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CN-122008641-A - Packaging film, preparation method and packaging bag

CN122008641ACN 122008641 ACN122008641 ACN 122008641ACN-122008641-A

Abstract

The invention discloses a packaging film, a preparation method and a packaging bag, which belong to the technical field of packaging materials, wherein the packaging film at least comprises a high polymer film, an adhesive layer and an aluminum foil, the adhesive layer is positioned between the high polymer film and the aluminum foil, raw materials of the adhesive layer comprise 8-12wt% of functional core-shell acrylate particles, and the functional core-shell acrylate particles comprise carboxylated core-shell acrylate particles and epoxidized core-shell acrylate particles with the mass ratio of (1-2): 1. The bonding layer added with the functional core-shell acrylate particles can effectively resist cracks and stress concentration generated under dynamic kneading, maintain the structural stability of the packaging film, form a dynamic cross-linking network between carboxyl and epoxy groups, not only can effectively disperse stress, but also can enhance the interfacial bonding force between the bonding layer and the high polymer film as well as between the bonding layer and the aluminum foil, and the finally obtained packaging film has good kneading resistance and good barrier property after the kneading action.

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
20260413

Claims (10)

  1. 1. The packaging film is characterized by at least comprising a high-molecular polymer film, an adhesive layer and an aluminum foil, wherein the adhesive layer is positioned between the high-molecular polymer film and the aluminum foil; the raw materials of the adhesive layer comprise 8-12wt% of functional core-shell acrylate particles, wherein the functional core-shell acrylate particles comprise carboxylated core-shell acrylate particles and epoxidized core-shell acrylate particles with the mass ratio of (1-2): 1.
  2. 2. The packaging film according to claim 1, wherein the raw material of the adhesive layer further comprises a polyurethane-based adhesive, and the polyurethane-based adhesive comprises one or a combination of two of polyether polyurethane and polyester polyurethane.
  3. 3. The packaging film according to claim 1, wherein the carboxylated core-shell acrylate particles are prepared from butyl acrylate, methyl methacrylate and a carboxyl acrylic acid monomer in a mass ratio of 100 (20-30): (5-10), and the epoxidized core-shell acrylate particles are prepared from butyl acrylate, methyl methacrylate and an epoxy acrylic acid monomer in a mass ratio of 100 (20-30): (5-10).
  4. 4. The packaging film of claim 3, wherein the carboxylic acrylic monomer comprises a combination of one or more of methacrylic acid, methacryloxyethyl succinate and methacryloxyethyl maleate, and the epoxy acrylic monomer comprises a combination of one or more of glycidyl methacrylate, glycidyl acrylate and phenyl glycidyl ether acrylate.
  5. 5. A packaging film according to claim 3, wherein the functional core-shell acrylate particles are prepared according to the following method: S101, adding an emulsifier into water, uniformly mixing, keeping the temperature of the solution at 70-80 ℃, adding 5-8wt% of butyl acrylate and a cross-linking agent, stirring for 10-20 min, adding an initiator, and stirring for reacting for 60-90 min to obtain seed emulsion; S102, dropwise adding residual butyl acrylate into the seed emulsion, simultaneously adding an emulsifier and a cross-linking agent, and dropwise adding an initiator after 40-60 min to initiate the growth of a nuclear layer to obtain a nuclear layer emulsion; S103, dropwise adding a carboxyl acrylic acid monomer or an epoxy acrylic acid monomer, an emulsifier and methyl methacrylate into the core-layer emulsion, dropwise adding an initiator after 30-40 min to initiate shell growth, keeping the temperature of the solution at 75-85 ℃, and cooling, filtering, freezing, washing, suction filtering and drying after 1-2 h to obtain carboxylated core-shell acrylate particles or epoxidized core-shell acrylate particles; s104, mixing the carboxylated core-shell acrylate particles and the epoxidized core-shell acrylate particles to obtain the functional core-shell acrylate particles.
  6. 6. The packaging film of claim 5, wherein the emulsifier comprises a combination of one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfonate, the crosslinker comprises a combination of one or more of allyl methacrylate, 1, 4-butanediol diacrylate, ethylene glycol diacrylate, and trimethylolpropane triacrylate, and the initiator comprises a combination of one or more of ammonium persulfate, potassium persulfate, and azobisisobutyronitrile.
  7. 7. The packaging film according to claim 1, wherein the aluminum foil is coated with modified slurry on one side, which is not connected with an adhesive layer, and the modified slurry comprises, by mass, 3-5 parts of nano silicon dioxide, 8-10 parts of sodium alginate and 45-55 parts of deionized water.
  8. 8. The packaging film according to claim 7, wherein the coating amount of the modified slurry is 3-5 g/m 2 .
  9. 9. A method of producing a packaging film according to any one of claims 1 to 8, comprising the following process steps: S201, adding functional core-shell acrylic ester particles into a polyurethane adhesive, stirring and mixing to obtain an adhesive, coating the surface of a high polymer film with the adhesive, and forming an adhesive layer, wherein the adhesive coating amount is 2.5-3.5 g/m 2 ; S202, compounding the adhesive layer with the aluminum foil, coating modified slurry on the other side of the aluminum foil, drying, and rolling; S203, carrying out curing treatment after winding to obtain the packaging film.
  10. 10. A packaging bag, characterized in that it is produced by using the packaging film according to any one of claims 1 to 8.

