UV screening pigments

It is an important component of polypropylene, alone or with talc, for rigidity and whiteness that resists weathering. Metallocene-produced polypropylenes, with greater self-reinforcement, can tolerate higher loadings, for better whiteness. 

Surface-treated rutile titanium dioxide pigment meets the durability and optical requirements of the European plastics industry, without compromising 

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Some studies have shown no changes in flavonoid levels in response to UV. Originally, only the flavonoids were thought to serve as UV-screening pigments. It is now clear, however, that other phenolics, such as hydroxycinnamic acids and their esters, are also... 

Schnitzler, J.-P. et al., UV-B screening pigments and chalcone synthase mRNA in needles of Scots pine seedlings, New Phytol, 132, 247, 1996. 

These were believed originally to function entirely as uv screening agents (6). It was thought that, like pigments such as carbon black or titanium dioxide, they had the ability to absorb the uv light and dissipate this as thermal rather than as chemical energy. 

Uses Heat and light (UV screening and antioxidizing) stabilizer for vinyl plastics and chlorinated paraffins U V stabilizer and antbxidant in painls wh. rust-inhibitive pigment in paints and plastics acid acceptor in rubber processing... 

Precaution DOT Flamm. solid Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of lead and POx Storage Store in closed containers below 400 F, away from open flame or sparks Uses Heat and light (UV screening and antioxidizing) stabilizer for vinyl plastics and chlorinated paraffins UV stabilizer and antioxidant in paints wh. rust-inhibitive pigment in paints and plastics acid acceptor in rubber processing Manuf./Distrib. D.N. Lukens http //www.dniukens.com] Nichem... 

UV and visible absorption (also reflectance) microspectrometry has an extensive use in screening pigments and colors in paints, inks, and fibers, whereas it has found applications mostly for quantitative measurements in drug analysis (in particular for barbiturates). The development of sensitive IR spectrometers with Fourier transformation and... 

Prior to the introduction of the Acitainer, PE acid containers which came into contact with sunlight were pigmented black (carbon black) to act as a UV screen. However, since the acid container of the Acitainer is completely shielded from daylight by the outer vessel it can be of any colour. But since the inner container is not normally visible it is left unpigmented, i.e. natural colour. 

Properties affected Colour carbon black also has useful anti-static properties, can provide electrical conductivity black pigments also give effective UV screening also used as a reinforcement in rubber compounds (the largest overall use)... 

Absorption of, or screening from, UV light. UV absorbers are receptive to UV radiation and dissipate the energy harmlessly as heat. UV screening can, of course, be effected by some pigments, the most effective of which is carbon black - but its application is obviously limited. Titanium dioxide can also be used, but it is expensive and there can be side effects, as noted below. 

Ultraviolet-screening pigments have been used extensively to protect polymers against the harmful effect of uv radiation. For example, carbon black imparts an extraordinary stabilizing power, mainly on account of its high uv-absorbing capacity However, like other UVA, carbon black has additional photoantioxidant... 

Colours + 0.5% UV stabiliser Outdoor life (sunshine hours) Screening power relative to natural non-UV stabilised polymer Screening power relative to non-UV stabilised pigment formulation... 

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