High performance composite aluminum film packaging bag and preparation method thereof

Abstract

The application discloses a high-performance composite aluminum film packaging bag and a preparation method thereof, and belongs to the technical field of packaging bags. The packaging bag has a three-layer structure, and comprises, from outside to inside, an aluminized film layer, an intermediate film layer and a heat-seal film layer. The aluminized film layer, the intermediate film layer and the heat-seal film layer are connected through a two-component polyurethane adhesive. The two-component polyurethane adhesive comprises a main agent and a curing agent. The main agent contains a Ti3AlC2 / SiO2 composite material modified by distearoyl phosphatidyl ethanolamine-polyethylene glycol-silane and loaded with menthol. Through optimization of the composition of the adhesive, the adhesive not only realizes the close connection between the layers, but also greatly improves the adhesion of the adhesive under high-temperature and high-humidity conditions, thereby guaranteeing the cooking resistance of the packaging bag. In addition, the packaging bag has certain heat storage performance, can better maintain the stability of the internal temperature, and optimizes the use experience of consumers.

Description

Technical Field

[0001] This invention belongs to the field of packaging bag technology, specifically relating to a high-performance composite aluminum film packaging bag and its preparation method. Background Technology

[0002] Plastic composite film is currently the most widely used food packaging material. Aluminum-plastic composite film, in particular, combines plastic with aluminized film and possesses excellent flexibility, moisture resistance, oxygen barrier properties, light-blocking properties, shielding properties, antistatic properties, vacuum capability, and color printing properties, making it widely used in the food, pharmaceutical, pesticide, chemical, and electromechanical product industries. Depending on the properties of the contents and storage requirements, aluminum-plastic composite films can be made by combining different types of plastic layers with aluminized film.

[0003] The existing method for preparing aluminum foil packaging bags involves printing the surface layer, then dry-laminating the surface layer with aluminum foil, a protective layer, and a heat-sealing layer using an adhesive. The bags are then cured in an oven, and finally cut and made into bags. This method has a short production cycle. The adhesive is generally polyurethane. However, due to the poor heat resistance of polyurethane adhesive, existing aluminum foil packaging bags commonly suffer from delamination and leakage after high-temperature cooking, and even bag breakage, leading to spoilage of the packaged food. Summary of the Invention

[0004] The purpose of this invention is to provide a high-performance composite aluminum film packaging bag and its preparation method, thereby solving the problem of poor heat resistance of existing composite aluminum film packaging bags.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A high-performance composite aluminum film packaging bag has a three-layer structure, which, from the outside to the inside, includes an aluminum-plated film layer, an intermediate film layer, and a heat-sealing film layer. The aluminum-plated film layer, the intermediate film layer, and the heat-sealing film layer are connected by a two-component polyurethane adhesive.

[0007] Preferably, the two-component polyurethane adhesive includes a main agent and a curing agent, with a mass ratio of the main agent to the curing agent of 100:18-20.

[0008] Preferably, the preparation process of the main agent is as follows:

[0009] Polyether polyol was dehydrated under vacuum at 120°C for 2 hours. After cooling, isophorone diisocyanate and stannous octoate were added. Under nitrogen protection, the mixture was stirred at 80°C for 2-3 hours. Then, diethylene glycol was added, and the reaction was continued at 80°C for 2-4 hours. Functional filler was added, and the mixture was stirred for 1 hour. The mixture was then cooled to 40°C and discharged to obtain the main agent.

[0010] Preferably, in the above preparation process, the mass ratio of polyether polyol, isophorone diisocyanate, stannous octoate, diethylene glycol and functional filler is 25-35:5-15:0.01-0.05:3-5:5-10.

[0011] Preferably, the polyether polyol is polyether polyol MN-700.

[0012] Preferably, the curing agent is HDI trimer, and more preferably N3390 manufactured by Bayer.

[0013] Preferably, the functional filler is a Ti3AlC2 / SiO2 composite material modified with distearate-phosphatidylethanolamine-polyethylene glycol-silane (DSPE-PEG-Silane) and loaded with menthol.

