A high-strength barrier-modified paper product packaging material and a method for producing the same

Abstract

The application discloses a kind of high-strength barrier modified paper product packaging materials and preparation method thereof, belong to environmental protection packaging material technical field.The packaging material with cellulose fiber as matrix, compound microfibrillated cellulose and hydrophobic modified SiO2 Aerogel, and realize in-situ chemical crosslinking through crosslinking agent, form the gradient density three-layer structure of surface layer dense barrier, core layer high-strength support.The application is strengthened by gradient structure design and in-situ crosslinking, significantly improves the mechanical strength of paper product, oxygen and water vapor barrier property, while solving the problems such as filler easy to fall off, surface powdering etc.The preparation process is compatible with existing papermaking production line, product is plastic and degradable, environment-friendly, can be widely used in food preservation, logistics transportation and other high-end environmental protection packaging fields.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of environment-friendly packaging materials, and particularly relates to a high-strength barrier modified paper product packaging material and a preparation method thereof. BACKGROUND

[0002] With the promotion of environmental protection plastic limit policy, degradable paper-based packaging has become the mainstream direction to replace plastic. However, traditional paper products have defects such as insufficient strength, poor barrier property, weak water resistance and the like, and are difficult to meet the needs of high-end packaging such as food and electronics. The current common modification methods mostly adopt surface coating or simple blending, which can improve the performance to a small extent, but have problems such as easy peeling of the coating, uneven dispersion of components, and difficulty in synergistic optimization of strength and barrier.

[0003] Microfibrillated cellulose (MFC) can enhance fiber bonding force and densify pore structure, and aerogel has excellent oxygen and water vapor barrier properties. The combination of the two becomes an important direction of paper-based modification. However, the existing technology generally adopts homogenization compounding without structure gradient design, resulting in insufficient barrier of the surface layer and decreased strength of the core layer. Meanwhile, MFC and aerogel are only physically combined, the interface bonding force is weak, and problems such as aggregation, powdering and poor stability easily occur. In addition, there is a lack of in-situ micro-crosslinking strengthening means, and the comprehensive performance is difficult to meet the standards.

[0004] In order to solve the above-mentioned bottlenecks, it is urgent to develop a high-strength barrier paper product with gradient density structure and MFC-aerogel in-situ micro-crosslinking, realize double strengthening of structure and interface, and break through the performance limitations of traditional paper-based packaging. SUMMARY

[0005] In view of the above-mentioned problems, the application provides a high-strength barrier modified paper product packaging material and a preparation method thereof. The material realizes synergistic enhancement through gradient density structure and microfibrillated cellulose-aerogel in-situ micro-crosslinking, has excellent mechanical strength and barrier performance, has stable interface bonding, uniform dispersion, and can be completely degraded, and can meet the complex application requirements of high-end environment-friendly packaging.

[0006] In order to achieve the above-mentioned purposes, the application adopts the following technical scheme: A high-strength barrier modified paper product packaging material is prepared from the following raw materials by weight: 100 parts of cellulose fiber, 5-15 parts of microfibrillated cellulose, 2-10 parts of aerogel, and 0.5-3 parts of crosslinking agent. The packaging material has a gradient density three-layer structure, the surface layer is a dense barrier layer rich in microfibrillated cellulose and aerogel, and the core layer is a high-strength support layer mainly composed of cellulose fiber; the microfibrillated cellulose and the aerogel form in-situ chemical crosslinking combination under the action of the crosslinking agent.

[0007] Optionally, the cellulose fiber is one or more of wood pulp fiber, waste paper pulp fiber, bamboo pulp fiber, and bagasse pulp fiber.

[0008] Optionally, the aerogel is hydrophobic modified SiO2 with a particle size of 50-200 nm and a specific surface area of ​​800-1200 m2 / g.

[0009] Optionally, the crosslinking agent is selected from one or more of polyamide epichlorohydrin, butanediol diglycidyl ether, citric acid, and sodium trimetaphosphate.

