Benzophenone UV absorbers

Uvasorb. [3-V Sigma Prodotti Chimici] Benzophenones uv absorbers for cosmetics, plastic additives. 

Benzophenone. Benzophenone UV absorbers are mature products and have been used for many years in polyolefins, PVC, and other resins. These products also have wide use in cosmetic preparations as sunscreens and protectants. 

Specific examples of benzotriazole and benzophenone UV absorbers are given in Table 3.14. 

Benzophenone UV absorbers have been used for many years in polyolefins, PVC, and other resins. Benzotriazole UV absorbers are highly effective in high-temperature resins such as acrylics and polycarbonates. They also find extensive use in the coatings industry. Benzoates and salicylates, such as 3,5-di-f-butyl-4-hydroxybenzoic acid n-hexadecyl ester, function by rearranging in 2-hydroxyben-zophenone analogs when exposed to UV light to perform as UV absorbers. 

A very compatible, cost-efficient benzophenone UV absorber... 

UV absorbers (UVA) act by absorbing UV light hence retarding the photolysis of hydroperoxides. Their activity is also associated with hydrogen bonding between the 2-hydroxy group and the carbonyl chromo-phore [22]. Typical examples are based on 2-hydroxy-benzophenones and 2-hydroxybenztriazoIes (e.g., Table lb, AO 23 and AOs 24-26). 

The UV absorber (UVA) class (e.g., 2-hydroxy-benzophenones and benzotriazoles, see AO 23-27 in Table lb) are stable to UV light and have high extinction coefficients in the region 330-360 nm. They operate pri-... 

Sun worshipers and those who work outside can protect themselves from ultraviolet exposure with skin creams that contain UV-absorbing molecules. The UV-absorbing molecule in the first sunscreens was PABA, para-aminobenzoic acid. However, this compound may have toxic effects of its own. The UV-absorbing components of current sunscreens are derivatives of cinnamic acid and benzophenone. 

Only a limited range of nitro, azo and anthraquinone disperse dyes exhibit adequate fastness to dry heat, light and weathering for application on polyester automotive fabrics. The structure of Cl Disperse Yellow 86 was modified to incorporate UV absorbers of the benzophenone, benzotriazole or oxalanilide types into the dye molecule. The derived dyes showed better fastness properties than the parent unsubstituted dye. Positioning of the photostabilising moiety within the dye molecule had little influence on the light fastness obtained, however. Built-in benzophenone residues were more effective than the other two types [177]. Nevertheless, several further monoazo and nitrodiphenylamine disperse dye... 

Nonloaded and loaded SLN were already investigated with respect to use in cosmetics. Although adequate controls are difficult to prepare, first experiments indicate an increase in skin hydration and a reduction in wrinkle depth following SLN application [68]. Moreover, cetyl palmitate-nanodispersions act both as particulate ultraviolet (UV) blockers themselves and as carriers for UV absorbing agents (e.g., 2-hydroxy-4-methoxy benzophenone Eusolex 4360). This results in a threefold... 

Set B Based on the results of set A discussed below, a third set. Set B, was prepared (Table IV). Cyasorb 531 (a benzophenone UV light absorber) was found to be the most effective stabilizer in Set A. It was therefore rerun at an even lower add-on in Set B, and since it was the only UV light absorber included in Set A, a second type of UV absorber, Tinuvin 327 (a benzotriazole) was included in Set B. Two new non-polymeric hindered amine light stabilizers (HALS) Tinuvin 770 and Tinuvin 765 were also evaluated in Set B with the hope that they might be more effective than the polymeric HALS (Chimassorb 944LD) included in Set A which was quite detrimental to the heat stability. Combinations of these four additives were also applied in Set B. The three new compounds evaluated have been reported to be effective light stabilizers for polyester and polyamide fibers (Capocci, G., Ciba Geigy Corporation, Ardsley, NY, personal communication, 1986). 

The application of UV absorbers, i.e. compounds absorbing the harmful solar radiation, represents an effective solution of the problem (Rabek, 1990). The absorbed radiation is deactivated by intramolecular radiative and radiationless processes. The ideal UV absorber is expected to absorb all terrestrial UV-A and UV-B radiation but no radiation having wavelengths higher than 400 nm. Different classes of commercialized UV absorbers fulfil requirements on effective plastics protection. A group of UV absorbers acting by excited state intramolecular proton transfer (ESIPT) mechanism (Pospfsil and Nespurek, 1997) includes phenolic derivatives of benzophenone (37), various benzotriazoles, such as 38 or 39, and 1,3,5-triazine 40. Non-phenolic UV absorbers are represented by oxamide 41 and a-cyanoacrylate 42. 

Kimura et al. [107] made a light resistant formulation of a block E-P copolymer by extruding it at 220 °C with Mg(OH)2, and 2-hydroxy-4-octoxybenzophenone. The injection molded product (at 800 kg cm pressure) shows fire retardation also due to MgO filler and the benzophenone derivative is an efficient UV absorber. 

The most common UV absorbers used commercially are hindered amine light stabilizers, which can also function as heat stabilizers in some plastics. Other UV absorbers include benzotriazoles and benzophenones, salicylate esters, cyanoacrylates, malonates and benzilidenes. Factors such as the nature of the resin, type and level of pigments being used, and the presence of crosslinkers and catalysts govern the selection of UV absorber to be used. 

The common UV absorbers available for product protection are benzophenone, methylbenzyledine camphor, and para-aminobenzoic acid (PABA). 

Also benzophenone [ 15] might act as an anthropogenic marker. It is mainly used along with substituted diphenyl ketones as UV-absorber in creams, as a fixative in perfumes and soap as well as an intermediate in pharmaceuticals and agricultural chemicals production. As well, only low concentrations were found in the Havel and Spree river sediments in the range of 0.5 to 3 ng/g, recommending an optimized analytical procedure. 

UV absorbers may be used for two reasons to protect the plastic from UV degradation, and to prevent product degradation due to UV rays passing through the plastic. Chemically UV absorbers may be based on substituted phenols or benzophenones. Examples include 2-hydroxy-4-n-octoxybenzophenone, other hydroxy-benzophenones and compounds of oxalic anilide. These are usually added at a 0.1-0.2% level. Prevention of light penetration and protection of the plastic from light degradation can also be achieved by the addition of iron oxides and carbon. 

Uvtaiil . [BASF BASF AG] Benzophenones, acrylic acid derivs., or PABA derivs. uv absorbers for sunscreen prq)s., cosmetk s. 

ADK STAB 1413 AI3-00754 Benzene, benzoyl- Benzophenone Benzoylbenzene Castvell No. 081G CCRIS 629 Diphenyl ketone Diphenylmethanone EINECS 204-337-6 EPA Pesticide Chemical Code 000315 FEMA No. 2134 HSDB 6809 Ketone, diphenyl Melhanone, diphenyl- NSC 8077 Phenyl ketone. UV absorber tor polyolefins, PVC, etc. good compatibility with polymers. Prisms mp = 47.8" bp = 305,4" 7,m = 252, 331 nm (e = 18600, 167, MeOH) insoluble in H2O, soluble in CeHe, MeOH, very soluble in EtOH, EtaO, MezCO, CHCI3, CS2, AcOH. Asahi Denka Kogyo. 

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