Methyltetrahydrophthalic Anhydride (MTHPA) 

Synonyms：4-Methyl-3a,4,5,6-tetrahydroisobenzofuran-1,3-dione compound & 4-methyl-4,5,6,7-tetrahydroisobenzofuran-1,3-dione; Tetrahydromethyl-1,3-isobenzofurandione

CAS No.：11070-44-3；19438-64-3；26590-20-5

EINECS No.：234-290-7；251-823-9

Molecular Formula：C₉H₁₀O₃

Molecular Weight：166.17

Structural Formula：

                                 

Standard：

Items	Specifications
Appearance	Light yellow transparent liquid
Content	≥98.0%
Viscosity（25℃）	30~70mPa·s
Anhydride Group content	≥41.0%
Freezing point	≤-15℃
Volatile	≤1.0%
Free acid	≤0.5%

Properties：It is a light yellow transparent oil liquid. Relative density (g/ml) : 1.20 ~ 1.22. Freezing point: ≤-15℃. Boiling point: 115~155℃. Refractive index: 1.4960 ~ 1.4980. Flash point: 137 ~ 150℃. Soluble in acetone, ethanol, toluene, etc.

Uses：Methyl tetrahydrophthalic anhydride is a solid acid anhydride, which can be isomerized by catalytic isomerization to obtain isomerized liquid mixtures, namely 4-methyl tetrahydrophthalic anhydride and 3-methyl tetrahydrophthalic anhydride (Melting point: 65°C and 63°C). It has good stability in the air, is not easy to precipitate crystallization, can be stored for a long time at room temperature, and has low freezing point, small volatility, good miscibility, low toxicity and excellent properties. It is widely used in epoxy resin curing agent, LED digital pipe potting-sealing adhesive, fiberglass composite wind turbine blade, dry transformer, high voltage switch, high voltage capacitor, transformer, home appliance capacitor, power capacitor resistance, integrated circuit impregnation, pouring, winding and other fields.

Storage：Store in a cool, ventilated, moisture-proof and light-proof storeroom, keep container sealed and away from fire. The storage period is one year.

Packing：25kg plastic drum, 220kg iron barrel, or IBC drum