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CN-122013602-A - Hydrophobic and oleophobic packaging paper bag and preparation method thereof

CN122013602ACN 122013602 ACN122013602 ACN 122013602ACN-122013602-A

Abstract

The invention discloses a hydrophobic and oleophobic packaging paper bag and a preparation method thereof, belonging to the technical field of packaging processing, wherein hydrophobic modified nano silicon dioxide is added into a polymethyl methacrylate polymerization system, and adding paraffin wax after polymerization is completed, mixing to form coating liquid, coating the coating liquid on the surface of the paper bag body, and drying to form a film to obtain the hydrophobic oleophobic packaging paper bag. According to the invention, the roughness of a coating layer is increased by utilizing nano silicon dioxide with smaller particle size, and polydimethylsiloxane is used for grafting and hydrophobic modification, a hydrophobic long chain on the surface of the modified nano silicon dioxide is entangled with a gradually growing polymethyl methacrylate molecular chain in the monomer polymerization process, paraffin is gathered around the hydrophobic nano silicon dioxide through hydrophobic induction, and paraffin which is migrated to the surface after being dried to form a film exists in a peripheral gap of the hydrophobic modified nano silicon dioxide, so that the effect of compensating hydrophobic defects among particles is achieved, and the packaging paper bag has excellent hydrophobic and oleophobic performance under the condition that a fluorine-containing material is not used.

Inventors

  • FANG XIANG
  • FANG SHUGUANG
  • TAN YUJIE

Assignees

  • 湖南大道新材料有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The preparation method of the hydrophobic and oleophobic packaging paper bag is characterized by comprising the following steps of: Dispersing nano silicon dioxide in toluene, adding phenyl diisocyanate under anhydrous and anaerobic conditions, stirring, heating, refluxing for reaction for 4-6 hours, adding monohydroxy-terminated polydimethylsiloxane, continuously refluxing for reaction for 5-8 hours, centrifuging, washing precipitate with toluene, and drying to obtain hydrophobically modified silicon dioxide; step two, adding methyl methacrylate into a beaker, adding an initiator, uniformly stirring, adding hydrophobic modified silicon dioxide, stirring, heating and polymerizing, and mixing with paraffin after the reaction is finished to obtain a coating liquid; And thirdly, coating the surface of the paper bag body with the coating liquid, and drying the paper bag body to form a film to obtain the hydrophobic and oleophobic packaging paper bag.
  2. 2. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the particle size of the nano silicon dioxide is 10-50nm, and the concentration of the silicon dioxide in toluene is 10-20g/L.
  3. 3. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the phenyl diisocyanate is one of toluene diisocyanate and diphenylmethane diisocyanate, and the molar ratio of the phenyl diisocyanate to the nano silicon dioxide is 1-2:5.
  4. 4. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the molar ratio of the monohydroxy-terminated polydimethylsiloxane to the phenyl diisocyanate is 1:5-10.
  5. 5. The method for producing a hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the initiator is one of azobisisobutyronitrile and dibenzoyl peroxide.
  6. 6. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the mass of the initiator is 3-5% of the mass of the methyl methacrylate.
  7. 7. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the mass ratio of the hydrophobic modified silicon dioxide to the methyl methacrylate is 4-10:1.
  8. 8. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the temperature of the stirring, heating and polymerizing reaction is 90-110 ℃ and the reaction time is 60-90min.
  9. 9. The method for preparing the hydrophobic and oleophobic packaging paper bag according to claim 1, wherein the mass ratio of the paraffin in the coating liquid is 5-10%.
  10. 10. A hydrophobic oleophobic packaging paper bag, characterized in that it is prepared by the preparation method according to any one of claims 1-9.

