Papers by Keyword: Ceramic Pigment

Abstract: To meet the requirement of ceramic pigment for ink jet printing, CoAl₂O₄ pigment was prepared by nitrate-glycine method. The effect of nitrate/glycine ratio, calcination temperature and organic sacrificial agent on the particle size and chroma of the blue pigment were considered. The results show that the particle size of the pigment increases with the increase of glycine in the ratio and the decrease of the calcination temperature. However, the increase of the calcination temperature results in the broadening of the particle size distribution of the pigment. The addition of the organic sacrificial agent contributes to decrease the particle size of the pigment, which is about 2.0 μm. The chroma of the pigment is L*=47.62、a*=9.49、b*=-51.41. The blue pigment can be used in ink jet printing.

Abstract: The Silicon-chrome-green Pigment is synthesized with solid reaction process, and is tested by XRD. Influence of mineralizer on color and mechanism of action are discussed. The variety and content of mineralizer which suit the Silicon-chrome-green Pigment are determined.

Abstract: Black pigment is an important pigment in the ceramic decoration. The traditional black pigment is spinel type matter containing Co, Fe or Cr elements. Carbon black is the best black pigment and is nontoxic. However, carbon black is oxygenated in the ceramic sintering process at atmosphere. Carbon black enclosed in the crystal latter of ZrSiO₄ was reported. However, the content of carbon black is little which decreases the color generation. Carbon black coated with SiO₂ was prepared by sol-gel method using combustion method using SiO₂ sol and black ink as raw materials. The obtained black pigmen_{Subscript text}t was characterized by XRD, TEM and ultraviolet-visible spectrophotometer. The results show that the black pigment does not change its color after calcinations at 1300 °C at atmosphere implying the carbon black is coated completely with SiO₂.

Abstract: ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.

Abstract: synthesis and characterization of a new chromium- calcium titanate red ceramic pigment is described in this communication. The pigment is based on the solid solution of chromium (IV) in calcium titanate and was characterized as red-brown pigment in a CaO-ZnO-SiO2 transparent glaze used for ceramic tiles (1080°C). XRD, UV-Vis-NIR spectroscopy and CIE-L*a*b* techniques of characterization have been employed. The L*a*b* valour of the optimal pigment with 0,015 mol/mol of chromium fired at 1100°C with a soaking time of 3 hours and 5% weight added to the transparent glaze is 59.3/12.5/9.5. Likewise 5%w. addition of NHCl used as flux agent increase b* and decrease L* valour (L*a*b*=45.2/15.3/5.3).

Abstract: Research on new ceramic dyes is addressed to obtain best pigmenting materials in order to reach higher thermal stability (e.g. for porcelainised stoneware) than classical pigments, higher chemical stability towards the coloured matrix or low toxicity in order to satisfy health and environmental requirements. The earlier developments on the research in new ceramic pigments based on new crystal structures (e.g. perovskite, hexaaluminates, fergusonite, pseudobrookite …), new chromophores (e.g. ruthenium, bismuth and rare earth ions), or new methods of preparation are discussed in this communication.

Abstract: We report the preparation of ceramic pigments using industrial wa stes as primary sources. An Al-rich sludge (generated in the wastewater treatment unit of an anodising or surface coating industrial plant), a galvanizing sludge (from the Cr/Ni plating process ), a Fe-rich sludge (generated during steel wiredrawing), a foundry sand and a marble sawing sludge are combined to formulate distinct pigment structures via the solid state reaction method. In particular, a black spinel and a novel blue pigment based on the hibonite structure are detailed. A green olivine, and brown and pink sphenes are also reported. The pigments were fully characterized, and then were tested in a standard transparent bright ceramic glaze. Typical working conditions and colour development are fully described.

Abstract: Ancient ceramic wall tiles, called “azulejo”, firstly used on Portuguese churches, monasteries and palaces (15-18th century) have progressively been used in particular houses till the last century. These tiles and its use in huge decorative panels can be considered as a precious but fragile cultural heritage from Brazil to India, in several countries influenced by Portuguese culture. Morphologically, these tiles are composed by a porous clay-based ceramic body, the terracotta, covered by a protective glassy phase, the glaze. As artistic paintings, these murals incorporated various kinds of pigments in the glaze layer to create a pictorial impact on the walls of rich palaces or churches, real and durable monumental works-of-art. In the 21st century, degradation marks are visible on these ceramic tiles because of their use under corrosive conditions (moisture, atmospheric cycles…) along centuries. In order to promote their conservation and enhance their restoration, the physical-chemical characterization of the azulejos is performed in the present work, using mainly non-destructive processes like micro-Raman spectroscopy or X-Ray diffraction. In particular, Raman spectroscopy allows the detection of some nano/microcrystals present in the amorphous glaze due to pigments or opacifying agents or related to the elaboration process of the azulejo. Based on the observation of various selected fragments, one states that very few pigments have been used as colouring agents in this ceramic art during 17-18th centuries. Thus, the relationship between the different colours, the introduced pigments and the structural aspects of the glass will be focused. Some features related with the ancient ceramic technology will also be discussed.