MTHPA HMT-908M1 - Pre-Accelerated Methyltetrahydrophthalic Anhydride (CAS 11070-44-3)
A modified grade of methyltetrahydrophthalic anhydride with a built-in tertiary amine accelerator: faster gelation without dosing a separate accelerator, low viscosity of 50–100 mPa·s, and a crystallization point below −15 °C for pumpable handling all year round. EU REACH fully registered, ISO 9001 / 14001 / 45001 certified production.
One Grade, Two Decisions Already Made
HMT-908M1 is methyltetrahydrophthalic anhydride supplied in a modified formulation: the anhydride base (approximately 90%) is blended with a measured dose of tertiary amine accelerator, so the cure reaction starts on schedule without a separate promoter addition. For formulators this removes one raw material, one weighing step and one source of batch-to-batch dosing error.
The grade is built for electrical and composite applications that need room-temperature storage stability, a low freezing point, low volatility and low toxicity - casting, sealing and impregnation of motors, dry-type and high-voltage transformers, capacitors, ignition coils and IC packages, as well as solvent-free paints, laminated boards and epoxy adhesives.
| Grade | HMT-908M1 |
| CAS No. / EC No. | 11070-44-3 / 234-290-7 |
| Molecular formula / weight | C9H10O3 / 166.17 g/mol |
| Appearance | Transparent liquid, no impurity |
| Type | Modified (pre-accelerated) anhydride curing agent |
Acid value 664.3 mgKOH/g (spec 600.0–675.0)
Viscosity 72 mPa·s @ 25 °C (spec 50–100)
Anhydride group content 41.79% (spec ≥ 35.00%)
Crystallization point < −16 °C (spec ≤ −15 °C)
Free acid 0.17% · Density 1.21 g/cm³
The Composition Behind the Grade
Standard MTHPA cures with an amine accelerator added by the formulator. HMT-908M1 ships with that accelerator already blended in, in a controlled ratio. The typical composition declared in the SDS is:
| Component | CAS No. | Concentration (wt) | Function |
|---|---|---|---|
| Methyltetrahydrophthalic anhydride | 11070-44-3 | ∼ 90.0% | Anhydride curing agent base |
| Phenol | 108-95-2 | ∼ 5.0% | Cure modification |
| THPA (tetrahydrophthalic anhydride) | 85-43-8 | ∼ 4.0% | Co-anhydride component |
| Tertiary amine accelerator | 90-72-2 | ∼ 1.0% | Built-in cure accelerator - no separate promoter needed |
What this changes in practice: shorter gel time at the same cure temperature, one fewer raw material to weigh and store, and reproducible accelerator dosing because it is fixed at the plant instead of measured on your floor. If your process needs a custom ratio - faster, slower or accelerator-free - that is exactly what the customized programme covers.
HMT-908M1 Technical Specification
Values below are the released specification of the grade. Every batch is tested against this table and shipped with its own COA.
| Property | Specification |
|---|---|
| Appearance | Transparent liquid |
| Colour (Pt-Co) | ≤ 300# |
| Crystallization point | ≤ −15 °C |
| Viscosity (25 °C) | 50–100 mPa·s |
| Density (25 °C) | 1.210 ± 0.05 g/cm³ |
| Anhydride group content | ≥ 35.0% |
| Free acid | ≤ 0.3% |
| Heating loss (125 °C, 2 h) | < 1.00% |
| Acid value | 600.0–675.0 mgKOH/g |
| Solubility | Miscible with benzene, toluene, acetone, ethanol, ethyl acetate, chloroform and carbon tetrachloride; slightly soluble in petroleum ether; decomposes in water |
Specifications subject to the batch COA. Boiling point 295.3 °C at 1013 hPa (reference data per SDS). For safe handling consult the SDS; the product is classified GHS Eye Damage Cat. 1 / Skin & Respiratory Sensitization Cat. 1 (H318, H334, H317) but is not classified as dangerous goods for transport.
Where HMT-908M1 Is Used
The grade serves epoxy curing, encapsulation and insulation duties across electrical, electronics and composite manufacturing.
Casting and impregnation for motors, dry-type transformers, high-voltage switches, transformers and line-output transformers.
Power and high-voltage capacitors, resistors, ignition coils and insulative bushings where stable dielectric performance is required.
Integrated circuit impregnation, casting and sealing - the pre-accelerated formulation shortens cycle times on automated lines.
Two-component solvent-free coating systems where low volatility and low toxicity improve workshop conditions.
Laminated boards and epoxy adhesives requiring room-temperature storage stability and long pot life before cure.
