Abstract: Titanium dioxide powder with a greatly decreased volatile moisture content can be obtained by surface treating with titanium dioxide powder with addition of a calcium salt and/or a silane coupling agent, or by a surface treatment by addition of an aluminate together with these surface treatments. A masterbatch containing this titanium dioxide powder is of high quality, having no defect due to foam generation upon high temperature processing.

Abstract: A color concentrate which comprises (a) one or more of polypropylene resins and propylene copolymers having a melt flow rate in the range of 0.1-100, (b) one or more of organic and inorganic pigments; and (c) one or more pigment dispersants selected from the group consisting of polyethylene wax, polypropylene wax and derivatives thereof, zinc stearate, magnesium stearate, aluminium stearate, calcium stearate and ethylene bisamide, the contents of (a), (b) and (c) being, respectively, 11-30 wt %, 10-80 wt % and 10-50 wt % based on the total of (a), (b) and (c); and molded or extruded articles of thermoplastic resins other than (a) colored with the color concentrate.