Carbon Black Pigment Research Articles

Facile synthesis of tunable polymer spheres for encapsulation pigment application

Polymer spheres with tunable particle size were synthesized by hydrothermal method derived from sucrose. Afterwards, zircon was coated on their surface to form the zircon encapsulated carbon (C@ZrSiO4) black pigment after calcination. The corresponding relationship between the particle size of polymer spheres and the chromaticity of C@ZrSiO4 pigments was investigated. The results revealed that the chromatic performance of C@ZrSiO4 pigment can be significantly improved by decreasing the colorant size and the relationship between them was approximately linear. The pigment exhibits deep black hue, as L∗ = 41.04, a∗ = 1.01, b∗ = 3.22, with the colorant size of 123 nm. Moreover, it also presents excellent thermal and chemical stability, indicating its potential candidate for ceramic decoration.

Application of cellulose nanofibers to remove water-based flexographic inks from wastewaters.

Water-based or flexographic inks in paper and plastic industries are more environmentally favourable than organic solvent-based inks. However, their use also creates new challenges because they remain dissolved in water and alter the recycling process. Conventional deinking technologies such as flotation processes do not effectively remove them. Adsorption, coagulation/flocculation, biological and membrane processes are either expensive or have negative health impacts, making the development of alternative methods necessary. Cellulose nanofibers (CNF) are biodegradable, and their structural and mechanical properties are useful for wastewater treatment. TEMPO-oxidised CNF have been evaluated for the decolourisation of wastewaters that contained copper phthalocyanine blue, carbon black and diarlyide yellow pigments. CNF in combination with a cationic polyacrylamide (cPAM) has also been tested. Jar-test methodology was used to evaluate the efficiency of the different treatments and cationic/anionic demand, turbidity and ink concentration in waters were measured. Results show that dual-component system for ink removal has a high potential as an alternative bio-based adsorbent for the removal of water-based inks. In addition, experiments varying CNF and cPAM concentrations were performed to optimise the ink-removal process. Ink concentration reductions of 100%, 87.5% and 83.3% were achieved for copper phthalocyanine blue, carbon black and diarlyide yellow pigments, respectively. Flocculation studies carried out show the decolourisation mechanism during the dual-component treatment of wastewaters containing water-based inks.

Characterization of Haku Maki prints from the “Poem” series using light-based techniques

Four brightly colored calligraphic prints from the “Poem” series (1970/71) by Japanese artist Haku Maki (1924–2000) were examined using multiple light-based analytical techniques in an effort to address conservation concerns regarding these artworks. A distracting white haze on the surface of some of the prints was determined by light microscopy and infrared microanalysis to be fungal mycelium from an inactive mold infestation that occurred prior to the artwork’s acquisition by the museum. Pigment analysis by Raman, X-ray fluorescence, and infrared microspectroscopies identified the artist’s palette as containing common printing ink colors such as aniline black (PBk1), carbon black (PBk7), phthalocyanine blue (PB15), Prussian blue (PB27), ultramarine blue (PB29), molybdate orange (PR104), chrome yellow (PY34), barium yellow (PY31), viridian (PG17), barium sulphate (PW21), and synthetic organic red pigments (PR3, PR22, PR48:3). Although aniline black and molybdate orange are common industrial pigments, reference vibrational spectra to assist in their identification have not appeared previously in the conservation literature. Moreover, this investigation includes to the authors’ knowledge the first published identification of these pigments in a work of fine art. Haku Maki’s unique ‘cement-on-woodblock’ printing technique in combination with his vibrant palette creates dynamic, embossed effects in these prints. However, lightfastness testing using a microfade tester identified the potential for light-based damage to the artwork, in some instances showing poorer lightfastness for colors reported to be stable pigments and greater stability than anticipated for others. These analyses are the first objective study of this innovative artist’s material choices, and they enhance our understanding of his printing technique while helping to determine the proper stewardship protocols to protect his artistic legacy.

