Applications ultramarine blues

In many applications ultramarine blue is stable to around 400 °C, violet to 250 °C, and pink to 200 °C. All have excellent lightfastness with a 7-8 rating (full and... 

In many applications ultramarine blue is stable to around 400 °C, violet to 280 °C and pink to 220 °C. All have excellent light fastness with a 7-8 rating (full and reduced shades) on the International Blue Wool Scale. Color fade attributed to light exposure or moderate heat is almost always caused by acid attack. Ultramarines react with all acids, and if there is sufficient acid, the pigment is completely decomposed, losing all color, to form silica, sodium and aluminum salts, sulfur, and hydrogen sulfide. Evolution of hydrogen sulfide with acids is a useful test for ultramarine. 

Ultramarine blues, reds and violets are acid sensitive. As such, their thermal and weathering properties are adversely affected in acidic media. Silica-encapsulated versions offer marked improvement in thermal stability and some improvement in weathering properties. The treated versions allow broad polymer usage, even in engineering plastics such as polycarbonate, and provide sufficient durability for automotive interior applications. Weatherability is highly dependent upon the degree of exposure to acid or alkaline conditions. 

Kaolin elay acts as ingredients for forming ultramarine blue pigments, which has dark blue eolom. Best quality ultramarine blue is used in all types of laundry while teehnieal and industrial grades for applications in coating, cosmetic, ink and plastic pigments. 

LDPE Heat stability normally up to 240°C Moderate light stability for many applications Easy dispersion important Red and yellow toners Selected Bis-aryiamides Isoindolinone Azo condensation Phthalocyanine Green Phthalocyanine Blue Cadmium pigments Iron oxides Lead pigments Ultramarine Blue Vat pigments Special monoazos... 

However, it would be reasonable to say that coloured pigments such as cadmium yellow, ultramarine blue and Permanent Red 2B could present the polymer technologist with light-stability problems in certain applications. The mechanism by which these pigments may act as photosensitizers is little understood and is evidently an area that requires clarification. 

In conclusion, the photostabilization of pigmented polymers is clearly a complex one for the polymer technologist. For outdoor applications the presence of a light stabilizer is essential, particularly if poor stabilizing pigments such as cadmium yellow, ultramarine blue. Permanent Red 23, anatase and uncoated rutile are being used. 

The structural complexity of the 3D framework aluminosilicates precludes a detailed treatment here, but many of the minerals are of paramount importance. The group includes the feldspars (which are the most abundant of all minerals, and comprise 60% of the earth s crust), the zeolites (which find major applications as molecular sieves, desiccants, ion exchangers and water softeners), and the ultramarines which, as their name implies, often have an intense blue colour. All are constructed from Si04 units in which each O atom is shared by 2 tetrahedra (as in the various forms of Si02 itself), but up to one-half of the Si... 

Apart from ultramarine (see marginal note on next page) [2], indigo was one of the few colourants to close this blue gap in the colour palette. In ancient times, it was reckoned as valuable on accoimt of its beauty and lightfastness, which lent itself to wider applications, not only for the colouring of precious textiles but also for artwork. 

Riederer thereafter discerns a general decrease in application, first in Italy and then in the Netherlands. Miihlethaler and Thissen regard the invention of Prussian blue, the discovery of synthetic ultramarine and of Thenard s blue (qq.v.) as the reason for the decline in usage of smalt (Muhlethaler and Thissen, 1993), although examples continue, such as specimens contained in the Hafkenscheid Collection (Pey, 1987). The pigment is currently available. 

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