Special plastic aluminum foil composite paper and preparation method thereof

Abstract

The application provides a special plastic aluminum foil composite paper and a preparation method thereof. The composite paper comprises an aluminum foil layer, a special plastic layer and a paper layer. The aluminum foil layer is a base layer, the special plastic layer is made of polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer and nano magnetic particle microcapsules, and is tightly attached to one side of the aluminum foil layer; the paper layer is made of raw paper wood pulp, polyester fiber pulp, ramie fiber pulp, silk fiber pulp, rosin glue, chitin, chitosan, allicin and bee glue, and is combined with the special plastic layer on the other side of the aluminum foil layer. The nano magnetic particle microcapsules are made of magnetic nano particles, capsule core materials, monomers and emulsifiers. The paper layer is formed by mixing two kinds of pulp uniformly and electrophoretic deposition. During preparation, the surface of the aluminum foil layer is pretreated, then the special plastic is prepared, the special plastic layer is coated, the paper layer is coated, and the finished product is obtained through hot pressing, and can be applied to the field of food packaging.

Description

Technical Field

[0001] This invention relates to the field of composite paper production technology, and in particular to a special plastic aluminum foil composite paper and its preparation method. Background Technology

[0002] With the rapid development of the packaging industry, the performance requirements for packaging materials are increasingly stringent. In food packaging and other fields, aluminum foil is widely used due to its excellent barrier properties, thermal conductivity, and corrosion resistance. However, traditional aluminum foil has gradually revealed some performance defects in practical use. On the one hand, ordinary aluminum foil lacks folding endurance and flexibility. After repeated folding or bending, it is prone to breakage, delamination, and creases, which not only affects its appearance but also reduces its performance. Simultaneously, its puncture resistance is limited. In scenarios requiring higher puncture resistance, ordinary aluminum foil can be easily punctured by sharp objects, leading to a decrease in its barrier properties and inability to effectively protect the contents. On the other hand, the moisture-proof performance of ordinary aluminum foil has room for improvement. When exposed to high humidity or in contact with water for extended periods, its moisture-proof ability gradually weakens, allowing moisture to penetrate the paper and affect the quality of the contents. Furthermore, in multi-layered composite aluminum foil, the bonding strength between layers is often insufficient, making delamination prone to occur during use, thus affecting overall performance and service life.

[0003] Furthermore, in applications requiring heat sealing, ordinary aluminum foil's heat sealing performance is not ideal, resulting in insufficient heat seal strength or a tendency to leak after heat sealing. Moreover, ordinary aluminum foil has limited corrosion resistance; it is prone to corrosion when in contact with certain chemicals or corrosive media, thus affecting its performance and service life. Summary of the Invention

[0004] In view of this, the present invention proposes a special plastic aluminum foil composite paper and its preparation method to solve the above problems.

[0005] The technical solution of this invention is implemented as follows: A special plastic aluminum foil composite paper includes an aluminum foil layer, a special plastic layer, and a paper layer. The aluminum foil layer serves as the base layer of the composite paper, and the special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made from the following raw materials in parts by weight: 40-60 parts polyimide, 30-50 parts polytetrafluoroethylene, 25-35 parts ethylene-tetrafluoroethylene copolymer, 20-29 parts ethylene-vinyl alcohol copolymer, and nano- 12-22 parts of magnetic microcapsules are bonded to the opposite side of the paper layer and the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 50-80 parts of base paper pulp, 15-22 parts of polyester fiber pulp, 10-20 parts of ramie fiber pulp, 10-20 parts of fibrous fiber pulp, 5-12 parts of rosin gum, 20-30 parts of chitin, 5-8 parts of chitosan, 2-4 parts of allicin, and 1-3 parts of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0006] Furthermore, the aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 1-20 μm.

[0007] Furthermore, the nano-magnetic microcapsules comprise the following percentages of raw materials: 40-50% magnetic nanoparticles, 10-30% core material, 2-4% monomer, 1-10% emulsifier, and the balance being water. The magnetic nanoparticles are iron(III) oxide, iron(II) oxide, or cobalt nanoparticles with a particle size of 1-100 nm.

