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CN-121976422-A - Water-resistant and oil-resistant paper-based coating, preparation method and water-resistant and oil-resistant paper product

CN121976422ACN 121976422 ACN121976422 ACN 121976422ACN-121976422-A

Abstract

The invention discloses a water-resistant and oil-resistant paper-based coating, a preparation method and a water-resistant and oil-resistant paper product, and belongs to the technical field of paper-based packaging materials. According to the invention, through esterification reaction of stearic acid and chemimechanical pulp CNF, hydrophobic modification is realized, and meanwhile, high-pressure homogenization treatment is combined, so that uniform dispersion of the hydrophobic chemimechanical pulp CNF is ensured, and the hydrophilic problem of CNF is radically solved; meanwhile, the prepared oil-proof agent takes soybean protein isolate as a substrate, and is matched with sodium montmorillonite to form a synergistic oil-proof system, and a coating is constructed on the surface of a paper substrate through hydrophobic slurry CNF dispersion liquid and oil-proof agent dispersion liquid, so that the coating has excellent water resistance and oil resistance. The coating prepared by the method has good compatibility with paper base materials, can be degraded together with the paper base after the subsequent paper is discarded, thoroughly eliminates the white pollution problem caused by polyethylene lamination, has degradable and renewable green properties, and realizes the environment protection, safety and sustainability of a coating system.

Inventors

  • LI YING
  • LI PEIYI
  • DU MENGXIN
  • JIANG ZHUOQI

Assignees

  • 陕西科技大学

Dates

Publication Date
20260505
Application Date
20260203

Claims (10)

  1. 1. The preparation method of the water-resistant and oil-resistant paper-based coating is characterized by comprising the following steps of: s1, preparing hydrophobic machine pulp nanocellulose, namely dispersing the machine pulp nanocellulose in water to form suspension, adding stearic acid, carrying out esterification reaction under the condition of heating and stirring, and carrying out high-pressure homogenization treatment after the reaction is finished to obtain hydrophobic machine pulp nanocellulose dispersion; s2, preparing an oil-proof agent, namely dissolving soybean protein isolate in water to prepare a solution, adding sodium montmorillonite into the solution under the stirring condition, and continuously stirring the solution until the solution is uniformly mixed to obtain an oil-proof agent dispersion liquid; s3, constructing a water-resistant and oil-resistant coating, namely constructing the coating on the surface of the paper base by utilizing the hydrophobic machine pulp nano cellulose dispersion liquid and the oil-resistant agent dispersion liquid.
  2. 2. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the addition amount of stearic acid is 5% -30% of the absolute dry mass of the chemical pulp nanocellulose.
  3. 3. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the addition amount of the sodium montmorillonite is 10% -50% of the mass of the soybean protein isolate.
  4. 4. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the coating is constructed on the paper-based surface by using a hydrophobic slurry nanocellulose dispersion liquid and an oil-resistant agent dispersion liquid, and specifically comprises the following steps: And (3) mixing the hydrophobic machine pulp nanocellulose dispersion liquid obtained in the step (S1) with the oil-proofing agent dispersion liquid obtained in the step (S2), uniformly stirring to obtain a composite coating liquid, coating the composite coating liquid on the surface of a paper substrate, and drying to form a coating.
  5. 5. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 4, wherein the mass ratio of the mixed solids of the hydrophobic slurry nanocellulose dispersion liquid and the oil-resistant agent dispersion liquid is (1:5) - (5:1).
  6. 6. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the coating is constructed on the paper-based surface by using a hydrophobic slurry nanocellulose dispersion liquid and an oil-resistant agent dispersion liquid, and specifically comprises the following steps: and (3) coating the hydrophobic machine pulp nanocellulose dispersion liquid obtained in the step (S1) on the surface of the paper base and drying to form a bottom hydrophobic coating, and coating the oil-proofing agent dispersion liquid obtained in the step (S2) on the bottom hydrophobic coating and drying to form a surface oil-proofing coating.
  7. 7. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the coating is constructed on the paper-based surface by using a hydrophobic slurry nanocellulose dispersion liquid and an oil-resistant agent dispersion liquid, and specifically comprises the following steps: And (3) coating the hydrophobic slurry nanocellulose dispersion liquid obtained in the step (S1) on the surface of the oil-proofing agent coated paper pretreated in the step (S2).
  8. 8. The method for preparing the water-resistant and oil-resistant paper-based coating according to claim 1, wherein the temperature of the esterification reaction is 60-90 ℃ and the reaction time is 1-4 hours; the pressure of the high-pressure homogenization treatment is 60-100 MPa; The mass concentration of the soybean protein isolate solution is 2% -10%, and the surface esterification grafting rate of the chemimechanical pulp nanocellulose is 15% -40%.
  9. 9. The water-resistant and oil-resistant paper-based coating is characterized by being prepared by adopting the preparation method of the water-resistant and oil-resistant paper-based coating according to any one of claims 1-8, wherein the water-resistant and oil-resistant paper-based coating has a compact grid structure formed by interweaving nanofibers and lamellar montmorillonite.
  10. 10. A water and oil resistant paper product comprising a paper substrate and the water and oil resistant paper substrate coating of claim 9 applied to at least one surface of said paper substrate.

