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US 6,312,511 B1Granted
Kaolin clays and methods of making and using same
AssigneeImerys Kaolin, Inc.
InventorsBomi M. Bilimoria, John A. Manasso, Mark S. Willis
Life of this patent
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Abstract
High brightness kaolin pigments and methods of making high brightness kaolin pigments are provided. Both delaminated and nondelaminated clays are provided having typical brightness of 87 or higher. The pigments have high brightness and good opacity, providing an optimum pigment for paper coating and paper filler. Also provided are blended high brightness kaolins having increased opacity properties.
Claims53
A method of making a high brightness kaolin clay comprising:
- a. applying magnetic separation to a blunged, degritted kaolin clay crude having a particle size distribution as follows:
- 50%-70% less than 2 microns, 20%-35% less than 0.5 microns and 5%-20% less than 0.3 microns, all e.s.d. as determined by Sedigraph for a period of time sufficient to achieve the brightness;
- b. fractionating the clay to retain a first fraction that is 90% less than two microns in particle size, separately from a second fraction of the remaining clay, wherein the retained 90% less than two micron fraction comprises the high brightness kaolin clay.
A method of making a high brightness kaolin clay comprising:
- a. applying magnetic separation to a blunged, degritted kaolin clay crude having a particle size distribution as follows:
- 50%-70% less than 2 microns, 20%-35% less than 0.5 microns and 5%-20% less than 0.3 microns, all e.s.d. as determined by Sedigraph for a period of time sufficient to achieve the brightness to make a purified feed;
- b. fractionating the clay into a first fraction of 90% less than 2 micron and a second fraction of remaining clay;
- c. blending the purified feed with the second fraction to form a blended clay having a ratio of purified feed to second fraction of from 100:0 to 0:100;
- d. grinding the blended clay to a particle size of from 60 to 90% less than two microns.
2 more elements
A method of making a high brightness kaolin clay comprising:
- a. applying magnetic separation to a blunged, degritted kaolin clay crude having a particle size distribution as follows:
- 50%-70% less than 2 microns, 20%-35% less than 0.5 microns and 5%-20% less than 0.3 microns, all e.s.d. as determined by Sedigraph for a period of time sufficient to achieve the brightness to make a purified feed;
- b. fractionating the clay into a first fraction of 90% less than 2 microns and a second fraction of remaining clay;
- c. blending the purified feed with the second fraction to form a blended clay having a ratio of purified feed to second fraction of from 100:0 to 0:100;
- d. grinding the blended clay to a particle size of from 60% to 90% less than two microns;
- and
- e. fractionating the ground clay to recover a fraction of about 90% less than two microns.
4 more elements
A method of making a high brightness kaolin clay comprising:
- a. applying magnetic separation to a blunged, degritted kaolin clay crude obtained from an area in the Rio Capim area of Brazil having coordinates south 02°-21″, west 47°-52′ and having a particle size distribution as follows:
- 50%-70% less than 2 microns, 20%-35% less than 0.5 microns and 5%-20% less than 0.3 microns, all e.s.d. as determined by Sedigraph for a period of time sufficient to achieve the brightness;
- b. fractionating the clay to retain a first fraction that is 90% less than two microns in particle size, separately from a second fraction of the remaining clay, wherein the retained 90% less than two micron fraction comprises the high brightness kaolin clay.
A nondelaminated high brightness kaolin clay having the following characteristics.
- a. particle size of 90% less than two microns (e.s.d. as measured by Sedigraph) and a ratio of:
- % less than 2.0 microns/% less than 0.5 microns <2.0;
- b. brightness of 87 or greater, and
- c. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 100 cp.
1 more element
A nondelaminated high brightness kaolin clay having the following characteristics:
- a particle size of at least 60% less than two microns (e.s.d. as measured by Sedigraph);
- b brightness of 87 or greater;
- and
- c. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 175 cp.
1 more element
A delaminated high brightness kaolin clay having the following characteristics:
- a. particle size of from 60% to 90% less than two microns (e.s.d. as measured by Sedigraph);
- b. brightness of 87% or greater;
- and
- c. Hercules viscosity of less than 1000 rpm at 18 dynes and 67% solids.
1 more element
A high brightness kaolin clay comprising a blend of the following component clays:
- a. a nondelaminated kaolin clay having the following characteristics:
- i. particle size of 90% less than two microns (e.s.d. as measured by Sedigraph) and a ratio of:
- % less than 2.0 microns/% less than 0.5 microns ≦2.0;
- ii. brightness of 87% or greater;
- and
- iii. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 100 cp;
- and
- b. a delaminated kaolin clay having the following characteristics:
- i. particle size of from 60% to 90% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Hercules viscosity of less than 1000 rpm at 18 dynes and 67% solids.
9 more elements
A high brightness kaolin clay comprising a blend of the following component clays:
- a. a nondelaminated kaolin clay having the following characteristics:
- i. particle size of 60% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 175 cp;
- and
- b. a delaminated kaolin clay having the following characteristics:
- i. particle size of from 60% to 90% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Hercules viscosity of less than 1000 rpm at 18 dynes and 67% solids.
8 more elements
A method of making a high brightness kaolin clay comprising blending the following component clays:
- a. a nondelaminated kaolin clay having the following characteristics:
- i. particle size of 90% less than two microns (e.s.d. as measured by Sedigraph) and a ratio of:
- % less than 2.0 microns/% less than 0.5 microns ≦2.0;
- ii. brightness of 87% or greater;
- and
- iii. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 100 cp;
- and
- b. a delaminated kaolin clay having the following characteristics:
- i. particle size of from 60% to 90% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Hercules viscosity of less than 1000 rpm at 18 dynes and 67% solids.
9 more elements
A method of making a high brightness kaolin clay comprising blending the following component clays:
- a. a nondelaminated kaolin clay having the following characteristics:
- i. particle size of 60% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Brookfield viscosity measured at 20 rpm and 71% solids of greater than 175 cp;
- and
- b. a delaminated kaolin clay having the following characteristics:
- i. particle size of from 60% to 90% less than two microns (e.s.d. as measured by Sedigraph);
- ii. brightness of 87% or greater;
- and
- iii. Hercules viscosity of less than 1000 rpm at 18 dynes and 67% solids.
8 more elements
Dependencies are inferred from the claim text.