[0010] Optionally, the packaging material has a ring crush strength of 8.5-12.0 N·m / g, an oxygen permeability of 0.5-1.5 cm3 / (m2·d·atm), and a water vapor permeability of 3.0-8.0 g / (m2·d).

[0011] Optionally, the preparation method of the high-strength barrier modified paper packaging material is as follows: S1. Add cellulose fibers to water and decompose them in a decomposition machine at a speed of 3000-5000 rpm for 20-40 minutes to obtain a pulp suspension with a concentration of 2%-5%; add microfibrillated cellulose dispersion with a mass concentration of 1%-3% in proportion, and shear and mix them in a high-speed shear machine at a speed of 8000-12000 rpm for 15-30 minutes, controlling the concentration of the mixed pulp to be 1.5%-3%; S2. Take 30%-50% of the mixed slurry from step S1 as the surface base slurry, add 0.5%-2% aerogel aqueous dispersion, then add crosslinking agent, and ultrasonically disperse at 150-300W power for 20-40 minutes, with the dispersion temperature controlled at 25-40℃ to obtain the surface slurry. S3. Three-layer headbox papermaking is adopted, which integrates the surface pulp and the core pulp into a three-layer wet paper sheet, and controls the basis weight of the wet paper sheet to be 80-150g / m2. S4. Feed the three layers of wet paper into a hot press and cross-link them for 10-25 minutes at a pressure of 0.3-0.8MPa and a temperature of 60-120℃ to achieve in-situ chemical cross-linking of microfibrillated cellulose and aerogel. S5. Segmented low-temperature drying is adopted. The first stage drying temperature is 40-50℃ and the drying time is 30-60min. The second stage drying temperature is 60-80℃ and the drying time is 20-40min. After drying until the paper moisture content is ≤8%, it is calendered under 0.1-0.3MPa pressure for 1-3min to obtain the finished product.

[0012] Optionally, the preparation method of the microfibrillated cellulose dispersion in step S1 is as follows: the cellulose raw material is mechanically ground to a particle size of 50-200 nm, deionized water is added and ultrasonically dispersed for 10-20 min to prepare a stable dispersion with a mass concentration of 1%-3%.

[0013] Optionally, the preparation method of the aerogel aqueous dispersion in step S2 is as follows: add hydrophobic SiO2 aerogel powder to deionized water, add a dispersant accounting for 0.1%-0.5% of the aerogel mass, and ultrasonically disperse for 15-25 minutes to obtain a uniform dispersion; the dispersant is selected from Tween 80 or Span 60.

[0014] The beneficial effects of this invention are as follows: The packaging material prepared by this invention has excellent mechanical strength, with a ring crush strength of 8.5-12.0 N·m / g, and outstanding oxygen and water barrier properties, with an oxygen permeability as low as 0.5-1.5 cm3 / (m2·d·atm) and a water vapor permeability of only 3.0-8.0 g / (m2·d), effectively blocking external media; the gradient density structure and in-situ micro-crosslinking work synergistically to ensure uniform dispersion of MFC and aerogel and stable interfacial bonding, completely solving the problems of easy dust shedding and agglomeration of traditional modified paper; the material uses natural fiber as the base material, is plastic-free and biodegradable, and meets environmental protection policy requirements; at the same time, the preparation process is compatible with existing paper production lines, requiring no additional special equipment, is simple to operate, and has controllable costs, combining excellent performance and industrial feasibility, and is suitable for high-end packaging needs in multiple scenarios such as food and logistics. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0016] Figure 1 This is a bar chart comparing the ring crush strength of different samples in this invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] Example 1: This Example 1 describes a high-strength barrier modified paper packaging material, prepared from the following raw materials in parts by weight: Cellulose fiber: 100 parts wood pulp fiber, 8 parts microfibrillated cellulose; aerogel: 5 parts hydrophobically modified SiO2 aerogel; crosslinking agent: 1.5 parts polyamide epichlorohydrin (PAE). The preparation method of hydrophobically modified SiO2 aerogel is as follows: S1. Take 10 parts of the original SiO2 aerogel powder, add 100 parts of anhydrous ethanol, and ultrasonically disperse for 15 minutes at a power of 200W to form a uniform suspension. S2. Heat the suspension to 50°C and slowly add 2 parts of hexamethyldisilazane (HMDS) while stirring. Keep the temperature for 2 hours to allow HMDS to undergo a silanization reaction with the hydroxyl groups on the surface of SiO2 aerogel. S3. After the reaction is complete, centrifuge (8000 rpm, 10 min), collect the precipitate, wash it three times with anhydrous ethanol to remove unreacted HMDS, and vacuum dry it at 80℃ for 2 h to obtain hydrophobic modified SiO2 aerogel powder (water contact angle 125°±5°) for later use. The obtained hydrophobic modified SiO2 aerogel has a particle size of 123 nm and a specific surface area of ​​1007 m2 / g.

