Additive system for use in paper making and process of using the same
The embodiments of the present invention relate to an additive system comprising a cationic latex and an anionic polymer; as well as a process utilizing the additive system for making paper where the process is effective in all grades of paper, particularly those grades used for printing and writing.
1 . An additive system comprising a combination of a cationic latex and an anionic polymer, wherein the cationic latex comprises a cationic polymer absorbed onto a surface of an anionic and/or nonionic latex particle.
2 . The additive system according to claim 1 wherein the cationic polymer comprises polyamidoamine-epihalohydrin resins, cationic functionalized polyacrylamides, acrylamide-based crosslinkable polymers, polyamines, polyimines, polymers or copolymers of diallyldimethylammonium chloride and polyamines, epichlorohydrin resins and combinations thereof.
3 . The additive system according to claim 1 , wherein the cationic polymer comprises polyamidoamine-epihalohydrin resins and cationic functionalized polyacrylamides.
4 . The additive system according to claim 1 , wherein the anionic polymer is a homopolymer or a copolymer.
5 . The additive system according to claim 4 , wherein the copolymer comprises at least one anionic monomer and at least one nonionic monomer.
6 . The additive system according to claim 1 , wherein the anionic polymer comprises at least one anionic monomer.
7 . The additive system according to claim 6 , wherein the at least one anionic monomer comprises free acids and salts of acrylic acid and combinations thereof, styrene sulfonate, maleic acid, itaconic acid, methacrylic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, vinyl sulfonic acid, vinylphosphonic acid, acrylamidoglycolic acid and combinations thereof.
8 . The additive system according to claim 5 , wherein the at least one nonionic monomer comprises acrylamide, methacrylamide N-alkylacrylamides; N,N-dialkylacrylamide; methyl acrylate; methyl methacrylate acrylonitrile; N-vinyl methylacetamide; N-vinyl methyl formamide; vinyl acetate; N-vinyl pyrrolidone, alkyl acrylates, alkyl methacrylates, alkyl acryamides, alkyl methacrylamides, and alkyloxylated acrylates and methacrylates, and alkyl polyethyleneglycol methacrylates.
9 . The additive system according to claim 5 , wherein the at least one anionic monomer is acrylic acid and the at least one nonionic monomer is an acrylamide.
10 . The additive system according to claim 1 , wherein the cationic latex and anionic polymer are in a ratio ranging from about 0.03:1 to about 10:1.
11 . The additive system according to claim 10 , wherein the cationic latex and anionic polymer are in a ratio ranging from about 0.05:1 to about 4:1.
12 . The additive system according to claim 11 , wherein the cationic latex and anionic polymer are in a ratio of about 1:1 to about 3:1
13 . The additive system according to claim 12 , wherein the cationic latex and anionic polymer are in a ratio of about 1:1 to about 2:1
14 . A process for making paper comprising:
(a) producing an aqueous slurry of cellulosic fibers; and
(b) adding the additive system of claim 1 comprising:
(i) adding a cationic latex to the aqueous slurry, and
(ii) adding an anionic polymer to the aqueous slurry.
15 . The process according to claim 14 , further comprising (c) forming a paper sheet.
16 . The process according to claim 14 , wherein the additive system is added to the aqueous slurry in an amount ranging from about 5 lbs/ton of pulp to about 100 lbs/ton of dry paper.
17 . The process according to claim 16 , wherein the additive system is added to the aqueous slurry in an amount ranging from about 15 lb/ton of pulp to about 50 lb/ton of dry paper.
18 . The process according to claim 17 , wherein the additive system is added to the aqueous slurry in an amount ranging from about 20 lb/ton of pulp to about 40 lb/ton of dry paper.
19 . The process according to claim 1 , wherein aqueous slurry comprises a filler.
20 . The process according to claim 19 , wherein the filler comprises a mineral composition.
21 . The process according to claim 20 , wherein the mineral composition comprises an alumina, clay, calcium sulfate, diatomaceous silica, silicates, calcium carbonate, silicas, silicoaluminates, talc, and titanium dioxide.
22 . The process according to claim 19 , wherein the filler is present in an amount ranging from about 5 wt-% to about 60 wt-% of the aqueous slurry.
23 . The process according to claim 22 , wherein the filler is present in an amount ranging from about 15 wt-% to about 50 wt-%.
24 . The process according to claim 23 , wherein the filler is present in an amount of about 20 wt-% to about 40 wt-% of the aqueous slurry.
25 . The process according to claim 24 , wherein the filler is present in an amount of about 25 wt-% to about 40 wt-% of the aqueous slurry.
26 . An aqueous slurry of cellulose fibers comprising the additive system of claim 1 .
27 . The aqueous slurry of cellulose fibers according to claim 26 , further comprising a filler.
28 . A paper sheet made according to the process of claim 14
29 . A paper sheet comprising the additive system of claim 1.