Surface Treatment Method

Abstract

The present invention provides a method of colouring and surface treating the surface of a particulate material, such as a silica-based material like sand, where the method includes the steps of: a) optionally heating the particulate material to a temperature between 3° and 85° C.; b) preparing an aqueous dispersion of a colourant, an alkoxy silane, a silyl alkanoate, a polysiloxane, or a mixture of these; c0) optionally treating the particulate material c1) mixing the dispersion prepared in step b) with the particulate material of step a); c2) optionally adding an alkoxy silane, a silyl alkanoate, a polysiloxane, or a mixture of these; c3) heating the mixture to a temperature of between 2° and 80° C. for a period of 1 minute to 24 hours; and d) optionally mixing the treated sand formed in step c) with an aqueous dispersion of a colourant, an alkoxy silane, a silyl alkanoate, a polysiloxane, or a mixture of these. Steps a) (where used) and b) can be conducted simultaneously or sequentially in either order. At least one step includes the use of an alkoxy silane, a silyl alkanoate, and/or a polysiloxane. At least one step includes use of a colourant. The aqueous dispersion of step d) may be the same or different to that of step b). The invention further provides a coloured particulate material which is surface modified on at least one surface with a colourant and at least one of a silyl alkyl group or silyl alkenyl group. The material may be made by the method of the invention. The invention also provides filled moulding material comprising the coloured particulate filler material.

Dependencies are inferred from the claim text.