Patent ID: 9732473
Date: 2017-08-15
CPC Classifications: C01P,C09C,C09D,D21H,G01F,Y10T

Claim:
1. A method of preparing a basecoat, the method comprising: providing a pigment blend comprising a ground calcium carbonate component and a platy clay component, wherein at most 60 percent of the ground calcium carbonate component has a particle size smaller than 2 microns, wherein the platy clay component has an average aspect ratio of at least 40:1, and wherein the pigment blend has a sediment void volume of at least 45 percent; providing a carrier; and dispersing the pigment blend in the carrier; wherein the sediment void volume is measured by preparing a pigment blend sample having the desired weight percentage of the clay component to the calcium carbonate component; diluting the pigment blend sample with water to 50 percent by weight solids to provide a slurry; placing a 70 gram sample of the slurry into a centrifuge tube; spinning the sample at about 8000 g for about 90 minutes; removing the sample from the centrifuge; separating the clear supernatant liquid from the sample; weighing the clear supernatant liquid; determining the weight of water still contained in the voids of the sediment based on the weight of the clear supernatant liquid removed; and using particle densities, converting the weight of water in the voids into percent sediment void volume.