[0008] Furthermore, the core material is a mixture of liquid paraffin, olive oil, and vegetable oil in a mass ratio of (12-15):(20-30):(3-8).

[0009] Furthermore, the monomer is selected from styrene or acrylonitrile.

[0010] Furthermore, the emulsifier is selected from alkylphenol polyoxyethylene ether, sodium dodecyl sulfate, or dodecyltrimethylammonium bromide.

[0011] Furthermore, the magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 20-40 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 5-8 hours, with a radiation dose of 0.2-30 KGy and a dose rate of 0.3-10 Gy / s, to form magnetic microcapsules.

[0012] Furthermore, the paper layer is prepared by mixing and beating base wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 90-120℃ and 2000-3000rpm to obtain pulp I; mixing rosin gum, chitin, chitosan, allicin, and propolis and stirring evenly at 4000-6000rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 20-40 minutes, controlling the voltage at 50-100V and the current at 10-100mA / cm. 2 This process forms paper material, which is then processed into an ordered, layered paper structure.

[0013] Furthermore, a method for preparing a special plastic-aluminum foil composite paper includes the following steps:

[0014] S1. Surface pretreatment of aluminum foil layer: Impregnate aluminum foil paper with a titanium salt solution with a mass concentration of 80-90% at a temperature of 40-80℃ for 10-15 minutes.

[0015] S2. Preparation of special plastics: Polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, and nano magnetic microcapsules are mixed and stirred to obtain special plastics;

[0016] S3. Coating with a special plastic layer: Spray the special plastic onto the surface of the aluminum foil layer. The spray gun pressure is 0.5-0.8MPa, the spraying distance is 10-25cm, the paint flow rate is 3-20g / min, the spray gun speed is 0.1-1m / s, and the spraying temperature is 15-30℃.

[0017] S4. Coating the paper layer: Combine the paper layer with the special plastic side, and then hot press the combined aluminum foil layer, special plastic layer, and paper layer on both sides at a temperature of 150-250℃ and a pressure of 120-150KN for 20-30 minutes to obtain the special plastic aluminum foil composite paper.

[0018] Furthermore, the application of a special plastic-aluminum foil composite paper in the food packaging field.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] Significantly improved folding endurance and flexibility: Through the optimized combination of materials and manufacturing process of each layer, the composite paper is less prone to breakage, delamination or creases when repeatedly folded and bent, and can better adapt to different shapes and packaging needs, improving performance and extending service life.

[0021] Enhanced puncture resistance: The addition of materials such as nano-magnetic microcapsules and the synergistic effect of each layer structure enable the composite paper to withstand the puncture of sharp objects, maintain good barrier properties, and better protect the items inside the packaging.

[0022] Enhanced moisture resistance: The properties and tight bonding of each layer of material enable the composite paper to effectively prevent moisture penetration even in high humidity environments or when in contact with water, providing a stable dry environment for the internal items.

[0023] Excellent composite strength: Through specific processes and material bonding, the layers have high bonding strength and are not prone to delamination during use, ensuring the overall stability of the composite paper.

[0024] Improved heat-sealing performance: The optimized composite paper has high heat-sealing strength and good sealing performance after heat sealing, making it less prone to leakage problems and meeting the heat-sealing performance requirements of food packaging and other products.

[0025] Enhanced corrosion resistance: It can maintain stable performance when in contact with chemicals or corrosive media, reducing the impact of corrosion on the performance of composite paper, and is suitable for various complex use environments.

[0026] When applied in the food packaging field, it can effectively maintain the quality and safety of food, extend its shelf life, and has broad market application prospects and commercial value. Detailed Implementation

[0027] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0028] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0029] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0030] Example 1

[0031] A special plastic aluminum foil composite paper: comprising an aluminum foil layer, a special plastic layer, and a paper layer, wherein the aluminum foil layer serves as the base layer of the composite paper;

[0032] The aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 1-20 μm;

[0033] The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made of the following raw materials in parts by weight: 40 parts polyimide, 30 parts polytetrafluoroethylene, 25 parts ethylene-tetrafluoroethylene copolymer, 20 parts ethylene-vinyl alcohol copolymer, and 12 parts nano-magnetic microcapsules.