Cabot raises carbon black pigment prices worldwide by up to 6%

Cabot raises carbon black pigment prices worldwide by up to 6%

Novel Solar Thermal Collector Systems in Polymer Design – Part 3: Aging Behavior of PP Absorber Materials

A novel, accelerated aging test method was used to characterize the long-term stability of commercial black-pigmented polypropylene (PP) model materials for solar thermal absorbers at elevated temperatures. The PP model materials investigated, PP-B1 and PP-B2, are based on carbon black pigmented PP block copolymer grades. Using an automatized planning technique, sliced 100 μm thick specimens were prepared, aged in hot air and heat carrier fluid (mixture of 60 vol.-% deionized water and 40 vol.-% commercial propylene glycol) at 95 ̊C, 115 ̊C and 135 ̊C for up to 15,000 hours, and characterized in terms of various aging indicators (i.e., remaining primary stabilizer content, oxidation temperature, carbonyl index and ultimate mechanical properties). In general two major trends were discerned. First, the aging processes of the PP compounds depend on the stabilizer system, but even more heavily on the interaction of the stabilizers with the carbon black pigments and the structure and morphology of the polymer. Although the compound PP-B2 exhibited much faster stabilizer loss and an associated drop in oxidation temperature than PP-B1, mechanical investigations proved a better long-term stability for PP-B2. Second, it was shown for the compounds investigated that exposure to hot air causes harsher aging than exposure to hot heat carrier fluid. This is, presumably related to the reduced quantity of dissolved oxygen and triazole-based corrosion inhibitors used in the heat carrier fluid. While PP-B1 is use for absorbers in unglazed collectors and overheating-protected glazed collectors, the investigations clearly revealed that PP-B2 is a promising alternative.

Orion Engineered Carbons showcased flagship specialty carbon black pigments for coatings at ACS

Orion Engineered Carbons showcased flagship specialty carbon black pigments for coatings at ACS

Identifying and quantifying amorphous and crystalline content in complex powdered samples: application to archaeological carbon blacks

Carbon black materials have been frequently used from prehistory as pigments for drawings and paintings and also as dyes, inks and cosmetics, since they are easy to make by burning organic matter. However, the carbonaceous phases they form are often ill-ordered and not easy to characterize. Five carbon black Roman micro samples found in vessels in houses in Pompeii were studied. These precious powders correspond to mixed phase samples that contain both crystalline and ill-ordered components. Here, a methodological approach that accomplishes the identification, quantification and mapping of the different phases in these heterogeneous samples using synchrotron-based techniques is proposed. The results were compared with those from scanning electron microscopy. Information about the nature of the mixtures and the origin of carbon black pigments is obtained. The use of charred vegetable materials is concluded, independently of the shape and the nature of the container.

Orion Engineered Carbons shows Carbon Black Pigments at ABRAFATI

Orion Engineered Carbons shows Carbon Black Pigments at ABRAFATI

11th International GeoRaman Conference

11th International GeoRaman Conference

Weathering of wood-polypropylene and wood-wollastonite-polypropylene composites containing pigments in Finnish climatic conditions

