Bio-based high-barrier waterproof and oilproof paper-based packaging material and preparation method thereof

Abstract

The invention discloses a bio-based high-barrier, waterproof and oilproof paper-based packaging material and a preparation method of the bio-based high-barrier, waterproof and oilproof paper-based packaging material, and belongs to the technical field of packaging materials. And further performing ionic crosslinking on the paint by using metal ions to obtain a crosslinked coating. Natural rubber or epoxidized natural rubber provides better water resistance; the nano cellulose provides excellent gas resistance and oil resistance; and ionic crosslinking can further improve the barrier property of the coating, so that the paper-based packaging material with high barrier property, water resistance and oil resistance is prepared, the raw materials of the paper-based packaging material with high barrier property, water resistance and oil resistance are all derived from bio-based materials, and the paper-based packaging material is degradable, does not pollute the environment, is simple in preparation method and is suitable for large-scale industrial application.

Description

Technical Field

[0001] The invention relates to a packaging material, in particular to a bio-based high-barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, belonging to the technical field of packaging materials. Background Art

[0002] The extensive use of non-degradable plastic packaging materials has placed a serious burden on the environment. With the release of "plastic bans" by countries and organizations such as China and the European Union, the sustainable development concept of "replacing plastic with paper" has received more attention. However, paper has poor barrier properties and water resistance, especially in high humidity environments, and its performance decreases rapidly. Therefore, it is usually necessary to coat the surface or compound it with other materials to improve its barrier properties, water and oil resistance, and thus meet the use requirements in the high barrier field.

[0003] In order not to affect the bio-based and degradable characteristics of paper packaging, the use of bio-based and degradable materials to prepare coatings is also the focus of research and attention in related fields. Natural latex or epoxidized natural rubber is a bio-based renewable polymer derived from plants. As a non-polar material, it is widely used in waterproof coatings, adhesives, etc. However, natural rubber has poor gas barrier properties and is not suitable for use as a coating for paper-based packaging materials alone. Cellulose is one of the most abundant biomass materials known on the earth. It has a wide range of sources and is renewable and degradable. Nanocellulose extracted from cellulose is a new type of nanomaterial with excellent mechanical properties, biocompatibility and other characteristics. At the same time, due to the strong hydrogen bonding between nanocellulose and other factors, nanocellulose film has excellent gas barrier properties, thus having broad application prospects in advanced functional materials, food packaging and other fields. However, due to its hydrophilic characteristics, nanocellulose has poor water barrier properties, and its various properties drop sharply under high humidity conditions. In addition, in the prior art, the raw materials need to be screened and filtered, and crushed to avoid particles inside that cannot be crushed. Therefore, a bio-based high-barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof are designed to solve the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a bio-based high-barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] A bio-based high-barrier, waterproof and oil-proof paper-based packaging material, comprising base paper and a high-barrier waterproof and oil-proof coating;

[0007] The high-barrier waterproof and oil-proof coating comprises the following raw materials in parts by weight: 100 parts of natural rubber or epoxidized natural rubber, 5-60 parts of nanocellulose, and 0.5-20 parts of an ion crosslinking agent.

[0008] Preferably, the natural rubber or epoxidized natural rubber is derived from latex, has a solid content of 15-60%, and the epoxidation degree of the epoxidized natural rubber is 10-50%;

[0009] The nanocellulose is one or both of cellulose nanocrystals and cellulose nanofibrils;

[0010] The ionic crosslinking agent is one or more of ferric chloride, calcium chloride and zinc chloride.

[0011] A method for preparing a bio-based high-barrier, waterproof and oil-proof paper-based packaging material, characterized by:

[0012] The method comprises the following preparation steps:

[0013] S1. adding the nanocellulose dispersion to natural rubber latex or epoxidized natural rubber latex, and using ultrasonic dispersion after mechanical stirring to uniformly mix the nanocellulose and rubber latex;

[0014] S2. Dissolve 0.5-20 parts of an ionic crosslinking agent in water, add dropwise to the mixed dispersion obtained in S1 and disperse evenly to obtain a bio-based high barrier waterproof and oil-proof coating;

[0015] S3. The bio-based high barrier, waterproof and oil-proof coating obtained in S2 is evenly coated on the surface of kraft paper, and after drying, a bio-based high barrier, waterproof and oil-proof paper-based packaging material is obtained.

[0016] Preferably, the amount of nanocellulose is 10-50% of the mass of the rubber;

[0017] The coating process is one or more of dipping, blade coating or spraying.

