| 摘要 |
<p>New synthetic zeolite pigments are prepared by a process which comprises: (a) heating a mixture comprising crystalline aluminosilicate zeolite (especially type A, X or Y zeolite) and each of a reducible sulphur source (e.g. elemental sulphur), a reducing agent (e.g. elemental carbon or a carbon-containing salt) and a source of additional cations, under non-oxdising conditions at a temperature of preferably from 300 to 600 °C; and (b) recovering therefrom a synthetic inorganic zeolite pigment. The pigment recovered immediately after the above step (a) is, in preferred embodiments, green. Preferably, this pigment product is subjected to a further heating step which comprises heating the product of step (a) in a oxidising atmosphere, e.g. sulphur dioxide, at a similar temperature to that in the first heating step. The pigment recovered after this second heating step is, in preferred embodiments, blue. The pigments are characterised by chemical composition and unique x-ray powder diffraction patterns and exhibit useful properties including adsorption of foreing molecules, ion exchange and characteristic colours.</p> |