Purpose – The purpose of this paper is to study the resistance of wood-polypropylene and wood-wollastonite-polypropylene composites containing pigments to natural weathering. Design/methodology/approach – Natural weathering of composites was conducted in Finnish climatic conditions for one year. The colour of the composites was determined with a spectrophotometer, the morphology of the composite surface was analysed by scanning electron microscopy (SEM), and the changes in the polymer structure in surface layer of the composites were analysed with differential scanning calorimetry (DSC). Charpy impact strength was determined with an impact tester. Findings – The pigments used in this study reduced the colour change of the composites exposed to outdoor weathering as compared with the un-coloured composite. The carbon black pigment was more effective than the iron oxide pigment. Moreover, only the carbon black pigment was found to reduce the degradation of the surface layer of the composites. The addition of the carbon black pigment had a positive effect on the dimensional stability of the composites in a water absorption test. Only the combination of the carbon black pigment and wollastonite resulted in a composite which was capable to retain its Charpy impact strength both after one year of outdoor weathering and cyclic treatment. Research limitations/implications – This study is a part of continuous research on the development of wood-polymer composites (WPUs) suitable for outdoor applications in Finnish climatic conditions. The first part of the study, which has been published earlier, showed the results of weathering of composites in accelerated tests in comparison with 1,000 hours outdoor exposure during summer time (June and July). Outdoor weathering limited to 1,000 hours cannot give an objective view on the weathering behaviour of composites in Finnish climatic conditions. The results of the current study were obtained from one-year outdoor exposure of composites. Originality/value – The wood-polypropylene composite made with the combination of the carbon black pigment and wollastonite can be recommended for outdoor applications. The study provides useful information on the resistance of wood-polypropylene composites to weathering in Finnish climatic conditions.

Germany & US: Huntsman – carbon black, iron oxide & other colour pigments

Germany & US: Huntsman – carbon black, iron oxide & other colour pigments

Preparation and Chromatic Properties of Encapsulated Carbon Black Pigment via Layer-by-Layer Self-Assembly Method

Encapsulated carbon black pigment was prepared by layer-by-layer self-assembly method. The RX8002 carbon black particles were well coated by a SiO2 layer, which makes it has good connection with ZrSiO4 layer. Meanwhile, dense ZrSiO4 layer was coated on the C@SiO2 particles surface to prevent the corrosive effects of glaze. The structure and morphology of samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The chromatic value of the pigments was measured by the CIE color system. The results show that the carbon black particles can be well coated by SiO2 and ZrSiO4 layer. When the TEOS/H2O ratio is 0.002 and the ZrSiO4/C ratio is 0.71, the chromatic value of the encapsulated carbon black pigment is 42.55, and the pigment has a good stability in glaze.

黒色薄膜有機被覆鋼板の皮膜特性に及ぼす黒色アゾ系金属錯塩染料の影響

Effects of azo-metal complex dyes on properties such as lightness value were investigated to examine a black thin organic coating (1-2 μm) on galvanized steel sheet for electrical appliances. This product consists of chromate coating and black thin organic coating on an electrogalvanized steel sheet or a Zn-Ni alloy plated steel sheet.(1) Solvent azo-metal complex dye, solvent azo dye, carbon black pigment, and aniline black pigment were surveyed. The L-values of the thin coatings containing solvent azo-metal complex dye with 30-40 wt% content were less than 15, whereas the L-value of coatings containing carbon black pigment were more than 23. The dye was considered to be solved uniformly, although carbon black pigment aggregated in the thin coatings. (2)The weathering resistance of the coating containing azo-metal complex dyes was superior to that of coatings containing azo dyes. (3)The black thin coating containing azo-metal complex dyes can provide both good corrosion resistance and spot weldability. (4) Results demonstrate that the black thin organic coating (1-2 μm), consisting of azo-metal complex dye and organic resin, can provide a good black appearance, weathering resistance, corrosion resistance, and spot weldability.

Preparation and chromatic properties of C@ZrSiO4 inclusion pigment via non-hydrolytic sol–gel method

A zirconium silicate coated carbon (C@ZrSiO4) black pigment was prepared via a non-hydrolytic sol–gel (NHSG) process. Phenolic resin was carbonized at high temperature in N2 atmosphere and dense ZrSiO4 was coated on its surface to prevent it to be oxidized for the glaze application. The structure and morphology of samples were studied by using X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The chromatic value of the pigments was characterized by the CIE color system. XRD results reveal that the ZrSiO4 phase can be obtained at 650 °C and degree of crystallinity increases with increasing the calcination temperature. The darkness of the samples prepared by different solvents was decrease in sequence of isopropyl alcohol, alcohol and benzene, which is consistent with their solubility to phenolic resin. After calcining at 900 °C for 2 h, the small in-situ carbon was tightly coated by zirconium silicate to form the inclusion pigment. This pigment exhibits excellent chromatic value (L* = 42.01) and good stability in transparent glaze, which indicates it is a potential candidate for ceramic pigments application.