[0018] Preferably, in S1, an automatic dosing device is used when adding natural latex or epoxidized natural latex, and the automatic dosing device includes a protective shell provided at the upper end of the weighing device, a connecting plate 1 is slidably connected to the inner side of the front end of the protective shell, a storage tank is fixedly connected to the upper end of the protective shell, a storage cover is movably connected to the upper end of the storage tank, a first leakage tank is fixedly connected to the lower end of the storage tank, a first rolling block is movably connected to the inner side of the first leakage tank, a second leakage tank is fixedly connected to the lower end of the first leakage tank, a second rolling block is movably connected to the inner side of the second leakage tank, a drainage tank is fixedly connected to the lower end of the second leakage tank, a first drainage port is provided at the lower end of the drainage tank, a first latch is provided at the lower end of the connecting plate 1, a baffle 1 is movably connected to the first latch, a baffle 2 is provided above the baffle 1, the baffle 2 slides at the lower end of the storage tank, and the baffle 1 slides at the lower end of the drainage tank.

[0019] Preferably, two groups of first movable blocks are fixedly connected to the outer side of the storage tank, a second movable block is movably connected between the two groups of the first movable blocks via a rotating shaft, one end of the second movable block is fixedly connected to the storage cover, and a second handle is fixedly connected to the upper end of the storage cover;

[0020] A support plate 2 is provided on one side of the storage groove, a first guide plate with a certain inclination angle is fixedly connected to the lower end of the storage groove, the first guide plate is fixedly connected to the first drain groove, a support plate 1 is provided on one side of the first drain groove, a second guide plate with a certain inclination angle is fixedly connected to the lower end of the first drain groove, the second guide plate is fixedly connected to the second drain groove, and the hole on the second drain groove is smaller than the hole on the first drain groove.

[0021] Preferably, the support plate 2 and the support plate 1 are both fixedly connected to the protective shell, a limiting groove 1 is provided on the inner side of the front end of the protective shell, the connecting plate 1 slides in the limiting groove 1, the upper end of the connecting plate 1 is fixedly connected to the first connecting rope and the second connecting rope, the front end of the connecting plate 1 is fixedly connected to the handle 1, the rear end of the connecting plate 1 is fixedly connected to the connecting block, the connecting block is fixedly connected to the first latch tooth, and the connecting plate 1 is L-shaped;

[0022] The first connecting rope passes through the upper side of the second support plate and is fixedly connected to the first rolling block, the second connecting rope passes through the upper side of the first support plate and is fixedly connected to the second rolling block, the first rolling block is adapted to the first leakage groove, and the second rolling block is adapted to the second leakage groove.

[0023] Preferably, a first slide groove is provided on the outer side of the front end of the protective shell, a second slide groove is provided on the inner wall of the front end of the protective shell, the handle slides inside the first slide groove, and the connecting block is slidably connected to the second slide groove;

[0024] A fixing plate is fixedly connected between one side of the protective shell and the drainage groove, a rotating rod 1 and a rotating rod 2 are rotatably connected to the fixing plate, and the fixing plate is L-shaped;

[0025] A first gear is meshed with one side of the first tooth, and the first gear is fixedly connected to the rotating rod 1. One end of the rotating rod 1 is fixedly connected to the second gear through a fixing plate. A third gear is meshed with the lower end of the second gear, and the third gear is fixedly connected to the rotating rod 2. One end of the rotating rod 2 is fixedly connected to the fourth gear through a fixing plate. A second gear is meshed with one side of the fourth gear, and the second gear is fixedly connected to the baffle 1.

[0026] Preferably, one side of the second latch tooth and the baffle plate 1 is fixedly connected with a connecting plate 2, the connecting plate 2 is fixedly connected with the baffle plate 2, a third slide groove and a fourth slide groove are provided on the inner wall of the rear end of the protective shell, the baffle plate 2 slides inside the third slide groove, the second latch tooth and the baffle plate 1 slide inside the fourth slide groove, a limiting groove 2 is provided on the inner side of the rear end of the protective shell, and the connecting plate 2 slides inside the limiting groove 2;

[0027] The baffle plate 1 is provided with a second drainage port, and the second drainage port is the same size as the first drainage port.

