Cinnamate modified the application of UV absorbers
Disinfection with ultraviolet light, physical health, promote vitamin D synthesis
and other functions beneficial to humans, but, UV also brought a lot of harm to
human beings. Now commonly used UV absorbers include salicylic acid esters, the
amino acid esters, Benzophenone, p-methoxy cinnamic acid esters, benzotriazole,
instead of acrylonitrile type, diphenyl formyl methane. These UV absorbers have been
widely used in various polymer materials, sunscreen cosmetics, anti-UV fabric, UV
coatings and many other fields. However, UV absorbers are small molecules, in the
application process there are disadvantages: Mostly UVB areas UV absorbers, light
thermal stability; When used for cosmetic anti-poor water resistance, sweat, easy loss,
irritation, allergy prone skin; When applied to polymer compatibility is poor, the
polymer molding and extrusion processing, storage, use may evaporate from the
plastic, migration, leaking, and some heat, poor weather, but also may reduce polymer
strength, when applied to textiles is not easy fixing, easy to spread, poor wash fastness,
may cause skin allergy.
To overcome these shortcomings of conventional UV absorbers, researchers in
Isotope Institute of Henan Academy of Sciences, with cinnamic acid derivatives and
γ-chloropropyl trimethoxysilane the main raw material for the synthesis of the seven
groups containing reactive organic silicon-based UV absorbers. By NMR, 13C NMR,
IR, its structure was identified by its UV absorption properties of UV analysis, found
that p-methoxy cinnamic acid trimethoxy-acrylic ester is an ideal area of UVB
ultraviolet reactive absorbent; 4-- dimethylamino-trimethoxy-acrylic acid ester is an
ideal reactive UV absorber UVA area. The two mixtures, can form an excellent
full-band (280 ~ 400nm) reactive UV absorbers.
Further experiments found that the UV absorbent compound there are several
good application the following: 1, by spraying or dipping the surface treatment
method of the receptor, and then by heating, irradiation, etc. to the surface of the
receptor molecule chemical reactions, thereby permanently firmly with the receptor
surface.This way can be easily prepared by UV glass, UV glasses, anti-UV fabric and
UV aging of rubber products. As the production process is simple and limited to
surface treatment, it can significantly reduce costs;2, the use of the product and D4
copolymerization with UV absorbers of polysiloxane side groups, can be easily
applied to preparation of sunscreen cosmetics, and thus reduce or even eliminate the
irritating chemical sunscreen class, improve the anti-sweat water resistance; 3, the use
of the product of the inorganic sunscreens, can be easily used to prepare a variety of
high SPF sunscreen cosmetics. 4, through the blending method for the preparation of
UV aging of rubber and plastic products and UV coatings, due to the presence of
organic silicon coupling agent, product compatibility and the strength of the final
products, will greatly increase the water resistance.