Coated printable substrates resistant to acidic highlighters and printing solutions
An article in the form of a paper substrate having a first surface and a second surface and an acid-resistant water-swellable substrate coating which provides an ink-receptive porous surface on at least one of the first and second surfaces. The substrate coating has an amount of an acid-resistant coating pigment sufficient to impart a Parker Print Smoothness value of at least about 4 to the at least one of the first and second surfaces and is dispersed in an acid-resistant water-swellable crosslinked polymer coating pigment binder matrix, with the coating pigment having from about 30 to 100% larger coating pigment particles with a mean particle size above about 1 micron in diameter. Also, a method for preparing such coated paper substrates.
1. An article comprising:
a paper substrate having a first surface and a second surface; and
an acid-resistant water-swellable substrate coating on at least one of the first and second surfaces which provides an ink-receptive porous surface, wherein the substrate coating comprises:
an acid-resistant water-swellable crosslinked polymer coating pigment binder matrix; and
an amount of an acid-resistant coating pigment sufficient to impart a Parker Print Smoothness value of at least about 4 to the at least one of the first and second surfaces and which is dispersed in the binder matrix, wherein the acid-resistant coating pigment comprises from about 30 to 100% larger coating pigment particles having a mean particle size above about 4 microns in diameter;
wherein the acid-resistant coating pigment comprises one or more of: clay, kaolin, talc, calcined clay, alumina, titanium dioxide, barium sulfate, bentonite clay, or absorptive plastic pigments,
wherein the substrate coating has a weight ratio of the acid-resistant coating pigment to binder matrix in the range of about 2:1 to about 20:1.
2. The article of claim 1 , wherein the substrate coating is on both the first and second surfaces.
3. The article of claim 1 , wherein the substrate coating has a weight ratio of the acid-resistant coating pigment to binder matrix in the range of about 2:1 to about 10:1.
4. The article of claim 1 , wherein the coating pigment comprises acid-resistant clay particles, acid-resistant absorptive plastic pigment particles, or a mixture thereof.
5. The article of claim 1 , wherein the binder matrix comprises one or more chemically crosslinked polymers.
6. The article of claim 1 , wherein the binder matrix comprises one or more physically crosslinked polymers.
7. The article of claim 1 , wherein the acid-resistant coating pigment imparts a Parker Print Smoothness value of from about 4 to about 12.
8. The article of claim 7 , wherein the acid-resistant coating pigment imparts a Parker Print Smoothness value of from about 4 to about 8.
9. The article of claim 1 , wherein the acid-resistant coating pigment comprises from about 40 to 100% larger coating pigment particles.
10. The article of claim 1 , wherein the binder matrix comprises one or more of: water-soluble polymer binders or polymer latex binders, wherein the one or more water-soluble polymer binders or polymer latex binders have been crosslinked so that the binder matrix is water-swellable.
11. The article of claim 10 , wherein the water-soluble polymer binders comprise one or more of: starch binders, cellulosic binders, polyvinyl alcohol binders, polyacrylic acid binders, polymethacrylic acid binders, polyvinylamine binders, polyacrylamide binders, polyether binders, sulfonated polystyrene binders, or carboxylated polystyrene binders.
12. The article of claim 11 , wherein the water-soluble polymer binders comprise a starch binder.
13. The article of claim 10 , wherein the polymer latex binders comprise one or more of: styrene butadiene rubber latexes, acrylic polymer latexes, polyvinyl acetate latexes, styrene acrylic copolymer latexes, polyurethane latexes, starch/acrylic copolymer latexes, starch/styrene acrylic copolymer latexes, polyvinyl alcohol/styrene acrylic copolymer latexes, polyvinyl alcohol/acrylic copolymer latexes, or epoxy latexes.
14. The article of claim 13 , wherein the polymer latex binder comprises a styrene acrylic latex binder.
15. The article of claim 10 , wherein the one or more water-soluble polymer binders or polymer latex binders are chemically crosslinked with glyoxals, borate salts, organic titanate salts, zirconium salts, or azirdines.
16. The article of claim 15 , wherein the one or more water-soluble polymer binders or polymer latex binders are chemically crosslinked with a glyoxal.