[0014] Preferably, the preparation process of the functional filler is as follows:

[0015] Distearate phosphatidylethanolamine-polyethylene glycol-silane and deionized water were mixed and stirred at 45-60℃ for 20-30 min to obtain a hydrolysate. The menthol-loaded Ti3AlC2 / SiO2 composite material was placed in a mixer and sprayed onto the surface of the menthol-loaded Ti3AlC2 / SiO2 composite material while stirring at 25-32℃. After spraying, it was naturally dried at 25-32℃ to obtain the functional filler.

[0016] Preferably, in the above preparation process, the mass ratio of the hydrolysate and the menthol-loaded Ti3AlC2 / SiO2 composite material is 0.5-1.5:5, and the ratio of distearylphosphatidylethanolamine-polyethylene glycol-silane to deionized water in the hydrolysate is 1g:5-10mL. When distearylphosphatidylethanolamine-polyethylene glycol-silane is added to water, the -Si(OCH2CH3)3 structure in the distearylphosphatidylethanolamine-polyethylene glycol-silane molecular chain undergoes a hydrolysis reaction to generate silanol (-Si-OH)3. The silanol can undergo a condensation reaction with the hydroxyl groups on the surface of the menthol-loaded Ti3AlC2 / SiO2 composite material to complete the modification and obtain the functional filler.

[0017] The preferred preparation process of the menthol-loaded Ti3AlC2 / SiO2 composite material is as follows:

[0018] Menthol was added to dimethyl sulfoxide and stirred for 5-10 min. Then, Ti3AlC2 / SiO2 composite material was added and stirred at 60°C for 2-4 h. After centrifugation, the precipitate was dried to obtain the menthol-loaded Ti3AlC2 / SiO2 composite material.

[0019] Preferably, in the above preparation process, the ratio of menthol, dimethyl sulfoxide and Ti3AlC2 / SiO2 composite material is 2-5g: 20-50mL: 1-3g. Menthol is dissolved in dimethyl sulfoxide, and menthol is loaded onto the pores of the Ti3AlC2 / SiO2 composite material to obtain a menthol-loaded Ti3AlC2 / SiO2 composite material.

[0020] Preferably, the melting point of menthol is 34-36℃.

[0021] Preferably, the preparation process of the Ti3AlC2 / SiO2 composite material is as follows:

[0022] S1. Mix sodium fluoride and hydrochloric acid solution evenly, add Ti3AlC2 in batches, and then treat at 60℃ for 48h to obtain pretreated Ti3AlC2.

[0023] S2. Pretreated Ti3AlC2 was added to deionized water and sonicated for 20 min. Then, hexadecyltrimethylammonium bromide and urea were added and sonicated for another 60 min. A mixture of n-pentanol and cyclohexane was added dropwise. After the addition was complete, the mixture was stirred for 5 min. Tetraethyl orthosilicate was added and stirred for 40 min. The mixture was then transferred to a reaction vessel and reacted at 120 °C for 4 h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed with anhydrous ethanol and dried to obtain a dry sample. The dry sample was dispersed in an ethanol solution, concentrated hydrochloric acid was added, and the mixture was stirred at 60 °C for 4 h. After centrifugation, the precipitate was washed with anhydrous ethanol and dried to obtain the Ti3AlC2 / SiO2 composite material.

[0024] Ti3AlC2 is a two-dimensional ternary layered material with advantages such as high specific surface area, good electrical conductivity, high elastic modulus and corrosion resistance. In this invention, Ti3AlC2 / SiO2 composite material is obtained by using it as a substrate, tetraethyl orthosilicate as silicon source and hexadecyltrimethylammonium bromide as template agent to grow mesoporous silica on the surface of Ti3AlC2.

[0025] Preferably, the ratio of sodium fluoride, hydrochloric acid solution and Ti3AlC2 in S1 is 1-2g: 20-60mL: 2g.

[0026] Preferably, the concentration of hydrochloric acid solution in S1 is 9-12M.

[0027] Preferably, the ratio of the amounts of pretreated Ti3AlC2, deionized water, hexadecyltrimethylammonium bromide, urea, n-pentanol-cyclohexane mixed solution, tetraethyl orthosilicate, ethanol solution and concentrated hydrochloric acid in S2 is 10mg:40mL:0.5g:0.3g:40-41.5mL:1.6mL:48mL:4mL.

[0028] Preferably, the n-pentanol-cyclohexane mixed solution in S2 is composed of n-pentanol and cyclohexane in a volume ratio of 1-1.5:39-400.

