ITX (CAS 5495-84-1)
| CAS No. | 5495-84-1 |
|---|---|
| Alias | Isopropylthioxanthone |
| Category | Photoinitiators |
| Purity | ≥98.00% (HPLC) |
| Packaging | 20kg/carton |
ITX is a general-purpose free radical photoinitiator with long absorption wavelength and excellent solubility. It is especially effective for curing colored systems when combined with α-hydroxyl ketone photoinitiators, and can also be used as an efficient sensitizer for iodonium salt cationic initiators. Its main applications include UV-curable inks such as PCB ink and inkjet inks.
Equivalent grades. The same substance is sold by other manufacturers as Omnirad ITX, Speedcure ITX, Genocure ITX. It is the same CAS number (5495-84-1) and the same chemistry, so a formulation written around one of those grades transfers directly.
Introduction
ITX solves a specific problem: curing through pigment and colour. Its absorption reaches 382 nm, well past where most Type I initiators stop, so it can be excited by light that would never reach an alpha-hydroxy ketone buried under titanium dioxide or an organic pigment.
It is a Type II initiator, which means it does not generate radicals on its own. It abstracts hydrogen from a co-initiator, and in practice that co-initiator is almost always a tertiary amine. Without one, ITX will absorb light all day and start nothing at all. Formulators who report that ITX does not work have usually left the amine out of the formulation.
Physical & Chemical Properties
Light yellow to off-white powder. Molecular formula C16H14OS, molecular weight 254.40, purity ≥98.00% by HPLC, melting range 68–72 °C, loss on drying ≤0.50%. Absorption maxima at 258 nm and 382 nm.
Applications
Free radical use at 1–3%, or as a sensitiser at 0.5–1% where it transfers energy to an iodonium salt in cationic systems. Main applications are UV inks: PCB solder resist, inkjet, and the coloured printing inks where a 184-only system leaves the deeper layers wet. Combining ITX with an alpha-hydroxy ketone is the standard answer.
Regulatory status and migration
ITX has no harmonised classification under CLP. It is listed in Swiss Annex 10 at 0.05 mg/kg and appears in German Anlage 14, category V, at entry 204, grouped with 4-ITX. ITX came under scrutiny in 2005 after it was found migrating into beverages from printed cartons. EFSA's December 2005 opinion concluded that ITX at the levels found gave hardly any cause for health concern, and BfR Opinion 028/2008 accepts it where migration stays at or below 50 µg/kg. If your end use is food packaging, check the migration limit that applies to your market before specifying it.
Handling & Storage
Store sealed, cool, dark and well ventilated. Avoid dust formation. One year shelf life from production. Consult the SDS.
Packaging
20 kg cartons. COA per batch, SDS in English, samples for line trials on request.
Applications & Industries
Coatings & Paints
Metal driers (cobalt, manganese, zirconium octoate, naphthenates) and photoinitiators for coatings, paints, varnishes and industrial finishes — with COA & MSDS per batch.
UV Curing & Printing Inks
Free radical photoinitiators for UV-curable inks, coatings, adhesives and 3D printing — 1173, 184, 369, 907, ITX, DETX, TPO/TPO-L and liquid blends, QC-tested per batch.
Related Products
Frequently Asked Questions
What is your minimum order quantity (MOQ)?
MOQ depends on the product and specification. For most chemicals we can supply from 1 kg sample orders up to full container loads (FCL). Contact us with the product name and CAS number for a specific MOQ quotation.
Can you provide samples before I place a bulk order?
Yes. Samples are available for most products — typically 100g to 1kg. Sample fees may apply for expensive products and are usually deducted from your first bulk order. We recommend independent testing of samples before committing to bulk.
What documents do you provide with each shipment?
Every shipment includes a batch-specific Certificate of Analysis (COA), MSDS/SDS, commercial invoice, packing list and bill of lading. Certificates of origin, REACH/SVHC declarations and third-party inspection reports are available on request.
What is your typical lead time?
Production usually takes 10–20 days depending on the product and quantity. Sea freight to most destinations takes 15–30 days; air freight 5–10 days for samples and small orders. Our five warehouses in China allow fast dispatch of stocked items.
What payment terms do you accept?
We commonly accept 30% deposit + 70% against copy of bill of lading, T/T bank transfer, and Letters of Credit (L/C) for larger orders. Payment terms are confirmed in writing before production starts.
Are you a factory or a trading company?
We are an integrated supplier with three in-house manufacturing plants, supported by five warehouses across China. This gives us direct control over production quality while maintaining a broad product range.