Effect pigments

The quantity of pigment used should be kept to a minimum, normally in the range of 0.25 to a maximum of 5%. The pigmenting effect will reach a maximum and then stay relatively constant. Too much pigment will only degrade the quality of the part and add extra cost. 

Lai S, Lai S. Chlorpromazine-induced cutaneous pigmentation—effect of replacement with clozapine. J Psychiatry Neurosci 2000 25(3) 281. 

Fig. 5.15 Optical properties of absorption pigments, effect pigments and natural pearls.

CAS 1333-86-4. A finely divided form of carbon, practically all of which is made by burning vaporized heavy-oil fractions in a furnace with 50% of the air required for complete combustion (partial oxidation). This type is also called furnace black. Carbon black can also be made from methane or natural gas by cracking (thermal black) or direct combustion (channel black), but these methods are virtually obsolete. All types are characterized by extremely fine particle size, which accounts for their reinforcing and pigmenting effectiveness. 

Dye and pigment effects on polymers as well as their inherent stability are still subjects of considerable complexity and interest. Additive effects on the stability of dyed systems have been reviewed as has general dye photofading. ... 

The cause of melasma is still widely debated, and potential pathogenic factors include the influence of UVs, the hyper-pigmenting effect of some cosmetics, genetic predisposition, hormone therapy and pregnancy. Estrogens and possibly progestogens can trigger melasma. 

Tsatsaroni, E., Liakopoulou-Kyriakides, M., and Eleftheradis, I. 1998. Comparative study of dyeing properties of two yellow natural pigments—effects of enzymes and proteins. Dyes Pigments 37, 307-315. 

Pigment Effects. These effects are achieved in practice only with precipitated silicates. This effect is of special significance in emulsion or latex paints and in paper coatings. These applications play a more minor role in the United States than they do in Europe and Asia. Part of the titanium dioxide content in the paint and paper-coating applications is substituted with precipitated silicates without causing a deterioration in the brightness or opacity. The amount of silicate added must not exceed... 

Surface effects Pigment effects Electrical effects Adsorption Catalysis... 

The flame retardation is also attributed to the consumption of thermal energy by these endothermic reactions, to the inhibition reactions in the flame, and to the release of hydrochloric acid directly in the flame. The pigmentation effect of mixtures containing Sb203 is a disadvantage that limits their use for light-colored and transparent products. 

One drawback of antimony trioxide is its pigmenting effect even in coloured grades it can not be used at all for transparent articles. 

This chapter will cover the state-of-the-art of in vitro human skin models and the utility of these models fdrug development applications including screening for skin sensitization, phototoxicity, irritation, genotoxicity, pigmentation effects, and percutaneous absorption. The validation status of the various models and applications and areas where further development is needed are also highlighted. 

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