Description

Uv-329 is a high-performance benzotriazole-class ultraviolet light absorber, also known by its CAS number 3147-75-9. It is essential for protecting polymers and coatings from the degrading effects of UV radiation, thereby extending product lifespan and maintaining aesthetic qualities. This additive is a critical component for manufacturers in the plastics, coatings, and synthetic fiber industries seeking to enhance the durability of their products.

Application

• Plastics Stabilization: Used in polyolefins (PP, PE), PVC, polycarbonates, and engineering plastics to prevent yellowing, embrittlement, and loss of mechanical strength caused by UV exposure.
• Coatings & Paints: Incorporated into automotive coatings, industrial paints, wood varnishes, and architectural finishes to protect against gloss loss, chalking, and color fading.
• Adhesives & Sealants: Enhances the weatherability and long-term performance of adhesive films and sealant formulations exposed to sunlight.
• Synthetic Fibers: Applied in the production of outdoor textiles, automotive interiors, and tarpaulins to improve resistance to photodegradation.
• Packaging Materials: Used in certain plastic films and containers to help preserve the integrity and appearance of packaged goods.

Basic Information

Product Name	Uv-329
CAS No.	3147-75-9
Molecular Formula	C₂₀H₂₅N₃O
Molecular Weight	323.43 g/mol
Synonyms	2-(2'-Hydroxy-5'-tert-octylphenyl)benzotriazole; UV-329; Tinuvin 329; BLS 5411; 2-(2H-Benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol; Octrizole; Eversorb 73; Uvinul 3029; Lowilite 29
EINECS	221-573-5

Quality Control

Our Uv-329 is produced under a stringent quality management system. Every batch undergoes comprehensive analytical testing, including HPLC for assay and purity, to ensure it meets exacting specifications for performance and consistency. Certificates of Analysis (COA) are provided with each shipment, and we can support compliance with relevant global regulatory frameworks such as REACH.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 99.0%
Melting Point	103 - 108 °C
Loss on Drying	≤ 0.5%
Transmittance	≥ 95% (425 nm) ≥ 97% (500 nm)
Ash Content	≤ 0.1%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.