acid catalyst (pKa value of <1). Usually, 0.5-1.0% (based on binder solids) of CYCAT® 4040 catalyst or CYCAT® 600 catalyst is recommended for a 15-20 minute bake schedule at 120-150°C. Higher concentrations might be necessary if there are basic pigments or additives in the formulation. Because of its high functionality and low tendency to self-condense, CYMEL 303 resin is a very effective crosslinking agent. When used with polyester resins, in particular, it can provide films with high flexibility and formability. Its effective equivalent weight will typically range from 130-190, but the CYMEL 303 resin loading should be determined experimentally for each formulation and with consideration of the performance properties to be optimized. STABILIZATION Solvent based coating formulations containing CYMEL 303 resin can be stabilized by adding either alcohol solvents or amines. For many high solids formulations, a combination of both is desired. Typically, for optimum pot life or storage stability, a formulation to be cured at 125°C could be catalyzed with 1% CYCAT® 4045 catalyst (an amine salt of p-toluene sulfonic acid) and 20-30% butanol solvent, both based on total resin solids. For a water borne system, the pH should be kept at >8 for optimum stability. FDA STATUS CYMEL 303 resin has FDA acceptance for food contact use as directed in the following sections of the Code of Federal Regulations: 21 CFR 175.300 Resinous and polymeric coatings 21 CFR 176.170 Components of paper and paperboard in contact with aqueous and fatty foods. 21 CFR 176.180 Components of paper and paperboard in contact with dry food. 21 CFR 175.320 Resinous and polymeric coatings for polyolefin films. 21 CFR 175.105 Adhesives. 21 CFR 177.2260 Filters, resin-based. It should be noted that some applications covered are subject to extractive limitations. We suggest that you consult the Code of Federal Regulations for specific details. Commercial grade of hexamethoxymethylmelamine supplied in liquid form at >98% non-volatile. Versatile crosslinking agent for a wide range of polymeric materials, both organosoluble and water borne. The polymeric materials should contain either hydroxyl, carboxyl or amide groups and would include alkyds, polyesters, acrylic, epoxy, urethane, and cellulosics. Solvent-free. Provides wide compatibility and solubility, excellent stability, excellent hardness-film flexibility, fast catalyzed cure response. Can be used for high solids finishes, water borne finishes, coil coatings, automotive finishes, container coatings, general metals finishes. Soluble in most commonly used organic solvents, e.g., aromatic hydrocarbons, alcohols, esters, and ketone solvents. Solubility in water is limited; when blended with most other water-reducible resins, tolerates dilution in water. Because of its high extent of alkylation, the reaction with hydroxyl, carboxyl and amide funtionalities on other polymers is typically catalyzed by the presence of a strong acid catalyst (pKa value of <1). Very effective crosslinking agent because of its high functionality and low tendency to self-condense. When used with polyester resins, in particular, it can provide films with high flexibility and formability. Its effective equivalent weight will typically range from 130-190. But loading should be determined experimentally for each formulation and with consideration of the performance properties to be optimized. Solvent based coating formulations containing it can be stabilized by adding either alcohol solvents or amines. For many high solids formulations, a combination of both is desired. For a water borne system, the pH should be kept at >8 for optimum stability. Has FDA acceptance for food contact use as directed in the following sections of the Code of Federal Regulations.