2-(2-HYDROXY-3-tert-BUTYL-5-METHYLPHENYL)-5-CHLORO-2H-BENZOTRIAZOLE

PRODUCT IDENTIFICATION

3896-11-5

223-445-4

Oral rat LD50: 5000 mg/kg

SMILES

n1(c2c(c(cc(c2)C)C(C)(C)C)O)nc2ccc(cc2n1)Cl

CLASSIFICATION

Benzotriazole, UV absorber, Light stabilizer

PHYSICAL AND CHEMICAL PROPERTIES

141 C

1.32

Insoluble

REFRACTIVE INDEX

GENERAL DESCRIPTION

2-(3'-tert-Butyl-2-hydroxy-5'-methylphenyl)-5-chlorabenzotriazole is used as a UV absorber for polymer. It is a phenolic benzotriazole derivative that has two substrates (methyl and branched butyl group). It is suitable for polyolefins and cold cured polyesters. It is used in combination with HALS (Hindered Amine Light Stabilizer) for synergy effect. It has a low volatility at high temperatures and high resistance to thermal degradation and can therefore be used without significant loss or decomposition in the polyolefin compounding and molding processes. In the use for the UV protection of polyester resins, UV Absorber-326 does not form colored complexes with the metallic salts used for the curing process of these resins.

The main hydroxyphenylbenzotriazole UV Absorbers include:

• 2-(2'-Hydroxy-5'-methylphenyl)benzotriazole (CAS NO. 2440-22-4, Drometrizole, UV Absorber-P)
• 2-(2'-Hydroxy-5'-tert-octylphenyl)benzotriazole (CAS NO. 3147-75-9, Octrizole, UV Absorber-329)
• 2-(3',5'-Di-tert-butyl-2'-hydroxyphenyl)-5-chloro-2H-benzotriazole (CAS NO. 3864-99-1, UV Absorber-327)
• 2-(2-Hydroxy-3-tert-butyl-5-methylphenyl)-5-chloro-2H-benzotriazole (CAS NO. 3896-11-5, Bumetrizole, UV Absorber-326)
• 2-(3,5-Di-tert-pentyl-2-hyroxyphenyl) benzotriazolee (CAS NO. 25973-55-1, UV Absorber-328)
• 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (CAS NO. 70321-86-7, UV Absorber-234)

APPEARANCE

MELTING POINT

138 - 141 C

VOLATILES

0.5% max

93.0% (460nm), 96.0 (500nm)

EXTERNAL LINKS

http://botkinchemie.com/
Ultraviolet (UV) absorbers act largely by shielding the interior of the part from damaging UV radiation. Before the advent of hindered amines, light stabilization was accomplished with systems based on UV absorbers in combination with other additives. Today UV absorbers are often used in combination with HALS and sometimes other additives for the stabilization of polypropylene. They are also used in plastic packaging applications to provide content protection. All of the compounds of this class share several general characteristics:

1. Strong UV absorption, especially in the 290 nm to 350 nm range which is very damaging to organic materials, and

2. Excited states formed upon UV absorption relax to the ground state extremely rapidly (picosecond time frame) and efficiently via radiation-less processes, which imparts high efficiency and excellent photostability.

Chemical classes of UV absorbers suitable for use in polyolefins include 2-hydroxybenzophenones (e.g.UVA-1), 2-(2-hydroxyphenyl)-2H-benzotriazoles (e.g. UVA-2, UVA-3), tris-aryl-o-hydroxyphenyl-striazines (e.g. UVA-4), and cyanoacrylate derivatives (e.g. UVA-5, UVA-6). Chemical structures of representative UV absorbers are given in the Appendix. For food contact applications, products that have been designated as food contact compliant in polypropylene by the US FDA include UVA-1, UVA-3, UVA-4, and UVA-6.........