CYMEL® UI-21-E

If acetone is being considered for reduction of calculated VOC, extended storage stability testing of formulated coatings with various levels of acetone should be completed to ensure acceptable color stability.

CYMEL® UI-21-E Resin requires the addition of primary alcohols, such as n-butanol and ethanol, at concentrations of 10-25% on total resin solids to extend catalyzed pot life. Faster evaporating alcohols will improve speed of dry.

CYMEL® UI-21-E Resin responds to both weak acids and sulfonic acid catalysts, like CYCAT® 4040 catalyst. Generally, 6-10% CYCAT® 4040 catalyst on total resin solids of the formulation is sufficient to obtain fast drying behavior at room temperature.

• CYMEL® UI-21-E Resin is a very effective crosslinking agent for backbone polymer resins containing hydroxyl functional groups, such as alkyd, polyester, or acrylic resins.
• The optimum level of CYMEL® UI-21-E Resin in an acid-curing wood coating formulation should be in the range of 25-35% on total resin solids.
• To obtain coatings with optimum resistance properties, addition of a melamine resin, such as CYMEL® MB-98, at levels of 5-10% on total resin solids is recommended.

• CYMEL® UI-21-E Resin has a shelf life of 24 months from the date of manufacture when stored at temperatures between 5°C and 30°C. Although lower temperatures are not detrimental to stability, the viscosity of the product will increase, making the resin more difficult to pump or pour.
• CYMEL® UI-21-E Resin viscosity can be returned to normal by gentle re-warming; however, care should be taken to avoid excessive localized heating as this can cause irreversible viscosity increase.