[0029] Preferably, the ethanol solution in S2 has a mass fraction of 50-80%, and the concentrated hydrochloric acid has a mass fraction of 36-38%.

[0030] Preferably, the molecular weight of distearate phosphatidylethanolamine-polyethylene glycol-silane is 1-5K.

[0031] Preferably, the molecular structure of distearylphosphatidylethanolamine-polyethylene glycol-silane is as follows:

[0032] It is obtained by bridging DSPE (1,2-distearate-sn-glycerol-3-phosphoethanolamine) and silane groups with PEG (polyethylene glycol), and contains highly hydrophobic 18 saturated carbons, phospholipids and silane groups. The silane groups on its molecules are highly reactive to materials such as silicon dioxide.

[0033] Preferably, the aluminized film layer is composed of an aluminized film, which is at least one of aluminized polyester film (VMPET), aluminized biaxially oriented polypropylene film (VMBOPP), aluminized cast polypropylene film (VMCPP), and aluminized polyethylene film (VMPE), with a thickness of 5-10 μm.

[0034] Preferably, the intermediate film layer is composed of a biaxially oriented film, which is a biaxially oriented polyurethane film or a biaxially oriented nylon film with a thickness of 10-20 μm.

[0035] Preferably, the heat-sealable film layer is composed of cast polypropylene film with a thickness of 50-150 μm.

[0036] The preparation method of the above-mentioned high-performance composite aluminum film packaging bag includes the following steps:

[0037] Step 1: Mix the main agent and the curing agent evenly to obtain a two-component polyurethane adhesive. Add ethyl acetate to dilute the two-component polyurethane adhesive to obtain the adhesive material for later use.

[0038] Step 2: Coat the adhesive material onto one side of the aluminized film and dry it at 78-85℃ for 5 minutes. Then, hot press the biaxially oriented film onto the adhesive-coated side of the aluminized film. The hot press roller temperature is 40-70℃. After that, cure it at 50-55℃ for 24-48 hours and cool it to room temperature to obtain the intermediate film.

[0039] Step 3: Apply adhesive to the side of the intermediate film away from the aluminized film, dry at 78-85℃ for 5 minutes, then hot press the cast polypropylene film onto the side of the intermediate film coated with adhesive, with the hot press roller temperature at 40-70℃, and then cure at 50-55℃ for 24-48 hours, cool to room temperature to obtain the composite aluminum film.

[0040] Step 4: Pack the composite aluminum film into a bag using a three-side sealing bag machine.

[0041] Preferably, the mass ratio of ethyl acetate to the two-component polyurethane adhesive is 1.3-1.6:1.

[0042] Preferably, the amount of adhesive applied is 4-5 g / m². 2 .

[0043] The beneficial effects of this invention are:

[0044] This invention provides a high-performance composite aluminum film packaging bag, comprising an aluminized film layer, an intermediate film layer, and a heat-sealing film layer. By optimizing the composition of the adhesive, not only is a tight bond between the layers achieved, but the adhesion of the adhesive under high temperature and humidity conditions is also significantly improved, ensuring the packaging bag's resistance to boiling. In addition, it also has a certain heat storage capacity, which can better maintain the stability of the internal temperature and optimize the consumer's user experience. For example, in food packaging, the heat storage material can maintain the temperature of the food, allowing consumers to enjoy the best-tasting food immediately after purchase. Furthermore, the heat storage material can also reduce the deformation and breakage of the packaging bag during refrigeration or freezing, thereby maintaining the integrity and aesthetics of the packaging.

[0045] This invention relates to a two-component polyurethane adhesive containing a Ti3AlC2 / SiO2 composite material modified with distearate phosphatidylethanolamine, polyethylene glycol, and silane and loaded with menthol. This composite material enhances the adhesive's resistance to boiling through a layered barrier effect, the hydrophobic effect of long alkyl chains, the complexation effect of phosphate esters, and the reinforcing effect of inorganic fillers. The material also contains menthol, which has a melting point of 34-36°C. Below 34°C, it is solid, and above 36°C, it is liquid. The transition between the liquid and solid states absorbs or releases a large amount of heat, helping to maintain a stable temperature inside the packaging. The high thermal conductivity of the Ti3AlC2 material further improves the heat transfer rate of the system, enhancing temperature control. In addition, menthol has a cooling odor and a certain insect-repellent effect, preventing the packaging from being torn by insects or cockroaches and contaminating the food. Detailed Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application are available on the market or can be prepared by existing methods.