Determination and Comparison of Material Properties of Commercial Wood-Plastic Composite Products

Outdoor applications of wood-plastic composites (WPCs) have raised question about the durability of such materials. WPCs are vulnerable to weathering factors such as UV radiation, moisture and freeze-thaw action. Weathering can cause discoloration, chalking, dimensional changes and loss of mechanical properties.This comparative study examines the effects of increased moisture content and artificial weathering on the properties of wood-plastic composites. Five commercial wood-plastic composite products from five different manufacturers were chosen and their water absorption, thickness swelling, impact strength and resistance to artificial weathering analyzed. An in-house manufactured wood-polypropylene composite with carbon black pigment was used as a reference product. In addition to quantitative investigation of material properties, the measured values were also compared with the values ​​reported by the manufacturers.The composite samples were exposed to accelerated weathering in a xenon weathering chamber for 500 hours. The color change was estimated by spectrophotometer method. The weathering resulted in no significant color fading of the composites. After weathering, the general trend was a minor decrease in impact strength. Also the water absorption and thickness swelling of commercial WPC products remained on a low level.

Synthesis and the Surface Resistivity of Carbon Black Pigment on Black Silicone Thermal Control Coating

Thermal control has become more and more important in the development of the spacecraft technology. The thermal control coatings are exposed to electrostatic charges that develop on the external surface of the spacecraft. In this research, the synthesis, the surface resistivity, and the influence of the type, percent of the pigments, and adhesive properties on the coating were studied. The weight fraction of the pigment in coatings fabricated by carbon black with a sponge-like structure are lower compared to coatings fabricated by carbon black with a nonporous structure also, the surface resistance decreased with increasing pigment contents.

The Study of Stages and Operations Involved in the Preservation and Restoration of two XIX-th Century Icons, on Wooden Support

Abstract The paper presents the stages and the operations involved in the preservation and restoration of two icons on wooden support, from the XIX-th century, which are part of the heritage of the ”Sfinții Arhangheli Mihail and Gavriil” church, from Galați. The two icon have inventory numbers as part of the collection as followed: 112 for the first icon and 113 for the second one. Both icons have the same theme, ”The Grieving Mother from Rohia” and are made by anonymous painters in egg tempera, on lime wooden support, without ground. Being part of the same collection, they were deposited in the same place and as a direct consequence, they suffer from similar deteriorations and degradations that affect both the support and the painting layer. Both panels are attacked by xylophagous insects and the painting layer has detachments, gaps, cracks, clogged dirt and a cracked and degraded varnish layer. Ten samples taken from the already detached areas were analyzed by optical microscope, SEM-EDX and micro-FTIR. Based on the chemical elements identified in the EDX spectrums, the pigments used to create the painting layer are: ultramarine natural blue Na8-10Al6Si6O24S2-4, carbon black, earth green, K[(Al,FeIII),(FeII,Mg)](AlSi3,Si4)O10(OH)2, ocher (FeO), burned or natural umber Fe2O3· H2O + MnO2·n H2O+ Al2O3, lead white (2PbCO3·Pb(OH)2) and yellow iron oxide (Fe2O3·4H2O). It was also determined that the gold leaf usually used in byzantine icons was replaced in the case of both icons: the icon number 112 has silver leaf covered with varnish, while the halo of the icon number 113 was created with yellow metallic pigments (realgar or orpigment).The pigments were also identified by determining specific peaks in micro-FTIR spectrums. For natural ultramarine blue the peaks between 628 - 724 cm-1 were assigned; the peaks in the interval 795 - 887 cm-1 confirm the presence of carbonates (calcium and lead based). The earth green pigment (aluminum - silicates) had the peaks between 1464 - 1599, while the carbon black pigment was confirmed by the peaks in the interval 921 - 1060 cm-1. After the pigments and the materials used by the author were identified, the restoration process begun with the following stages: consolidation of the painting layer (fish glue 8% and japanese paper), stopping the xylophagous attack (encapsulation with nitrogen), consolidation of the wood supports (colophon and wax, 1:1), cleaning the painting layer (ethylic alcohol and distilled water, 1:1), filling the gaps and reintegrating the fillings in tratteggio, all followed by the process of varnishing the two icons.