Description

Water-resistant and oil-resistant paper-based coating, preparation method and water-resistant and oil-resistant paper product Technical Field The invention relates to the technical field of paper-based packaging materials, in particular to a water-resistant and oil-resistant paper-based coating, a preparation method and a water-resistant and oil-resistant paper product. Background Paper-based materials are widely used in the fields of food packaging, disposable products and the like due to the advantages of degradability, reproducibility, low cost and the like. However, the hydrophilicity and porous structure of natural fibers cause that common paper is easy to be permeated by water and oil, and has poor barrier property, so that the application of the paper in a wet and oil-containing environment is severely limited. At present, polyethylene coating or fluorine-containing compound treatment is often adopted to endow paper with water resistance and oil resistance, but the polyethylene coating or fluorine-containing compound treatment is difficult to recover and degrade to cause white pollution, and the polyethylene coating or fluorine-containing compound treatment has potential biotoxicity and is high in cost. Therefore, how to develop a coating with high-efficiency water-resistant and oil-resistant properties, which is environment-friendly, has become a technical problem to be overcome by those skilled in the art. Disclosure of Invention The invention aims to provide a water-resistant and oil-resistant paper-based coating, a preparation method and a water-resistant and oil-resistant paper product, so as to solve the problem that water-resistant and oil-resistant materials adopted in the prior art are difficult to meet the recycling and environment-friendly requirements. The invention solves the technical problems by the following technical proposal: The invention provides a preparation method of a water-resistant and oil-resistant paper-based coating, which comprises the following steps: s1, preparing hydrophobic machine pulp nanocellulose, namely dispersing the machine pulp nanocellulose in water to form suspension, adding stearic acid, carrying out esterification reaction under the condition of heating and stirring, and carrying out high-pressure homogenization treatment after the reaction is finished to obtain hydrophobic machine pulp nanocellulose dispersion; s2, preparing an oil-proof agent, namely dissolving soybean protein isolate in water to prepare a solution, adding sodium montmorillonite into the solution under the stirring condition, and continuously stirring the solution until the solution is uniformly mixed to obtain an oil-proof agent dispersion liquid; s3, constructing a water-resistant and oil-resistant coating, namely constructing the coating on the surface of the paper base by utilizing the hydrophobic machine pulp nano cellulose dispersion liquid and the oil-resistant agent dispersion liquid. The invention is further improved in that the addition amount of the stearic acid is 5% -30% of the absolute dry mass of the chemical pulp nanocellulose. The invention is further improved in that the addition amount of the sodium montmorillonite is 10% -50% of the mass of the soybean protein isolate. The invention is further improved in that a coating is constructed on the surface of a paper base by utilizing a hydrophobic machine pulp nanocellulose dispersion liquid and an oil-proof agent dispersion liquid, and the method specifically comprises the following steps: And (3) mixing the hydrophobic machine pulp nanocellulose dispersion liquid obtained in the step (S1) with the oil-proofing agent dispersion liquid obtained in the step (S2), uniformly stirring to obtain a composite coating liquid, coating the composite coating liquid on the surface of a paper substrate, and drying to form a coating. The invention is further improved in that the mass ratio of the mixed solids of the hydrophobic slurry nanocellulose dispersion liquid and the oil-proofing agent dispersion liquid is (1:5) - (5:1). The invention is further improved in that a coating is constructed on the surface of a paper base by utilizing a hydrophobic machine pulp nanocellulose dispersion liquid and an oil-proof agent dispersion liquid, and the method specifically comprises the following steps: and (3) coating the hydrophobic machine pulp nanocellulose dispersion liquid obtained in the step (S1) on the surface of the paper base and drying to form a bottom hydrophobic coating, and coating the oil-proofing agent dispersion liquid obtained in the step (S2) on the bottom hydrophobic coating and drying to form a surface oil-proofing coating. The invention is further improved in that a coating is constructed on the surface of a paper base by utilizing a hydrophobic machine pulp nanocellulose dispersion liquid and an oil-proof agent dispersion liquid, and the method specifically comprises the following steps: And (3) coating the hydrophobic slu