C(=O)([O-])[O-].[Mg+2:5].O.[OH:7][P:8]([OH:11])([OH:10])=[O:9].[Cr]([O-])([O-])(=O)=O.[Pb+2]>C(O)C>[P:8]([O-:11])([O-:10])([O-:9])=[O:7].[Mg+2:5].[P:8]([O-:11])([O-:10])([O-:9])=[O:7].[Mg+2:5].[Mg+2:5]A saturated solution of magnesium phosphate is prepared by mixing 75 gm of magnesium carbonate in 350 ml boiling water. 100 ml of 85% H3PO4 is then added. To one-half of the solution is added 48% HF to form the fluorophosphate complex. The two solutions are each slurried with lead chromate pigment after which ethanol is slowly added to each to cause formation of the sol which deposits on the particles. The encapsulated pigments are filtered and dried at 170°C for 2 hours without darkening and when incorporated into general purpose polystyrene both were thermally stable at 625°F.
Loading…