[0048] Preparation Example 1

[0049] The preparation steps for functional fillers are as follows:

[0050] 1g of distearate phosphatidylethanolamine-polyethylene glycol-silane and 5mL of deionized water were mixed and stirred at 45℃ for 20min to obtain a hydrolysate. 10g of menthol-loaded Ti3AlC2 / SiO2 composite material was placed in a mixer and sprayed with 1g of the hydrolysate while stirring at 25℃. After spraying, the material was naturally dried at 25℃ to obtain the functional filler.

[0051] The preparation process of the menthol-loaded Ti3AlC2 / SiO2 composite material is as follows:

[0052] Add 20g of menthol to 200mL of dimethyl sulfoxide, stir for 5min, then add 10g of Ti3AlC2 / SiO2 composite material, stir and mix at 60℃ for 2h, centrifuge, precipitate and dry to obtain menthol-loaded Ti3AlC2 / SiO2 composite material.

[0053] The preparation process of Ti3AlC2 / SiO2 composite material is as follows:

[0054] S1. Mix 10g of sodium fluoride and 200mL of 9M hydrochloric acid solution evenly, add 20g of Ti3AlC2 in 4 equal portions, with an interval of 5min between each portion, and then treat at 60℃ for 48h to obtain pretreated Ti3AlC2.

[0055] S2. Add 10g of pretreated Ti3AlC2 to 40L of deionized water, sonicate for 20min, then add 500g of hexadecyltrimethylammonium bromide and 300g of urea, continue sonicating for 60min, then add 40L of a mixture of n-pentanol and cyclohexane dropwise. After the addition is complete, stir for 5min, then add 1.6L of tetraethyl orthosilicate, stir for 40min, and then transfer to a reaction vessel. React at 120℃ for 4h. After the reaction is complete, centrifuge, wash the precipitate with anhydrous ethanol and dry to obtain a dry sample. Disperse the dry sample in 48L of ethanol solution, add 4L of concentrated hydrochloric acid, stir at 60℃ for 4h, centrifuge, wash the precipitate with anhydrous ethanol and dry to obtain the Ti3AlC2 / SiO2 composite material.

[0056] The n-pentanol and cyclohexane mixed solution in S2 is composed of n-pentanol and cyclohexane in a volume ratio of 1:400. The mass fraction of the ethanol solution in S2 is 50%, and the mass fraction of the concentrated hydrochloric acid is 36%.

[0057] The molecular weight of distearate phosphatidylethanolamine-polyethylene glycol-silane is 1K.

[0058] Preparation Example 2

[0059] The preparation steps for functional fillers are as follows:

[0060] 1g of distearate phosphatidylethanolamine-polyethylene glycol-silane and 10mL of deionized water were mixed and stirred at 60℃ for 30min to obtain a hydrolysate. 10g of menthol-loaded Ti3AlC2 / SiO2 composite material was placed in a mixer and sprayed with 3g of the hydrolysate while stirring at 32℃. After spraying, the surface was naturally dried at 32℃ to obtain the functional filler.

[0061] The preparation process of the menthol-loaded Ti3AlC2 / SiO2 composite material is as follows:

[0062] Add 50g of menthol to 500mL of dimethyl sulfoxide and stir for 10min. Then add 30g of Ti3AlC2 / SiO2 composite material and stir at 60℃ for 4h. Centrifuge, precipitate and dry to obtain menthol-loaded Ti3AlC2 / SiO2 composite material.

[0063] The preparation process of Ti3AlC2 / SiO2 composite material is the same as that in Preparation Example 1.

[0064] The molecular weight of distearate phosphatidylethanolamine-polyethylene glycol-silane is 5K.

[0065] Compare with Example 1

[0066] The preparation of the functional filler differs from that in Preparation Example 1 only in that an equal mass of Ti3AlC2 / SiO2 composite material is used instead of an equal mass of menthol-loaded Ti3AlC2 / SiO2 composite material. The preparation process of the Ti3AlC2 / SiO2 composite material is the same as that in Preparation Example 1.

