US 6,150,289 A · Coating composition for ink jet paper and a product thereof

Abstract

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.sup.3 /g to 2.00 cm.sup.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 fastness 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.

Claims15

Dependent claims

A coating composition for use in a coating formulation applied to a substrate to produce a coated surface for a matte grade coated ink jet paper which receives an anionic dye or ink in an ink jet printing process, said coating composition consisting essentially of:

(a) an aqueous slurry containing about 30 to about 70 weight % solids, based on the weight of said aqueous slurry, of a calcined kaolin clay;
and
(b) an effective amount of a cationic polymer or cationic polymer admixture which reacts with said calcined kaolin clay to chemically treat said calcined kaolin clay to produce a net positive charge on said calcined kaolin clay,
said calcined kaolin clay being a porous engineered clay and having a narrow particle size distribution such that about 90 weight % of the particles are less than 2 microns E.S.D., about 80 weight % of the particles have an E.S.D. less than 1 micron, and about 30 weight % of the particles have an E.S.D. less than 0.5 microns.

1 more element

A coating formulation applied to a substrate to produce a coated surface for a matte grade coated ink jet paper which receives an anionic dye or ink in an ink jet printing process, said coating formulation comprising a coating composition and said coating composition consisting essentially of:

(a) an aqueous slurry containing about 30 to about 70 weight % solids, based on the weight of said aqueous slurry, of a calcined kaolin clay;
and
(b) an effective amount of a cationic polymer or cationic polymer admixture which reacts with said calcined kaolin clay to chemically treat said calcined kaolin clay to produce a net positive charge on said calcined kaolin clay,
said calcined kaolin clay being a porous engineered clay and having a narrow particle size distribution such that about 90 weight % of the particles are less than 2 microns E.S.D., about 80 weight % of the particles have an E.S.D. less than 1 micron, and about 30 weight % of the particles have an E.S.D. less than 0.5 microns, said calcined kaolin clay causing said anionic ink or dye to react with said calcined kaolin clay in said ink jet printing process to affix said anionic ink or dye to said coated surface of said matte grade coated ink jet paper, and whereby said anionic ink or dye is capable of penetrating into said calcined clay for complete drying thereof on said coated surface of said matte grade coated paper.

1 more element

A method of preparing a coating composition for use in a coating formulation for coating a substrate to produce a matte grade coated ink jet paper which receives an anionic dye or ink in an ink jet printing process, the steps consisting essentially of:

a) preparing a calcined kaolin clay aqueous slurry containing about 30 to about 70 weight % solids, based on the total weight of said aqueous slurry;
and b) adding an effective amount of at least one cationic polymer to said aqueous slurry to chemically treat said calcined clay to produce a net positive charge on said clay, which clay reacts with said anionic dye or ink on said ink jet paper, and c) using said coating composition of steps (a) and (b) in said coating formulation, to coat said substrate, said calcined kaolin clay being a porous engineered calcined kaolin clay and having a narrow particle size distribution such that about 90 weight % of the particles are less than 2 microns E.S.D., about 80 weight % of the particles have an E.S.D. less than 1 micron, and about 30 weight % of the particles have an E.S.D. less than 0.5 microns.

Dependencies are inferred from the claim text.

Coating composition for ink jet paper and a product thereof

Life of this patent

Coating composition for ink jet paper and a product thereof

Life of this patent

Abstract

Claims15