| 摘要 |
<p>Delustred polyamide fibres are spun from a polyamide containing bitanium dioxide which has been treated with a water-soluble manganese salt and orthophosphoric acid and/or a water-soluble orthophosphate to render the TiO2 photo stable (see Division C1). The pigment so coated with manganous orthophosphate can be also coated with silica and hydrated metal, e.g. aluminium, oxide, or substantially water-insoluble compound. In Example 3 the pigment is incorporated in nylon 6 fibres.ALSO:Titanium dioxide pigment is produced by treating titanium dioxide, maintained in suspension in an aqueous medium, with a water-soluble divalent manganese salt and orthophosphoric acid and/or a water-soluble orthophosphate. The mixture is neutralized if necessary and the treated pigment is separated, washed, dried and ground. Additionally the pigment may be treated with a water-soluble metal, e.g. aluminium, salt and a water-soluble silicate, to produce on neutralization a substantially colourless and insoluble hydrated metal oxide or compound or silica. The preferred range of divalent manganese salt added is 0.05-2% Mn by weight with a most preferred range of 0.1-1.0% Mn.</p> |
