A layered structure paper-based composite film and a laminating composite processing system thereof

Abstract

The application relates to the technical field of layered products and laminating composite devices, and discloses a layered structure paper-based composite film and a laminating composite processing system thereof, which comprises a barrier layer, the barrier layer comprises a base paper layer and base barrier function coating layers arranged on the double sides of the base paper layer respectively, and a plasma-enhanced chemical vapor deposition silicon oxide layer is arranged on the base barrier function coating layers. The laminating composite processing system comprises a base paper layer coating unit, a calender, a plasma-enhanced chemical vapor deposition device and a multilayer film composite unit arranged in sequence. The technical problem that the existing barrier film needs to be dried for multiple times after coating multiple times and the production efficiency is limited is solved.

Description

Technical Field

[0001] This invention relates to the field of layered products and lamination equipment, specifically to a layered paper-based composite film and its lamination processing system. Background Technology

[0002] Vacuum insulation panels (VIPs) are a type of vacuum insulation material developed in recent years. They are composed of a core material and a vacuum protective surface layer. They effectively prevent heat transfer caused by air convection and are mainly used for thermal insulation, such as in refrigerators, freezers, electric water heaters, vending machines, freezers, refrigerated containers, building wall insulation, and the storage and transportation of LNG (liquefied petroleum gas) and semiconductor wafers.

[0003] The VIP structure on the market mainly consists of three parts: the core insulation material (hereinafter referred to as the core material), the gas adsorption material, and the sealed barrier film. By maximizing the internal vacuum level, heat conduction is isolated, achieving the purpose of heat preservation and energy saving. As an encapsulation material, the barrier film is a barrier that forms a vacuum environment inside the board, playing the roles of covering and isolating, preventing penetration, heat insulation, waterproofing, and gas isolation.

[0004] Barrier films typically consist of an outer protective layer, a barrier layer, and an inner sealing layer. The inner sealing layer is generally composed of low-density or high-density polyethylene (PE) film, used for heat sealing and encapsulating the core material within the barrier film bag, working together with the other layers of the barrier film to seal the core material. The barrier layer can be aluminum foil (AL) or a multi-layer metal coating, its purpose being to prevent gas and moisture penetration. The outer protective layer is made of a material with sufficient strength to ensure it will not be torn during transportation and installation. High-barrier film materials are widely used in the market for packaging food, pharmaceuticals, and chemicals, electronic device packaging, semiconductor wafer storage and transportation, and fuel cell membranes due to their excellent barrier performance, low cost, ease of use, good transparency, strong printability, and good mechanical properties.

[0005] Existing technologies use aluminum as the barrier layer, achieving excellent oxygen and water vapor barrier performance. However, its high thermal conductivity leads to the following drawbacks: 1. Because the core material of the vacuum insulation panel (VIP) is non-uniform, heat is conducted along the planar direction of the barrier film at the seal. For example, heat is more easily transferred along the highly thermally conductive aluminum layer, thus creating a thermal bridge effect at the VIP seal edge. 2. During the heat sealing process, if the inner sealing layer (such as the PE layer) is crushed or insufficiently melted, the aluminum films on both sides of the seal may come into direct contact. Once the aluminum layers are in direct contact, the heat conducted along the film planar direction will increase dramatically, and the equivalent thermal conductivity will rise sharply, significantly exacerbating the thermal bridge effect.

[0006] To solve the above-mentioned technical problems, the inventors began to develop paper-based barrier layers. They used at least three coating processes on the paper base layer to form a barrier film with oxygen and moisture barrier functions. However, each coating layer had to be heated and dried after coating, which resulted in a long production process, huge energy consumption, and limited production efficiency. Summary of the Invention

[0007] The present invention aims to provide a layered paper-based composite film and its lamination and composite processing system to solve the technical problem that the existing barrier film requires multiple drying after multiple coatings, which limits the production efficiency.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A layered paper-based composite film includes a barrier layer, which comprises a base paper layer and a basic barrier functional coating disposed on both sides of the base paper layer. The surface roughness of the printed surface of the paper base layer with the basic barrier functional coating is less than 1.2 μm. A plasma-enhanced chemical vapor deposition silicon oxide layer is disposed on the basic barrier functional coating.

