Photoinitiators
Photoinitiator BMS
4-(4-Methylphenylthio)benzophenone
Macromolecular benzophenone — the low-migration Type II for packaging inks.
Product Description
BMS is a thio-bis benzophenone derivative whose bulky, effectively macromolecular structure dramatically reduces migration compared to simple benzophenone. After cure, its high effective molecular weight keeps residual photoinitiator locked in the film — the key requirement for food-contact packaging inks under Nestlé and Swiss Ordinance guidance.
It functions as a Type II initiator with amine synergists (EDB, EHA) and as a sensitizing co-initiator boosting the surface cure of Type I packages. Typical loadings are 2–4 wt% in inks and 1–3 wt% in clear coatings.
Key Features
- Dramatically lower migration than simple benzophenone
- Designed for food-packaging compliance
- Efficient surface cure with amine synergists
- White solid — no color contribution to films
Applications
- UV inks for food and sensitive packaging
- Paper and board overprint varnishes
- Low-odor clear coatings
- Adhesives for laminated packaging
- Type I booster in ink packages
Specifications
| CAS No. | 83846-85-9 |
|---|---|
| Molecular Formula | C20H16OS |
| Molecular Weight | 304.41 |
| Appearance | White to off-white powder |
| Assay (HPLC) | ≥ 98.0% |
| Melting Point | 73 – 87 °C |
Packaging & Storage
25 kg fiber drum with PE liner. Store cool, dry and protected from light; shelf life 24 months in original sealed packaging.
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