2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol
[CAS# 70321-86-7]

Identification

• Classification: Catalysts and additives >> UV absorber
• Name: 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol
• Synonyms: 2-(benzotriazol-2-yl)-4,6-bis(2-phenylpropan-2-yl)phenol
• Molecular Formula: C₃₀H₂₉N₃O
• Molecular Weight: 447.58
• CAS Registry Number: 70321-86-7
• EC Number: 274-570-6
• SMILES: CC(C)(C1=CC=CC=C1)C2=CC(=C(C(=C2)N3N=C4C=CC=CC4=N3)O)C(C)(C)C5=CC=CC=C5

Properties

• Density: 1.1±0.1 g/cm³, Calc.^*
• Melting point: 139-143 °C
• Index of Refraction: 1.619, Calc.^*
• Boiling Point: 589.3±60.0 °C (760 mmHg), Calc.^*
• Flash Point: 310.2±32.9 °C, Calc.^*, 195 °C
• Water solubility: insoluble, <0.04 ppm at 20 °C

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335-H412-H413
• Safety Statements: P261-P264-P264+P265-P271-P273-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	3	H336

Discovery and Applications

2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, commonly known as UV absorber 329, is a synthetic organic compound primarily used for its ultraviolet (UV) light absorption properties. It was developed in response to the need for effective UV stabilizers to protect various materials from the harmful effects of sunlight, particularly in applications involving plastics, coatings, and fibers. The compound features a benzotriazole moiety, which is known for its strong ability to absorb UV radiation, coupled with a phenolic structure that enhances its stability and performance.

The discovery of UV absorber 329 dates back to the late 20th century, when researchers were exploring ways to improve the durability and longevity of polymers exposed to sunlight. Benzotriazoles had been identified as effective UV absorbers, and the introduction of additional substituents on the phenolic ring was found to enhance their performance. As a result, 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol emerged as a compound with improved light-stabilizing properties, making it suitable for a variety of commercial applications.

One of the primary applications of UV absorber 329 is in the plastics industry. It is incorporated into polyolefins, polyvinyl chloride (PVC), polystyrene, and other polymer matrices to prevent UV-induced degradation. This compound effectively absorbs UV radiation, thereby reducing the risk of discoloration, brittleness, and loss of mechanical strength in plastic products. Its ability to enhance the weatherability of outdoor applications, such as roofing materials and automotive parts, has made it an essential additive in these sectors.

In addition to plastics, UV absorber 329 is also utilized in coatings and paints to enhance their resistance to UV light. By incorporating this compound into formulations, manufacturers can significantly prolong the life of coatings applied to surfaces exposed to sunlight, such as exterior wood, metal, and concrete. This not only helps maintain aesthetic qualities but also protects the underlying materials from environmental damage.

Moreover, the compound is employed in the textile industry, where it is added to fibers and fabrics to improve their resistance to UV light. This application is particularly relevant for outdoor textiles, such as awnings, canopies, and upholstery, which are susceptible to fading and degradation due to prolonged exposure to sunlight.

Despite its widespread use, there are some concerns regarding the environmental impact of UV absorber 329. As with many synthetic additives, there is ongoing research to assess its biodegradability and potential effects on aquatic ecosystems. Regulatory frameworks are being established to ensure that its application does not pose risks to human health or the environment.

In summary, 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol is a vital UV stabilizer with diverse applications in the plastics, coatings, and textile industries. Its discovery and development have significantly contributed to enhancing the durability and longevity of materials exposed to UV radiation, addressing a critical need in various sectors while prompting discussions about environmental safety and sustainability.

References

2018. Determination of six benzotriazole ultraviolet filters in water and cosmetic samples by graphene sponge-based solid-phase extraction followed by high-performance liquid chromatography. Analytical and Bioanalytical Chemistry, 410(22).
DOI: 10.1007/s00216-018-1301-6

2015. The washout effect during laundry on benzothiazole, benzotriazole, and their derivatives in clothing textiles. Environmental science and pollution research international, 22(20).
DOI: 10.1007/s11356-015-5405-7

2004. Migration of a UV stabilizer from polyethylene terephthalate (PET) into food simulants. Food Additives and Contaminants, 21(10).
DOI: 10.1080/02652030400010447