Characteristics, types and applications of UV absorbers
Quick answer: In most UV systems, photoinitiators are selected by balancing wavelength fit, through-cure, color control, and line speed. Buyers usually compare a blended package instead of one isolated product.
UV absorber is such a class of substances, it can absorb sunlight or fluorescent light source in the ultraviolet wavelength part, and its own physical properties, structure does not change. UV absorbers can be divided into the following categories according to their chemical structure: salicylates, benzophenones, benzotriazoles, substituted acrylonitrile, triazines, etc. The more common ones on the market are benzophenones, benzotriazoles and triazines. They all work on the principle of converting high-energy UV light energy into heat or non-destructive longer light waves released, thus protecting the organic materials with UV absorbers from UV damage.
UV absorbers as additives for polymer materials, generally require its initial color light, no color stain; and polymer materials have good compatibility; with processing requirements of heat resistance, chemical stability, etc.. If used in food packaging materials, UV absorbers are also required to meet the environmental requirements of food packaging and migration resistance.
Above we explain the role of UV absorbers is to selectively absorb the high energy of the light source of ultraviolet light, by energy conversion, so that the high energy of ultraviolet light into harmless thermal energy release or consumption. The type of polymer is different, so that its aging damage to the UV wavelength (sensitive band) is not the same. As the following table.
| Material Category | Sensitive waveband (nm) |
| Polyethylene | 300 |
| Polyvinyl chloride | 310 |
| Polystyrene | 318 |
| Polyester | 325 |
| Polypropylene | 310 |
| Vinyl Chloride – Ethyl Acetate Copolymer | 322-364 |
| Polycarbonate | 300-320 |
| Polycarbonate (PC) | 295 |
| Nitrocellulose | 310 |
| Polymethyl methacrylate | 290-315 |
| Thermoplastic resins | 290-320 |
| Unsaturated Polyester | 325 |
As the table shows, different types of polymer materials are sensitive to different wavelengths of ultraviolet light, and different UV absorbers can absorb different ranges of shielding light waves. Therefore, different resins choose the appropriate UV absorber to achieve good light stabilization effect.
In summary, as a UV absorber than the need to have the following conditions.
1, can strongly absorb UV ;
2, good chemical stability, no chemical reaction with other components in the material; good photochemical stability itself, not decomposition and discoloration.
3, good thermal stability, small volatility, and will not change due to heat in processing; ④
4、Good compatibility with polymer materials, can be uniformly dispersed in the material, no frosting, no precipitation ;
5, other properties, such as colorless, non-toxic, odorless; resistant to washing; cheap, easy to obtain.
Same series products
| Product name | CAS NO. | Chemical name |
| lcnacure® TPO | 75980-60-8 | Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide |
| lcnacure® TPO-L | 84434-11-7 | Ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate |
| lcnacure® 819/920 | 162881-26-7 | Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide |
| lcnacure® ITX | 5495-84-1 | 2-Isopropylthioxanthone |
| lcnacure® DETX | 82799-44-8 | 2,4-Diethyl-9H-thioxanthen-9-one |
| lcnacure® BDK/651 | 24650-42-8 | 2,2-Dimethoxy-2-phenylacetophenone |
| lcnacure® 907 | 71868-10-5 | 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone |
| lcnacure® 184 | 947-19-3 | 1-Hydroxycyclohexyl phenyl ketone |
| lcnacure®MBF | 15206-55-0 | Methyl benzoylformate |
| lcnacure®150 | 163702-01-0 | Benzene, (1-methylethenyl)-, homopolymer, ar-(2-hydroxy-2-methyl-1-oxopropyl) derivs |
| lcnacure®160 | 71868-15-0 | Difunctional alpha hydroxy ketone |
| lcnacure® 1173 | 7473-98-5 | 2-Hydroxy-2-methylpropiophenone |
| lcnacure®EMK | 90-93-7 | 4,4′-Bis(diethylamino) benzophenone |
| lcnacure® PBZ | 2128-93-0 | 4-Benzoylbiphenyl |
| lcnacure®OMBB/MBB | 606-28-0 | Methyl 2-benzoylbenzoate |
| lcnacure® 784/FMT | 125051-32-3 | BIS(2,6-DIFLUORO-3-(1-HYDROPYRROL-1-YL)PHENYL)TITANOCENE |
| lcnacure® BP | 119-61-9 | Benzophenone |
| lcnacure®754 | 211510-16-6 | Benzeneacetic acid, alpha-oxo-, Oxydi-2,1-ethanediyl ester |
| lcnacure®CBP | 134-85-0 | 4-Chlorobenzophenone |
| lcnacure® MBP | 134-84-9 | 4-Methylbenzophenone |
| lcnacure®EHA | 21245-02-3 | 2-Ethylhexyl 4-dimethylaminobenzoate |
| lcnacure®DMB | 2208-05-1 | 2-(Dimethylamino)ethyl benzoate |
| lcnacure®EDB | 10287-53-3 | Ethyl 4-dimethylaminobenzoate |
| lcnacure®250 | 344562-80-7 | (4-Methylphenyl) [4-(2-methylpropyl)phenyl] iodonium hexafluorophosphate |
| lcnacure® 369 | 119313-12-1 | 2-Benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone |
| lcnacure® 379 | 119344-86-4 | 1-Butanone, 2-(dimethylamino)-2-(4-methylphenyl)methyl-1-4-(4-morpholinyl)phenyl- |
A practical selection route for photoinitiator-related projects
When technical buyers or formulators screen photoinitiators, the most useful decision frame is usually cure quality plus application fit: which package cures reliably, keeps appearance acceptable, and still works under the lamp, film thickness, and substrate conditions of the actual process.
- Match the package to the lamp first: mercury lamps, UV LEDs, and visible-light systems can rank the same photoinitiators very differently.
- Check depth cure and surface cure separately: a film that feels dry on top can still be weak underneath.
- Balance yellowing with reactivity: the strongest deep-cure route is not always the best commercial choice if color or migration risk becomes unacceptable.
- Use the final formula as the benchmark: pigment load, monomer package, and film thickness can all change the apparent ranking of the same initiator.
Recommended product references
- CHLUMINIT TPO-L: A strong low-yellowing reference for LED-oriented UV systems.
- CHLUMINIT 819: Useful when a formulation needs stronger absorption and deeper cure support.
- CHLUMINIT 184: A classic free-radical benchmark for fast surface cure in many UV systems.
- CHLUMINIT 1173: A practical comparison point for classic short-wave UV initiation.
FAQ for buyers and formulators
Why are blended photoinitiator packages so common?
Because one product may control yellowing or lamp fit well while another improves cure depth or line-speed performance, so the full package is often stronger than any single grade.
Should incomplete cure always be solved by adding more initiator?
Not automatically. The real limitation may be the lamp, film thickness, pigment shading, or the rest of the reactive system rather than simple under-dosage.