[0034] The aforementioned magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 20 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 5 hours at a dose of 0.2 kGy and a dose rate of 0.3 Gy / s, resulting in magnetic microcapsules.

[0035] The paper layer is bonded to the opposite side of the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 50 parts of base paper pulp, 15 parts of polyester fiber pulp, 10 parts of ramie fiber pulp, 10 parts of fibrous fiber pulp, 5 parts of rosin gum, 20 parts of chitin, 5 parts of chitosan, 2 parts of allicin, and 1 part of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0036] The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 90°C and 2000 rpm to obtain pulp I; mixing rosin gum, chitosan, chitosan, allicin, and propolis and stirring evenly at 4000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 20 minutes, controlling the voltage at 50V and the current at 10mA / cm. 2 This process forms paper material, which is then processed into an ordered, layered paper structure.

[0037] Example 2

[0038] A special plastic aluminum foil composite paper: comprising an aluminum foil layer, a special plastic layer, and a paper layer, wherein the aluminum foil layer serves as the base layer of the composite paper;

[0039] The aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 20 μm;

[0040] The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made of the following raw materials in parts by weight: 60 parts of polyimide, 50 parts of polytetrafluoroethylene, 35 parts of ethylene-tetrafluoroethylene copolymer, 29 parts of ethylene-vinyl alcohol copolymer, and 22 parts of nano-magnetic microcapsules.

[0041] The aforementioned magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 40 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 8 hours at a dose of 30 kGy and a dose rate of 10 Gy / s, resulting in magnetic microcapsules.

[0042] The paper layer is bonded to the opposite side of the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 80 parts of base paper pulp, 22 parts of polyester fiber pulp, 20 parts of ramie fiber pulp, 20 parts of fibrous fiber pulp, 12 parts of rosin gum, 30 parts of chitosan, 8 parts of chitosan, 4 parts of allicin, and 3 parts of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0043] The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 120°C and 3000 rpm to obtain pulp I; mixing rosin gum, chitosan, chitosan, allicin, and propolis and stirring evenly at 6000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 40 minutes, controlling the voltage at 100V and the current at 100mA / cm. 2 This process forms paper material, which is then processed into an ordered, layered paper structure.

[0044] Example 3

[0045] A special plastic aluminum foil composite paper: comprising an aluminum foil layer, a special plastic layer, and a paper layer, wherein the aluminum foil layer serves as the base layer of the composite paper;

[0046] The aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 15 μm;

[0047] The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made of the following raw materials in parts by weight: 50 parts of polyimide, 40 parts of polytetrafluoroethylene, 30 parts of ethylene-tetrafluoroethylene copolymer, 25 parts of ethylene-vinyl alcohol copolymer, and 17 parts of nano-magnetic microcapsules.

[0048] The aforementioned magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 30 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 7 hours at a dose of 15 kGy and a dose rate of 5 Gy / s, resulting in magnetic microcapsules.

[0049] The paper layer is bonded to the opposite side of the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 70 parts of base paper pulp, 18 parts of polyester fiber pulp, 15 parts of ramie fiber pulp, 15 parts of fibrous fiber pulp, 8 parts of rosin gum, 25 parts of chitosan, 7 parts of chitosan, 3 parts of allicin, and 2 parts of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0050] The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 100°C and 2500 rpm to obtain pulp I; mixing rosin gum, chitosan, chitosan, allicin, and propolis and stirring evenly at 5000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 30 minutes, controlling the voltage at 80V and the current at 50mA / cm. 2 This forms paper material, which is then processed into an ordered, layered paper structure.

[0051] The above Examples 1-3 were prepared using the following methods:

[0052] S1. Surface pretreatment of aluminum foil layer: The aluminum foil paper is impregnated with a titanium salt solution with a mass concentration of 85% at a temperature of 60°C for 12 minutes.