[0019] This embodiment describes a method for preparing a high-strength barrier modified paper packaging material, with the following specific preparation steps: S1. Take MFC, add 392 parts of deionized water, and process it in a high-speed shear machine at 20000 rpm for 3 min to prepare a stable dispersion with a mass concentration of 2%. S2. Take hydrophobically modified SiO2 aerogel dry powder, add 495 parts of deionized water, and then add 0.015 parts of Tween 80. Disperse the mixture ultrasonically at 250W power for 20 minutes (dispersion temperature 30℃) to prepare a uniform dispersion with a mass concentration of 1%. S3. Add wood pulp fibers to deionized water and decompose them in a desolvator at 4000 rpm for 30 minutes to obtain a pulp suspension with a concentration of 3%. S4. Add the MFC dispersion obtained in S1 to the pulp suspension in S3, and shear and mix in a high-speed shear machine at 10000 rpm for 20 min, controlling the concentration of the mixed pulp to be 2%; S5. Take 40% of the mixed slurry in S4 as the surface base slurry, add the aerogel aqueous dispersion and PAE prepared in S2, and ultrasonically disperse at 250W power for 30 minutes to obtain the surface slurry. S6. The three-layer headbox synchronous papermaking process is adopted, and the core layer pulp and the two side surface pulp are simultaneously fed onto the wire and formed into a three-layer wet paper sheet with gradient density, controlling the basis weight of the finished paper sheet to 120g / m2. S7. Feed the three layers of wet paper into the hot press and cross-link them at a pressure of 0.5MPa and a temperature of 80℃ for 15 minutes to achieve in-situ chemical cross-linking of MFC and aerogel. S8. Segmented low-temperature drying is adopted. The first stage is dried at 45℃ for 40 minutes, and the second stage is dried at 70℃ for 30 minutes, until the moisture content of the paper is ≤8%. Then, it is calendered under 0.2MPa pressure for 2 minutes to obtain the finished product.

[0020] Example 2: This Example 2 describes a high-strength barrier modified paper packaging material, prepared from the following raw materials in parts by weight: Cellulose fiber: 100 parts wood pulp fiber, 12 parts microfibrillated cellulose, aerogel: 5 parts hydrophobically modified SiO2 aerogel, crosslinking agent: 1.5 parts polyamide epichlorohydrin; The preparation method of the hydrophobic modified SiO2 aerogel is the same as that in Example 1. The resulting hydrophobic modified SiO2 aerogel has a particle size of 123 nm and a specific surface area of ​​1007 m2 / g. The preparation method of a high-strength barrier modified paper packaging material in this embodiment is the same as that in Example 1, except that the amount of microfibrillated cellulose is adjusted to 12 parts.

[0021] Example 3: This Example 3 describes a high-strength barrier modified paper packaging material, prepared from the following raw materials in parts by weight: Cellulose fiber: 100 parts wood pulp fiber, 8 parts microfibrillated cellulose; aerogel: 8 parts hydrophobically modified SiO2 aerogel; crosslinking agent: 1.5 parts polyamide epichlorohydrin. The preparation method of the hydrophobic modified SiO2 aerogel is the same as that in Example 1. The resulting hydrophobic modified SiO2 aerogel has a particle size of 123 nm and a specific surface area of ​​1007 m2 / g. The preparation method of the high-strength barrier modified paper packaging material in this embodiment is the same as that in Example 1, except that the amount of hydrophobic modified SiO2 aerogel is adjusted to 8 parts.