[0010] Beneficial effects:

[0011] 1. This invention provides an initial barrier coating on the surface of a base paper layer, effectively modifying the paper surface and reducing the roughness of the printed surface. Then, plasma-enhanced chemical vapor deposition (PECVD) is used to directly deposit a nanoscale silicon oxide film as the core barrier layer. This process combines wet coating and dry deposition, using the coating process only in the initial application of the basic barrier coating, followed by silicon oxide deposition. This eliminates multiple coating and drying steps, fundamentally solving the technical problems of high energy consumption and low efficiency in multilayer aqueous coating processes, and achieving the green and efficient preparation of paper-based high-barrier materials.

[0012] 2. Plasma-enhanced chemical vapor deposition (PECVD) technology is relatively mature on plastic films, especially PET films, but there are few reports on how to effectively deposit it on paper-based materials. This technology can coat a basic barrier functional coating onto the paper-based material to effectively modify the paper surface, reduce the surface roughness of the printed area, and then deposit a silicon oxide layer to achieve a better barrier effect. The inventors' experiments found that for high-density base paper without any coating, the deposition of silicon oxide did not significantly improve the barrier performance; the oxygen permeability still exceeded the equipment range, and the water vapor permeability was reduced by only 12%. However, for base paper with a basic barrier functional coating, the deposition of silicon oxide significantly improved both oxygen and moisture barrier performance, with reductions in oxygen permeability and water vapor permeability exceeding 90%. Therefore, directly depositing silicon oxide on uncoated paper cannot effectively improve barrier performance. This technology takes a different approach, setting a basic barrier functional coating on the base paper layer and then depositing a silicon oxide layer to effectively improve barrier performance.

[0013] Preferably, as an improvement, it also includes an outer protective layer and an inner sealing layer, with a barrier layer located between the outer protective layer and the inner sealing layer.

[0014] Beneficial effects: The outer protective layer can protect the inner layer and provide strong support for the relatively soft paper-based composite film, making the entire packaging material more sturdy and less prone to wrinkles.

[0015] Preferably, as an improvement, the inner sealing layer includes a heat-sealable BOPP film, and the outer protective layer includes a moisture-barrier PET film.

[0016] Beneficial effects: While ensuring the barrier effect, it also has excellent aging resistance.

[0017] Preferably, as an improvement, a moisture-proof PET film is also provided between the heat-sealed BOPP film and the barrier layer.

[0018] Beneficial effects: Further enhances barrier properties and aging resistance.

[0019] Preferably, as an improvement, the basic barrier functional coating includes washed kaolin, styrene-butadiene latex, and polyvinyl alcohol, wherein the amount of washed kaolin is greater than the amount of styrene-butadiene latex, which is greater than the amount of polyvinyl alcohol; the amount of polyvinyl alcohol is 2.5 to 5 parts, the amount of styrene-butadiene latex is 8 to 12 times the amount of polyvinyl alcohol, and the amount of washed kaolin is 1.2 to 1.5 times the amount of styrene-butadiene latex.

[0020] Beneficial effects: The inventors' experiments revealed that when the amount of PVA is less than 2.5 parts, the coating's film-forming properties are insufficient, the internal adhesion of the coating decreases, and microcracks or pinhole defects easily appear in the coating after drying, leading to a reduction in the basic barrier performance. When the amount of PVA is greater than 5 parts, the coating viscosity is too high, severely affecting the coating's leveling and uniformity, easily producing coating streaks or uneven thickness; at the same time, the drying load increases, production efficiency decreases, and the coating's flexibility decreases, making it prone to brittleness.

[0021] When the amount of styrene-butadiene latex is less than 8 times the amount of PVA, the excessive viscosity of the coating system or the excessively low solids content can easily lead to various coating obstacles such as coating streaks and large-scale adhesive migration, hindering the improvement of barrier performance. When it is greater than 12 times the amount of PVA, the insufficient water retention of the coating will cause the coating to cure too quickly, resulting in a large-scale adhesive migration problem, which seriously affects the density of the coating and is not conducive to improving barrier performance. When the amount of washed kaolin is less than 1.2 times the amount of styrene-butadiene latex, the proportion of inorganic pigments in the coating is too low, and the surface of the coating is seriously wet and sticky after drying. At the same time, it is not conducive to improving the surface smoothness of the coating in both macroscopic and microscopic dimensions, which seriously restricts the deposition effect of subsequent silica deposition. When the amount is greater than 1.5 times the amount of styrene-butadiene latex, the pigment volume concentration exceeds the optimal pigment volume concentration. After drying, the porosity and permeability of the coating increase significantly, which is not conducive to improving the barrier performance of the final coating.

[0022] In summary, when washed kaolin, styrene-butadiene latex, and PVA meet the above-mentioned requirements, they can achieve the best synergistic effect.

