Coated temperature resistant iron oxide yellow

Abstract

The invention relates to iron oxide yellow pigment, in particular to a coated temperature resistant iron oxide yellow. The iron oxide yellow comprises an iron oxide yellow core and alumina and zinc oxide that are coated on the iron oxide yellow core. The preparation method comprises the steps of: 1) putting prepared iron oxide yellow slurry in a reaction kettle, slowly adding an aluminum sulfate solution under stirring, then adding glycerol and zinc carbonate into the feed solution in the reaction kettle, adjusting the pH value of the feed solution in the reaction kettle to 11-12, and when thepH value becomes stable, closing the cover of the reaction kettle; 2) raising the temperature to 220DEG C-250DEG C, and when the temperature in the reaction kettle reaches 220-250DEG C, making the reaction kettle enter a heat preservation and pressure maintaining state; and 3) after heat preservation for 1-3h and cooling to a temperature below 60DEG C, opening the kettle cover, adjusting the pH to 7.5-8.5, after the pH is stabilized, conducting rinsing and pumping filtering, performing drying at 100-120DEG C, and finally carrying out crushing. The coated iron oxide yellow synthesized by the invention has the advantages of good heat resistance, more uniform coating, simple synthesis method, low cost, safety, environmental protection, etc.

Description

technical field [0001] The invention relates to an iron oxide yellow pigment, in particular to a coated heat-resistant iron oxide yellow. Background technique [0002] Iron oxide yellow, also known as iron oxyhydroxide, its molecular formula is FeOOH or Fe 2 o 3 ·H 2 O, in the form of yellow powder, its particle shape is needle-like, has high coloring power, hiding power, and is non-toxic and harmless. It is an environment-friendly inorganic pigment, and its light resistance reaches 6-7 grades. Iron oxide yellow pigments are widely used in building materials, coatings, paints, plastics, rubber, electronics, industrial catalysts, tobacco, cosmetics and other industries. [0003] The surface of ordinary iron oxide yellow is not coated, and the crystal water contained in it is easily lost at high temperature, thus turning into iron oxide red. At present, the coating technology of iron oxide yellow pigment is mainly the technology of coating at normal temperature. Since the ...

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Problems solved by technology

[0005] In order to solve the problem of uneven coating of iron oxide yellow pigment, the present invention affects the heat resistance performance, the first object of the present invention is a kind of coated heat-resistant iron oxide yellow, adding glycerin in the preparation method of the iron oxide yellow, which can After dissolving in water, it adheres to the surface of the dispersed iron oxide yellow, making it difficult to agglomerate and making the coating of aluminum more uniform. In addition, the high temperature and high pressure reaction conditions can promote the improvement of coating efficiency, and its coating cycle is only ordinary oxidation. 1 / 10-1 / 5 of the coating cycle of iron oxide yellow, and further, the present invention coats iron oxide yellow with a layer of dense aluminum oxide and zinc oxide layers to improve the heat resistance of iron oxide yellow