OBM (CAS 606-28-0)
| CAS No. | 606-28-0 |
|---|---|
| Alias | Methyl 2-benzoylbenzoate |
| Category | Photoinitiators |
| Purity | ≥99.00% (HPLC) |
| Packaging | 20kg/carton (paper drum with PE liner) |
OBM is a general-purpose free radical photoinitiator with high initiation efficiency, low odor, and non-toxic properties. It is specifically suitable for materials in direct contact with the human body, such as coatings and food packaging inks. When used together with TPO, OBM delivers enhanced curing performance.
Equivalent grades. The same substance is sold by other manufacturers as Omnirad OMBB. It is the same CAS number (606-28-0) and the same chemistry, so a formulation written around one of those grades transfers directly.
Introduction
OBM is a benzoate ester rather than a ketone, and that changes its behaviour in useful ways. It absorbs at 254 nm and acts as a photoinitiator in its own right, but it is also used as a sensitiser alongside other initiators, where it improves the cure without contributing much colour of its own.
Its low odour and low yellowing are the reasons it turns up in coatings where the cured film will be seen or handled. In the market it is known by the trade code OMBB, and it is frequently paired with TPO, where the combination cures more effectively than either does alone.
Physical & Chemical Properties
White crystalline powder. Molecular formula C15H12O3, molecular weight 240.26, purity ≥99.00% by HPLC, melting range 48.0–54.0 °C, loss on drying ≤0.40%. Absorption maximum at 254 nm.
Applications
Recommended at 3–5%. Used where low odour matters and as a performance booster with TPO. Good solubility in common acrylate systems.
Regulatory status
OBM has no harmonised classification under CLP and is not on the REACH Candidate List. It is not listed in Swiss Annex 10.
Its use in applications involving contact with people is common in this market, and we would rather flag the boundary than let it go unstated. Low odour is a sensory property, not a safety assessment. Whether OBM is acceptable in a given food-contact construction depends on the migration measured from that construction and on the rules of the destination market, neither of which we can answer from a specification sheet. Ask us and we will tell you what we hold and what you need to test.
Handling & Storage
Store sealed in a cool, dry, ventilated area. Consult the SDS.
Packaging
20 kg cartons. COA per batch, SDS in English, samples available.
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.
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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.
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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.
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