Description

2-(2'-Hydroxy-3',5'-Di-tert-Butylphenyl)-5-Chlorobenzotriazole is a highly effective ultraviolet (UV) light absorber belonging to the hydroxyphenyl benzotriazole class. This compound matters for its exceptional ability to protect polymers and coatings from photodegradation, significantly extending product lifespan and maintaining color integrity. It is primarily needed by manufacturers in the plastics, coatings, and synthetic fiber industries seeking to enhance the weatherability and durability of their products. Its specific chlorinated structure offers superior performance in demanding applications where long-term UV stability is critical.

Application

• Primary use as a UV stabilizer in polyolefins such as polypropylene (PP) and polyethylene (PE).
• Protective additive for industrial coatings, automotive paints, and wood finishes to prevent chalking and gloss loss.
• Enhancing the light fastness of synthetic fibers and textiles, including polyamide and polyester.
• Stabilizer component in adhesives, sealants, and elastomers to prevent cracking and embrittlement.
• Used in agricultural films to extend service life under intense sunlight.
• Additive for engineering plastics and masterbatches requiring high-performance UV protection.

Basic Information

Product Name	2-(2'-Hydroxy-3',5'-Di-tert-Butylphenyl)-5-Chlorobenzotriazole
CAS No.	3864-99-1
Molecular Formula	C20H24ClN3O
Molecular Weight	357.88 g/mol
Synonyms	UV-327; Tinuvin 327; 5-Chloro-2-(3,5-di-tert-butyl-2-hydroxyphenyl)-2H-benzotriazole; 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-butylphenol, 5-chloro derivative; BLS 327; Lowilite 27; 2-(3,5-Di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole; 5-Chloro-2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole
EINECS	223-383-8

Quality Control

Our production of 2-(2'-Hydroxy-3',5'-Di-tert-Butylphenyl)-5-Chlorobenzotriazole adheres to stringent quality management protocols. Every batch undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation, to ensure it meets the high standards required for industrial polymer stabilization. Certificates of Analysis (COA) documenting all key parameters are available upon request to support your quality assurance and regulatory compliance needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at ambient temperature (15-25°C). Keep away from heat sources and incompatible materials. The product is light-sensitive and should be stored away from direct light exposure.

Specification

Item	Specification
Appearance	Light yellow to pale beige powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 99.0%
Melting Point	154 - 158 °C
Loss on Drying	≤ 0.5%
Ash Content	≤ 0.1%
Transmittance (425 nm / 500 nm)	≥ 95% / ≥ 97%

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