Pearl luster pigments

Natural pearl essence (Essence d Oriente, Fish Silver) is a pigment suspension derived from fish scales, skin, or bladder. It is the oldest commercial pearl luster pigment, consisting mainly of a mixture of the purines guanine [73-40-5] (75-97%) and hypoxanthine [68-94-0] (25-3%). [Pg.216]

Ti02-mica pigments are used in all color formulations of conventional pigments where brilliance and luster are required in addition to color, i.e., in plastics, coatings, printing, and cosmetics. A major market for silver white pigments (pearl pigments, white metallic ) is the plastics industry. [Pg.220]

Pearl luster pigments regular reflection takes place on highly refractive parallel pigment platelets (example titanium dioxide on mica)... [Pg.8]

A) conventional pigment B) metal effect pigment C) natural pearl D) pearl luster pigment... [Pg.231]

Pearl luster pigments simulate the luster of natural pearls. They consist of alternating transparent layers with differing refractive indices. The layers consist of CaCOa (high refractive index) and proteins (low refractive index). [Pg.231]

This difference in refractive indices, arising equally on the interface between an air/oil film or oil film/water, is a prerequisite for the well-known iridescent color images in these media. Small highly refractive platelets of pearl luster pigments align themselves parallel in optically thin systems such as paints, printing inks, or plastics. Interference effects develop when the distances of the various layers or the thicknesses of the platelets have the right values. [Pg.231]

Synthetic pearl luster pigments are either transparent or light-absorbing plateletshaped crystals. They can be monocrystalline, as in Pb(OH)2 2 PbCOs and BiOCl, or... [Pg.231]

Pearl luster pigments are used to obtain pearl, iridescent (rainbow), or metaUic effects, and in transparent color formulations to obtain briUiance or two-tone color, luster flops, and color travel effects (changing with viewing angle). The most important appUcations are plastics, industrial coatings, printing inks, cosmetics, and automotive paints. [Pg.232]

Optical Principles of Pearl Luster and Interference Pigments... [Pg.232]

The physical background of optical interference effects has been the subject of many publications [5.122-5.125, 5.127-5.130]. The optical principles of pearl luster (interference) pigments are shown in Figure 5.16 for a simplified case of nearly normal... [Pg.232]

With given nj and rii the maximum and minimum intensities of the reflected light, seen as interference colors, can be calculated and agree well with experimental results. Values for the refractive indices of the most important materials for pearl luster pigments are shown in Table 5.14. [Pg.234]

Color effects depend on the viewing angle. Pearl luster pigment platelets split white light into two complementary colors that depend on the platelet thickness. The reflected (interference) color dominates under regular (maximum) reflection, i.e., when the object is observed at the angle of regular reflection. The transmitted part... [Pg.234]

Substrate-Free Pearl Luster Pigments Natural Pearl Essence... [Pg.235]

Natural pearl essence is very expensive but shows some advantages over synthetic pearl luster pigments. For example, it shows a high but soft luster (no = 1.79 (parallel) to 1.91 (perpendicular)). It is not brittle and has a relatively low density of 1.6 g cm which reduces setthng in liquid formulations. It is almost exclusively used in expensive cosmetic applications. [Pg.235]

The first commercially successful synthetic pearl luster pigments were hexagonal lead salt crystals, especially basic lead carbonate Pb(OH)2 2 PbCOs. Basic lead carbonate is precipitated from aqueous lead acetate with carbon dioxide under carefully... [Pg.235]

The dominant class of pearl luster pigments is based on platelets of natural mica coated with thin films of transparent metal oxides [5.122-5.125, 5.127-5.130, 5.137]. The mica substrate acts as a template for the synthesis and as a mechanical support for the deposited thin optical layers of the pearl luster pigments. Mica minerals are sheet layer silicates. Pearl luster pigments are usually based on transparent muscovite mica only some are based on synthetic phlogopite. Although muscovite occurs worldwide, few deposits are suitable for pigments. Natural mica is biologically inert and approved for use as a filler and colorant. [Pg.237]

The development of the mica-based pigments started with pearl luster colors (Figure 5.18(A), Ti02-mica). This was followed by brilliant, mass-tone-colored, combination pigments (i.e., mica-Ti02, and another metal oxide) with one color (interference... [Pg.237]

Pearl luster pigment Advantages Disadvantages Main application field... [Pg.241]

Pearl luster pigment shape Particle size Thickness Density... [Pg.241]

Improved color strength and very high luster are produced by the combination of precise thickness silica flake substrate materials, selected for their interference chro-maticity, and by deposition of titania or iron oxide coating layers of the precise thickness required to generate the same interference color. These pearl luster pigments show stronger chromaticity L a b -values than can be produced with mica-based designs. [Pg.246]

Special effect pigments are used as colorants or part of color formulations for all systems where traditional pigments are applied, but where additional color depth, brilliance, iridescence, color travel, and other spectacular effects are required [5.122, 5.123]. Mica-based pigments dominate their combination of pearl and interference effects, brilliance, stability and behavior in different application systems is as yet unsurpassed. Pearl luster pigments require transparent or at least translucent binders. Formulations with absorption pigments have to take their transparency and color mixing rules into account... [Pg.251]

Fig. 29 Comparison of differences in size of pigments at the same magnification. Red iron oxide (A), titanium dioxide (B), talc (C), mica (D), and two pearl luster pigments Iriodin 110 (E) and Iriodin 100 (F).

Fig. 31 Cross-section of films from Aquacoat ECD 30 pigmented with 20% (V/V) of the pearl luster pigment Iriodin 100.

Iriodin. [EM Industries E. Merck] Lead carbonate pearl luster pigments. [Pg.186]

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