Aluminum Company of America

James J Koenig

Kenneth Paul Goodboy

H Philip Hsieh

Hsiun P Hsieh

An improved process for dispersing alumina trihydrate in a polyester resin is disclosed wherein the improvement comprises lowering the viscosity of the polyester-trihydrate dispersion by dehydrating the alumina trihydrate to a reduction in the initial loss on ignition in a range of from 0.2 to 5.0 percent prior to adding the trihydrate to the polyester resin.

Method of reducing the viscosity of polyester-alumina _trihydrate

An improved process for dispersing inorganic fillers, such as alumina trihydrate, in a polyester resin is disclosed wherein the improvement comprises significantly lowering the viscosity of the polyester-filler dispersion by coating the filler with 0.05 to 1.0 percent, based on the weight of the filler, of a polar phosphate ester surfactant containing acid groups and polar ether groups, prior to adding the filler to the polyester resin.

Phosphate ester coating on inorganic fillers for polyester resins

A low soda pseudoboehmite gel is provided by reacting a NaAlO.sub.2 solution with a NaHCO.sub.3 solution having a concentration of less than 75 grams/liter and preferably less than 50 grams/liter. The soda content of the resulting AlO(OH) gel can be further lowered by repeated washing and/or redispersing (repulping) in water and/or further neutralization with a carboxylic acid having 1 to 6 carbon atoms.

Process for preparing low soda pseudoboehmite gel

Alumina monohydrate crystals of uniform particle size in the range of 0.2-0.7 microns suitable for use as pigments in paper, paints, or ink are produced by grinding Bayer trihydrate to a median particle size of 1-3 microns followed by digestion in the presence of a controlled amount of mineral acid.

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Belleville, IL, United States of America

James J Koenig