[0022] Comparative Example 1: The packaging material of Comparative Example 1 was prepared from the following parts by weight of raw materials: Cellulose fiber: 100 parts wood pulp fiber, 8 parts microfibrillated cellulose; aerogel: 5 parts hydrophobically modified SiO2 aerogel; crosslinking agent: 1.5 parts polyamide epichlorohydrin. The preparation method of the hydrophobic modified SiO2 aerogel is the same as that in Example 1. The resulting hydrophobic modified SiO2 aerogel has a particle size of 123 nm and a specific surface area of ​​1007 m2 / g. In this comparative example, the preparation method of the packaging material is the same as that in Example 1. No layered papermaking is performed, and the surface slurry and core slurry are not separated. All the mixed slurries are uniformly mixed and then formed using a single-layer headbox.

[0023] Comparative Example 2: The packaging material of Comparative Example 2 was prepared from the following parts by weight of raw materials: Cellulose fiber: 100 parts wood pulp fiber, 8 parts microfibrillated cellulose; aerogel: 5 parts hydrophobically modified SiO2 aerogel; crosslinking agent: 1.5 parts polyamide epichlorohydrin. The preparation method of the hydrophobic modified SiO2 aerogel is the same as that in Example 1. The resulting hydrophobic modified SiO2 aerogel has a particle size of 123 nm and a specific surface area of ​​1007 m2 / g. In this comparative example, the preparation method of the packaging material is the same as that in Example 1, except that the hot-press crosslinking treatment in step S7 is not performed, and the material is directly put into the drying step after layering and papermaking.

[0024] Comparative Example 3: The packaging material of Comparative Example 3 was prepared from the following parts by weight of raw materials: Cellulose fiber: 100 parts wood pulp fiber, 8 parts microfibrillated cellulose, aerogel: 5 parts SiO2 aerogel, crosslinking agent: 1.5 parts polyamide epichlorohydrin; In this comparative example, the preparation method of the packaging material is the same as that in Example 1, except that the hydrophobic modified SiO2 aerogel is replaced with unmodified original SiO2 aerogel. The unmodified original SiO2 aerogel has a particle size of 125 nm and a specific surface area of ​​1003 m2 / g.

[0025] Performance testing 1. Ring crush strength test The ring crush strength test was performed according to the national standard GB / T 2679.8-2017. The specific steps were as follows: 10 samples with dimensions of 152mm × 12.7mm were cut from the finished paper sheets prepared in the examples and comparative examples along both the longitudinal and transverse directions, ensuring that the sample edges were flat, burr-free, and undamaged; the cut samples were placed in a standard environment at 23℃ and 50% relative humidity for 24 hours to equilibrate; then the samples were placed between the upper and lower pressure plates of the ring crush strength tester, aligning the sample axis with the center line of the pressure plate, ensuring that the sample was placed vertically and without skewing; the tester was started, and pressure was applied to the sample at a compression speed of 1mm / min until the sample was crushed, and the maximum pressure value displayed by the tester was recorded; finally, the average maximum pressure value of the longitudinal and transverse samples was calculated, and the ring crush strength was obtained by converting the sample basis weight (unit: g / m2) measured in GB / T 451.2-2002, with the unit being N·m / g.

[0026] Table 1. Ring crush strength test data for different samples

[0027] The ring crush strengths of Examples 1-3 were 9.5-11.2 N·m / g, significantly higher than the 6.5-7.2 N·m / g of the comparative examples. Among them, Example 2, with optimized MFC dosage, showed the best performance. This result indicates that reasonable control of MFC dosage can strengthen the interfiber bonding force. Combined with gradient structure design and hot-press crosslinking process, it can further improve the structural density of paper products and effectively improve mechanical load-bearing performance. In contrast, the comparative examples, lacking these key designs, showed significantly insufficient ring crush strength due to loose fiber bonding.