[0028] Beneficial technical effects of the present invention:

[0029] The present invention provides a bio-based high-barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof. By holding the handle one and pulling it downward, the handle one will drive the connecting plate one to slide downward. When the connecting plate one moves downward, the first rolling block and the second rolling block will be pulled out of the first leakage groove and the second leakage groove respectively. The connecting plate one moves downward so that the first latch tooth also moves downward. At the same time, the first latch tooth meshes with the first gear to make it rotate. The first gear is fixedly connected to the second gear, so that the second gear can rotate accordingly. The second gear meshes with the third gear to drive it to rotate. The third gear is fixedly connected to the fourth gear, and the fourth gear will also rotate. The fourth gear will drive the second latch tooth to move through meshing, and move the second drainage port provided on the baffle plate one fixedly connected thereto to the bottom of the first drainage port. When the baffle plate one moves, the baffle plate two will also move out from the bottom of the storage tank. The raw materials stored in the storage tank will enter the first leakage groove along the first drainage plate. When the handle one is released, the first rolling block falls into the first leakage groove due to its own gravity. , and at the same time, the connecting plate 1 is driven to move upward, and the first latching tooth fixedly connected to the connecting plate 1 also moves upward, so that the baffle plate 2 moves back to the bottom of the storage tank to block it, so that the raw materials no longer flow out, and the first crushing block falls into the first leakage tank, crushes the raw materials in the first leakage tank, and the handle 1 is pulled downward again, and the crushed raw materials fall from the hole along the second guide plate into the second leakage tank, and the handle 1 is released, and the second crushing block falls into the second leakage tank due to its gravity, crushes the raw materials again, and the crushed raw materials flow out of the hole. Gathered in the drainage trough, when the first drainage port and the second drainage port are aligned, the raw materials flow into the container. When not in use, the second drainage port will be moved away from below the first drainage port, and the baffle will block the first drainage port so that the raw materials will no longer flow out, so that the raw materials are in a closed space to avoid pollution. The first rolling block and the second rolling block can roll the raw materials to facilitate the use of the raw materials and avoid the problem of agglomeration. The weighing device can weigh the weight of the raw materials, and this process is repeated until the required weight of the raw materials is taken out.

[0030] The raw materials used in the present invention are all derived from bio-based materials, which are renewable and degradable. No organic solvent is used in the entire process, so the present invention is environmentally friendly and has high safety in use.

[0031] Based on the synergistic effect of the water barrier property of bio-based rubber and the gas barrier property of nanocellulose, the present invention further improves the comprehensive performance of the coating through cross-linking, thereby realizing the preparation of high-barrier, waterproof and oil-proof paper-based packaging materials. At the same time, the bio-based latex in the coating can also act as an adhesive, avoiding the bonding process and reducing production costs.

[0032] The invention adopts a simple physical mixing process, and the preparation method is simple, efficient, practical and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 It is a partial structural cross-sectional view of the present invention;

[0035] Figure 3 It is a partial structural cross-sectional view of the present invention;

[0036] Figure 4 It is a partial structural cross-sectional view of the present invention;

[0037] Figure 5 It is a partial structural schematic diagram of the present invention;

[0038] Figure 6 It is a partial structural cross-sectional view of the present invention;

[0039] Figure 7 It is a partial structural schematic diagram of the present invention;

[0040] Figure 8 It is a schematic diagram of the enlarged structure of part A of the present invention;

[0041] Fig. 9 It is a schematic diagram of the enlarged structure of part B of the present invention;

[0042] Fig.10 The scanning electron microscope surface photos of Example 1 and Example 2;

[0043] Fig.11 The scanning electron microscope surface photos of Example 3 and Example 4;

[0044] Fig.12 This is a scanning electron microscope surface photograph of Comparative Example 1;

[0045] Fig.13 The oil resistance of base paper, comparative example 1 and different embodiments.

[0046] In the figure: 1, weighing device; 2, protective shell; 3, first slide slot; 4, storage slot; 5, storage cover; 6, first guide plate; 7, first drain slot; 8, support plate 1; 9, second guide plate; 10, second drain slot; 11, drainage slot; 12, first drainage port; 13, support plate 2; 14, limit slot 1; 15, connecting plate 1; 16, handle 1; 17, second slide slot; 18, connecting block; 19, first latch; 20, rotating rod 1; 21, first gear; 22 , the second gear; 23, the third gear; 24, the second rotating rod; 25, the fourth gear; 26, the second latch; 27, the first baffle; 28, the second drainage port; 29, the second connecting plate; 30, the second baffle; 31, the first connecting rope; 32, the second connecting rope; 33, the first rolling block; 34, the second rolling block; 35, the third slide; 36, the fourth slide; 37, the fixed plate; 38, the second limiting groove; 39, the second handle; 40, the first movable block; 41, the second movable block. DETAILED DESCRIPTION

[0047] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0048] Raw material information used in the embodiments and comparative examples:

[0049] Nanocellulose whiskers (CNC): purchased from Qihong Technology, with a diameter of 4-10 nm, a length of 100-500 nm, and a solid content of 4%; Nanocellulose fibrils (CNF): purchased from Qihong Technology, with a diameter of 4-10 nm, a length of 1-3 um, and a solid content of 1%.