[0067] Compare with Example 2

[0068] The functional filler preparation differed from Preparation Example 1 only in that an equal mass of menthol-loaded SiO2 composite material was used instead of an equal mass of menthol-loaded Ti3AlC2 / SiO2 composite material. The preparation process of the menthol-loaded SiO2 composite material is as follows:

[0069] Add 20g of menthol to 200mL of dimethyl sulfoxide, stir for 5min, then add 10g of mesoporous SiO2, stir and mix at 60℃ for 2h, centrifuge, precipitate and dry to obtain menthol-loaded SiO2 composite material, wherein the mesoporous SiO2 is SBA-15.

[0070] Compare with Example 3

[0071] This comparative example is a Ti3AlC2 / SiO2 composite material loaded with menthol. The preparation process of the Ti3AlC2 / SiO2 composite material loaded with menthol is the same as that of Preparation Example 1.

[0072] Example 1

[0073] A method for preparing a high-performance composite aluminum film packaging bag includes the following steps:

[0074] Step 1: Mix the main agent and curing agent evenly at a mass ratio of 100:18 to obtain a two-component polyurethane adhesive. Dilute the two-component polyurethane adhesive with ethyl acetate at a mass ratio of 1.3 times to obtain the adhesive material for later use.

[0075] Step 2: Apply adhesive to one side of the aluminized film, with an adhesive application amount of 4g / m². 2 Dry at 78℃ for 5 minutes, then hot press the biaxially oriented film onto the side of the aluminized film coated with adhesive, with the hot press roller temperature at 40℃, then cure at 50℃ for 24 hours, and cool to room temperature to obtain the intermediate film.

[0076] Step 3: Apply adhesive to the side of the intermediate film furthest from the aluminized film, with an adhesive application amount of 4 g / m². 2 Dry at 78℃ for 5 minutes, then hot press the cast polypropylene film onto one side of the intermediate film coated with adhesive, with the hot press roller temperature at 40℃, and then cure at 50℃ for 24 hours, and cool to room temperature to obtain the composite aluminum film.

[0077] Step 4: Pack the composite aluminum film into a bag using a three-side sealing bag machine.

[0078] The aluminized film is a polyester aluminized film (VMPET) with a thickness of 10μm.

[0079] The biaxially oriented membrane is a biaxially oriented polyurethane membrane with a thickness of 15 μm.

[0080] The thickness of the cast polypropylene film is 100μm.

[0081] The preparation process of the main agent is as follows:

[0082] 25 parts by weight of polyether polyol were vacuum dehydrated at 120°C for 2 hours. After cooling, 5 parts by weight of isophorone diisocyanate and 0.01 parts by weight of stannous octoate were added. The mixture was stirred at 80°C for 2 hours under nitrogen protection. Then, 3 parts by weight of diethylene glycol were added, and the mixture was stirred at 80°C for another 2 hours. Finally, 5 parts by weight of the functional filler from Preparation Example 1 were added, and the mixture was stirred for 1 hour. The mixture was then cooled to 40°C and discharged to obtain the main agent.

[0083] The polyether polyol is polyether polyol MN-700.

[0084] The curing agent is HD I trimer, specifically Bayer's N3390.

[0085] Example 2

[0086] A method for preparing a high-performance composite aluminum film packaging bag includes the following steps:

[0087] Step 1: Mix the main agent and curing agent evenly at a mass ratio of 100:19 to obtain a two-component polyurethane adhesive. Dilute the two-component polyurethane adhesive with ethyl acetate at a mass ratio of 1.5 times to obtain the adhesive material for later use.

[0088] Step 2: Apply adhesive to one side of the aluminized film, with an adhesive application amount of 4.5 g / m². 2 Dry at 80℃ for 5 minutes, then hot press the biaxially oriented film onto the side of the aluminized film coated with adhesive, with the hot press roller temperature at 60℃, then cure at 52℃ for 40 hours, and cool to room temperature to obtain the intermediate film.

[0089] Step 3: Apply adhesive to the side of the interlayer film furthest from the aluminized film, with an adhesive application amount of 4.5 g / m². 2 Dry at 80℃ for 5 minutes, then hot press the cast polypropylene film onto one side of the intermediate film coated with adhesive, with the hot press roller temperature at 60℃, and then cure at 52℃ for 40 hours, and cool to room temperature to obtain a composite aluminum film.