[0023] Preferably, as an improvement, the paper base layer with a basic barrier coating is subjected to high-temperature calendering treatment, resulting in a printing surface roughness of less than 1.2 μm.

[0024] Beneficial effects: After high-temperature calendering, the surface roughness of the printed paper base is less than 1.2μm. Further deposition of a PECVD silicon oxide layer on this smooth surface can significantly reduce both oxygen permeability and water vapor permeability compared to before deposition, thereby achieving ultra-high barrier performance.

[0025] Preferably, as an improvement, the thickness of the plasma-enhanced chemical vapor deposition silicon oxide layer is 50~100 nanometers; the coating amount of the basic barrier functional coating on each side is a, 25≥a≥10g / m 2 / noodle.

[0026] Beneficial effects:

[0027] 1. The basic barrier coating provides basic oxygen barrier properties and effectively finishes the paper surface, significantly improving the surface properties of the paper base material and providing a solid foundation for the subsequent deposition of the PECVD silica layer. Experiments show that a coating weight exceeding 25 g / m² is effective. 2While the barrier function and surface properties are improved, the increased coating amount significantly reduces production efficiency; below 10g / m² 2 / Surface will result in insufficient surface finishing and barrier properties.

[0028] 2. When the thickness of the silicon oxide layer in plasma-enhanced chemical vapor deposition is less than 50 nm, the silicon oxide nanoparticles are not dense enough, resulting in high porosity and insufficient barrier performance. When the thickness is greater than 100 nm, the coating becomes too brittle due to excessive nanoparticle stacking, making it prone to cracking during processing and use, thus increasing the coating defect rate and affecting the improvement of barrier performance.

[0029] This technology also provides a lamination and composite processing system, including a base paper coating unit, a calender, a plasma-enhanced chemical vapor deposition device, and a multilayer film composite unit arranged in sequence.

[0030] Beneficial effects: This technology utilizes the above-mentioned equipment. The first three sets of equipment are used to form the barrier film, and the last step is used to combine them to form a paper-based composite film. Compared with the previous method of preparing barrier films from paper-based materials, which required multiple wet coatings and multiple drying processes, this technology not only has low energy consumption, but also has higher continuous production efficiency in each process, making it more conducive to promotion.

[0031] Preferably, as an improvement, the base paper coating unit is a coating machine used to coat the base paper layer with a basic barrier functional coating; the deposition equipment includes a plasma-enhanced chemical vapor deposition device; and the multilayer film composite unit includes a solvent-free composite machine.

[0032] Beneficial effects: The inventors have studied the effects of dry lamination, single-component solvent-free lamination, and two-component solvent-free lamination on paper-based composite barrier films. They found that the three lamination methods have the greatest impact on the interlayer bond strength and heat-seal peel strength. Dry lamination can achieve higher interlayer bond strength and heat-seal peel strength, but it will cause obvious hardening after lamination. However, solvent-free lamination hardly causes any hardening. Therefore, solvent-free lamination is the better method. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the barrier layer in Example 1.

[0034] Figure 2 This is a schematic diagram of the structure of the paper-based composite film A in Example 4.

[0035] Figure 3 This is a schematic diagram of the structure of the paper-based composite film B in Example 4.

[0036] Figure 4 This is a schematic diagram of the base paper coating unit and calender in Example 5.

[0037] Figure 5 This is a schematic diagram of the deposition equipment in Example 5.

[0038] Figure 6 This is a schematic diagram of the multilayer film composite unit in Example 5.

[0039] Figure 7 This is a schematic diagram of the coating process using the slot extrusion coating machine in Example 6.

[0040] Figure 8 This is a schematic diagram of the coating process using a roller coater in Example 6.

[0041] The reference numerals in the accompanying drawings include: barrier layer 1, base paper layer 11, basic barrier functional coating 12, plasma-enhanced chemical vapor deposition silicon oxide layer 13, heat-sealed BOPP film 2, moisture-barrier PET film 3, base paper layer coating unit 4, unwinding roller 41, first coating area 42, coating platform 421, doctor blade 422, second coating area 43, coating roller 431, hot air drying oven 432, upper mold 433, lower mold 434, calender 5, hard roller 51, soft roller 52, deposition equipment 6, multilayer film composite unit 7, first unwinding coating unit 71, barrier layer roller area 711, adhesive roller 712, second unwinding coating unit 72, outer layer roller 721, take-up and unwinding composite unit 73, inner layer roller 731, finished product take-up roller 732. Detailed Implementation

[0042] Example 1

[0043] like Figure 1 As shown, a layered paper-based composite film includes a barrier layer 1. The barrier layer 1 comprises a base paper layer 11 and a basic barrier functional coating 12 disposed on both sides of the base paper layer 11. The basic barrier functional coating 12 has a solid content of 40-50% and a viscosity of 500-1000 mPa·s. The coating amount on each side of the basic barrier functional coating is a, where 25 ≥ a ≥ 10 g / m². 2 / noodle.