Spinning, structure and properties of PP/CNTs and PP/carbon black composite fibers

In this paper, the effect of the compatibilisers-dispersants and other nanofillers on melt spinning of the polypropylene (PP) composites, containing carbon nanotubes (CNTs), and carbon black pigment (CBP) has been investigated. Further, the structure and selected properties of composite fibers, such as mechanical and electrical have been studied. The results revealed, that percolation threshold for PP/CBP composite fibres was situated within the concentration of 15 – 20 wt%, what is several times higher than for PP/CNTs fibers.

Use of iron oxides to influence the weathering characteristics of wood surfaces: a systematic survey of particle size, crystal shape and concentration

Iron oxide pigments may be an alternative treatment for limiting weathering of wood surfaces instead of stains or clear coatings. An earlier study suggested the ability of iron oxides to protect against discoloration varied with particle size. In this study, iron oxides with different crystal shapes and particle sizes were investigated along with a carbon black pigment. Loblolly pine (Pinus taeda L.) samples were impregnated with water borne iron oxide dispersions, exposed to predetermined amounts of solar radiation in the high desert of Eastern Oregon, and then evaluated for discoloration, checking and changes in chemical composition. The results from this observational study suggest that much higher levels of iron oxide are required than previously thought to prevent discoloration and limit lignin degradation. Large particle sizes led to greater opacity and provided greater protection, but no iron oxide protected as well as carbon black. The findings also suggested that iron oxides had no effect on checking, indicating that the mechanisms of discoloration and checking were not directly related.

Analysis of archaeological samples using XRPD-PDF and Raman spectroscopy

Carbon black materials have been frequently used from prehistory as pigments for drawings and paintings and also as dyes, inks and cosmetics. If these material are easy to make by burning organic matter from animal or vegetal origin (e.g. peach black), they form carbonaceous phases, often ill-ordered, that can hardly be characterized [1]. This project is part of studies on archaeological cosmetics, shedding light on ancient manufacturing in physical-chemistry. Six black Roman micro samples found in vessels in Pompeii Houses were studied. To understand the composition of these complex, heterogeneous (mixture of organic/mineral, crystallized/amorphous phases) and precious black powders, a new methodology had to be developed. X-ray powder diffraction tomography enabled to locate the various phases (either crystallized or not) in virtual slices among which ill-ordered materials were analyzed using the Pair Distribution Function (PDF) [2]. X-ray diffraction data were recorded on D2AM beamline at ESRF on the samples and on reference modern carbon black powders purchased from pigments suppliers to help the interpretation of the diffuse signal. High Q data were acquired by scanning the 2D detector and using 25 keV X-rays. This enabled us to obtain well-resolved PDFs to study the amorphous carbonaceous phases contained in our samples (see figure). A comparison between archaeological samples and pure carbon black references was carried out after identification and quantitative analysis of the crystallized phases using Rietveld refinement. The proportion of crystallized phases versus ill-ordered carbonaceous ones was estimated on the PDFs using the maximization of Pearson product-moment correlation coefficients [3]. Results were confronted with those from Raman spectroscopy, known to account for the degree of disorder of non-graphitic carbons. The combination of both methods also provided specific information about the origin (plant, animal or mineral) of carbon black pigments.