CYMEL® 323

In solvent borne systems:

• CYMEL® 323 Resin is a methylated melamine-formalde- hyde crosslinking agent with a medium to high degree of alkylation, a low methylol content and medium to high imino functionality.
• CYMEL® 323 Resin is a very effective crosslinking agent for backbone polymers containing hydroxyl, amide and, to some extent, carboxyl functional groups, such as epoxy, alkyd/polyester or acrylic resins.
• CYMEL® 323 Resin is suitable for a wide range of industrial stoving systems, providing exceptional fast cure response.
• The baking volatiles from CYMEL® 323 Resin contain very low levels of formaldehyde even though the tendency to self condensation takes prefer- ence over the crosslinking reaction. Compared to other high imino, methylated crosslinking agents, CYMEL® 323 Resin shows improved film hardness, solvent and humid- ity resistance.

In water borne systems:

• CYMEL® 323 Resin is soluble in water, and has an excel- lent compatibility with water soluble backbone polymers.
• The carboxyl functionality of anionic backbone polymers is sufficiently acidic to catalyze the reaction at relatively low temperature curing schedules.
• In all water bomne sys- tems where speed of cure is very important, CYMEL® 323 Resin is strongly recommended.

Catalysis:

• CYMEL® 323 Resin requires weak acid catalysts for cure at normal baking schedules.
• The acidity of the primary film former is usually sufficient to initiate the curing process.
• The cure can be additionally catalyzed by weak organic or inorganic acids such as CYCAT 296-9 catalyst, which has proved to be a very effective catalyst for these systems.

• Formulated systems containing CYMEL® 323 have to be stabilized with primary alcohols, amines or with a combination of these.
• For water borne systems a pH value between 7.0-8.5 should be maintained to achieve stability.

Typical Thin-down Curve in Isobutanol/water (at 23°C):

• Storage stability at ambient temperatures is minimum one year after delivery. Avoid direct sunshine.