초록 ▼

Paper coating composition comprising an engineered kaolin pigment containing stacks and platelets of unground coarse particles where greater than 96% by weight is less than 5 microns, of which some kaolinite books or stacks are concentrated in the greater than 1 micron size fraction; 88% to 95% by w

Paper coating composition comprising an engineered kaolin pigment containing stacks and platelets of unground coarse particles where greater than 96% by weight is less than 5 microns, of which some kaolinite books or stacks are concentrated in the greater than 1 micron size fraction; 88% to 95% by weight is less than 2 microns; 65% to 85% by weight is less than 1 micron; and 15% to 25% by weight is less than 0.25 micron. A first embodiment comprises particles with a shape factor Ad between 7 and 9 which represents a significant number of stacks and some platelets. A second embodiment comprises particles with a shape factor of 11 or 12 which represents the presence of some stacks with a majority of platelets. The kaolin clay pigments form clay-water slurries of 69% solids or greater. As a coating, the composition gives a G. E. brightness between 88 and 94. The engineered pigment is processed so that the desired shape factor is met, which shape factor is equated to the aspect ratio or morphology of the pigment.

대표청구항 ▼

1. A composition for a kaolin clay pigment for a coating application on paper, said kaolin clay pigment comprising:kaolin clay particles having a particle size distribution characterized as (a) more than 96% by weight of the kaolin clay particles are finer than 5 microns of which about 5% to about 5

1. A composition for a kaolin clay pigment for a coating application on paper, said kaolin clay pigment comprising:kaolin clay particles having a particle size distribution characterized as (a) more than 96% by weight of the kaolin clay particles are finer than 5 microns of which about 5% to about 50% by weight or by volume are kaolinite stacks or books concentrated in the greater than 1 micron size fraction; (b) about 88% to about 95% by weight of the kaolin particles are finer than 2 microns; (c) about 65% to about 85% by weight of the kaolin particles are finer than 1 micron; and (d) about 15% to about 25% of the kaolin particles are finer than 0.25 micron.