Enhanced surface sizing of paper
Size press compositions and methods for producing sized paper products, including liner board, are disclosed. The size press compositions contain at least one non-reactive cationic surface sizing agent, at least one reactive sizing agent, at least one promoter resin, at least one binder, and water. The at least one non-reactive cationic surface sizing agent may be a polymer in the form of a dispersion, an emulsion or a latex with a positive zeta potential below about pH 6. The at least one reactive sizing agent may be a dispersion, an emulsion or a latex including an alkyl ketene dimer or an alkyl succinic anhydride. The at least one promoter resin may be a polyaminoamide-epichlorohydrin resin or poly (dimethyldiallylammonium chloride).
1. A size press composition for sizing paper, comprising:
(a) at least one non-reactive cationic surface sizing agent,
(b) at least one reactive sizing agent,
(c) at least one promoter resin,
(d) water, and
(e) at least one binder,
wherein component (a) is present from about 0.15 to about 1% by weight based on the total weight of the size press composition, component (b) is present from about 0.025 to about 0.8% by weight based on the total weight of the size press composition, component (c) is present from about 0.01 to about 0.2% by weight based on the total weight of the size press composition, and binder (e) is present from about 2 to about 12% based on the total weight of the size press composition, and
wherein the size press composition pH is about 6 or below.
2. The size press composition as claimed in claim 1 , wherein the at least one binder is a starch.
3. The size press composition as claimed in claim 1 , wherein the at least one non-reactive cationic surface sizing agent is a polymer having monomeric units based on styrene, acrylates, or combinations thereof.
4. The size press composition as claimed in claim 1 , wherein the at least one reactive sizing agent comprises an alkyl ketene dimer or an alkyl succinic anhydride.
5. The size press composition as claimed in claim 1 , wherein the at least one promoter resin comprises at least one cationic polymer or copolymer comprising monomeric units based on dimethyldiallylammonium chloride (DADMAC), methylalkylallyl ammonium chloride or diallylammonium chloride (DAAC) monomers, or at least one cationic polymer that is a polyaminoamide resin.
6. A paper composition, comprising:
paper that is treated with a size press composition for sizing paper comprising:
(a) at least one non-reactive cationic surface sizing agent,
(b) at least one reactive sizing agent, and
(c) at least one promoter resin,
wherein on a dry weight basis component (a) is present in the paper in an amount greater than about 0.05% by weight based on the total weight of the paper composition, component (b) is present in the paper in an amount greater than about 0.02% by weight based on the total weight of the paper composition, and component (c) is present in the paper in an amount greater than about 0.005% by weight based on the total weight of the paper composition, and
wherein the size press composition pH is about 6 or below.
7. The paper composition as claimed in claim 6 , wherein the at least one non-reactive cationic surface sizing agent is a polymer having monomeric units based on styrene, acrylates or combinations thereof.
8. The paper composition as claimed in claim 6 , wherein the at least one reactive sizing agent comprises an alkyl ketene dimer or an alkyl succinic anhydride.
9. The paper composition as claimed in claim 6 , wherein the at least one promoter resin comprises at least one cationic polymer or copolymer comprising monomeric units based on dimethyldiallylammonium chloride (DADMAC), methylalkylallyl ammonium chloride or diallylammonium chloride (DAAC) monomers, or at least one cationic polymer that is a polyaminoamide resin.
10. The paper composition as claimed in claim 6 , wherein the paper is recycled liner board paper, and wherein the paper has a basis weight between about 100 to about 200 g/m 2 .
11. A method of producing a paper composition, comprising:
applying a size press composition to a paper or liner board paper, wherein the size press composition comprises:
(a) at least one non-reactive cationic surface sizing agent,
(b) at least one reactive sizing agent,
(c) at least one promoter resin,
(d) water, and
(e) at least one binder,
wherein component (a) is present from about 0.15 to about 1% by weight based on the total weight of the size press composition, component (b) is present from about 0.025 to about 0.8% by weight based on the total weight of the size press composition, component (c) is present from about 0.01 to about 0.2% by weight based on the total weight of the size press composition, and binder (e) is present from about 2 to about 12% based on the total weight of the size press composition, and
wherein the size press composition pH is about 6 or below.
12. The method of producing a paper composition as claimed in claim 11 , wherein the size press composition is applied to the paper on the paper machine or is applied separately in a size press off the paper machine.
13. The method of producing a paper composition as claimed in claim 11 , wherein the at least one non-reactive cationic surface agent is a polymer having monomeric units based on styrene, acrylates or combinations thereof.
14. The method of producing a paper composition as claimed in claim 11 , wherein the at least one reactive sizing comprises an alkyl ketene dimer or an alkyl succinic anhydride.
15. The method of producing a paper composition as claimed in claim 11 , wherein the at least one promoter resin comprises at least one cationic polymer or copolymer comprising monomeric units based on dimethyldiallylammonium chloride (DADMAC), methylalkylallyl ammonium chloride or diallylammonium chloride (DAAC) monomers, or at least one cationic polymer that is a polyaminoamide resin.