[0044] The paper substrate 11 with the basic barrier functional coating 12 is subjected to high-temperature calendering treatment, and the surface roughness of the printed surface is less than 1.2 μm. A plasma-enhanced chemical vapor deposition silicon oxide layer 13 is provided on the basic barrier functional coating 12 on both sides or one side. In this embodiment, a plasma-enhanced chemical vapor deposition silicon oxide layer 13 is provided on the basic barrier functional coating 12 on both sides, with a thickness of 50~100 nanometers. Using this method, the oxygen permeability and water vapor permeability can be significantly reduced compared with those before deposition, thereby achieving ultra-high barrier performance.

[0045] The basic barrier coating consists of washed kaolin, styrene-butadiene latex, and polyvinyl alcohol (PVA). The proportions of washed kaolin > styrene-butadiene latex > PVA. The amount of washed kaolin is 1.2 to 1.5 times that of styrene-butadiene latex, and the proportion of styrene-butadiene latex is 8 to 12 times that of PVA. Washed kaolin forms the main framework of the coating. Styrene-butadiene latex has good compatibility, resulting in a denser and more continuous film formation for pigment coatings, thus providing more efficient basic barrier properties. Increasing the amount of PVA improves barrier performance but significantly affects the coating viscosity. The specific amount of PVA used is 2.5 to 5 parts.

[0046] Specifically, the basic barrier coating consists of 55 parts washed kaolin, 41 parts styrene-butadiene latex, and 4 parts PVA (polyvinyl alcohol).

[0047] A processing method for a layered paper-based composite film is as follows:

[0048] Step 1: Use base paper as the base paper layer 11. The base paper basis weight is ≥60.5 g / m², and the density is ≥1.09 g / cm³. Preferably, the base paper basis weight is 60.5 g / m², the density is 1.09 g / cm³, the air permeability is <0.01 μm / Pa.s, and the water vapor transmission rate is 1200 g / (m²). 2 •24h).

[0049] Step 2: Apply a basic barrier coating 12 to both sides of the base paper layer 11. The coating 12 has a solid content of 45% and a viscosity of 750 mPa·s. The coating method selected includes one of roller coating, doctor blade coating, or extrusion coating. In this embodiment, doctor blade coating is preferred, with a coating amount of 15 g / m². 2 / Surface; then dry to form a paper base layer with a basic barrier coating.

[0050] Step 3: High-temperature calendering treatment of the paper base layer with basic barrier coating, resulting in a printed surface roughness of 0.98μm.

[0051] Step 4: Using a roll-to-roll plasma-enhanced chemical vapor deposition (PECVD) apparatus, a plasma-enhanced chemical vapor deposition silicon oxide layer 13 (PECVD silicon oxide layer) is further deposited on the smooth surface after high-temperature photolithography in step 3. In this embodiment, the thickness of the plasma-enhanced chemical vapor deposition silicon oxide layer 13 is specifically 75 nm; thus forming a barrier layer 1.

[0052] The oxygen permeability and water vapor permeability of the structural layers in each of the above steps were tested. The testing methods were as follows: oxygen permeability was measured using an isobaric sensor method at 25℃ and 50% relative humidity. Water vapor permeability was measured using a cup method at 38℃ and 90% RH. The test results are as follows:

[0053]

[0054] As can be seen from the table above, the barrier layer formed by the "base paper layer + basic barrier functional coating + high temperature calendering + deposited silicon oxide" technology has excellent oxygen and moisture barrier properties.

[0055] 1. Based on the above, the inventors also conducted experiments on the thickness of the silicon oxide layer deposited by plasma-enhanced chemical vapor deposition. Following Example 1, the deposited silicon oxide layers were 45nm, 50nm, 75nm, 100nm, and 105nm thick, with other parameters remaining unchanged. It was found that when the deposited silicon oxide layers were 50nm, 75nm, and 100nm thick, the barrier performance consistently achieved an oxygen permeability of <0.1cm. 3 / (m 2 •24h•0.1Mpa), water vapor transmission rate <1.0g / (m 2 •24h). When the deposited silicon oxide layer is 45nm, the silicon oxide nanoparticles are not densely packed, the porosity is high, and the barrier performance is insufficient, failing to meet the requirements; when the deposited silicon oxide layer is 105nm, the coating formed by the excessive thickness of the nanoparticles increases the brittleness, making it easy for the coating to crack during processing and use, increasing the coating defect rate, and affecting the improvement of barrier performance.