[0050] Epoxidized natural rubber latex: commercially available, with epoxidation degrees of 24%, 30%, and 40% (abbreviated as ENR-24, ENR-30, and ENR-40, respectively), and a solid content of 20%.

[0051] Ferric chloride hexahydrate (FeCl3·6H2O): analytical grade, purchased from Fuchen Chemical Reagent Co., Ltd.

[0052] Kraft paper: prepared by the laboratory, specification is 80g / m 2 .

[0053] Specific experimental steps or conditions not specified in the examples can be carried out according to conventional operations or conditions described in the literature in the field. The raw materials or instruments used are all conventional products that can be obtained commercially, including but not limited to the raw materials or instruments used in the examples of this application.

[0054] Example 1

[0055] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0056] S1. Weigh 50g of ENR-40 with a solid content of 20%, slowly add 75g of CNC with a solid content of 4% (equivalent to 30% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0057] S2. Weigh 0.1 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper. Continue stirring for 30 minutes, then place it at 50 degrees Celsius while stirring and evaporating the water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0058] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0059] Example 2

[0060] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0061] S1. Weigh 50g of ENR-40 with a solid content of 20%, slowly add 75g of CNC with a solid content of 4% (equivalent to 30% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0062] S2. Weigh 0.3 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper, continue stirring for 30 minutes, and then place it at 50 degrees Celsius while stirring and evaporating water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0063] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0064] Example 3

[0065] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0066] S1. Weigh 50 g of ENR-40 with a solid content of 20%, slowly add 25 g of CNC with a solid content of 4% (equivalent to 10% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0067] S2. Weigh 0.1 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper. Continue stirring for 30 minutes, then place it at 50 degrees Celsius while stirring and evaporating the water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0068] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0069] Example 4

[0070] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0071] S1. Weigh 50 g of ENR-40 with a solid content of 20%, slowly add 100 g of CNF with a solid content of 1% (equivalent to 10% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0072] S2. Weigh 0.1 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper. Continue stirring for 30 minutes, then place it at 50 degrees Celsius while stirring and evaporating the water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0073] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0074] Example 5

[0075] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0076] S1. Weigh 50 g of ENR-24 with a solid content of 20%, slowly add 75 g of CNC with a solid content of 4% (equivalent to 30% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0077] S2. Weigh 0.1 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper. Continue stirring for 30 minutes, then place it at 50 degrees Celsius while stirring and evaporating the water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0078] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0079] Example 6

[0080] This embodiment provides a bio-based high barrier, waterproof and oil-proof paper-based packaging material and a preparation method thereof, comprising the following steps:

[0081] S1. Weigh 50g of ENR-40 with a solid content of 20%, slowly add 75g of CNC with a solid content of 4% (equivalent to 30% of the mass of ENR) under mechanical stirring, and continue stirring for 1 hour to achieve uniform dispersion;

[0082] S2. Weigh 0.1 g of FeCl3·6H2O, dissolve it in 10 mL of water, and slowly add it to the composite emulsion prepared in step S1 with constant stirring using a dropper. Continue stirring for 30 minutes, then place it at 50 degrees Celsius while stirring and evaporating the water to make the final solid content in the mixed dispersion 10%, and finally ultrasonically disperse it for 30 minutes and remove bubbles to obtain a uniformly dispersed bio-based high barrier coating;

[0083] S3. The bio-based high barrier coating obtained in S2 is evenly coated on the surface of kraft paper by blade coating, and the coating thickness is controlled to remain consistent. After drying, the next coating is performed. This step is repeated 3 times to obtain a bio-based high barrier, waterproof and oil-proof paper-based packaging material.

[0084] Comparative Example 1

[0085] This comparative example provides a coating containing only bio-based rubber and a preparation method thereof, comprising the following steps:

[0086] S1. 50 g of water was added to 50 g of ENR-40 emulsion having a solid content of 20%, mechanically stirred for 30 minutes, and then ultrasonically dispersed and defoamed for 1 hour to uniformly disperse the epoxidized natural rubber to obtain a bio-based rubber coating;

[0087] S2. The bio-based rubber coating obtained in S1 is evenly coated on the surface of kraft paper by blade coating, and the coating thickness is controlled to be consistent. After drying, the next coating is performed. This step is repeated 5 times to obtain a bio-based rubber-coated paper-based packaging material.