[0090] Step 4: Pack the composite aluminum film into a bag using a three-side sealing bag machine.

[0091] The aluminized film, biaxially oriented film, and cast polypropylene film are the same as in Example 1.

[0092] The preparation process of the main agent is as follows:

[0093] 30 parts by weight of polyether polyol were vacuum dehydrated at 120°C for 2 hours. After cooling, 10 parts by weight of isophorone diisocyanate and 0.03 parts by weight of stannous octoate were added. The mixture was stirred at 80°C for 2.5 hours under nitrogen protection. Then, 4 parts by weight of diethylene glycol were added, and the mixture was stirred at 80°C for another 3 hours. Finally, 8 parts by weight of the functional filler from Preparation Example 1 were added, and the mixture was stirred for 1 hour. The mixture was then cooled to 40°C and discharged to obtain the main agent.

[0094] The polyether polyol is polyether polyol MN-700.

[0095] The curing agent is HD I trimer, specifically Bayer's N3390.

[0096] Example 3

[0097] A method for preparing a high-performance composite aluminum film packaging bag includes the following steps:

[0098] Step 1: Mix the main agent and curing agent evenly at a mass ratio of 100:20 to obtain a two-component polyurethane adhesive. Dilute the two-component polyurethane adhesive with ethyl acetate at a mass ratio of 1.6 times to obtain the adhesive material for later use.

[0099] Step 2: Apply adhesive to one side of the aluminized film, with an adhesive application amount of 5g / m². 2 Dry at 85℃ for 5 minutes, then hot press the biaxially oriented film onto the side of the aluminized film coated with adhesive, with the hot press roller temperature at 70℃, then cure at 55℃ for 48 hours, and cool to room temperature to obtain the intermediate film.

[0100] Step 3: Apply adhesive to the side of the intermediate film furthest from the aluminized film, with an adhesive application amount of 5 g / m². 2 Dry at 85℃ for 5 minutes, then hot press the cast polypropylene film onto the side of the intermediate film coated with adhesive, with the hot press roller temperature at 70℃, and then cure at 55℃ for 48 hours, and cool to room temperature to obtain a composite aluminum film.

[0101] Step 4: Pack the composite aluminum film into a bag using a three-side sealing bag machine.

[0102] The aluminized film, biaxially oriented film, and cast polypropylene film are the same as in Example 1.

[0103] The preparation process of the main agent is as follows:

[0104] 35 parts by weight of polyether polyol were vacuum dehydrated at 120°C for 2 hours. After cooling, 15 parts by weight of isophorone diisocyanate and 0.05 parts by weight of stannous octoate were added. The mixture was stirred at 80°C for 3 hours under nitrogen protection. Then, 5 parts by weight of diethylene glycol were added, and the mixture was stirred at 80°C for another 4 hours. Finally, 10 parts by weight of the functional filler from Preparation Example 2 were added, and the mixture was stirred for 1 hour. The mixture was then cooled to 40°C and discharged to obtain the main agent.

[0105] The polyether polyol is polyether polyol MN-700.

[0106] The curing agent is HD I trimer, specifically Bayer's N3390.

[0107] Example 4

[0108] A method for preparing a high-performance composite aluminum film packaging bag differs from Example 1 only in that the weight of the functional filler in the preparation process of the main agent is adjusted from "5 parts by weight" to "10 parts by weight".

[0109] Example 5

[0110] A method for preparing a high-performance composite aluminum film packaging bag differs from Example 3 only in that the weight of the functional filler in the preparation process of the main agent is adjusted from "10 parts by weight" to "5 parts by weight".

[0111] Example 6

[0112] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the aluminized film is a polyester aluminized film (VMPET) with a thickness of 7 μm, the biaxially oriented film is a biaxially oriented polyurethane film with a thickness of 10 μm, and the cast polypropylene film has a thickness of 50 μm.

[0113] Example 7

[0114] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the aluminized film is a polyester aluminized film (VMPET) with a thickness of 5 μm, the biaxially oriented film is a biaxially oriented polyurethane film with a thickness of 20 μm, and the cast polypropylene film has a thickness of 150 μm.

[0115] Example 8

[0116] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the aluminum film is a biaxially oriented polypropylene aluminum film (VMBOPP).

[0117] Comparative Example 1

[0118] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the "functional filler" in Example 1 is replaced with the product prepared in Comparative Example 1.

