allnex supplies acid catalysts for accelerating the cure response of amino crosslinking agents. Each catalyst is designed to fulfill a specific applications requirement, and in most cases, one catalyst will be preferable over another depending on formula composition and curing conditions.
The reaction of amino resins and polyols is complex and often requires acidic catalysts. The relative efficiency of catalysts correlates to the acidity, and the overall reaction rate is directly proportional to the concentration of the catalyst.
Frequently used catalysts include:
- P-toluenesulfonic acid (PTSA)
- Dodecyl benzene sulfonic acid (DDBSA)
- Dinonyl naphthalene disulfonic acid (DNNDSA)
- Organic phosphoric acid.
Ionic or covalently blocked sulfonic acid catalysts are used in amino resin based stoving systems. The heat sensitive deactivation of the sulfonic acid is a very important tool to achieve the desired balance of storage stability of a catalyzed system followed by rapid cure when the coating reaches the desire cure temperature.