Methyltetrahydrophthalic Anhydride (MTHPA) CAS 11070-44-3

Methyl Tetrahydrophthalic Anhydride (MTHPA) is a high-performance, liquid alicyclic anhydride curing agent. It is widely preferred in the composite and electrical insulation industries due to its low viscosity at room temperature, low volatility, and long pot life. Unlike solid curing agents, MTHPA allows for easier handling and superior impregnation of complex components.

Our MTHPA series is synthesized via isomerization technology to ensure a stable structure. When cured with epoxy resins, it imparts excellent electrical properties, high heat resistance (high Tg), and superior mechanical strength to the final product. It is the gold standard hardener for casting, potting, and encapsulation applications.

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We offer customizable isomer ratios to fine-tune the freezing point and viscosity to match your specific climate and production environment.

Physicochemical Properties (Technical Data)

The following specifications represent our Standard Electronic Grade, typically used for high-voltage insulation and LED packaging.

Applications

MTHPA is the critical hardener for applications requiring durability and electrical insulation:

1. Electrical Encapsulation & Potting:

• Transformers & Coils: Used extensively for the impregnation and casting of ignition coils, high-voltage transformers, and mutual inductors due to its excellent dielectric properties.
• Capacitors: Provides a hermetic seal that protects internal components from moisture and vibration.

2. Electronic Components:

• LED Packaging: Its low color (APHA) and resistance to yellowing make it ideal for clear LED potting compounds.
• PCBs: Used in insulating varnishes for printed circuit boards.

3. Composite Materials:

• Wind Energy: Used in the vacuum infusion process for manufacturing wind turbine blades.
• FRP Piping: Acts as a curing agent for filament-wound fiberglass pipes requiring chemical resistance.

4. Industrial Adhesives:

• Formulates into high-strength structural adhesives for metal and ceramic bonding.

Quality Assurance (QA/QC)

At Industrochem, we ensure that every drop of MTHPA meets the stringent requirements of the electronics industry.

• Isomer Control: We use advanced Gas Chromatography (GC) to monitor the distribution of isomers (3-methyl and 4-methyl), which directly impacts the viscosity and freezing point of the product.
• Moisture Management: As anhydrides are sensitive to moisture (hydrolysis), our production lines are fully enclosed nitrogen-sealed systems. We strictly test Free Acid content to ensure no degradation has occurred.
• Color Stability: For LED grade products, we perform rigorous UV aging tests and colorimetry to guarantee low yellowing index over time.

For the corresponding bisphenol-A epoxy resin system, see Epoxy Resin (Bisphenol A).

Storage, Handling & Safety

Storage Conditions:

• Moisture Sensitivity: Critical. MTHPA reacts with atmospheric moisture to form acid. Containers must be kept tightly sealed at all times.
• Temperature: Store in a cool, dry place between 5°C and 30°C. Although it has a low freezing point, avoiding extreme cold prevents crystallization.
• Shelf Life: 12 months in original sealed packaging.

Safety Precautions (HSE):

• Skin & Eye Contact: Anhydrides can be irritating to the skin, eyes, and respiratory system. May cause sensitization.
• PPE Recommendations:
  • Respiratory: Wear a half-face respirator with organic vapor cartridges if ventilation is poor.
  • Skin: Butyl rubber or Neoprene gloves are recommended. Long-sleeved protective clothing is mandatory.
  • Eyes: Chemical splash goggles.
• Handling: operate in a well-ventilated area. In case of contact with skin, wash immediately with soap and plenty of water.

Optimize your curing process with premium MTHPA.

Whether for high-voltage casting or clear LED potting, our technical team is ready to support your formulation.

👉 Get a Quote: info@industrochem.com