Fiberglass irrigation pipes, oil pipes, water filter boxes and insulating paint - low-viscosity wetting of glass fibre at high filler loading.
Six Reasons Formulators Pick This Grade
The amine promoter is already in the drum at a fixed, plant-controlled ratio - no separate dosing step, no dosing variability between operators.
50–100 mPa·s at 25 °C lets you push silica or mineral filler content up while keeping the mix pumpable and well-wetting.
Crystallization point at or below −15 °C keeps drums liquid in cold warehouses and winter shipments - no reheating, no thawing procedures.
Long pot life before cure and stable storage at ambient temperature reduce waste from gelled leftovers.
Reduced exotherm during curing supports dimensional stability in thick sections; low volatility keeps formulations clean.
Made in our own plant, so viscosity, accelerator dose and acid value can be tuned to your formulation under the OEM/ODM programme.
Packaging Options and Container Loading
From 25 kg trial drums to isotank bulk, with published per-container net loads so you can plan freight before you ask for a quote.
| Package | Net weight per container |
|---|---|
| IBC container | 19.8 metric tons |
| Flexitank | 22 metric tons |
| Drum | 17.6 / 19.2 metric tons |
Retail sizes: 25 kg plastic drum, 220/240 kg drum, 1,100/1,200 kg IBC. Isotank and bulk available on request.
- FOB Ningbo - delivered to port of departure, target readiness 10 days, container loading report provided, dedicated client manager
- CIF - route and freight-rate planning, coordination with Maersk, ONE, KMTC and CMA, insurance handled by us
- Payment - 30% deposit, 70% before shipment (negotiable for repeat programmes)
Handling HMT-908M1 Correctly
- Keep containers tightly closed in a cool, dry, well-ventilated place
- Avoid moisture, fire and water contact - anhydrides hydrolyse on exposure to humidity
- Keep away from heat, direct sunlight and sources of ignition
- Incompatible with strong oxidizing agents and strong bases
- GHS classification: Eye Damage Cat. 1 (H318); Respiratory Sensitization Cat. 1 (H334); Skin Sensitization Cat. 1 (H317)
- Wear protective gloves, clothing and eye/face protection; avoid breathing vapour
- Acute oral LD50 (rat) 2,140 mg/kg; not classified as dangerous goods for transport (no UN number)
- Full first-aid and spill procedures in the SDS - request it with your sample
Registered, Certified, Documented
The paperwork travels with the product: every order can be supplied with the full documentation pack, and compliance documents are available on request for your customer audits.
Tetrahydromethylphthalic anhydride (MTHPA) is fully registered under EU REACH in the 100–1,000 t/y tonnage band. Registration certificate available on request.
ISO 9001, ISO 14001 and ISO 45001 certified production. Batches are released under enterprise standard Q/ZJHY003-2024.
TDS, SDS (English, v7.0) and batch COA issued with every order; additional purchase paperwork available on request.
HMT-908M1 - Frequently Asked Questions
The base anhydride is the same chemistry (CAS 11070-44-3), but HMT-908M1 ships with a controlled dose of tertiary amine accelerator already blended in, plus a small co-anhydride fraction. Practically, that means faster gelation at the same cure temperature and one less raw material for you to weigh, store and QC.
In most cases no - the promoter is built in at approximately 1%. If your cure schedule needs an extra push, a small additional dose can still be dosed on your side, but start by running the gel-time curve with the grade as supplied. We can provide cure-window guidance for your resin and filler system.
The grade stays liquid down to −15 °C and below, so drums and IBCs remain pumpable in cold seasons without heated storage or thawing procedures. That also means no risk of partial crystallisation disturbing your dosing accuracy.
Yes - this grade exists precisely because buyers asked for variations. Viscosity, accelerator dose and acid value can be tuned in our own plant. Send your target specification and the problem you are solving, and we will confirm feasibility before quoting.
Every batch ships with its own COA tested against the released specification. TDS and the English SDS (version 7.0) are available with the quotation, and the EU REACH registration certificate can be provided for your compliance file on request.
Yes. Tell us the grade and trial quantity, and let us know the critical parameter you will measure - gel time, Tg, colour - so we select the most suitable lot and ship its exact COA with the sample. Samples typically leave the plant within 3–5 days by DHL, UPS, FedEx or TNT.
Test HMT-908M1 in Your Own Formulation
Send your application and cure schedule - or the TDS of the grade you are replacing - and we will reply within 24 hours with pricing, the full document pack and a sample plan.
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