Streu dd-medien

Date: 31. 10. 2011

Editor: Dagmar Riefer

Red that stays red
As new additions to its DecoTint® PREMIUM W series of water-based tinting pastes for house paints and plasters, Protec® presents new pastes that will produce brilliant red tints outside the full-shade range. The organic red pigments they contain are distinguished by their outstanding light and weather fastness even in lighter tints.
Protec® Systempasten GmbH of Herdecke has complemented its DecoTint® PREMIUM W series of water-based tinting pastes for house paints and plasters with two new groups of organic red pigments.Even in crimson tints,pigments of the perylene class reach levels of light and weather fastness which used to be the sole preserve of scarlet. Quinacridone will produce brilliant, intense red tints across the entire spectrum from flame red to blue-tinged purple.
Red – a problem colour

Red façades are highly esteemed by architects and colour designers. Yet red is one of those critical tints that are prone to fade quickly, and if it does, many a façade will begin to look ‘under the weather’ rather soon. To be on the safe side, therefore, people opt for inorganic pigments, for these are highly resistant against ageing and extremely colour-fast, although their colour appears a little bit ‘hazy’. Among organic pigments, scarlet has been the first choice so far. It is indeed extremely durable and brilliant, but it is very expensive, and its colour range is limited to reddish-orange tints. For the first time now, the new pastes will produce brilliant and extremely weather-resistant red tints in other than fullshades, thus broadening the colour palette significantly.

The task facing the team of Protec® developers was not confined to discovering pigments for producing brilliant red tints that do not fade for a long time. The proper objective was to develop high-performance paste systems that give excellent results in a mixing machine. To achieve this, they compared the dispersion behaviour and other properties of several pigments from each colour index in order to determine which is best in terms of rheology, pumpability, and dosability. Moreover, the seven different red-168 pigments differed markedly with regard to their weatherability. They were tested in a weather-o-meter (WOM) and on our weathering roof. This pigment screening process went on for somewhat more than two years. In addition, we evaluated each pigment coloristically in various stages of brightness and in mixtures with other pigments.
The top 3 red pigments

Ultimately, the screening contest was won by three pigments: dibromanthanthron (P.R.168), already used in the façade system, and two newcomers, perylene (P.R.179) and quinacridone (P.V.19). All three are polycyclic pigments featuring several aromatic ring systems which give them their outstanding stability. In dibromanthanthron, six of these rings are responsible for the pigment’s stability and, consequently, for its outstanding weather-fastness even in lighter shades. Known from automobile paints, perylenes consist of a seven-ring system resulting in extraordinary stability. Quinacridone has five rings that account for the excellent weather-fastness of this red pigment. It can be made in different crystalline forms, each with its own influence on the pigment’s resistance. Among these, the gamma crystal modification was found to be particularly stable.

Wanting to make sure that the performance of the new pastes we are offering our customers for their tinting systems is indeed outstanding, we examined the technical and physical properties of all additives, including dispersing, wetting, binding, and humidifying agents with a relative content of more than 0.3%. Among the characteristics investigated were plaster liquefaction and hydrophilia as well as the formation of runs and seams. To test the stability of the new pastes, we ran pumping and dosing experiments on experimental paste formulations for several months.
Our new pastes are called DecoTint® Premium W Scarlet 257 RY (pigment red 168), DecoTint® Premium W Dark Red 277 RB (pigment red 179), and DecoTint Premium W Red 297 RB (pigment violet 19).
For further information, contact Protec® Systempasten GmbH, Wetterstrasse 58, D-58313 Herdecke, phone:[phone], fax: [phone], e-mail: [e-mail];www.protec-systempasten.de