UV Absorber 384: Synthesis, Detection and Application

General description

UV Absorber 384, chemical name is 3-[3-(2-H-benzotriazole-2-yl)-4-hydroxyl-5-tert-butyl phenyl] propionic acid octyl ester and propylene glycol methyl ether acetate mixture, belongs to benzotriazole ultraviolet absorbent, benzotriazole compound is the largest yield and most varieties of a class of products, It is a kind of organic compounds which can selectively absorb the ultraviolet rays of sunlight which is harmful to the polymer and have high light resistance. With good thermal stability, high temperature resistance and extraction resistance, suitable for automotive coatings and general industrial coatings; At the same time, UV 384 2 also has good compatibility, can be used in collaboration with blocked amine light stabilizer, can very well improve product performance, especially for the coating in yellow, cracking, foaming, shedding and extinction to provide better inhibition, has a broad market prospects. 

Synthetic routes

Fig. 1 The synthetic method of UV Absorber 384.

180 g of non-recrystallized 384 methyl ester, 81 g carboctathiol, 1.33 g of dibutyltin dilaurate and 400 g of 120# solvent oil were added to the reaction bottle, and the temperature of the reaction bottle was maintained at 110 ~ 115℃. After the reaction, 3.3 grams of activated carbon was added to the reaction bottle for decolorization, and the decolorized solution was filtered. After filtration, the temperature was controlled at 90 ~ 120℃ for decolorization. Then the filtrate obtained after the dissolution of atmospheric distillation to 120# solvent oil, and then low pressure distillation recovery of carboeightol, distillation temperature control at 120 ~ 130℃, the end of the distillation and then add quantitative propylene glycol methyl ether acetate mix, UV Absorber 384 products; The obtained UV Absorber 384 yield is 83.7 %, chroma (455 nm)233, transmittance (460 nm) 99.5% [1].

Detection method

In this study, Kawakami et al. aimed to develop a simple method for the simultaneous analysis of seven benzotriazole (BZT) UV absorbers that are commonly used in urethane fiber products. Acetone/chloroform shaking extraction, tetrahydrofuran dissolution, and acetone/hexane soaking extraction methods were examined, and acetone/hexane soaking extraction was used for analysis because its operation was simply and the low-toxicity and small consumption volume of extraction solvents. All the BZT UV absorbers investigated in this study were subjected to qualitative/quantitative analysis by high-performance liquid-chromatography with a photodiode array detector. To avoid interference by co-elution substances, a wavelength of 340nm was used for quantification. Good linearity of standard curve of every chemical was observed in the concentration range of 0.02-10 mu g/mL. Sufficient reproducibility was achieved because their recoveries and its variance of coefficients were good values. Furthermore, limits of detection and limits of quantification obtained from recovery tests were 0.095 to 0.56 mu g/g and 0.29 to 1.7 mu g/g, respectively. Among the 39 polyurethane textile products analyzed, only 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (UV-326), and 2-(2'-hydroxy-3',5'-di--cumylphenyl)-2H-benzotriazole (UV-234) were detected in 2 samples (1.2 to 1.7 mu g/g), 8 samples (0.62 to 384 mu g/g), and 16 samples (trace amounts to 935 mu g/g), respectively [2].

Application

Influence on the accelerated weathering stability of UV curing coating based on acrylate urethane resin

The purpose of this paper is to evaluate the photoprotective efficiency of organic UV absorber Tinuvin 384 (T384) on the photocurable acrylate urethane coating under the accelerated weathering condition. The coatings without and with 2 wt.% T384 were examined by UV/CON accelerated weathering testing device. The aging of the coatings was assessed by IR and FE-SEM analysis as well as the measurement of mechanical and weight loss. The obtained results showed that due to the photoprotection of T384, the urethane acrylate coating was stable under the effect of accelerated weathering factors. After 48 cycles of aging, the CH and CNH groups, the abrasion resistance and the weight of the paint films containing 2 wt.% T384 were slightly decreased. Its surface was damaged just a little, while that of the coating without T384 was severely degraded [3].

References

[1] Shen H, Zheng Q, Wu B, et al. Synthesizing ultraviolet absorber UV-384-2, comprises e.g. reacting methyl 3-(3-(2H-benzo(d)(1,2,3)triazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propanoate, octanol, catalyst and solvent, and carrying out transesterification reaction[P]. Faming Zhuanli Shenqing, CN114539175, 2022.

[2] Kawakami T, Isama K, Ikarashi Y. Determination of benzotriazole UV absorbers in textile products made of polyurethane fibers by high-performance liquid chromatography with a photo diode array detector[J]. Journal of Liquid Chromatography & Related Technologies, 2018, 41(13-14): 831-838.

[3] Vuong N T, Nguyet H M, Linh D T M. Influence of organic UV absorber on the accelerated weathering stability of UV curing coating based on acrylate urethane resin[J]. Vietnam Journal of Chemistry, 2020, 58(2): 173-179.

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