[0119] Comparative Example 2

[0120] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the "functional filler" in Example 1 is replaced with the product prepared in Comparative Example 2.

[0121] Comparative Example 3

[0122] A method for preparing a high-performance composite aluminum film packaging bag, which differs from Example 1 only in that the "functional filler" in Example 1 is replaced with the substance in Comparative Example 3.

[0123] The composite aluminum films and packaging bags obtained in Examples 1-8 and Comparative Examples 1-3 were subjected to performance tests, and the test procedures are as follows:

[0124] Peel strength: The pattern was made into a strip 15mm wide and 200mm long. The peel strength between the aluminum-plated film layer and the intermediate film layer in each group of composite aluminum films was tested at a speed of 250mm / min using a GGBL-L type electronic tensile testing machine. The same sample was tested 5 times and the average peel force was recorded.

[0125] Peel strength after high-temperature cooking: Place each group of composite aluminum films in a ZM-100 reverse pressure cooking sterilizer and cook at 135℃ for 30 minutes at a pressure of 0.2MPa. After cooling, test the peel strength again using the above method.

[0126] Temperature regulation performance: Ice cubes were packaged in each group of packaging bags and refrigerated at -10℃ for 2 hours. They were then placed in an environment with a room temperature of 38℃ for 10 minutes, and the volume of melted water was collected.

[0127] Insect repellency effect: Tested according to the insect repellency effect test method disclosed in Chinese Patent Application No. 2021114054399;

[0128] The results are shown in Table 1:

[0129] Table 1

[0130]

[0131] Analyzing the data recorded in Table 1, it can be seen that the peel strength between the aluminized film layer and the intermediate film layer in the packaging bags of Examples 1-8 is lower in Example 5, while it is higher in the others. This is mainly due to the lower content of functional fillers. Furthermore, Example 4 has the best overall performance, indicating that the packaging bags prepared by this invention have good resistance to boiling, as well as temperature regulation and insect repellency effects. Specifically, the test results of Example 1 and Comparative Example 1 show that the absence of menthol will significantly reduce the temperature regulation performance and insect repellency effect of the packaging bags. The test results of Example 1 and Comparative Example 2 show that the absence of Ti3AlC2 will significantly reduce the temperature regulation performance and resistance to boiling of the packaging bags. The test results of Example 1 and Comparative Example 3 show that the absence of distearylphosphatidylethanolamine-polyethylene glycol-silane will significantly reduce the peel strength and resistance to boiling of the packaging bags.

[0132] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0133] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-performance composite aluminum film packaging bag, having a three-layer structure, comprising, from the outside to the inside, an aluminized film layer, an intermediate film layer, and a heat-sealing film layer, wherein the aluminized film layer, the intermediate film layer, and the heat-sealing film layer are connected by a two-component polyurethane adhesive, characterized in that, Two-component polyurethane adhesives consist of a base agent and a curing agent. The preparation process of the base agent is as follows: Polyether polyol was vacuum dehydrated at 120℃ for 2 hours, then cooled and isophorone diisocyanate and stannous octoate were added. Under nitrogen protection, the mixture was stirred at 80℃ for 2-3 hours. Then diethylene glycol was added and the mixture was stirred at 80℃ for 2-4 hours. Functional filler was added and stirred for 1 hour. The mixture was then cooled to 40℃ and discharged to obtain the main agent. The functional filler is a Ti3AlC2 / SiO2 composite material modified with distearate phosphatidylethanolamine-polyethylene glycol-silane and loaded with menthol.

2. The high-performance composite aluminum film packaging bag according to claim 1, characterized in that, The mass ratio of polyether polyol, isophorone diisocyanate, stannous octoate, diethylene glycol and functional filler is 25-35:5-15:0.01-0.05:3-5:5-10.

3. A high-performance composite aluminum film packaging bag according to any one of claims 1-2, characterized in that, The preparation process of functional fillers is as follows: Distearate phosphatidylethanolamine-polyethylene glycol-silane and deionized water were mixed and stirred at 45-60℃ for 20-30 min to obtain a hydrolysate. The menthol-loaded Ti3AlC2 / SiO2 composite material was placed in a mixer and sprayed onto the surface of the menthol-loaded Ti3AlC2 / SiO2 composite material while stirring at 25-32℃. After spraying, it was naturally dried at 25-32℃ to obtain the functional filler.

