NPI-602 (CAS 75980-60-8)
| CAS No. | 75980-60-8 |
|---|---|
| Alias | Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide |
| Category | Photoinitiators |
| Purity | ≥99.00% (HPLC) |
| Packaging | 20 kg/carton |
NPI-602 is a general-purpose free radical photoinitiator featuring a long absorption wavelength, excellent deep-curing performance, and good photo-bleaching properties. It is particularly suitable for LED-curable coatings and inks, offering high purity and strict specifications for demanding applications. The product is also a higher-grade TPO variant used mainly for packaging and bonding in electronic circuit materials.
Introduction
NPI-602 is a high-purity TPO grade, held at 99.00% or above by HPLC against the 98.00% typical of the standard product, and aimed at electronic circuit packaging and bonding rather than at general coatings work.
At the application level it behaves exactly as TPO does: absorption at 273 and 370 nm, deep cure, photo-bleaching, and a strong fit with LED arrays. The difference is the specification and the application, not the chemistry.
Physical & Chemical Properties
Light yellow powder. Chemical name diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide. Molecular formula C22H21O2P, molecular weight 348.38, purity ≥99.00% by HPLC, melting range 85.0–95.0 °C, loss on drying ≤0.5%. Absorption maxima at 273 nm and 370 nm. Recommended at 1–3% by weight.
Regulatory status
NPI-602 is the same substance as TPO. Same CAS number, 75980-60-8, same regulatory position, and a house grade name does not change it. That means: on the REACH Candidate List as an SVHC since 2023; harmonised Repr. 1B applying from 1 September 2025; brought into Annex XVII by Commission Regulation (EU) 2025/1731 via Appendix 6 to Entry 30, which restricts supply to the general public rather than industrial use; removed from the EuPIA suitability list in January 2026; and recommended by ECHA in November 2025 for the Authorisation List, which is a recommendation and not yet law.
It remains positively listed in Swiss Annex 10 at 0.05 mg/kg. It is absent from the German Anlage 14 category V list and cannot use the German non-listed route either. If you are moving to NPI-602 for the purity, be aware that you are buying TPO, with TPO's regulatory file. See the TPO page for the full timeline.
Packaging
20 kg cartons. COA per batch, SDS in English.
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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