[0056] 2. The paper base layer with a basic barrier coating undergoes high-temperature calendering treatment, resulting in a printed surface roughness of less than 1.2 μm, more preferably less than 1 μm. According to the inventors' experiments, the printed surface roughness after high-temperature calendering treatment in this embodiment is 0.98 μm; the reduction in oxygen permeability and water vapor permeability is tested as follows:

[0057] Experimental Group 1: The oxygen and water vapor transmission rates of the product coated with the basic barrier coating and calendered were measured and recorded. The oxygen transmission rate was 0.983 cm⁻¹. 3 / (m 2 •d), water vapor transmission rate 26.37 g / (m 2 ·24h);

[0058] Experimental Group 2: A plasma-enhanced chemical vapor deposition (PECVD) silicon oxide layer was added to the product after it had been coated with a basic barrier coating and calendered. Oxygen and water vapor transmission rates were then recorded. Oxygen transmission rate: 0.063 cm⁻¹ 3 / (m 2 •d), water vapor transmission rate 0.89 g / (m 2 ·24h);

[0059] In summary, it can be seen that the reduction in oxygen permeability (OTR) and water vapor permeability (WVTR) after depositing the silicon oxide coating is approximately 94% and 97%, respectively. However, when the surface roughness of the printed surface is greater than 1.2 μm, for example, 1.5 μm, a comparison of the experimental records before and after reveals that the reduction in oxygen permeability and water vapor permeability is lower and not as good as the aforementioned results.

[0060] 3. Regarding the coating amount of the basic barrier functional coating, experiments showed that without the basic barrier functional coating, the oxygen permeability of the base paper exceeded the range, and the water vapor permeability was 1200. Subsequent double-sided coating experiments were conducted, with a coating amount of 9 g / m² on each side in each group of experiments. 2 10g / m 2 12 g / m 2 15 g / m 2 25 g / m 2 28 g / m 2 Tests showed that the oxygen permeability and water vapor permeability in the above experimental groups decreased sequentially, indicating that increasing the coating amount significantly improves the oxygen and moisture barrier properties. However, when the coating amount was 28 g / m²... 2 While barrier functionality and surface properties are improved when coating one side, coating efficiency and benefits decrease significantly. Furthermore, a coating weight of less than 10 g / m² per side is problematic. 2 / face, for example, 9g / m 2 This can lead to insufficient surface finishing and barrier properties. In this embodiment, it is preferable that the coating amount on each side of the double-sided coating is 15g / m². 2 It significantly improves oxygen and moisture barrier properties while maintaining coating efficiency and profitability.

[0061] Example 2

[0062] The difference between this embodiment and Embodiment 1 is that 20 parts of water-washed kaolin, 24 parts of styrene-butadiene latex, and 2.5 parts of PVA are used.

[0063] Example 3

[0064] The difference between this embodiment and Embodiment 1 is that 60 parts of water-washed kaolin, 90 parts of styrene-butadiene latex, and 5 parts of PVA are taken.

[0065] The basic barrier functional coating 12 obtained in Examples 2 and 3 was applied to both sides with a coating amount of 15 g / m² on each side. 2 The oxygen permeability and water vapor permeability are as follows when coated on the base paper layer 11:

[0066]

[0067] As shown in the table above, the basic barrier coating using this technology can effectively improve the barrier performance of the base paper layer, providing a good foundation for subsequent calendering and silica deposition. Furthermore, the inventors tested the solid content and viscosity of the basic barrier coating in the following experimental groups: 1. Solid content 40%, viscosity 500 mPa·s; 2. Solid content 50%, viscosity 1000 mPa·s; 3. Solid content 35%, viscosity 450 mPa·s; 4. Solid content 55%, viscosity 1050 mPa·s. It was found that experimental groups 1 and 2 could produce barrier coatings that met the target coating amount requirements, and the uniformity, smoothness, and density of the coatings all met the set indicators. However, experimental group 3, due to its low solid content and viscosity, resulted in excessive adhesive penetration into the paper base, failing to form a continuous and dense barrier layer. Experimental group 4, due to its high solid content and viscosity, exhibited poor leveling during coating, resulting in surface streaks, and also failed to meet the coating quality requirements.

