Chimassorb 944 is a high molecular weight hindered amine light stabilizer (HALS) designed for demanding applications where long-term UV protection, low volatility, and durability are essential.
This additive is especially effective in polyolefins, polyamides, and engineering plastics exposed to extreme weather and prolonged outdoor use.
| Property | Typical Value |
|---|---|
| Chemical Name | Polymeric HALS |
| CAS No. | 71878-19-8 |
| Appearance | White to light yellow powder or granules |
| Molecular Weight | High (polymeric) |
| Volatility | Extremely low |
| Melting Point | Approx. 100 °C |
| Processing Temp. | Up to 300 °C |
| Recommended Dosage | 0.1 – 1.0 phr |
| Problem | Chimassorb 944 Solution |
|---|---|
| Rapid UV aging of outdoor plastic parts | Provides long-term stabilization in sunlight |
| Additive blooming or surface migration | Polymeric HALS structure ensures low migration |
| High heat during processing | Stable at temperatures up to 300 °C |
| Environmental stress cracking | Retains plastic flexibility and integrity |
| Difficulties in pigment/additive blending | Compatible and easy to disperse in masterbatch |
Q1: What makes Chimassorb 944 different from Tinuvin 770 or 622?
Chimassorb 944 is a polymeric HALS with very high molecular weight, offering better permanence and weather resistance in long-lifetime plastics compared to monomeric types like Tinuvin 770.
Q2: Can I use it with UV absorbers like UV-329?
Yes, it is often combined with UV absorbers and antioxidants for synergistic UV protection, especially in clear or colored formulations.
Q3: Does it affect product color or clarity?
No. It has low color impact and can be used in both transparent and pigmented plastics.
Q4: Is Chimassorb 944 approved for food-contact materials?
Please check regional regulations; its low migration makes it a candidate for indirect food contact applications.
Q5: Can I use it in reprocessed or recycled plastic?
Yes. It helps stabilize recycled polyolefins during reprocessing and reuse.