4. The high-performance composite aluminum film packaging bag according to claim 3, characterized in that, The mass ratio of hydrolysate to menthol-loaded Ti3AlC2 / SiO2 composite material is 0.5-1.5:5, and the ratio of distearate phosphatidylethanolamine-polyethylene glycol-silane to deionized water in the hydrolysate is 1g:5-10mL.

5. A high-performance composite aluminum film packaging bag according to claim 3, characterized in that, The preparation process of the menthol-loaded Ti3AlC2 / SiO2 composite material is as follows: Menthol was added to dimethyl sulfoxide and stirred for 5-10 min. Then, Ti3AlC2 / SiO2 composite material was added and stirred at 60℃ for 2-4 h. After centrifugation, the precipitate was dried to obtain the menthol-loaded Ti3AlC2 / SiO2 composite material.

6. A high-performance composite aluminum film packaging bag according to claim 5, characterized in that, The ratio of menthol, dimethyl sulfoxide, and Ti3AlC2 / SiO2 composite material is 2-5g: 20-50mL: 1-3g.

7. A high-performance composite aluminum film packaging bag according to claim 5, characterized in that, The preparation process of Ti3AlC2 / SiO2 composite material is as follows: S1. Sodium fluoride and hydrochloric acid solution are mixed evenly, and Ti3AlC2 is added in batches. Then, the mixture is treated at 60℃ for 48h to obtain pretreated Ti3AlC2. S2. Pretreated Ti3AlC2 was added to deionized water and sonicated for 20 min. Then, hexadecyltrimethylammonium bromide and urea were added and sonicated for another 60 min. A mixture of n-pentanol and cyclohexane was added dropwise. After the addition was complete, the mixture was stirred for 5 min. Tetraethyl orthosilicate was added and stirred for 40 min. The mixture was then transferred to a reaction vessel and reacted at 120 °C for 4 h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed with anhydrous ethanol and dried to obtain a dry sample. The dry sample was dispersed in an ethanol solution, concentrated hydrochloric acid was added, and the mixture was stirred at 60 °C for 4 h. After centrifugation, the precipitate was washed with anhydrous ethanol and dried to obtain the Ti3AlC2 / SiO2 composite material.

8. A high-performance composite aluminum film packaging bag according to claim 7, characterized in that, The ratio of sodium fluoride, hydrochloric acid solution, and Ti3AlC2 in S1 is 1-2g: 20-60mL: 2g, and the concentration of hydrochloric acid solution is 9-12M.

9. A high-performance composite aluminum film packaging bag according to claim 7, characterized in that, The ratio of pretreatment Ti3AlC2, deionized water, hexadecyltrimethylammonium bromide, urea, n-pentanol-cyclohexane mixed solution, tetraethyl orthosilicate, ethanol solution, and concentrated hydrochloric acid in S2 is 10mg:40mL:0.5g:0.3g:40-41.5mL:1.6mL:48mL:4mL. The n-pentanol-cyclohexane mixed solution is composed of n-pentanol and cyclohexane in a volume ratio of 1-1.5:39-400, and the ethanol solution has a mass fraction of 50-80%.

10. A method for preparing a high-performance composite aluminum film packaging bag as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Mix the main agent and the curing agent evenly to obtain a two-component polyurethane adhesive. Add ethyl acetate to dilute the two-component polyurethane adhesive to obtain the adhesive compound. Step 2: Coat the adhesive material onto one side of the aluminized film and dry it at 78-85℃ for 5 minutes. Then, hot press the biaxially oriented film onto the adhesive-coated side of the aluminized film. The hot press roller temperature is 40-70℃. After that, cure it at 50-55℃ for 24-48 hours and cool it to room temperature to obtain the intermediate film. Step 3: Apply adhesive to the side of the intermediate film away from the aluminized film, dry at 78-85℃ for 5 minutes, then hot press the cast polypropylene film onto the side of the intermediate film coated with adhesive, with the hot press roller temperature at 40-70℃, and then cure at 50-55℃ for 24-48 hours, cool to room temperature to obtain the composite aluminum film. Step 4: The composite aluminum film is bagged using a three-side sealing bagging machine to obtain a high-performance composite aluminum film packaging bag.

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