[0068] Example 4

[0069] The difference between this embodiment and Embodiment 1 is that, as Figure 2 As shown, a layered paper-based composite film further includes an outer protective layer and an inner sealing layer. The inner sealing layer is a heat-sealable BOPP film 2, the outer protective layer is a moisture-barrier PET film 3, and the barrier layer 1 is located between the outer protective layer and the inner sealing layer. A processing method for a layered paper-based composite film, based on Example 1, further includes: step 5, using a solvent-free laminating machine to laminate the barrier layer 1, the heat-sealable BOPP film 2, and the moisture-barrier PET film 3 to form a paper-based composite film A of heat-sealable BOPP film 2 / barrier layer 1 / moisture-barrier PET film 3.

[0070] In other embodiments besides this one, the difference lies in, such as Figure 3 As shown, a layered paper-based composite film further includes an outer protective layer and an inner sealing layer. The inner sealing layer is a heat-sealable BOPP film 2, the outer protective layer is a moisture-barrier PET film 3, and a barrier layer 1 is located between the outer protective layer and the inner sealing layer. A moisture-barrier PET film 3 is also disposed between the heat-sealable BOPP film 2 and the barrier layer 1. A paper-based composite film B consisting of heat-sealable BOPP 2 / moisture-barrier PET film 3 / barrier layer 1 / moisture-barrier PET film 3 is formed using a solvent-free laminating machine.

[0071] I. Aging Resistance Test: An aging resistance test was conducted on paper-based composite film A and paper-based composite film B using an accelerated aging method. The films were placed at 70℃ and 90% RH for 28 days, and the following conclusions were drawn:

[0072]

[0073] As can be seen from the table above, the oxygen permeability of the completely aluminum-free paper-based composite barrier membrane developed in this technology reaches 0.058 cm⁻¹.3 / (m 2 •24h•0.1MPa) (25℃, 50%RH), the water vapor transmission rate reached 0.73 g / (m²). 2 •24h) (38℃, 90%RH). Moreover, both composite film A and composite film B of this technology can achieve good aging resistance, with composite film B exhibiting the best aging resistance; furthermore, the paper-based composite film formed by this technology retains more than 90% of its barrier properties after aging.

[0074] II. Solvent-free composite coating amount experiment

[0075] The properties of the paper-based composite films obtained by using a two-component solvent-free lamination method with different coating amounts are as follows:

[0076]

[0077] Based on the above experiments, when using two-component solvent-free lamination, the effect of adhesive coating amount on paper-based composite films is more evident in their appearance. To achieve a white spot-free appearance, the adhesive coating amount on each side should be less than 2.0 g / m² during lamination. 2 In terms of performance, paper-based composite films can achieve heat-sealing peel strength >40N / 15mm; transverse tensile strength >70N / 15mm; and longitudinal tensile strength >90N / 15mm.

[0078] In summary, this technology achieves 100% replacement of the aluminum layer in the barrier film material for VIPs, and the resulting paper-based composite film not only has a good barrier effect, but also excellent strength and aging resistance.

[0079] Example 5

[0080] This embodiment discloses a lamination composite processing system, such as Figures 4-6 As shown, the system includes a base paper coating unit 4, a calender 5, a deposition equipment 6, and a multilayer film composite unit 7 arranged in sequence, and forms a layered paper-based composite film through the above processing.