[0088] Comparative Example 2

[0089] This comparative example provides a coating containing only CNF and a preparation method thereof, comprising the following steps:

[0090] S1. 50 g of water was added to 50 g of a CNF dispersion having a solid content of 1%, and the mixture was stirred for 30 minutes, and then ultrasonically dispersed and defoamed for 1 hour to uniformly disperse the CNF to obtain a nanocellulose coating;

[0091] S2. The nanocellulose coating obtained in S1 is evenly coated on the surface of kraft paper by blade coating, the coating thickness is controlled to be consistent, and the next coating is performed after drying. This step is repeated 5 times to obtain a nanocellulose-coated paper-based packaging material.

[0092] Performance Testing

[0093] The bio-based high barrier, waterproof and oil-proof paper-based packaging materials obtained in the examples and comparative examples were subjected to performance tests, and the test results are shown in Table 1;

[0094] Table 1. Performance indicators of bio-based high barrier waterproof and oil-proof food packaging paper

[0095]

[0096]

[0097] As can be seen from Table 1, compared with the base paper, the pure epoxidized natural rubber and pure nanocellulose used as coating in the comparative example can improve the barrier properties of the paper to a certain extent. Compared with the comparative example, it can be seen that the water vapor permeability, Cobb water value and Cobb oil value of the coated paper-based material are greatly reduced, indicating that under the synergistic effect of rubber and nanocellulose, and through metal ion cross-linking, the molecular chain arrangement density of the coating can be improved, thereby improving the barrier properties and stability of the coated paper.

[0098] It should be noted that the bio-based high barrier, waterproof and oil-proof paper-based packaging material provided by the present invention is not just coated with a layer of coating, but has been specially designed and considered. Natural rubber is a natural polymer compound with the characteristics of high elasticity, high elongation, hydrophobicity, environmental friendliness, etc., and can be used for paper surface coating to improve the mechanical strength of paper and the barrier performance of paper to water. However, since paper is a hydrophilic material, the affinity of natural rubber and paper is poor, and the two cannot be tightly combined. Therefore, the natural rubber is epoxidized and modified, and the introduction of epoxy groups improves the molecular polarity, which is conducive to the natural rubber entering the inside of the paper to form a tight cross-linked network, improves the affinity with the paper, and avoids the use of an adhesive layer. Nanocellulose is a hydrophilic substance with a high affinity for paper. It can also be combined with epoxidized natural rubber, which is conducive to nanocellulose entering the inside of the paper to fill the gaps in the paper and block water vapor and oxygen from penetrating. Therefore, mixing nanocellulose and epoxidized natural rubber and then coating the paper surface can greatly improve the barrier of paper to oxygen and water vapor, and the waterproof and oil-proof properties of its surface are also greatly enhanced.

[0099] The automatic feeding device adopted includes a weighing device 1, a protective shell 2 is provided at the upper end of the weighing device 1, a connecting plate 15 is slidably connected to the inner side of the front end of the protective shell 2, a storage tank 4 is fixedly connected to the upper end of the protective shell 2, a storage cover 5 is movably connected to the upper end of the storage tank 4, a first drain slot 7 is fixedly connected to the lower end of the storage tank 4, a first rolling block 33 is movably connected to the inner side of the first drain slot 7, a second drain slot 10 is fixedly connected to the lower end of the first drain slot 7, a second rolling block 34 is movably connected to the inner side of the second drain slot 10, a drainage slot 11 is fixedly connected to the lower part of the second drain slot 10, a first drainage port 12 is opened at the lower end of the drainage slot 11, a first latch 19 is provided at the lower end of the connecting plate 15, the first latch 19 is movably connected to a baffle 1 27, a baffle 2 30 is provided above the baffle 1 27, the baffle 2 30 slides at the lower end of the storage slot 4, and the baffle 1 27 slides at the lower end of the drainage slot 11.

[0100] In this embodiment, two groups of first movable blocks 40 are fixedly connected to the outer side of the storage slot 4, and a second movable block 41 is movably connected between the two groups of first movable blocks 40 through a rotating shaft. One end of the second movable block 41 is fixedly connected to the storage cover 5, and a handle 2 39 is fixedly connected to the upper end of the storage cover 5.

[0101] Specifically, the storage cover 5 is opened through the second handle 39, the raw materials are stored in the storage tank 4, and the storage cover 5 is covered on the top of the storage tank 4 to store the raw materials in a sealed manner to prevent them from contacting the outside.

