Patent ID: 7338995

Claim:
A process for producing a pigmented melt processible polymer composition, comprising: (1) surface treating an inorganic pigment comprising titanium dioxide by contacting the inorganic pigment with a first surface treating amount of (a) a silicon-containing compound selected from the group consisting of a silane monomer, a silicone polymer having a reactive site, and mixtures thereof; and (b) a second surface treating amount of an organic compound selected from the group consisting of a carboxylic acid, a hydrocarbon wax, a silicone polymer which is different from the silicone polymer of (a) above and mixtures thereof; to form surface treated inorganic pigment (2) mixing the surface treated inorganic pigment with (a) a processing aid comprising a polymer derived from one or more fluorinated monomers selected from the group consisting of vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, tetrafluoroethylene and perfluoroalkyl perfluorovinyl ethers, and (b) a first melt processible polymer selected from the group consisting of one or more polymers of ethylenically unsaturated olefins and copolymers of ethylene with higher olefins or vinyl acetate, polyvinyl chloride, polyvinyl esters and copolymers thereof, phenolic resins, alkyd resins, amino resins, epoxy resins, phenoxy resins, polysulfones, polycarbonates, polyesters and chlorinated polyesters, polyethers, acetal resins, polyimides and polyoxyethylenes and mixtures thereof; to form a pigmented melt processible polymer masterbatch, and the processing aid being in an amount ranging from 0.01 wt. % to 5 wt. %, based on the total weight of the masterbatch; and (3) melt blending the pigmented melt processible polymer masterbatch with a let down polymer comprising a second melt processible polymer selected from the group consisting of one or more polymers of ethylenically unsaturated olefins and copolymers of ethylene with higher olefins or vinyl acetate, polyvinyl chloride, polyvinyl esters and copolymers thereof, phenolic resins, alkyd resins, amino resins, epoxy resins, phenoxy resins, polysulfones, polycarbonates, polyesters and chlorinated polyesters, polyethers, acetal resins, polyimides and polyoxyethylenes and mixtures thereof, to form a third melt processible polymer which is a pigmented melt processible polymer composition.