UV Absorber 328
UV Absorber 328

Item specifics

Light yellow powder

Product review


Product Description

Benzotriazole UV Absorber 328 / CAS NO. 25973-55-1

Chemical name : 2-(2'-Hydroxy-3',5'-di-tert-pentylphenyl)-benzotriazole

molecular formula: C22H29N3O


UV-328 is a highly effective light stabilizer for a variety of plastics and other organic substrates.
Its use is recommended for the stabilization of styrene homo- and copolymers, acrylic polymers,unsaturated polyesters, polyvinylchloride, polyolefins, polyurethanes, polyacetals, polyvinyl 
butyral, elastomers, and adhesives.
UV-328 features strong UV absorption, low initial color, excellent compatibility in a wide variety of substrates, good solubility in plasticizers and monomers, and moderately low volatility. It protects polymers as well as organic pigments from UV radiation, helping to preserve the original appearance and physical integrity of molded articles, films, sheets, and fibers during
outdoor weathering

The use levels of UV-328 range between 0.10 and 1.0%, depending on substrate and
performance requirements of the final application. The product can be used alone or in
combination with other additives such as light stabilizers (hindered amines), antioxidants
(hindered phenols, phosphites, thiosynergists, hydroxylamines, lactones), and other functional stabilizers and additives.
The use of UV-328 in combination with hindered amine light stabilizers is particularly
noteworthy in that a synergistic performance is often observed. Performance data for UV-328 alone and in combination with other additives are available in a variety of substrates
1. Unsaturated Polyester : 0.2-0.5wt% based on polymer weight
2.PVC: Rigid PVC : 0.2-0.5wt% based on polymer weight Plasticized PVC : 0.1-0.3wt% based on polymer weight
3.Polyurethane : 0.2-1.0wt% based on polymer weight
4.Polyamide : 0.2-0.5wt% based on polymer weight

Physical Properties:
Appearance: Light Yellowish powder 

Purity:≥99.0% by HPLC

Volatile matter:≤0.5% 

Melting point: 80-83°C 

Ash content :≤0.1% 

Transmittance: 460nm 97.0%min、500nm 98.0%min

Storage: 20/25kg drum or carton box.

Pale yellow crystal powder
99.0% min
Melting point
80.0-83.0°C min
Loss on drying
0.5% max
0.1% max
Transmittance( 460nm)
Transmittance( 500nm)
98% min