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 Requirements for Colorants in Construction The reason why Ultramarine Blue historically has not been used for cement coloration is because Ultramarine Blue is not chemically stable when is in contact with the cement paste. During the setting of mortar, different chemical interactions between them take place, so that the Ultramarine Blue’s chromophore is attacked and the blue color fades. During this chemical interaction there are two different reactions occurring simultaneously. First Calcium ions from cement are exchanged with Sodium ions from the Ultramarine Blue structure, producing some distortion in the crystaline structure of Ultramarine Blue. Second, because of the similarity of both structures, there is an overlap between the calcium hydroxide + calcium/aluminum silicate from cement paste with the Ultramarine Blue structure that favours the oxidation of the chromophore (  ); this combined chemical interaction leads to the complete fading of the blue color. It is important to highlight that this effect is more critical under highly alkaline conditions, high water content or regular contact with water, for example in long setting times.  Being aware of the limitation of the current Ultramarines, the importance of this market, the few color alternatives designers and architects have and the potential for Ultramarine Blue in these applications, Nubiola has dedicated more than 4 years to a product development program in collaboration with a very prestigious R&D Centre for Construction and has launched suitable products to be used in this kind of applications. Nubicem B series is a range of Ultramarine Blues specifically designed to be compatible in cementitious formulations. Thanks to Nubiola’s technology and knowledge in pigment encapsulation, Nubiola has succeeded in making a product that avoids (minimizes) the interaction with the cement paste. Nubicem B series consists of two different products:  Ultramarine Blue protected against possible interactions with cement. It is recommended for outdoor and indoor applications, when the contact with water (or high humidity) is not severe; i.e. in dry areas or when the formulation is highly hydrophobic.  Ultramarine Blue protected against possible interactions with cement, modified with Cobalt Blue. It is recommended for all kinds of indoor and outdoor applications, it provides additional protection for the most demanding applications. Therefore Nubicem B series matches the needs of the Construction market (cementitious applications) because of their outstanding properties i.e.
Nubicem B Series is recommended for applications where in the past Ultramarine Blue was not possible to be used, applications such as colored mortar / stucco / plaster, colored concrete (ready mix or pre-cast), or colored grout joints for ceramic tiles, but it also has additional benefits in non cementitious applications such as formulations based on lime, highly alkaline coatings or coatings over a high alkaline substrate. To take advantage of the Ultramarine Blue color in all its depth, the use of white cement is recommended, although it can also be used in grey cement; the color obtained in this case is a grey with a blue undertone.  |