Description

Hydrophobic and oleophobic packaging paper bag and preparation method thereof Technical Field The invention belongs to the technical field of packaging processing, and particularly relates to a hydrophobic and oleophobic packaging paper bag and a preparation method thereof. Background The paper and paperboard material has the advantages of long use history, abundant sources of raw materials, light weight, easy processing and the like, and is widely applied to packaging and protection of consumer products such as food and the like. Based on the environmental pollution hazards of plastic materials, packaging paper bags have been widely used in recent years. The packaging paper bag has the advantages of environmental protection compared with the plastic packaging material, but is easy to be damped and damaged, has poor waterproof and moistureproof performances, is not suitable for long-term storage or storage of commodities with heavy damp, and needs to prevent grease from penetrating when being used for packaging grease foods, so that the foods are protected from pollution, other objects are prevented from being polluted, and the natural paper material has poor liquid resistance, stability and chemical migration resistance and must be subjected to waterproof and oilproof treatment. The existing paper bag is mostly coated with a protective layer, and most of the coating materials comprise fluorine-containing materials, including perfluoro or polyfluoroalkyl compounds, have typical hydrophobic and oleophobic structures, and have C-F bonds in the structures, so that the paper bag has high chemical stability, and therefore has relatively slow biological and environmental degradation characteristics and bioaccumulation, and becomes a permanent pollutant with high concern in the global scope. For food contact paper, the performance of hydrophobicity, oleophobicity, high temperature resistance and the like of the paper can be effectively improved by adding the fluorine-containing material, but the contact of the treated paper product with the food can cause potential human health problems, along with the increasingly strict requirements on the food safety, the traditional fluorine-containing material is gradually controlled, and the water and oil proofing treatment by adopting the fluorine-free material to replace the fluorine-containing material is a hot spot in the current research. Disclosure of Invention The invention provides a hydrophobic and oleophobic packaging paper bag and a preparation method thereof, which can solve the problem of poor hydrophobic and oleophobic performance of the packaging paper bag in the prior art. The aim of the invention can be achieved by the following technical scheme: The invention provides a preparation method of a hydrophobic and oleophobic packaging paper bag, which comprises the following steps: Dispersing nano silicon dioxide in toluene, adding phenyl diisocyanate under anhydrous and anaerobic conditions, stirring, heating, refluxing for reaction for 4-6 hours, adding monohydroxy-terminated polydimethylsiloxane, continuously refluxing for reaction for 5-8 hours, centrifuging, washing precipitate with toluene, and drying to obtain hydrophobically modified silicon dioxide; step two, adding methyl methacrylate into a beaker, adding an initiator, uniformly stirring, adding hydrophobic modified silicon dioxide, stirring, heating and polymerizing, and mixing with paraffin after the reaction is finished to obtain a coating liquid; And thirdly, coating the surface of the paper bag body with the coating liquid, and drying the paper bag body to form a film to obtain the hydrophobic and oleophobic packaging paper bag. In the first step, phenyl diisocyanate is used as a connecting agent, isocyanate groups with higher activity on the phenyl diisocyanate react with silicon hydroxyl groups on the surface of nano silicon dioxide, and unreacted isocyanate groups with lower activity react with monohydroxy-terminated polydimethylsiloxane to enable the monohydroxy-terminated polydimethylsiloxane to be grafted on the surface of the nano silicon dioxide, so that the surface energy of the surface of the polydimethylsiloxane is obviously reduced due to the fact that the hydrophobic long chain of the polydimethylsiloxane changes from hydrophilic to hydrophobic. In the film-forming material coating, the hydrophobic and oleophobic properties of polytetrafluoroethylene are optimal, but because of the large amount of fluorine contained in the polytetrafluoroethylene, the polytetrafluoroethylene has great environmental pollution potential. Polymethyl methacrylate (PMMA) has good chemical stability, weather resistance and recoverability, little environmental pollution hazard and high light transmittance, and does not block pattern patterns of a packaging paper bag as a coating material, so that the appearance is not affected. The polymethyl methacrylate has certain hydrophobicity due to the fact that the