[0028] 2. Oxygen permeability test The oxygen transmission rate test was performed according to the national standard GB / T 19789-2005. The specific steps were as follows: the paper product samples prepared in the examples and comparative examples were cut into circular samples with a diameter of 100 mm and placed in a standard environment with a temperature of 23℃ and a relative humidity of 50% for 48 hours to adjust the condition; the treated samples were placed in the test chamber of the gas transmission rate tester, so that the two sides of the sample formed the oxygen side and the carrier gas side respectively. The temperature of the test chamber was controlled at 23℃ and the relative humidity at 50%. After the system stabilized, the oxygen content passing through the sample was detected by the sensor, and the oxygen transmission amount per unit area and per unit time was recorded and calculated. Finally, the oxygen transmission rate was obtained, and the unit was cm3 / (m2·d·atm).

[0029] Table 2 Oxygen Transmission Rate Test Data for Different Samples

[0030] The oxygen permeability of the examples was as low as 0.6-1.0 cm³ / (m²·d·atm), far superior to the 2.3-3.1 cm³ / (m²·d·atm) of the comparative examples. Example 3, with optimized aerogel dosage, showed the best barrier effect. It is evident that the modified aerogel forms a highly efficient oxygen barrier layer inside the paper product. Combined with the gradient structure and the optimized permeation path through thermo-pressing crosslinking, it can significantly hinder the penetration of oxygen molecules. In contrast, the comparative examples, due to their loose structure and the inability of the unmodified aerogel to function effectively, resulted in a significant decrease in barrier performance.

[0031] 3. Water vapor transmission rate test The water vapor transmission rate test was performed according to the dynamic airflow method in the national standard GB / T 22921-2008 "Determination of Water Vapor Transmission Rate of Paper and Paperboard Sheet Materials - Dynamic Airflow Method and Static Gas Method". The specific steps were as follows: Ten representative samples of the required size were cut from the finished paper sheets prepared in the examples and comparative examples (ensuring the samples were undamaged, creased, and clearly showing the front and back sides). According to GB / T 10739-2023, the samples were placed at a temperature of (23.0±1.0)℃ and a relative humidity of (50.0±2.0)%. In a standard environment, adjust the state to equilibrium (the interval between two weighings is ≥1h, and the mass difference is ≤0.25% of the previous mass); inject a saturated salt solution into the wet chamber of the water vapor transmission rate tester to maintain the predetermined humidity, clamp the sample between the dry and wet chambers and ensure a seal, set the test temperature to 23℃, and continuously purge the dry chamber with dry inert carrier gas. After the system stabilizes, detect the amount of water vapor carried by the carrier gas through the sensor, record the stable data, and calculate the amount of water vapor transmitted per unit area and per unit time to obtain the water vapor transmission rate, which is in g / (m2·d).

[0032] Table 3. Test data on water vapor transmission rate of different samples

[0033] The water vapor transmission rate of the examples was 3.8-5.2 g / (m²·d), far lower than that of the comparative examples (9.6-11.5 g / (m²·d). Example 3 demonstrated the best moisture-proof effect due to the optimized aerogel dosage. This indicates that the proper application of aerogel can inhibit the capillary penetration and diffusion of water vapor, and the gradient structure further optimizes the moisture absorption barrier properties. In contrast, the comparative examples, lacking an effective barrier design, allowed water vapor to easily penetrate through the internal pores, resulting in poor moisture-proof performance.

[0034] 4. Powder Loss Rate Test The dust shedding rate test procedure is as follows: Cut the paper product samples prepared in the examples and comparative examples into 100mm×100mm square samples. According to the requirements of GB / T 10739-2023, adjust the state for 24 hours under standard atmospheric conditions of temperature (23.0±1.0)℃ and relative humidity (50.0±2.0)%. Weigh the initial mass m1 of the sample using an analytical balance with an accuracy of 0.0001g. Place the sample in a reciprocating shaker and shake it at a frequency of 30 times / min for 10min (amplitude 20mm, to ensure no damage to the paper base). After removing the sample, gently sweep away the loose powder on the surface with a soft brush. Weigh the sample mass m2 again. Calculate the dust shedding rate using the formula: Dust shedding rate (%) = [(m1−m2) / m1]×100%. Test each group of samples in parallel 5 times and take the average value as the final test result.

