Light Stabilizer 944 (HALS 944), CAS 70624-18-9, is a triazine-based oligomeric hindered amine light stabilizer supplied as slightly yellow granules. With a number-average molecular weight of 2000-3100, high transmittance (425 nm min 90.0%, 450 nm min 93.0%), volatility max 1.0% and ash max 0.1%, it is the long-life HALS of choice for polypropylene fibres, polyethylene film and pipe, TPO automotive parts and agricultural film – applications where a monomeric HALS would volatilise or be extracted. PolyBlueChem supplies HALS 944 with per-batch COA and SDS.
Specifications
| Property | Specification |
|---|---|
| Appearance | Slightly yellow granular |
| Transmittance at 425 nm (%) | Min 90.0 |
| Transmittance at 450 nm (%) | Min 93.0 |
| Molecular weight (Mn) | 2000 – 3100 |
| Volatile matter (%) | Max 1.0 |
| Ash (%) | Max 0.1 |
| Packaging | 25 kg net, inner PE liner; 500 kg jumbo bags on request |
Basic Information
| Chemical name | Polymeric hindered amine (triazine-piperidinyl oligomer) |
| Common names | Light Stabilizer 944, HALS 944, UV-944 |
| CAS number | 70624-18-9 |
| Chemical class | Hindered amine light stabilizer (HALS), oligomeric, triazine-based |
| Appearance | Slightly yellow granular |
| Molecular weight (Mn) | 2000 – 3100 |
| Transmittance | 425 nm min 90.0%; 450 nm min 93.0% |
| Volatility | Max 1.0% |
| Ash | Max 0.1% |
Why the Oligomeric Structure Matters
HALS work by trapping the radical species that propagate photo-oxidation. Whether the stabilizer is still there after two summers is a question of physical persistence, and that is where molecular weight decides the outcome. A monomeric HALS such as UV-770 (Mn around 480) migrates readily: it volatilises in thin films and fibres, and it is extracted by water, oils and agricultural chemicals. HALS 944 at Mn 2000-3100 stays where it was put.
Because the triazine ring is part of the oligomer backbone, HALS 944 is also less basic than monomeric secondary-amine HALS. That lowers antagonism with acidic co-additives – halogenated flame retardants, acidic pigments and pesticide actives – which is why it is a standard choice in agricultural film and in formulations that cannot avoid acidic components.
Typical Applications
- Polypropylene fibres and tapes – BCF yarn, spunbond nonwovens, strapping and woven sacks, where high surface area makes volatility decisive.
- Polyethylene film and agricultural film – greenhouse covers and mulch film exposed to UV, sulphur-based pesticides and disinfectants.
- PE pipe, geomembrane and cable jacketing – long-life outdoor installations requiring extraction resistance.
- TPO and PP automotive parts – exterior trim, bumpers and interior components requiring low fogging.
- EVA, TPU and elastomers – where a low-volatility HALS is needed to avoid plate-out during processing.
- Masterbatch and compounds – granular form for dust-free feeding and good dispersion.
Formulation Notes
| Point | Guidance |
|---|---|
| Typical loading | 0.15 – 0.6% depending on wall thickness and target service life; thin films and fibres sit at the top of the range – confirm by weathering trial |
| Co-additives | Combine with a UV absorber (benzotriazole or triazine type) for surface protection, and with a primary/secondary antioxidant for processing stability |
| Blending with other HALS | Frequently blended with lower-MW or more basic HALS to tune both surface and bulk protection |
| Feeding | Granular form feeds cleanly; pre-disperse in masterbatch for thin-film and fibre lines |
| Processing window | Stable in normal polyolefin processing; keep residence time at peak temperature short to preserve transmittance |
Packaging, Storage and Documentation
Supplied in 25 kg net bags with an inner PE liner, or 500 kg jumbo bags for compounders. Store in a dry, ventilated place away from direct sunlight; the material is not moisture sensitive to the same degree as inorganic additives, but caking and colour drift are avoided by keeping bags sealed. Each batch is supplied with a COA covering appearance, transmittance at 425 and 450 nm, molecular weight, volatile matter and ash; SDS is available in English.
Related reading
- Light Stabilizer 944: chemistry, mechanism and applications
- HALS 944 in agricultural film and greenhouse covers
- Choosing a HALS: 944 vs 622 vs 770 vs 783
FAQ
What is the CAS number of Light Stabilizer 944? CAS 70624-18-9.
Is HALS 944 the same as UV-944? Yes – “UV-944” is a common commercial shorthand for the same triazine-based oligomeric HALS.
How much HALS 944 should I add? Typically 0.15-0.6% in polyolefins, higher for thin films and fibres; validate by accelerated weathering (e.g. xenon arc) at the thickness you will actually produce.
Can it be used in food-contact or agricultural applications? Regulatory status depends on the jurisdiction and on the final article; we confirm documentation for the destination market at enquiry stage rather than assume it from a generic datasheet.
Contact PolyBlueChem for specifications, samples and quotations.