[0053] S2. Preparation of special plastics: Polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, and nano magnetic microcapsules are mixed and stirred to obtain special plastics;

[0054] S3. Coating a special plastic layer: Spray the special plastic onto the surface of the aluminum foil layer. The spray gun pressure is 0.7MPa, the spray distance is 15cm, the paint flow rate is 15g / min, the spray gun speed is 0.5m / s, and the spray temperature is 22℃.

[0055] S4. Coating the paper layer: Combine the paper layer with one side of the special plastic. After bonding the aluminum foil layer, special plastic layer and paper layer, hot press both sides at 200℃ and 130KN for 25 minutes to obtain the special plastic aluminum foil composite paper.

[0056] Example 4

[0057] A special plastic aluminum foil composite paper: comprising an aluminum foil layer, a special plastic layer, and a paper layer, wherein the aluminum foil layer serves as the base layer of the composite paper;

[0058] The aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 15 μm;

[0059] The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made of the following raw materials in parts by weight: 50 parts of polyimide, 40 parts of polytetrafluoroethylene, 30 parts of ethylene-tetrafluoroethylene copolymer, 25 parts of ethylene-vinyl alcohol copolymer, and 17 parts of nano-magnetic microcapsules.

[0060] The aforementioned magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 30 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 7 hours at a dose of 15 kGy and a dose rate of 5 Gy / s, resulting in magnetic microcapsules.

[0061] The paper layer is bonded to the opposite side of the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 70 parts of base paper pulp, 18 parts of polyester fiber pulp, 15 parts of ramie fiber pulp, 15 parts of fibrous fiber pulp, 8 parts of rosin gum, 25 parts of chitosan, 7 parts of chitosan, 3 parts of allicin, and 2 parts of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0062] The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 100°C and 2500 rpm to obtain pulp I; mixing rosin gum, chitosan, chitosan, allicin, and propolis and stirring evenly at 5000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 30 minutes, controlling the voltage at 80V and the current at 50mA / cm. 2 This forms paper material, which is then processed into an ordered, layered paper structure.

[0063] The preparation method used in Example 4 above is as follows:

[0064] S1. Surface pretreatment of aluminum foil layer: Impregnate aluminum foil paper with a titanium salt solution with a mass concentration of 80-90% at a temperature of 40℃ for 10 minutes.

[0065] S2. Preparation of special plastics: Polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, and nano magnetic microcapsules are mixed and stirred to obtain special plastics;

[0066] S3. Coating a special plastic layer: Spray the special plastic onto the surface of the aluminum foil layer. The spray gun pressure is 0.5MPa, the spraying distance is 10cm, the paint flow rate is 3g / min, the spray gun speed is 0.1m / s, and the spraying temperature is 15℃.

[0067] S4. Coating the paper layer: Combine the paper layer with the special plastic side, and then hot press the combined aluminum foil layer, special plastic layer, and paper layer on both sides at a temperature of 150℃ and a pressure of 120KN for 20 minutes to obtain the special plastic aluminum foil composite paper.

[0068] Example 5

[0069] A special plastic aluminum foil composite paper: comprising an aluminum foil layer, a special plastic layer, and a paper layer, wherein the aluminum foil layer serves as the base layer of the composite paper;

[0070] The aluminum foil layer is an aluminum foil with a purity of 99.5% or higher and a thickness of 15 μm;

[0071] The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made of the following raw materials in parts by weight: 50 parts of polyimide, 40 parts of polytetrafluoroethylene, 30 parts of ethylene-tetrafluoroethylene copolymer, 25 parts of ethylene-vinyl alcohol copolymer, and 17 parts of nano-magnetic microcapsules.

[0072] The aforementioned magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 30 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 7 hours at a dose of 15 kGy and a dose rate of 5 Gy / s, resulting in magnetic microcapsules.

[0073] The paper layer is bonded to the opposite side of the special plastic layer. The paper layer is made of the following raw materials in parts by weight: 70 parts of base paper pulp, 18 parts of polyester fiber pulp, 15 parts of ramie fiber pulp, 15 parts of fibrous fiber pulp, 8 parts of rosin gum, 25 parts of chitosan, 7 parts of chitosan, 3 parts of allicin, and 2 parts of propolis. The base paper pulp is selected from softwood pulp or hardwood pulp.

