GB419445A - Improvements in and relating to the manufacture of coloured moulding compositions - Google Patents

Abstract

A process for the manufacture of a moulding composition from synthetic resins and a filler comprises colouring finely divided filler--e.g. wood flour, wood meal, asbestos powder--with an aqueous medium. The filler may be coloured by dyeing with direct cotton, sulphur, mordant or vat dyes. In an example, 100 grams of micro-asbestos are wet out with one litre of water. Then 2 grams of a soluble or partially soluble acid dyestuff such as Orange II (Colour Index No. 151) are wet out with 1 gram of turkey red oil and dissolved in water. This is added to the wood meal bath and the temperature raised to the boil during agitation. Then 4 grams of barium chloride (in solution) are added to the bath and the boiling continued for 5 minutes. The coloured asbestos is later filtered off, washed with cold water, pressed and dried. In other examples Caledon Blue R.C., Diphenyl Chlorine Yellow F.F. and Eclipse Blue B are used.ALSO:A process for the manufacture of a moulding composition consists in colouring finely divided filler-e.g. wood flour, wood meal, asbestos powder-by an aqueous medium and then mixing the resulting coloured filler by the aid of heat and in substantial absence of water with undyed synthetic resin of the kinds hereafter specified whereby the filler is impregnated with the synthetic resin. The resins are substantially waterfree intermediate condensation products of phenol-formaldehyde, urea-formaldehyde, thiourea-formaldehyde or like resins, or vinyl resins, including styrol resins. The colouring of the filler may take place after the filler has been added to the resin provided that the water is substantially removed before the filler is finally mixed with the resin. The filler may be coloured by dyeing with direct cotton, sulphur, mordant or vat dyes. In examples, Caledon Blue R.C., Diphenyl Chlorine Yellow F.F., Eclipse Blue B. and Orange II are used.