- ▸ High-sensitivity Type I oxime-ester photoinitiator for fast cure of pigmented and highly filled UV systems (Coatings & Construction)
- ▸ Workhorse initiator for color-filter resists, black-matrix and photoresist imaging in display/electronics (Industrial Manufacturing)
- ▸ Cures pigmented UV-curable plastics, photoresists and printing-plate resins (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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This oxime ester is a high-sensitivity Type I photoinitiator for photoresists and display manufacturing. Oxime esters cleave very efficiently under UV, giving fast cure and high resolution in pigmented resist films where ordinary initiators struggle. Identity: CAS 253585-83-0.
What it is
1-Octane-1,2-dione 2-(O-benzoyloxime) (CAS 253585-83-0) is an oxime-ester photoinitiator, a pale solid. Oxime esters are the high-performance class used for color filters, black matrix and photoresists.
How it cures
A Type I initiator: UV photolysis cleaves the N–O bond of the oxime ester to release radicals (and decarboxylation gives further reactive species), making it exceptionally efficient even in heavily pigmented resist films — no amine required.
Applications
Used in color-filter resists, LCD black matrix, photoresists and high-resolution imaging, where high photosensitivity through pigment is essential. Related high-activity options: the carbazole oxime ester and aminoketones (369).
Forms, grades and handling
It is supplied as a pale solid. 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 1-Octane-1,2-dione 2- 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 I, oxime ester) |
| Photoinitiator type | Type I (cleavage), oxime ester |
| Absorption | UV — high photosensitivity |
| CAS Number | 253585-83-0 |
| Molecular Formula | C27H27NO3S |
| Molecular Weight | 445.6 g/mol |
| Handling | Light-sensitive; refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 454-610-0
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 1-octane-1,2-dione 2-(O-benzoyloxime) used for?
It is a high-sensitivity Type I oxime-ester photoinitiator (CAS 253585-83-0) used in color-filter resists, LCD black matrix and photoresists, where it cures efficiently through heavy pigment.
Why are oxime esters used in photoresists?
Oxime esters cleave very efficiently under UV and remain active in heavily pigmented films, enabling fast cure and high resolution in color filters, black matrix and resists where ordinary initiators are too weak.
How is bulk this oxime-ester photoinitiator supplied and quoted?
RawSource supplies this oxime-ester photoinitiator 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 1-octane-1,2-dione 2-(O-benzoyloxime)?
1-octane-1,2-dione 2-(O-benzoyloxime) (CAS 253585-83-0) 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 454-610-0).