E.i. Dupont De Nemours and Company

Andrejs Baidins

Michael Patrick Diebold

Edward William Gillow

A coated TiO.sub.2 pigment is disclosed with coatings of porous alumina and dense alumina, such dense alumina being formed in the presence of soluble molybdate.

High gloss durable TiO.sub.2 pigment

The invention relates to a process for preparing vesiculated cross-linked polyester resin granules by polymerizing a water-in-oil-in-water emulsion formed from a polymerizable water-immiscible oil phase, composed of an ethylenically unsaturated monomer and a polyester condensation product and an aqueous phase. The polymerization is effected essentially instantaneously and substantially immediately following the formation of the emulsion by contacting the water-immiscible oil phase at a temperature from 10.degree. to 40.degree.C. with an aqueous phase containing a strong base and having a temperature from 65.degree. to 95.degree.C. Polymerization is thereby effected while the size of the oil phase globules of the water-in-oil emulsion is at a minimum and before appreciable agglomeration can take place, resulting in a reduction in particle size and particle size distribution. The product is especially useful as an opacifying pigment for latex paints and the like, wherein it contributes improved hiding power.

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Wilmington, DE, United States of America

Andrejs Baidins