[0102] In this embodiment, a support plate 2 13 is provided on one side of the storage groove 4, and a first drain plate 6 with a certain inclination angle is fixedly connected to the lower end of the storage groove 4, and the first drain plate 6 is fixedly connected to the first drain groove 7, and a support plate 1 8 is provided on one side of the first drain groove 7, and a second drain plate 9 with a certain inclination angle is fixedly connected to the lower end of the first drain groove 7, and the second drain plate 9 is fixedly connected to the second drain groove 10, and the hole on the second drain groove 10 is smaller than the hole on the first drain groove 7.

[0103] Specifically, the raw materials in the storage tank 4 can be moved to the first drain tank 7 through the first drain plate 6 , and the raw materials in the first drain tank 7 can be moved to the second drain tank 10 through the second drain plate 9 .

[0104] In this embodiment, support plate 2 13 and support plate 1 8 are both fixedly connected to the protective shell 2, a limiting groove 14 is provided on the inner side of the front end of the protective shell 2, a connecting plate 15 slides in the limiting groove 14, the upper end of the connecting plate 15 is fixedly connected with a first connecting rope 31 and a second connecting rope 32, the front end of the connecting plate 15 is fixedly connected with a handle 16, the rear end of the connecting plate 15 is fixedly connected with a connecting block 18, the connecting block 18 is fixedly connected with the first latch tooth 19, and the connecting plate 15 is L-shaped.

[0105] The first connecting rope 31 passes through the upper side of the support plate 2 13 and is fixedly connected to the first rolling block 33, and the second connecting rope 32 passes through the upper side of the support plate 1 8 and is fixedly connected to the second rolling block 34. The first rolling block 33 is adapted to the first leakage groove 7, and the second rolling block 34 is adapted to the second leakage groove 10.

[0106] A first slide groove 3 is provided on the outer side of the front end of the protective shell 2 , and a second slide groove 17 is provided on the inner wall of the front end of the protective shell 2 . The handle 16 slides inside the first slide groove 3 , and the connecting block 18 is slidably connected to the second slide groove 17 .

[0107] Specifically, by holding the handle 16 and pulling it downward, the handle 16 will drive the connecting plate 15 to slide downward. When the connecting plate 15 moves downward, the first rolling block 33 and the second rolling block 34 will be pulled out from the first leakage groove 7 and the second leakage groove 10 respectively. The downward movement of the connecting plate 15 causes the first latch tooth 19 to move downward as well.

[0108] In this embodiment, a first gear 21 is meshed on one side of the first latch tooth 19, and the first gear 21 is fixedly connected to the rotating rod 20. One end of the rotating rod 20 is fixedly connected to the second gear 22 through the fixing plate 37. The lower end of the second gear 22 is meshed with a third gear 23. The third gear 23 is fixedly connected to the rotating rod 24. One end of the rotating rod 24 is fixedly connected to the fourth gear 25 through the fixing plate 37. One side of the fourth gear 25 is meshed with a second latch tooth 26, and the second latch tooth 26 is fixedly connected to the baffle 1 27.

[0109] Specifically, the first latch tooth 19 is engaged with the first gear 21 to rotate, the first gear 21 is fixedly connected with the second gear 22, and the second gear 22 will rotate accordingly, the second gear 22 is engaged with the third gear 23 to drive them to rotate, the third gear 23 is fixedly connected with the fourth gear 25, and the fourth gear 25 will also rotate, and the fourth gear 25 will drive the second latch tooth 26 to move through engagement.

[0110] In this embodiment, the second latch tooth 26 and one side of the baffle plate 1 27 are fixedly connected with a connecting plate 29, and the connecting plate 29 is fixedly connected with the baffle plate 2 30. The inner wall of the rear end of the protective shell 2 is provided with a third sliding groove 35 and a fourth sliding groove 36. The baffle plate 2 30 slides on the inside of the third sliding groove 35, and the second latch tooth 26 and the baffle plate 1 27 slide on the inside of the fourth sliding groove 36. A limiting groove 2 38 is provided on the inner side of the rear end of the protective shell 2, and the connecting plate 29 slides on the inside of the limiting groove 2 38.

[0111] Specifically, when the baffle plate 1 27 moves, the baffle plate 2 30 will also move out from the bottom of the storage tank 4 .

[0112] In this embodiment, a second drainage port 28 is formed on the baffle plate 1 27 , and the second drainage port 28 is the same size as the first drainage port 12 .

[0113] Specifically, the raw material flows into the container through the first inlet 12 and the second inlet 28 when they are aligned, and the weighing device weighs the weight of the raw material.

