摘要 |
Matte grade coated ink jet paper comprises a cellulosic substrate coated with a coating composition comprising a calcined kaolin clay particulate pigment comprising porous aggregates with a total pore volume of 0.60 cm<3>/g to 2.00 cm<3>/g, a narrow particle size distribution where about 90 weight % has an E.S.D. less than 2 microns, a mean pore size less than 0.8 microns in diameter, and a cationic polymer with an average molecular weight in the range of 1,000 to 5 million daltons which polymer acts as a dispersant in a precursor slurry and produces a net positive charge on the calcined clay pigment. This chemically treated clay pigment is used in a final coating formulation for the substrate to provide high printing ink density, printed and coating gloss, water fasteness resistance, low wicking, and low bleeding on most ink jet papers. The calcined kaolin clay provides a high coating solids of about 30 to about 70 weight % solids, based on the weight of the slurry, and good viscosities and rheology, therefore, making the pigment suitable for most commercial high speed coaters.
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