Description

Packaging film, preparation method and packaging bag Technical Field The invention belongs to the technical field of packaging materials, and particularly relates to a packaging film, a preparation method and a packaging bag. Background Due to the characteristics of protein, fat and other components in the food and the easy microorganism breeding, the food packaging material is determined to have certain barrier property, the good oxygen barrier property can reduce the permeation amount of oxygen in the environment into the package, the deterioration problems of mildew, oxidization and the like of the food are prevented, and the good barrier property has important significance for prolonging the shelf life of the food. The aluminum foil has various excellent characteristics of light material, high barrier, light shielding, ultraviolet resistance, moisture resistance, corrosion resistance, quick heat conduction and the like, has good processing applicability, can be directly compounded with a plastic film to obtain an aluminum-plastic compound package with high barrier property, can be used for packaging cooked meat products, space foods, sauces or pasty foods and the like, and prolongs the shelf life of the foods. However, in the production process of the aluminum foil, inevitable tiny pinholes are generated on the surface of the aluminum foil due to the limitations of production raw materials, production process and workshop environment, and the barrier property of the aluminum foil is affected to a certain extent. In the process of food sterilization, vacuumizing or finished product transportation and storage, the aluminum-plastic composite packaging material obtained by compounding the aluminum foil and the plastic film is inevitably subjected to the rubbing actions of folding, bending and the like of external force, pinholes on the surface of the aluminum foil are gradually enlarged, the layer structure of the packaging material is also damaged, the barrier property of the packaging material is greatly reduced, and even leakage and the like caused by penetrating pinholes exist, so that the quality guarantee effect of the final packaging material is affected. Disclosure of Invention The invention aims to provide a packaging film, a preparation method and a packaging bag, which are used for solving the problem of poor rubbing resistance of an aluminum-plastic composite packaging material. The aim of the invention can be achieved by the following technical scheme: In a first aspect, the invention provides a packaging film which at least comprises a high polymer film, an adhesive layer and an aluminum foil, wherein the adhesive layer is positioned between the high polymer film and the aluminum foil; The raw materials of the adhesive layer comprise 8-12wt% of functional core-shell acrylate particles, wherein the functional core-shell acrylate particles comprise carboxylated core-shell acrylate particles and epoxidized core-shell acrylate particles with the mass ratio of (1-2): 1. Preferably, the raw material of the bonding layer further comprises a polyurethane adhesive, and the polyurethane adhesive comprises one or a combination of two of polyether polyurethane and polyester polyurethane. Preferably, the high molecular polymer film includes any one of polyethylene terephthalate film, polypropylene film, polyethylene film and polyamide film. By adopting the technical scheme, core-shell acrylic ester particles are also added in the adhesive layer, and because the traditional adhesive comprises the polyurethane adhesive selected by the invention, brittle fracture easily occurs under the action of dynamic kneading stress, so that interface stripping or new stress concentration is generated between the adhesive and the aluminum foil, the kneading resistance of the packaging film is reduced, and the performance of the packaging film is reduced. The core-shell acrylic ester particles are composed of a soft core layer and a hard shell layer, when the core-shell acrylic ester particles are dispersed in the adhesive layer, the soft core layer can enhance the elastic modulus and the elongation at break of the adhesive layer, so that the composite packaging film still keeps bonding integrity when being subjected to dynamic kneading action, and the overall structural stability of the packaging film is improved. The hard shell layer can effectively terminate silver grain expansion, and simultaneously cooperate with the soft core layer to absorb impact energy to form a multiple energy dissipation path, so that stress damage of the bonding layer is prevented, and brittle fracture under kneading stress is inhibited. The packaging film obtained by connecting the aluminum foil and the high polymer film by the adhesive layer containing the core-shell acrylic ester particles can prevent microcracks generated by rubbing, inhibit the diffusion of the microcracks to an adjacent layer, maintain the barrier property of the packagin