초록 ▼

A kaolin clay pigment comprises a coarse kaolin clay or a blend of a coarse kaolin clay with a fine kaolin clay. The coarse kaolin clay is a delaminated and defined pigment product with an overall shape factor greater than about 12. If the coarse kaolin clay is fluid at about 65% to about 75% solids

A kaolin clay pigment comprises a coarse kaolin clay or a blend of a coarse kaolin clay with a fine kaolin clay. The coarse kaolin clay is a delaminated and defined pigment product with an overall shape factor greater than about 12. If the coarse kaolin clay is fluid at about 65% to about 75% solids, then it is used by itself as the kaolin pigment. If it is not fluid, it is blended with a fine kaolin clay in amounts ranging from about 0.1% to about 30.0% by weight of the blend. The coarse kaolin clay fraction has a Hinckley Crystallinity Index greater than about 0.6 and the fine kaolin clay has a Hinckley Crystallinity Index less than about 0.5. The pigment has a G.E. brightness of about 90.5 and a particle size distribution such that at least about 90% by weight of the particles has an e.s.d. less than about 2 .mu.m and about 30% by weight of the particles has an e.s.d. less than about 0.25 microns. At about 65% to about 75% solids, the Hercules viscosity is greater than 250 rpm at about 18 dynes and when used in a coating formulation, exhibits improved sheet brightness, sheet gloss, sheet opacity and print gloss.

대표청구항 ▼

1. A kaolin clay pigment for use in a coating formulation for paper, said kaolin clay pigment comprising kaolin clay having the following characteristics:(1) Particle Size (e.s.d. as determined by Sedigraph) (a) Particles less than 2 microns: greater than or equal to about 90%; (b) Particles less th

1. A kaolin clay pigment for use in a coating formulation for paper, said kaolin clay pigment comprising kaolin clay having the following characteristics:(1) Particle Size (e.s.d. as determined by Sedigraph) (a) Particles less than 2 microns: greater than or equal to about 90%; (b) Particles less than 0.25 microns: about 30% or less; wherein the ratio: [EQU1](2) Particle shape factor: greater than or equal to about 12; and (3) Hercules viscosity: greater than or equal to about 250 rpm at 18 dynes/cm 10-5 when said kaolin is prepared as a slurry containing about 65% to about 75% solids.