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Carbazole Oxime-Ester Photoinitiator

CAS 478556-66-0

A yellow carbazole oxime-ester photoinitiator offering high UV sensitivity for pigmented photoresists, color filters, and black-matrix display applications.

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CAS Number
478556-66-0
Material Family
Specialty Additives
At a Glance
Material Family
Specialty Additives
Record Type
Polymer fluid
Primary Role
Crosslinking / Curing
Functional Roles
Applications & Use Cases
  • Photoimaging of color-filter and black-matrix resists in LCD/OLED display manufacturing
  • Initiator for deeply pigmented and black UV-curable inks and coatings
  • Curing of photoresists and printing-plate resins
  • Through-cure of highly filled UV-curable plastics
Safety & Handling
Full SDS available on request

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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Chemical Identity
CAS Number
478556-66-0
Synonyms & Trade Names
Carbazole oxime ester Oxime ester photoinitiator OXE photoinitiator OXE-02 1-ethanone 1-(O-acetyloxime) Comparable to Irgacure OXE 02
Full Description

This carbazole oxime ester is an ultra-high-sensitivity Type I photoinitiator for advanced photoresists and displays. The carbazole chromophore red-shifts and strengthens absorption, making it one of the most efficient initiators for heavily pigmented color-filter and black-matrix resists. Identity: PubChem / CAS 478556-66-0.

What it is

1-[9-Ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime) (CAS 478556-66-0) is a carbazole-based oxime ester, a yellow solid. The carbazole core gives strong, red-shifted absorption versus simple oxime esters.

How it cures

A Type I initiator: UV photolysis cleaves the oxime-ester N–O bond to release radicals very efficiently, and the carbazole chromophore both red-shifts absorption and boosts quantum yield — so it cures heavily pigmented resist films at low loadings, with no amine needed.

Applications

Used in high-end color-filter resists, LCD/OLED black matrix, photoresists and microelectronics imaging, where maximum photosensitivity through pigment is required. Compare the OXE-01-type oxime ester.

Forms, grades and handling

It is supplied as a yellow 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 Carbazole Oxime-Ester 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. 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, carbazole oxime ester)
Photoinitiator type Type I (cleavage), carbazole oxime ester
Absorption Near-UV / longer UV — very high sensitivity
CAS Number 478556-66-0
Molecular Formula C26H24N2O3
Molecular Weight 412.5 g/mol
Handling Light-sensitive; refer to the current SDS

Regulatory & registration requirements

  • TSCA (US):
  • REACH (EU):
  • EC number: 455-590-6

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

Frequently Asked Questions

What is the carbazole oxime-ester photoinitiator used for?

It is an ultra-high-sensitivity Type I carbazole oxime-ester photoinitiator (CAS 478556-66-0) used in high-end color-filter resists, LCD/OLED black matrix and microelectronics photoresists, curing heavily pigmented films at low loadings.

Why is the carbazole oxime ester so sensitive?

Its carbazole chromophore red-shifts and strengthens absorption while the oxime ester cleaves efficiently, giving very high quantum yield — ideal for the most demanding pigmented resist films.

How is bulk this carbazole oxime-ester photoinitiator supplied and quoted?

RawSource supplies this carbazole 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 Carbazole Oxime-Ester Photoinitiator?

Carbazole Oxime-Ester Photoinitiator (CAS 478556-66-0) 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 455-590-6).

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.