Enhanced performance of mineral based aqueous barrier coatings
A method for preparing an aqueous based coating system, and coating systems made thereby, for coating onto paper and/or paperboard for providing barrier to liquid, moisture vapor, oil and grease including a pigment and a polymer emulsion system or natural based binding system. One alternative of the method includes surface treating a pigment to form a pigment system and mixing a polymer emulsion system or natural based binding system with the pigment system. Another alternative of the method includes mixing a pigment and polymer emulsion system or natural based binding system and hydrophobizing the polymer emulsion system or natural based binding system by adding silanes, siloxanes, siloxane/silicone resin blends, or their carbon based analogs.
1. A method for preparing an aqueous based coating system comprising:
surface treating a pigment to form a pigment system; and
mixing a polymer emulsion system or natural based binding system with the pigment system, wherein the pigment is surface treated with (1) a styrene-acrylic latex emulsion, a styrene-butadiene latex emulsion, or a blend of a styrene acrylic latex emulsion and a styrene butadiene latex emulsion and (2) a silane, a siloxane, a siloxane/silicone resin blend, or a carbon-based analog thereof, and wherein the styrene-acrylic latex emulsion, the styrene-butadiene latex emulsion, or the blend of the styrene acrylic latex emulsion and the styrene butadiene latex emulsion forms a film, and wherein the pigment has been modified by a thermal treatment process.
2. The method of claim 1 , wherein the pigment is at least one inorganic material selected from the group consisting of kaolin, bentonite, mica, talc, attapulgite, and zeolite.
3. The method of claim 1 , wherein the polymer emulsion system comprises a styrene-acrylic resin emulsion.
4. The method of claim 1 further comprising mixing an additive to improve blocking with the polymer emulsion system or natural based binding system and the pigment system.
5. The method of claim 4 , wherein the additive to improve blocking comprises a material selected from the group consisting of calcium stearate, styrene-acrylic resin, acrylic resin, and polyethylene-paraffin wax emulsion.
6. An aqueous based coating system comprising a polymer emulsion system or natural-based binding system and a pigment system,
wherein the pigment system comprises a surface treated pigment,
wherein the pigment has been surface treated with (1) a styrene-acrylic latex emulsion, a styrene-butadiene latex emulsion, or a blend of a styrene acrylic latex emulsion and a styrene butadiene latex emulsion and (2) a silane, a siloxane, a siloxane/silicone resin blend, or a carbon-based analog thereof, and wherein the styrene-acrylic latex emulsion, the styrene-butadiene latex emulsion, or the blend of the styrene acrylic latex emulsion and the styrene butadiene latex emulsion forms a film, and wherein the pigment has been modified by a thermal treatment process.
7. The aqueous based coating system of claim 6 , wherein the pigment comprises at least one inorganic material selected from kaolin, bentonite, mica, talc, attapulgite, and zeolite.
8. The aqueous based coating system of claim 6 , wherein the polymer emulsion system comprises a styrene-acrylic resin emulsion.
9. The aqueous based coating system of claim 6 further comprising an additive to improve blocking with the polymer emulsion system or natural-based binding system and the pigment system.
10. The aqueous based coating system of claim 9 , wherein the additive to improve blocking comprises a material selected from the group consisting of calcium stearate, styrene-acrylic resin, acrylic resin, and polyethylene-paraffin wax emulsion.
11. A coating system comprising a pigment and a polymer emulsion or natural-based binding system wherein the pigment has been surface treated with (1) a styrene-acrylic latex emulsion, a styrene-butadiene latex emulsion, or a blend of a styrene acrylic latex emulsion and a styrene butadiene latex emulsion and (2) a silane, a siloxane, a siloxane/silicone resin blend, or a carbon-based analog thereof, and wherein the styrene-acrylic latex emulsion, the styrene-butadiene latex emulsion, or the blend of the styrene acrylic latex emulsion and the styrene butadiene latex emulsion forms a film, and wherein the pigment has been modified by a thermal treatment process.
12. The coating system of claim 11 , wherein the pigment comprises at least one inorganic material selected from the group consisting of kaolin, bentonite, mica, talc, attapulgite, and zeolite.
13. The coating system of claim 11 , wherein the pigment comprises kaolin having a particle size of at least 20% by weight finer than 2 micrometers.
14. The coating system of claim 11 , wherein the polymer emulsion system comprises a styrene-acrylic resin emulsion.
15. The coating system of claim 11 further comprising an additive to improve blocking with the polymer emulsion system or natural-based binding system and the pigment system.
16. The coating system of claim 15 , wherein the additive to improve blocking comprises a material selected from the group consisting of calcium stearate, styrene-acrylic resin, acrylic resin, and polyethylene-paraffin wax emulsion.
17. The aqueous based coating system of claim 6 , wherein the pigment has been surface treated with the siloxane, wherein the siloxane comprises a polydimethylsiloxane resin.
18. The coating system of claim 11 , wherein the polymer emulsion or natural-based binding system has been hydrophobized by a polydimethylsiloxane resin.
19. The method of claim 2 , wherein the at least one inorganic material includes kaolin.
20. The aqueous based coating system of claim 7 , wherein the at least one inorganic material includes kaolin.
21. The coating system of claim 12 , wherein the at least one inorganic material includes kaolin.
22. The method of claim 1 , wherein the entire surface of the pigment is surface treated.
23. The coating system of claim 11 , wherein the entire surface of the pigment is surface treated.
24. The method of claim 1 , wherein the styrene-acrylic latex emulsion has a glass transition temperature of from −50° C. to 25° C.
25. The coating system of claim 11 , wherein the styrene-acrylic latex emulsion has a glass transition temperature of from −50° C. to 25° C.