[0035] Table 4. Test data on powder loss rate of different samples

[0036] The dust loss rate of the examples was only 0.2%-0.4%, which is at a low and stable level, while the dust loss rate of Comparative Example 2 (without hot-press crosslinking) and Comparative Example 3 (with unmodified aerogel) was as high as 3.8%-4.2%. This confirms that the hot-press crosslinking process can enhance the interfacial bonding strength between the fiber and the aerogel, and the addition of MFC also plays an auxiliary role in improving the bonding strength, effectively preventing the surface material from falling off. However, the comparative examples are prone to dust loss under external disturbances due to the loose interfacial bonding.

[0037] 5. Contact Angle Test The contact angle test was performed according to TAPPI T 458 cm-04 and ASTM D724-99 (2003). First, the paper / paperboard sample was cut into 50mm×50mm flat pieces and conditioned to equilibrium for 24 hours under standard atmospheric conditions of (23.0±1.0)℃ and (50.0±2.0)% relative humidity, according to GB / T 10739-2023. The sample was laid flat and fixed on the contact angle measuring instrument platform without wrinkles or damage. 3-5μL of deionized water (23℃ surface tension ≥72mN / m) was taken with a micro-syringe and dropped at a distance of 0.5±0.1mm from the sample surface to form a stable droplet. The droplet outline was captured by a high-speed camera system and the instrument automatically calculated the static water contact angle. Each sample was tested in parallel at 5 different positions. The arithmetic mean was taken after removing the maximum and minimum values ​​and the unit was °.

[0038] Table 5. Contact Angle Test Data for Different Samples

[0039] The water contact angle of the example was stable at 124°-126°, exhibiting excellent hydrophobic properties, while the contact angle of the unmodified aerogel in Comparative Example 3 was only 72°, showing significant hydrophilicity. This indicates that the present technology, through aerogel modification and formulation optimization, forms a stable hydrophobic interface on the surface of paper products, reducing hydrophilicity. Furthermore, the gradient structure and hot-pressing process do not damage the integrity of the hydrophobic layer, fully ensuring the surface hydrophobic effect.

[0040] 6. Moisture content test The moisture content test was performed according to GB / T 462-2023 "Determination of Moisture Content in Analytical Samples of Paper, Paperboard and Pulp". First, the samples were conditioned to equilibrium under standard atmospheric conditions of (23.0±1.0)℃ and (50.0±2.0)% relative humidity, as per GB / T 10739-2023. Representative samples were cut, and the initial mass m0 of the samples was weighed using an analytical balance with an accuracy of 0.0001g. The samples were then laid flat in an electric thermostatic drying oven preheated to (105±2)℃ and dried to constant weight under ventilation. After removal, the samples were immediately placed in a desiccator to cool to room temperature (approximately 30 minutes), and the mass m1 of the cooled samples was weighed again. The moisture content was calculated using the formula: Moisture Content (%) = [(m0−m1) / m0]×100%. Each group of samples was tested in parallel three times, and the average value was taken as the final test result.

[0041] Table 6. Test data on moisture content of different samples

[0042] The equilibrium moisture content of the example was controlled at 5.7%-6.1%, which is within the suitable range of 5%-9% for paper packaging materials and lower than that of the comparative example (7.3%-8.3%). This indicates that the optimized formulation of MFC and modified aerogel, combined with a gradient structure and hot-press crosslinking process, improves the hygroscopic stability of paper products, enabling them to maintain a low moisture content under standard conditions. In contrast, the comparative example, due to insufficient compatibility between its structure and filler, exhibits stronger hygroscopic capacity and a higher moisture content.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-strength barrier modified paper packaging material, characterized in that, The packaging material is prepared from the following raw materials in parts by weight: 100 parts cellulose fiber, 5-15 parts microfibrillated cellulose, 2-10 parts aerogel, and 0.5-3 parts crosslinking agent; The packaging material has a gradient density three-layer structure. The outer layer is a dense barrier layer rich in microfibrillated cellulose and aerogel, and the core layer is a high-strength support layer mainly composed of cellulose fibers. The microfibrillated cellulose and aerogel form an in-situ chemical cross-linking bond under the action of a cross-linking agent.