[0074] The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 100°C and 2500 rpm to obtain pulp I; mixing rosin gum, chitosan, chitosan, allicin, and propolis and stirring evenly at 5000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 30 minutes, controlling the voltage at 80V and the current at 50mA / cm. 2 This forms paper material, which is then processed into an ordered, layered paper structure.

[0075] The preparation method used in Example 5 above is as follows:

[0076] S1. Surface pretreatment of aluminum foil layer: The aluminum foil paper is impregnated with a titanium salt solution with a mass concentration of 90% at an impregnation temperature of 80℃ for 15 minutes.

[0077] S2. Preparation of special plastics: Polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, and nano magnetic microcapsules are mixed and stirred to obtain special plastics;

[0078] S3. Coating a special plastic layer: Spray the special plastic onto the surface of the aluminum foil layer. The spray gun pressure is 0.8MPa, the spraying distance is 25cm, the paint flow rate is 20g / min, the spray gun speed is 1m / s, and the spraying temperature is 30℃.

[0079] S4. Coating the paper layer: Combine the paper layer with the special plastic side, and then hot press the combined aluminum foil layer, special plastic layer, and paper layer on both sides at a temperature of 250℃ and a pressure of 150KN for 30 minutes to obtain the special plastic aluminum foil composite paper.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 3 is that the special plastic layer is made from the following raw materials in parts by weight: 70 parts polyimide, 25 parts polytetrafluoroethylene, 20 parts ethylene-tetrafluoroethylene copolymer, 18 parts ethylene-vinyl alcohol copolymer, and 10 parts nano-magnetic microcapsules.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 3 is that the raw material of the special plastic layer does not contain nano-magnetic microcapsules.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 3 is that the paper layer is made from the following raw materials in parts by weight: 40 parts of base paper wood pulp, 25 parts of polyester fiber pulp, 8 parts of ramie fiber pulp, 25 parts of fibrous fiber pulp, 3 parts of rosin gum, 35 parts of chitin, 2 parts of chitosan, 5 parts of allicin, and 5 parts of propolis.

[0086] Experimental Example 1 - Effect Test

[0087] The special plastic aluminum foil composite paper prepared in Examples 1-5 and Comparative Examples 1-3 were used as 10 samples for testing:

[0088] 1. Flexural endurance test:

[0089] At least five samples were randomly selected from the plastic-aluminum foil composite paper samples to be tested. Each sample measured 150 mm × 15 mm. The samples were clamped vertically onto the clamps of the MIT folding endurance tester, with the folded portion of the sample positioned in the center of the clamp. The folding angle of the MIT folding endurance tester was set to 135°, and the folding speed to 175 times / minute. The instrument was started, and the samples were repeatedly folded. The number of folds at the point of breakage for each sample was recorded.

[0090] 2. Flexibility test:

[0091] At least five samples were randomly selected from the plastic-aluminum foil composite paper samples to be tested, each measuring 200 mm × 25 mm. One end of the sample was fixed, and the other end was placed horizontally on the cylindrical shaft of the cylindrical shaft bending test apparatus. The sample was bent 180° around the cylindrical shaft at a speed of 2-3 seconds, and the surface of the sample was observed for cracks, fractures, or delamination. Starting with a cylindrical shaft with a larger diameter, the bending operation was gradually repeated with smaller diameter cylindrical shafts until the sample was damaged. The diameter of the cylindrical shaft at this point was recorded.

[0092] 3. Puncture resistance

[0093] The puncture strength test was conducted according to the relevant requirements of section 6.6.13 of GB / T10004-2008, "Dry Lamination and Extrusion Lamination of Plastic Composite Films and Bags for Packaging". Five circular samples with a diameter of 100 mm were cut from the surface of the plastic-aluminum foil composite paper using a sampler, ensuring that the samples were of uniform thickness and free from wrinkles, creases, stains, and other obvious defects. The puncture needle was used to puncture the sample at a speed of (50±5) mm / min. Once the needle penetrated the sample, the testing machine automatically stopped and recorded the maximum load value. The above steps were repeated until all samples were tested.

