- ▸ Type II diethylthioxanthone sensitizer paired with amine co-initiators for UV-curing pigmented inks and coatings (Coatings & Construction)
- ▸ Long-wavelength absorption improves through-cure and speed in UV/UV-LED printing and electronics (Industrial Manufacturing)
- ▸ Low-odor alternative to ITX for sensitizing pigmented UV-cure plastics and adhesives (Plastics & Polymers)
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
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2,4-Diethylthioxanthone (DETX) is a long-UV Type II thioxanthone photoinitiator/sensitizer. Like ITX it absorbs at longer UV wavelengths to cure pigmented systems, with better solubility and a lower-odor/low-migration profile — used with an amine synergist. Identity: CAS 82799-44-8.
What it is
2,4-Diethylthioxanthone (CAS 82799-44-8) is a diethyl-substituted thioxanthone, a yellow solid. The diethyl substitution improves solubility and is often preferred over ITX for migration-sensitive and high-solubility systems.
How it cures
A Type II thioxanthone: under UV it reaches an excited state and abstracts a hydrogen from an amine co-initiator to form curing radicals. Its long-UV absorption lets it cure through pigment and sensitize other initiators. Pair with an amine synergist such as EDB or EHA.
Applications
Used in pigmented UV inks and coatings, screen and offset inks, paired with an amine synergist and often an aminoketone (907). It is a frequent ITX alternative where solubility or migration matters.
Forms, grades and handling
DETX is supplied as a yellow powder. Photoinitiators are light-sensitive — store cool, dry and dark, away from light and ignition sources. Handle per the current Safety Data Sheet (SDS); each lot ships with a Certificate of Analysis (CoA) and Technical Data Sheet (TDS).
Bulk supply and RFQ
RawSource sources 2,4-Diethylthioxanthone direct from producers in bulk, with CoA, TDS and SDS per lot. Tell us your lamp (mercury or LED wavelength), system (clear or pigmented) and cure target, and we will quote the right grade. Compare the full range and selection logic in the photoinitiators guide.
Typical Properties
Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.
| Property | Typical Value |
|---|---|
| Chemical / type | Photoinitiator (Type II, thioxanthone) |
| Photoinitiator type | Type II (H-abstraction), thioxanthone |
| Absorption | Long UV — cures through pigment |
| CAS Number | 82799-44-8 |
| Molecular Formula | C17H16OS |
| Molecular Weight | 268.4 g/mol |
| Handling | Light-sensitive; refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 280-041-0
TSCA Inventory flag PMN: a commenced PMN (premanufacture notice) substance (EPA flag legend).
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Frequently Asked Questions
What is DETX used for?
DETX (2,4-diethylthioxanthone, CAS 82799-44-8) is a Type II thioxanthone photoinitiator/sensitizer for pigmented UV inks and coatings; its long-UV absorption helps cure through color and it is used with an amine synergist.
What is the difference between DETX and ITX?
Both are Type II thioxanthones used with amine synergists; DETX (diethyl) typically offers better solubility and a more favorable migration profile, so it is often chosen over ITX (isopropyl) in solubility- or migration-sensitive systems.
How is bulk DETX supplied and quoted?
RawSource supplies DETX in bulk with CoA, TDS and SDS per lot. Pricing is quote-based on grade and volume; submit an RFQ with your target quantity.
What is the REACH and TSCA regulatory status of 2,4-Diethylthioxanthone (DETX)?
2,4-Diethylthioxanthone (DETX) (CAS 82799-44-8) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 280-041-0).