Blends of anionic copolymers suitable for surface size and methods of making the same
View Patent ↗A sizing composition comprises a blend of at least two anionic copolymers.
1. A sizing composition comprising a blend of an anionic styrene-maleic acid copolymer and an anionic ethylene-acrylic acid copolymer, wherein the anionic ethylene-acrylic acid copolymer is present in an amount of about 5 weight percent to about 45 weight percent, based on a combined weight of the anionic styrene-maleic acid copolymer and the anionic ethylene-acrylic acid copolymer.
2. The sizing composition of claim 1 , wherein the styrene-maleic acid copolymer comprises about 50 weight percent to about 85 weight percent styrene.
3. The sizing composition of claim 1 , wherein the styrene-maleic acid copolymer has a molecular weight of about 5,000 to about 200,000.
4. The sizing composition of claim 1 , wherein the ethylene-acrylic acid copolymer has a molecular weight of about 2,000 to about 250,000.
5. The sizing composition of claim 1 , wherein the styrene-maleic acid copolymer comprises styrene-maleic acid partially imidized.
6. The sizing composition of claim 5 , wherein a degree of styrene-maleic acid imidization is about 25% to about 75% maleic acid units.
7. The sizing composition of claim 1 , wherein the blend further comprises a styrene-acrylic ester dispersion (SAE).
8. The sizing composition of claim 7 , wherein a ratio of the styrene-maleic acid copolymer and the ethylene-acrylic acid copolymer to the styrene-acrylic ester dispersion (SAE) is about 0.1:1 to about 10:1.
9. The sizing composition of claim 2 , wherein the blend has a solids particle size of 0.01 micrometers to 2.0 micrometers, a pH of about 7.5 to about 10, and a solids content of 15 weight percent to 50 weight percent.
10. A sizing composition comprising:
a blend of a styrene-maleic acid copolymer and an ethylene acrylic acid copolymer, wherein the styrene-maleic acid copolymer comprises about 50 weight percent to about 85 weight percent styrene, the styrene-maleic acid copolymer has a molecular weight of about 5,000 to about 200,000, and the ethylene acrylic acid copolymer has a molecular weight of about 2,000 to about 250,000 and comprises about 5 weight percent to about 45 weight percent acrylic acid, and wherein the ethylene acrylic acid copolymer is present in an amount of about 5 weight percent to about 45 weight percent, based on a combined weight of the styrene-maleic acid copolymer and the ethylene acrylic acid copolymer.
11. The sizing composition of claim 10 , wherein styrene-maleic acid copolymer is partially imidized.
12. The sizing composition of claim 11 , wherein a degree of styrene-maleic acid imidization is about 25% to about 75% maleic acid units.
13. The sizing composition of claim 10 , wherein the blend further comprises a styrene-acrylic ester dispersion (SAE).
14. The sizing composition of claim 13 , wherein a ratio of the styrene-maleic acid copolymer and the ethylene acrylic acid copolymer to the styrene-acrylic ester dispersion (SAE) is about 0.1:1 to about 10:1.
15. The sizing composition of claim 10 , wherein the blend has a solids particle size of 0.01 micrometers to 2.0 micrometers, a pH of about 7.5 to about 10, and a solids content of 15 weight percent to 50 weight percent.
16. The sizing composition of claim 1 , wherein the anionic ethylene-acrylic acid copolymer is present in an amount of about 5 weight percent to about 33 weight percent, based on the combined weight of the anionic styrene-maleic acid copolymer and the anionic ethylene-acrylic acid copolymer.
17. The sizing composition of claim 1 , wherein the ethylene-acrylic acid copolymer is present in an amount of about 16 weight percent to about 33 weight percent, based on the combined weight of the anionic styrene-maleic acid copolymer and the anionic ethylene-acrylic acid copolymer.
18. The sizing composition of claim 10 , wherein the ethylene acrylic acid copolymer is present in an amount of about 5 weight percent to about 33 weight percent, based on the combined weight of the styrene-maleic acid copolymer and the ethylene acrylic acid copolymer.
19. The sizing composition of claim 1 , further comprising a solubilizing compound, wherein the solubilizing compound comprises ammonia, monoethanolamine, diethanolamine, triethanolamine, or a mixture thereof.
20. A method for the surface sizing of a fabricated cellulosic product comprising applying the sizing composition of claim 1 onto a surface of the fabricated cellulosic product and then heating the fabricated cellulosic product.
21. A method for the surface sizing of a fabricated cellulosic product comprising applying the sizing composition of claim 10 onto a surface of the fabricated cellulosic product and then heating the fabricated cellulosic product.