[0114] During operation, the raw materials are stored in the storage tank 4, and the container is placed above the weighing device 1 and below the baffle plate 27. The handle 16 is held and pulled downward, and the handle 16 drives the connecting plate 15 to slide downward. When the connecting plate 15 moves downward, the first rolling block 33 and the second rolling block 34 are pulled out of the first drain groove 7 and the second drain groove 10 respectively. The connecting plate 15 moves downward to make the first latch 19 move downward as well. At the same time, the first latch 19 meshes with the first gear 21 to make it rotate, and the first gear 21 and the second gear 22 are fixed. The second gear 22 is connected, and the second gear 22 rotates accordingly. The second gear 22 meshes with the third gear 23 to drive it to rotate. The third gear 23 is fixedly connected to the fourth gear 25, and the fourth gear 25 also rotates. The fourth gear 25 meshes with the second latch 26 to move, and the second drainage port 28 opened on the baffle plate 1 27 fixedly connected thereto is moved to the bottom of the first drainage port 12. When the baffle plate 1 27 moves, the baffle plate 2 30 is also moved out from the bottom of the storage tank 4, and the raw materials stored in the storage tank 4 enter the first drain tank 7 along the first drainage plate 6. , release the handle 16, the first crushing block 33 falls into the first drain groove 7 due to its own gravity, and at the same time drives the connecting plate 15 to move upward, and the first latch 19 fixedly connected to the connecting plate 15 also moves upward, so that the baffle plate 2 30 moves back to the bottom of the storage tank 4 to block it, so that the raw material no longer flows out, and the first crushing block 33 falls into the first drain groove 7, crushing the raw material in the first drain groove 7, and the handle 16 is pulled downward again, and the crushed raw material falls from the hole along the second guide plate 9 into the second drain groove 10, and the handle 16 is released, and the second crushing block 34 is Its gravity falls into the second leakage groove 10, and the raw material is crushed again. The crushed raw material flows out from the hole and gathers in the drainage groove 11. When the first drainage port 12 and the second drainage port 28 are aligned, they flow into the container. The weighing device will weigh the weight of the raw material. This process is repeated until the required weight of the raw material is taken out. When not in use, the second drainage port 28 will be moved away from the bottom of the first drainage port 12, and the baffle 27 will block the first drainage port 12 to prevent the raw material from flowing out, so that the raw material is in a closed space to prevent people from contaminating the raw material.

[0115] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A bio-based high barrier, waterproof and oil-proof paper-based packaging material, characterized by: Includes base paper and high barrier waterproof and oil-proof coating; The high-barrier waterproof and oil-proof coating comprises the following raw materials in parts by weight: 100 parts of natural rubber or epoxidized natural rubber, 5-60 parts of nanocellulose, and 0.5-20 parts of an ion crosslinking agent.

2. The bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 1, characterized in that: The natural rubber or epoxidized natural rubber is derived from latex, has a solid content of 15-60%, and the epoxidation degree of the epoxidized natural rubber is 10-50%; The nanocellulose is one or both of cellulose nanocrystals and cellulose nanofibrils; The ionic crosslinking agent is one or more of ferric chloride, calcium chloride and zinc chloride.

3. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 2, characterized in that: The method comprises the following preparation steps: S1. adding the nanocellulose dispersion to natural rubber latex or epoxidized natural rubber latex, and using ultrasonic dispersion after mechanical stirring to uniformly mix the nanocellulose and rubber latex; S2. Dissolve 0.5-20 parts of an ionic crosslinking agent in water, add dropwise to the mixed dispersion obtained in S1 and disperse evenly to obtain a bio-based high barrier waterproof and oil-proof coating; S3. The bio-based high barrier, waterproof and oil-proof coating obtained in S2 is evenly coated on the surface of kraft paper, and after drying, a bio-based high barrier, waterproof and oil-proof paper-based packaging material is obtained.

4. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 3, characterized in that: The amount of nanocellulose used is 10-50% of the rubber mass; The coating process is one or more of dipping, blade coating or spraying.

5. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 4, characterized in that: In S1, an automatic dosing device is used in the process of adding natural latex or epoxidized natural latex, and the automatic dosing device includes a protective shell (2) provided at the upper end of the weighing device (1), a connecting plate (15) is slidably connected to the inner side of the front end of the protective shell (2), a storage tank (4) is fixedly connected to the upper end of the protective shell (2), a storage cover (5) is movably connected to the upper end of the storage tank (4), a first drain groove (7) is fixedly connected to the lower end of the storage groove (4), a first rolling block (33) is movably connected to the inner side of the first drain groove (7), and a first roller (33) is fixedly connected to the lower end of the first drain groove (7). A second leakage groove (10), the inner side of the second leakage groove (10) is movably connected to a second rolling block (34), the lower side of the second leakage groove (10) is fixedly connected to a drainage groove (11), the lower end of the drainage groove (11) is provided with a first drainage port (12), the lower end of the connecting plate (15) is provided with a first latching tooth (19), the first latching tooth (19) is movably connected to a baffle plate (27), a baffle plate (30) is provided above the baffle plate (27), the baffle plate (30) slides at the lower end of the storage groove (4), and the baffle plate (27) slides at the lower end of the drainage groove (11).

6. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 5, characterized in that: Two groups of first movable blocks (40) are fixedly connected to the outer side of the storage tank (4); a second movable block (41) is movably connected between the two groups of the first movable blocks (40) via a rotating shaft; one end of the second movable block (41) is fixedly connected to the storage cover (5); and a second handle (39) is fixedly connected to the upper end of the storage cover (5); A second support plate (13) is provided on one side of the storage groove (4); a first guide plate (6) having a certain inclination angle is fixedly connected to the lower end of the storage groove (4); the first guide plate (6) is fixedly connected to the first drain groove (7); a first support plate (8) is provided on one side of the first drain groove (7); a second guide plate (9) having a certain inclination angle is fixedly connected to the lower end of the first drain groove (7); the second guide plate (9) is fixedly connected to the second drain groove (10); the hole on the second drain groove (10) is smaller than the hole on the first drain groove (7).

7. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 6, characterized in that: The support plate 2 (13) and the support plate 1 (8) are both fixedly connected to the protective shell (2); a limiting groove 1 (14) is provided on the inner side of the front end of the protective shell (2); the connecting plate 1 (15) slides in the limiting groove 1 (14); the upper end of the connecting plate 1 (15) is fixedly connected to a first connecting rope (31) and a second connecting rope (32); the front end of the connecting plate 1 (15) is fixedly connected to a handle 1 (16); the rear end of the connecting plate 1 (15) is fixedly connected to a connecting block (18); the connecting block (18) is fixedly connected to the first latch tooth (19); and the connecting plate 1 (15) is L-shaped; The first connecting rope (31) passes through the upper side of the second support plate (13) and is fixedly connected to the first rolling block (33), and the second connecting rope (32) passes through the upper side of the first support plate (8) and is fixedly connected to the second rolling block (34). The first rolling block (33) is compatible with the first drain groove (7), and the second rolling block (34) is compatible with the second drain groove (10).

8. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 7, characterized in that: A first slide groove (3) is provided on the outer side of the front end of the protective shell (2), a second slide groove (17) is provided on the inner wall of the front end of the protective shell (2), the handle (16) slides inside the first slide groove (3), and the connecting block (18) is slidably connected to the second slide groove (17); A fixing plate (37) is fixedly connected between one side of the protective shell (2) and the drainage groove (11), and a rotating rod 1 (20) and a rotating rod 2 (24) are rotatably connected to the fixing plate (37), and the fixing plate (37) is L-shaped; A first gear (21) is meshed with one side of the first latching tooth (19), and the first gear (21) is fixedly connected to the rotating rod 1 (20). One end of the rotating rod 1 (20) passes through a fixing plate (37) and is fixedly connected to the second gear (22). A third gear (23) is meshed with the lower end of the second gear (22), and the third gear (23) is fixedly connected to the rotating rod 2 (24). One end of the rotating rod 2 (24) passes through a fixing plate (37) and is fixedly connected to a fourth gear (25). A second latching tooth (26) is meshed with one side of the fourth gear (25), and the second latching tooth (26) is fixedly connected to the baffle 1 (27).

9. The method for preparing a bio-based high barrier, waterproof and oil-proof paper-based packaging material according to claim 8, characterized in that: A second connecting plate (29) is fixedly connected to one side of the second latching tooth (26) and the baffle plate 1 (27), and the second connecting plate (29) is fixedly connected to the second baffle plate (30). A third sliding groove (35) and a fourth sliding groove (36) are provided on the inner wall of the rear end of the protective shell (2). The second baffle plate (30) slides inside the third sliding groove (35), and the second latching tooth (26) and the baffle plate 1 (27) slide inside the fourth sliding groove (36). A second limiting groove (38) is provided on the inner side of the rear end of the protective shell (2), and the second connecting plate (29) slides inside the second limiting groove (38). The baffle plate 1 (27) is provided with a second drainage port (28), and the second drainage port (28) is the same size as the first drainage port (12).

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