[0081] The base paper coating unit 4 is used to coat the base paper layer 11 with a basic barrier coating 12, employing methods such as extrusion coating, roller coating, and doctor blade coating. Specific equipment can be, but is not limited to, slot extrusion coating machines, roller coating machines, and doctor blade coating machines; this technology preferably uses a doctor blade coating machine. Figure 4As shown, the base paper coating unit 4 includes a feeding roller 41, a first coating area 42, a hot air drying chamber 432, a second coating area 43, and a hot air drying chamber 432 arranged sequentially. The feeding roller 41 includes a roller frame and a base paper material roller rotatably connected to the roller frame. One end of the base paper material roller is equipped with an unwinding motor, such as a servo motor. A coating platform 421 fixed to the frame is provided at the first coating area 42. A doctor blade 422 is mounted above the coating platform 421. The doctor blade 422 moves up and down by a cylinder or hydraulic press. Negative pressure holes are evenly distributed on the surface of the coating platform 421. Below the coating platform 421 is a negative pressure chamber connected to a negative pressure machine, which is used to adsorb and flatten the paper base layer. The paper base layer passes through the gap between the doctor blade 422 and the coating platform 421 to remove excess coating. Alternatively, a method can be considered where a doctor blade and a supporting back roller work in tandem. The doctor blade is positioned above the supporting back roller and its vertical movement is achieved by a cylinder or hydraulic press. In use, the base paper layer is passed around the supporting back roller, the coating is applied to the substrate, and then the excess is scraped off as the coating and substrate pass through the gap between the upper doctor blade and the lower supporting back roller. The principle described above is the same as existing doctor blade coating principles, and will not be elaborated further here. The difference lies in that this technology sets up two doctor blade coating areas for double-sided coating of the base paper layer 11 with the basic barrier coating 12. In other embodiments besides this one, only one doctor blade coating area can be set up. Then, by setting up a feed roller 41 and a take-up roller on both sides of the doctor blade coating area, after the first coating is dried, the take-up roller is removed and placed on the roller frame at the station of the feed roller 41, and then pulled for reverse coating.

[0082] Calender 5 uses the combined action of high temperature and high pressure to shape and compact the surface of the base paper layer 11, combined with Figure 4 As shown, the calender 5 is equipped with a three-roll group: a hard roller 51 in the middle, and soft rollers 52 on the upper and lower sides respectively; or in other embodiments besides this embodiment, a pair of roller groups can be used: the hard rollers 51 and soft rollers 52 arranged vertically cooperate to form a pressing zone. The number of roller groups can be set as needed. For example, multiple vertically arranged roller groups can be set in the calender to form multiple pressing zones in series. In this pressing zone, the paper is uniformly squeezed, making the bond between fibers tighter, compressing the fiber pores, and making the entire paper surface more compact and smooth. The hard roller 51 is equipped with heat-conducting oil or electric heating wire to achieve the purpose of heating. After the base paper layer 11 coated with the basic barrier functional coating 12 is dried in the hot air drying oven 432, it enters the calender 5 for high-temperature calendering treatment. The intermediate product after calendering treatment is wound up by the winding roller. In other embodiments besides this embodiment, the calender 5 can be a supercalender, which is also within the protection scope of this technology.

[0083] The base paper layer 11 exiting the calender 5 enters the deposition equipment 6, which is a plasma-enhanced chemical vapor deposition (PECVD) system used to deposit a silicon oxide layer on the substrate surface. Specifically, it employs a roll-to-roll PECVD apparatus, a vacuum coating device capable of continuous, large-scale, and high-efficiency thin film deposition on flexible substrates. The deposition equipment 6 includes an unwinding roll area, a deposition chamber, and a rewinding roll area, where the product, after being calendered in the previous process, is placed. The deposition chamber is connected to a gas supply system, including a silicon source gas path, an oxidant path, and an inert gas path, for introducing HMDSO, O2, and Ar gases respectively, and forming a reaction atmosphere within the deposition zone. Specifically, hexamethyldisiloxane (HMDSO, 99%) is used as the silicon source, oxygen (O2, 99.99%) as the oxidant, and argon (Ar, 99.99%) as the auxiliary ionization gas, which does not participate in the reaction. All three are simultaneously introduced into the reaction chamber, where a chemical vapor phase reaction occurs under the action of radio frequency plasma to generate a SiOx coating. The background vacuum is 2 Pa, and the RF discharge power is 50 W. The gas supply system controls the flow ratio of HMDSO and O2 separately through a mass flow controller. The film deposition pressure is 20 Pa, the deposition time is 3 min, and the flow rate of the auxiliary ionization gas Ar is 4 m³ / s. 3 / h. Using the above method, a silicon oxide layer with a thickness of 50-100 nanometers is deposited on the base paper layer 11 of the base barrier functional coating 12, forming the barrier layer 1. The barrier layer 1 exiting the deposition equipment 6 is wound onto a take-up roller, and all the roller shafts of the take-up rollers are connected to motors. The take-up rollers are removed and placed in the feeding area of ​​the multilayer film composite unit 7 for this composite processing step; in other embodiments besides this one, the barrier layer 1 exiting the deposition equipment 6 can also be directly pulled to the multilayer film composite unit 7 for the next composite processing step. Tension rollers and conveyor rollers can be set up as needed between the base paper coating unit 4, calender 5, deposition equipment 6, and multilayer film composite unit 7. The tension rollers are used to adjust the tension of the conveyed material. The conveyor rollers include a drive wheel and a driven wheel. The drive wheel is driven by a motor, and the film passes between the drive wheel and the driven wheel to achieve film conveying.

