Résumé–Cet article traite de la découverte de lithopone phosphorescent sur des dessins à l'aquarelle, datés entre 1890 et 1905, de l'artiste Américain John La Farge et de l'histoire du lithopone dans l'industrie des pigments à la fin du 19e et au début du 20e siècle. Malgré de nombreuses qualités souhaitables pour une utilisation en tant que blanc dans les aquarelles et les peintures à l'huile, le développement du lithopone comme pigment pour artistes a été compliqué de par sa tendance à noircir lorsqu'il est exposé au soleil. Sa disponibilité et son usage par les artistes demeurent incertains parce que les catalogues des marchands de couleurs n'étaient généralement pas explicites à indiquer si les pigments blancs contenaient du lithopone. De plus, lors d'un examen visuel, le lithopone peut être confondu avec le blanc de plomb et sa phosphorescence de courte durée peut facilement être ignorée par l'observateur non averti. À ce jour, le lithopone phosphorescent a seulement été documenté sur une autre œuvre: une aquarelle de Van Gogh. En plus de l'histoire de la fabrication du lithopone, cet article décrit le mécanisme de sa phosphorescence et son identification à l'aide de la spectroscopie Raman et de la spectrofluorimétrie.

Dr Peter  Dingle (BEd, BSc, PhD)

To put this all into context maybe we should go back to the beginning & Bluescope steel who make all of our lovely Australian colour bond iron roofs.

Characteristics of Common White Pigments

The EU expert panel did not identify an immediate health concern linked to TiO₂ when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO₂ nanoparticles, the panel concluded that TiO₂ as a food additive (E171) could no longer be considered safe.

TiO2 itself was officially first named and created in a laboratory in the late 1800s. It wasn’t mass manufactured until the early 20th century, when it started to take over as a safer alternative to other white pigments.

FAQ – EFSA 2021 safety assessment of titanium dioxide (E171)

Titanium dioxide R-5566 can be widely used in indoor and outdoor coatings, latex paints, powder coatings, inks, papermaking, rubber, plastics, masterbatches.

Zinc oxide. Zinc oxide is a popular cross-linking agent for rubber and for various resins. It is essential in the formulation of solvent-borne polychloroprene adhesives. Furthermore, zinc oxide is a good UV stabilizer, has biocidal activity and has a relatively high refractive index (2.0) which makes it an efficient white pigment. Some typical properties are: density 5.6 g/cm³; particle size 0.036-3 μm; oil absorption 10–20 g/100 g; specific surface area 10–45 m²/g. Zinc oxide is produced by reaction of the metal in the vapour state with oxygen. Zinc oxide is nonporous and is quite pure. Thus, the high surface area of some grades is due to the small particle size of zinc oxide. Some grades, especially for use in the rubber industry, are surface modified by deposition of 0.2-0.4% of stearic acid, propionic acid, or light oil [47].

Titanium Dioxide Description

Lithopone can also be used as raw material of putty to fill gaps; Adding 20% lithopone to the concrete to make artificial quartz without harming its light resistance and solidification; It can improve the impact resistance and electrical performance when used in fire safety polyester chemicals; These are the raw materials of audio vinyl records used for turbojet engine dye and thermal insulation coating and insulating layer.

Because of health risks, France banned titanium dioxide as a food additive in 2020. Two years later the European Union also banned titanium dioxide as a food additive. 

As an professional Lithopone factory, Jinan Hongquan Titanium Industry Co., Ltd is located in Jinan, a beautiful spring city. The company’s scientific research personnel sincerely cooperate with well-known domestic universities and various titanium dioxide production enterprises to study and produce active Lithopone with great concentration. Some of its products have been widely used in chemical, textile, paper, plastic, paint and other production fields.