PIGMENT BASED ON MIXTURES OF MICRO- AND NANOPOWDERS OF ALUMINIUM OXIDE Russian patent published in 2014 - IPC C09C1/64 

FIELD: chemistry.

SUBSTANCE: invention relates to compositions of pigments for white paints and coatings, including thermoregulating coatings of spacecraft. A pigment for light-reflecting coatings contains a mixture of aluminium oxide particles of micron sizes with aluminium oxide nanoparticles. The mixture is mixed in a magnetic mixer with the addition of distilled water. The obtained solution is evaporated in a drying chamber at 150°C for 6 hours, ground, heated at 800°C for 2 hours and re-ground. To increase light resistance in irradiation by the solar spectrum ultraviolet the concentration of aluminium oxide nanoparticles constitutes 4 wt %.

EFFECT: claimed pigment possesses higher photoresistance to the action of the solar spectrum ultraviolet due to the creation of relaxation centres, formed by radiation of defects in the form of aluminium oxide nanoparticles on the surface of aluminium oxide grains and granules; reflective ability of the pigment in the solar range of spectrum is at the level of a reflective ability of white pigments.

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