- ▸ Type I alpha-aminoketone photoinitiator giving strong through-cure of white and pigmented UV coatings (Coatings & Construction)
- ▸ Workhorse for pigmented screen and UV inks where surface-only initiators under-cure (Industrial Manufacturing)
- ▸ Cures pigmented UV-curable plastics, adhesives and solder masks (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.
Request SDS →This photoinitiator (CAS 71868-10-5) is 2-methyl-4′-(methylthio)-2-morpholinopropiophenone, a pale powder. Identity: PubChem.
What it is
A Type I α-aminoketone that cleaves efficiently and absorbs at longer UV than the hydroxyketones, so it cures pigmented and thicker films well. It is high-activity but can contribute more yellowing than hydroxyketones, so it is balanced accordingly in clears.
How it cures
This photoinitiator is a Type I α-aminoketone — a powerful initiator for pigmented and white systems and thicker films, where weaker initiators cannot drive cure. Its thioether group shifts absorption to longer UV, helping it cure through pigment.
Applications
It is used in pigmented and white UV coatings and inks, screen and flexo inks, solder masks and thicker films, often combined with a thioxanthone such as ITX and an amine synergist, and with BAPO for deep pigmented cure. Related aminoketone: 2-benzyl-2-dimethylamino-4′-morpholinobutyrophenone.
Forms, grades and handling
This photoinitiator is supplied as a pale powder. Photoinitiators are light-sensitive — store cool and dark. Many are fine powders or liquids that require dust/handling controls 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 this photoinitiator 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 or blend. 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 | 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone — Photoinitiator (Type I, aminoketone) |
| Type | Type I (cleavage), α-aminoketone |
| Cure | Pigmented / deep films; longer-UV absorption |
| Note | High activity; manage yellowing in clears |
| Appearance | Pale powder |
| CAS Number | 71868-10-5 |
| Molecular Formula | C15H21NO2S |
| Handling | Light-sensitive; refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 400-600-6
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
Regulatory restriction status
2-Methyl-4′-(methylthio)-2-morpholinopropiophenone (CAS 71868-10-5) appears on the regulatory list(s) below. This is public regulatory information about the substance — not a statement about any specific supplier’s material, and not a safety claim. Confirm the current status for your jurisdiction and intended use.
- REACH SVHC Candidate List (EU): listed 16 Jan 2020 on the basis of toxic for reproduction (Art. 57(c)). SVHC status triggers EU supplier-communication and notification duties above 0.1% w/w; it is not, by itself, a ban on sale.
Sources: ECHA Candidate List / Annex XIV / Annex XVII (echa.europa.eu); U.S. EPA TSCA; UN Stockholm Convention / EU POPs Regulation; California OEHHA Proposition 65 list. Retrieved 2026-07-13.
Frequently Asked Questions
What is 2-methyl-4′-(methylthio)-2-morpholinopropiophenone used for?
2-Methyl-4′-(methylthio)-2-morpholinopropiophenone (CAS 71868-10-5) is a Type I aminoketone used to cure pigmented and white UV coatings and inks, solder masks and thicker films, often with a thioxanthone and amine synergist.
Why is this photoinitiator good for pigmented systems?
Its thioether shifts absorption to longer UV wavelengths where pigment is less competitive, so it drives cure through colored and white films better than hydroxyketones.
Does this photoinitiator yellow?
It is more prone to yellowing than the hydroxyketones, so in clear systems it is used sparingly or in blends; in pigmented systems yellowing is less critical.
What is the CAS of this photoinitiator?
It is CAS 71868-10-5 (PubChem CID 92387), 2-methyl-4′-(methylthio)-2-morpholinopropiophenone. The CoA documents grade.
How is this photoinitiator supplied and quoted in bulk?
RawSource supplies it as a powder in bulk with CoA, TDS and SDS. Pricing is quote-based on grade and volume; submit an RFQ.
What is the REACH and TSCA regulatory status of 2-Methyl-4'-(methylthio)-2-morpholinopropiophenone?
2-Methyl-4'-(methylthio)-2-morpholinopropiophenone (CAS 71868-10-5) 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 400-600-6).