Tetrahydromethyl-1,3-isobenzofurandione

Methyltetrahydrophthalic anhydride (CAS 11070-44-3), commercially known as MTHPA, is a reactive cyclic anhydride used primarily as a curing agent and hardener for epoxy resin systems.

It delivers controlled crosslink density in thermoset formulations, making it a preferred choice where long pot life and low viscosity processing are required for industrial manufacturing.

MTHPA is extensively used in epoxy casting and encapsulation compounds for electrical and electronic components, where its liquid form enables void-free impregnation of transformers and coils.

In industrial coatings, it functions as a crosslinker to build chemical and corrosion resistance in high-performance protective finishes applied to metal substrates and heavy machinery.

Structural adhesives and composite laminates rely on MTHPA to achieve high glass transition temperatures and mechanical durability in demanding service environments and aerospace applications.

It also serves as a reactive intermediate in the synthesis of polyester resins and specialty lubricant additives where controlled acid functionality is required for chemical stability.

MTHPA is supplied as a low-viscosity liquid at ambient temperature, typically available in drum and IBC quantities for industrial procurement and large-scale chemical distribution.

Standard commercial grades are offered at purities of 96% and above, with technical and electronic grades available to meet specific application requirements and manufacturing standards.