Iron oxide pigments

Natural and synthetic iron oxide pigments are by far the most important colored pigments. Their high importance is based on the variety of stable colors ranging from yellow via orange, red and brown to black. Iron oxide yellow (α-FeOOH), iron oxide red (α-Fe2O3) and iron oxide black (Fe3O4) are the most important representatives of the iron oxide pigments. Synthetic iron oxide pigments are produced industrially on a large scale by solid-state processes, precipitation processes and by the Laux process. Main advantages of synthetic iron oxide pigments compared with natural types are their pure hue, the consistent, reproducible quality and their tinting strength. Iron oxide pigments are mainly used in construction materials, paints, coatings, and plastics, but also in cosmetics, pharmaceuticals and special applications such as ceramics, magnetic coatings and toners.

Innovative Alkyd Emulsion Composition Enhanced With Nanosize Iron Oxides for the Protection of Thermally Treated Wood in Outdoor Conditions

Wood has great potential for uses in outdoor conditions, but it can be easily degraded due to the action of environmental factors (solar radiation, moisture, fungi, insects, etc.). The protection of wood is therefore a very actual research topic, and it is also the object of this work. The main goal of this Doctoral Thesis is to obtain a water-based alkyd paint formulation in the form of emulsion and to optimize its composition with necessary additives, in particular, with nanosized red iron oxide pigments which can protect the decorative qualities of thermally treated wood (TTW) during outdoor exposure. In the literature review, the main factors responsible for the degradation of wood and their effect on the structure and properties of wood are summarized. The chemistry of coatings for the protection of wood and the challenges that are faced in reformulation of paints, due to more stringent regulations which limit the use of organic solvents and promote greener alternatives, like water-based paint formulations, are considered. In Europe, this is stated by the Directive 2004/42/EC of the European Parliament on the limitation of emissions of volatile organic compounds (VOC) from decorative paints and varnishes. In the first part of the experimental section, the optimal composition of the alkyd emulsion and the effects of additives on the film properties have been investigated. The different chemo-physical properties of thermally treated wood compared with those of untreated wood have been also evaluated. After thermal modification, wood becomes more hydrophobic and this has been confirmed from the changes of the surface energy of thermally treated wood: the polar component of the surface energy decreases with increasing temperature of thermal modification. In the second part of the experimental section, artificial and outdoor weathering tests have been done to determine the suitable concentration of red iron oxide nanoparticles which can give better protection against photodegradation. Results show that red iron oxide pigments at a concentration of 8 % in alkyd emulsion are efficient to protect the wood surface against discoloration. During the outdoor weathering test, the performance of alkyd emulsion has been compared with that of the solvent-based formulation. Results confirm that the water-based alkyd emulsion gives better protection of the thermally treated wood surface than the solvent-based formulation, thus confirming that the replacement of organic solvent with water gives a product with equivalent or better properties for the protection of thermally treated wood in outdoor conditions.

DOMESTIC PIGMENTS FOR THE PRODUCTION OF IRON OXIDE DEHYDRATION CATALYSTS

В данной работе представлены результаты лабораторных испытаний катализаторов дегидрирования метилбутенов (изоамиленов) в изопрен, синтезированных на основе железоокисных пигментов от разных производителей. По результатам лабораторных и опытно-промышленных испытаний катализаторов установлено, что железооксидный контакт на основе отечественного пигмента в промышленных условиях не уступает по эксплуатационным показателям катализатору, синтезированному с использованием гематита импортной поставки. This work presents the results of laboratory tests of dehydrogenation catalysts of methylbutenes (isoamylenes) in isoprene synthesized based on iron oxide pigments from different manufacturers. According to the results of laboratory and pilot tests of the catalysts, it was found that the iron oxide contact based on domestic pigment under industrial conditions is not inferior in performance to the catalyst synthesized using imported hematite

Prospects for the Use of Pigments Obtained from Iron-Containing Sludge in the Composition of Construction and Paint compositions

Promising areas of application of pigments obtained on the basis of industrial wastes and containing a number of impurities are considered. The quality of the pigment obtained by the alternative technology from iron-containing sludge was evaluated in comparison with the red iron oxide pigments of the KA TU 2322-166-05011907-98 (Russia) and YIPIN S130 (China) grades. Quality indicators are stated and analyzed relative to the requirements of TU 2322-166-05011907-98. Primer GF-021 was analyzed for compliance with GOST 25129-82 and for the presence of anticorrosion properties by the potentiodynamic method and in the salt spray chamber. Pigments in the composition of fine-grained concrete were investigated for their coloring ability and effect on strength characteristics at the age of 1, 3, 7, 28 days. Deviations and competitive advantages of the pigment obtained by alternative technology are determined with respect to the standard both in the composition of the primer GF-021 and in the composition of painted fine-grained concrete.