titanium dioxide manufacturers in china

This article discusses the discovery of phosphorescent lithopone on watercolor drawings by American artist John La Farge dated between 1890 and 1905 and the history of lithopone in the pigment industry in the late 19th and early 20th centuries. Despite having many desirable qualities for use in white watercolor or oil paints, the development of lithopone as an artists’ pigment was hampered by its tendency to darken in sunlight. Its availability to, and adoption by, artists remain unclear, as colormen's trade catalogs were generally not explicit in describing white pigments as containing lithopone. Further, lithopone may be mistaken for lead white during visual examination and its short-lived phosphorescence can be easily missed by the uninformed observer. Phosphorescent lithopone has been documented on only one other work-to-date: a watercolor by Van Gogh. In addition to the history of lithopone's manufacture, the article details the mechanism for its phosphorescence and its identification aided by Raman spectroscopy and spectrofluorimetry.

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tion of the precipitate, the mass is filter pressed, dried, muflled and processed in the on the market, in that the {covering capacity of the pigment is greatly increased, as well The titanium oxide is peptized or held in as its fastness to light, and ease of working in oils. It is also superior to the so called double strength lithopone made by doubling the zinc sulphide conent, in that it is very neutral to acid vehicles. It is also far superior to other titanium compounds on the market, inasmuch as greater opacities are obtained with a relatively small amount of titanium oxide, than has heretofore been obtained with far greater proportions of titanium oxide, thereby effecting a considerable economy over that of other similar products containing'titanium oxide.

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