What are the key application trends for cis-1,2,3,6-tetrahydrophthalic anhydride?

What are the key application trends for cis-1,2,3,6-tetrahydrophthalic anhydride?
THPA is finding growing use in specialty polymer applications beyond traditional epoxy curing agents. In advanced solder resist formulations for printed circuit boards, THPA (referred to as DMPA in some technical contexts) serves as a key modifier. It reacts with hydroxyl groups on acrylic resin backbones to introduce carboxyl functionality, providing alkali solubility essential for photolithographic development. This application is particularly relevant as 5G/6G communications demand materials with lower dielectric constants and better flexibility. THPA's cyclic structure helps balance rigidity and flexibility in cured networks, improving adhesion to copper substrates while reducing brittleness. The shift toward high-frequency, high-speed electronics is pushing demand for such modified resins, creating a niche but growing market for THPA. Additionally, its use in epoxy curing systems for electrical insulation and composites remains a stable demand base.