Photoinitiators
Photoinitiator ITX
2-Isopropylthioxanthone
The surface-cure standard for heavily pigmented UV inks, used with amine synergists.
Product Description
ITX is a Type II thioxanthone photoinitiator whose long-wavelength absorption (peak ~380 nm) penetrates dense pigment films that stop conventional initiators. Upon UV exposure it forms an excited triplet state that abstracts hydrogen from amine synergists such as EDB, generating the initiating radicals.
The ITX/EDB combination is the industry-standard package for black and dark-colored offset, flexo and screen inks, delivering fastest surface cure at economical cost. ITX is also used as photosensitizer to boost the LED response of TPO and 819 in low-migration packaging systems.
Aolong ITX is recrystallized to ≥98.0% assay with controlled 4-isomer content, ensuring consistent ink rheology and cure response. Low residual solvent protects food-packaging migration testing.
Key Features
- Long-wavelength absorption cures through dense pigment films
- Industry standard for dark offset and flexo UV inks
- Synergizes with TPO/819 for UV LED packages
- Economical at typical 0.5–2 wt% use levels
Applications
- Black and dark-colored UV offset inks
- Flexo and screen UV inks for packaging
- Synergist component in UV LED ink systems
- Pigmented UV coatings and gel polishes
- Photopolymer plate making
Specifications
| CAS No. | 5495-84-1 |
|---|---|
| Molecular Formula | C16H14OS |
| Molecular Weight | 254.35 |
| Appearance | Yellow crystalline powder |
| Assay (HPLC) | ≥ 98.0% |
| Melting Point | 74 – 78 °C |
| Loss on Drying | ≤ 0.5% |
| Ash Content | ≤ 0.1% |
Packaging & Storage
25 kg fiber drum with PE liner, 1 kg aluminum-foil sample bag. Store cool, dry and protected from light; shelf life 24 months in original sealed packaging.
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