2. The high-strength barrier modified paper packaging material according to claim 1, characterized in that, The cellulose fiber is one or more of wood pulp fiber, waste paper pulp fiber, bamboo pulp fiber, and bagasse pulp fiber.

3. The high-strength barrier modified paper packaging material according to claim 1, characterized in that, The aerogel is a hydrophobic modified SiO2 with a particle size of 50-200 nm and a specific surface area of ​​800-1200 m2 / g.

4. The high-strength barrier modified paper packaging material according to claim 1, characterized in that, The crosslinking agent is selected from one or more of polyamide epichlorohydrin, butanediol diglycidyl ether, citric acid, and sodium tripolyphosphate.

5. A high-strength barrier modified paper packaging material according to any one of claims 1-4, characterized in that, The packaging material has a ring crush strength of 8.5-12.0 N·m / g, an oxygen permeability of 0.5-1.5 cm3 / (m2·d·atm), and a water vapor permeability of 3.0-8.0 g / (m2·d).

6. A method for preparing a high-strength barrier modified paper packaging material, used to prepare the high-strength barrier modified paper packaging material according to any one of claims 1-5, characterized in that, The specific preparation method is as follows: S1. Add cellulose fibers to water and decompose them in a decomposition machine at a speed of 3000-5000 rpm for 20-40 minutes to obtain a pulp suspension with a concentration of 2%-5%; add microfibrillated cellulose dispersion with a mass concentration of 1%-3% in proportion, and shear and mix them in a high-speed shear machine at a speed of 8000-12000 rpm for 15-30 minutes, controlling the concentration of the mixed pulp to be 1.5%-3%; S2. Take 30%-50% of the mixed slurry from step S1 as the surface base slurry, add 0.5%-2% aerogel aqueous dispersion, then add crosslinking agent, and ultrasonically disperse at 150-300W power for 20-40 minutes, with the dispersion temperature controlled at 25-40℃ to obtain the surface slurry. S3. Three-layer headbox papermaking is adopted, which integrates the surface pulp and the core pulp into a three-layer wet paper sheet, and controls the basis weight of the wet paper sheet to be 80-150g / m2. S4. Feed the three layers of wet paper into a hot press and cross-link them for 10-25 minutes at a pressure of 0.3-0.8MPa and a temperature of 60-120℃ to achieve in-situ chemical cross-linking of microfibrillated cellulose and aerogel. S5. Segmented low-temperature drying is adopted. The first stage drying temperature is 40-50℃ and the drying time is 30-60min. The second stage drying temperature is 60-80℃ and the drying time is 20-40min. After drying until the paper moisture content is ≤8%, it is calendered under 0.1-0.3MPa pressure for 1-3min to obtain the finished product.

7. The method for preparing a high-strength barrier modified paper packaging material according to claim 6, characterized in that, The preparation method of the microfibrillated cellulose dispersion in step S1 is as follows: the cellulose raw material is mechanically ground to a particle size of 50-200 nm, deionized water is added and ultrasonically dispersed for 10-20 min to prepare a stable dispersion with a mass concentration of 1%-3%.

8. The method for preparing a high-strength barrier modified paper packaging material according to claim 6, characterized in that, The preparation method of the aerogel aqueous dispersion in step S2 is as follows: add hydrophobic SiO2 aerogel powder to deionized water, add a dispersant accounting for 0.1%-0.5% of the aerogel mass, and ultrasonically disperse for 15-25 minutes to obtain a uniform dispersion; the dispersant is selected from Tween 80 or Span 60.

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