Modified aluminium oxide with a thin surface layer of organic alumino:phosphate

摘要

Modified aluminium oxide consisting of crystalline alpha -Al2O3 with a coating 1-1000 nm thick of aluminophosphate organic material on its surface is synthesised from 90-99.5% alpha -Al2O3 and 10.0-0.5% aluminophosphate organic substance. Also claimed is a process to obtain such a modified aluminium oxide by treating the alpha -Al2O3 with orthophosphoric acid in an aq. medium at pH 4.5-6.0 followed by treatment with an ionic surface active substance, polyelectrolyte or water soluble polymer.