[0094] 4. Data Results

[0095] Number of folding cycles Flexibility diameter (mm) Puncture resistance (N) Example 1 5205 6 14 Example 2 5120 7 14 Example 3 5320 6 15 Example 4 5100 6 13 Example 5 5050 8 12 Comparative Example 1 3460 15 5 Comparative Example 2 3450 17 6 Comparative Example 3 3350 17 7

[0096] The results above show that the example group significantly outperformed the comparative group in terms of folding endurance, flexibility, and puncture resistance. The process and material combination of the example group gives the plastic-aluminum foil composite paper significant advantages in mechanical and performance properties, better meeting the application requirements with high product performance demands.

[0097] Example 3, compared with Comparative Examples 1 and 3, demonstrates that the raw materials for the special plastic layer and paper layer can achieve better results when mixed in a certain ratio.

[0098] Compared with Comparative Example 2, Example 3 shows that the nano-magnetic microcapsules are uniformly dispersed in the plastic layer, which can play a role in stress dispersion when subjected to external force, preventing the rapid propagation of cracks, thereby improving the toughness and impact resistance of the plastic-aluminum foil composite paper.

[0099] Test Example 2 - Corrosion Resistance Test

[0100] Set the following comparison scale:

[0101] Comparative Example 4

[0102] The difference between this comparative example and Example 3 is that the paper layer material does not contain allicin.

[0103] Comparative Example 5

[0104] The difference between this comparative example and Example 3 is that the paper layer material does not contain propolis.

[0105] Example 3 and Comparative Examples 4 and 5 were selected as test samples and immersed in 5% hydrochloric acid solution and 10% sodium hydroxide solution, respectively. Their mass loss rate and appearance changes were tested within 24 hours.

[0106] Quality loss rate = (initial mass - final mass) / initial mass × 100%

[0107] The results are as follows:

[0108] Table 2: Results of corrosion resistance test in acidic environment (5% hydrochloric acid solution)

[0109] Quality loss rate (%) Description of appearance changes Example 3 0.30 Slight discoloration, no peeling Comparative Example 4 0.89 The color deepens, and the edges are slightly peeled. Comparative Example 5 0.75 Localized darkening of the surface

[0110] Table 3: Corrosion resistance test results in alkaline environment (10% sodium hydroxide solution)

[0111] Quality loss rate (%) Description of appearance changes Example 3 0.04 Almost no change Comparative Example 4 0.35 Slight decrease in gloss Comparative Example 5 0.44 The gloss level decreased significantly, but there was no peeling.

[0112] The results above show that, compared with Comparative Example 4, allicin, as a paper layer raw material, can capture and neutralize oxidizing substances in the environment (such as oxygen, ozone, etc.), reduce the erosion of composite paper by oxidation reaction, and delay the aging and corrosion process of paper layer and composite paper as a whole; allicin molecules can form an adsorption film on the surface of aluminum foil, blocking the direct contact between corrosive media (such as moisture, oxygen, corrosive ions, etc.) and the metal surface, thereby playing a certain role in corrosion inhibition and protection of aluminum foil layer.

[0113] Compared with Comparative Example 5, in Example 3, propolis, as a raw material for the paper layer, has active ingredients that react chemically with the surface of aluminum foil to form a stable protective film. This film prevents direct interaction between the aluminum foil and the corrosive medium, slows down the rate of electrochemical corrosion, and thus provides corrosion protection for the aluminum foil layer. The antioxidant components in propolis, such as phenols and flavonoids, can capture and neutralize free radicals in the environment, reduce the damage of oxidation reactions to organic components in the composite paper (such as polymer materials in the plastic layer and paper layer), delay the aging and corrosion process of the composite paper, and maintain the performance and structural stability of the composite paper.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A special plastic-aluminum foil composite paper, characterized in that: The composite paper comprises an aluminum foil layer, a special plastic layer, and a paper layer. The aluminum foil layer serves as the base layer of the composite paper. The special plastic layer is tightly bonded to one side of the aluminum foil layer. The special plastic layer is made from the following raw materials in parts by weight: 40-60 parts polyimide, 30-50 parts polytetrafluoroethylene, 25-35 parts ethylene-tetrafluoroethylene copolymer, 20-29 parts ethylene-vinyl alcohol copolymer, and 12-22 parts nano-magnetic microcapsules. The paper layer and the special plastic layer... The layers are bonded together on one side to form an aluminum foil layer-special plastic layer-paper layer structure. The paper layer is made of the following raw materials in parts by weight: 50-80 parts of base paper wood pulp, 15-22 parts of polyester fiber pulp, 10-20 parts of ramie fiber pulp, 10-20 parts of fibrous fiber pulp, 5-12 parts of rosin gum, 20-30 parts of chitin, 5-8 parts of chitosan, 2-4 parts of allicin, and 1-3 parts of propolis. The base paper wood pulp is selected from softwood pulp or hardwood pulp. The nano-magnetic microcapsules comprise the following percentages of raw materials: 40-50% magnetic nanoparticles, 10-30% core material, 2-4% monomers, 1-10% emulsifiers, and the remainder is water. The magnetic nanoparticles are iron(III) oxide, iron(II) oxide, or cobalt nanoparticles with a particle size of 1-100 nm. The core material is liquid paraffin, olive oil and vegetable oil in a mass ratio of (12-15):(20-30):(3-8); The monomer is selected from styrene or acrylonitrile; The emulsifier is selected from alkylphenol polyoxyethylene ether, sodium dodecyl sulfate, or dodecyltrimethylammonium bromide; The magnetic nanoparticle microcapsules are formed by mixing magnetic nanoparticles with a core material and stirring for 20-40 minutes to form a magnetic core emulsion. Under the action of an emulsifier, the magnetic core emulsion is mixed with monomers and water and stirred. The mixture is then irradiated with gamma rays for 5-8 hours, where the radiation dose of the gamma rays is 0.2-30 kGy and the dose rate is 0.3-10 Gy / s, to form magnetic microcapsules. The paper layer is prepared by mixing and beating wood pulp, polyester fiber pulp, ramie fiber pulp, and roving fiber pulp at 90-120℃ and 2000-3000 rpm to obtain pulp I; mixing rosin gum, chitin, chitosan, allicin, and propolis and stirring evenly at 4000-6000 rpm to obtain pulp II; and then mixing pulp I and pulp II evenly and performing electrophoretic deposition for 20-40 minutes, controlling the voltage at 50-100V and the current at 10-100mA / cm. 2 This process forms paper material, which is then processed into an ordered, layered paper structure.

2. The special plastic-aluminum foil composite paper as described in claim 1, characterized in that: The aluminum foil layer is made of aluminum foil with a purity of 99.5% or higher and a thickness of 1-20 μm.

3. The method for preparing a special plastic-aluminum foil composite paper as described in claim 1, characterized in that: Includes the following steps: S1. Surface pretreatment of aluminum foil layer: Impregnate aluminum foil paper with a titanium salt solution with a mass concentration of 80-90% at a temperature of 40-80℃ for 10-15 minutes. S2. Preparation of special plastics: Polyimide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, ethylene-vinyl alcohol copolymer, and nano magnetic microcapsules are mixed and stirred to obtain special plastics; S3. Coating with a special plastic layer: Spray the special plastic onto the surface of the aluminum foil layer. The spray gun pressure is 0.5-0.8MPa, the spraying distance is 10-25cm, the paint flow rate is 3-20g / min, the spray gun speed is 0.1-1m / s, and the spraying temperature is 15-30℃. S4. Coating the paper layer: Combine the paper layer with the special plastic side, and then hot press the combined aluminum foil layer, special plastic layer, and paper layer on both sides at a temperature of 150-250℃ and a pressure of 120-150kN for 20-30 minutes to obtain the special plastic aluminum foil composite paper.

4. The application of a special plastic aluminum foil composite paper as described in any one of claims 1-2 in the field of food packaging.