[0084] The multilayer film laminating unit 7 employs a solvent-free laminating machine to laminate the outer protective layer, barrier layer 1, and inner sealing layer to form a layered paper-based composite film material. The multilayer film laminating unit 7 includes a first unwinding coating unit 71, a second unwinding coating unit 72, and a take-up / unwinding laminating unit 73. The barrier layer 1, as an intermediate layer, is placed at the barrier layer roller area 711 of the first unwinding coating unit 71. The moisture-barrier PET film, as the outer protective layer, is placed at the outer layer roller 721 of the second unwinding coating unit 72. The heat-sealed BOPP, as the inner sealing layer, is placed at the inner layer roller 731 of the take-up / unwinding laminating unit 73. A finished product take-up roller is also provided on the frame of the take-up / unwinding laminating unit 73 for winding the layered paper-based composite film. Both the first unwinding coating unit 71 and the second unwinding coating unit 72 are equipped with adhesive coating rollers 712 for applying adhesive layers to each layer.

[0085] In other embodiments besides this one, a step-by-step lamination method can be used. Step 1: Using a solventless laminator, a first layer of two-component adhesive is applied to one side of the heat-sealable BOPP film, pressed together with the barrier layer, and then rolled up and placed in a curing chamber. Step 2: Using the already cured heat-sealable BOPP film / barrier layer composite film as the base film, a second layer of two-component adhesive is applied to the other side of the barrier layer and pressed together with the moisture-barrier PET film. It is then rolled up again and placed in a curing chamber for final curing. Similarly, the heat-sealable BOPP film / moisture-barrier PET film / barrier layer / moisture-barrier PET film paper-based composite film can also be laminated using the above two-by-two step-by-step lamination method; alternatively, the three films can be laminated and cured first, and then the remaining films can be laminated for final curing.

[0086] Example 6

[0087] The difference between this embodiment and embodiment 5 is that the base paper coating unit 4 is a slot extrusion coating machine, such as... Figure 7 As shown, the coating system includes a feeding roller 41, a first coating zone 42, and a second coating zone 43. Hot air drying chambers 432 are located before and after the second coating zone 43. The first coating zone 42 includes a coating die and a coating roller 431. The coating die includes an upper die 433 and a lower die 434. The lower die 434 has a paint inlet. The paint is applied by contacting the base paper layer 11 on the coating roller 431 through the coating gap between the upper die 433 and the lower die 434. The principle of the second coating zone is the same as described above. For specific coating principles, please refer to existing slot extrusion coating machines; details will not be elaborated here. The base paper layer 11 of the base barrier coating 12 is dried in the hot air drying chamber 43.

[0088] In other embodiments besides this one, the base paper coating unit 4 can also be a roller coater, such as... Figure 8 As shown, the base paper layer 11 passes between two coating rollers, and the coating in the coating storage area is applied to the base paper layer 11 through the metering roller, transfer roller, and coating roller, achieving simultaneous coating on both sides and reducing the number of drying cycles.

[0089] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A layered paper-based composite film, characterized in that, It includes a barrier layer, which comprises a base paper layer and a basic barrier functional coating disposed on both sides of the base paper layer. The surface roughness of the printed surface of the paper base layer with the basic barrier functional coating is less than 1.2 μm. A plasma-enhanced chemical vapor deposition silicon oxide layer is provided on the basic barrier coating.

2. The layered paper-based composite film according to claim 1, characterized in that, It also includes an outer protective layer and an inner sealing layer, with a barrier layer located between the outer protective layer and the inner sealing layer.

3. The layered paper-based composite film according to claim 2, characterized in that, The inner sealing layer includes a heat-sealed BOPP film, and the outer protective layer includes a moisture-barrier PET film.

4. The layered paper-based composite film according to claim 3, characterized in that, A moisture-proof PET film is also placed between the heat-sealed BOPP film and the barrier layer.

5. The layered paper-based composite film according to claim 1, characterized in that, The basic barrier coating comprises washed kaolin, styrene-butadiene latex, and polyvinyl alcohol, wherein the proportion of washed kaolin is greater than that of styrene-butadiene latex, which is greater than that of polyvinyl alcohol; the polyvinyl alcohol is 2.5 to 5 parts, the proportion of styrene-butadiene latex is 8 to 12 times that of polyvinyl alcohol, and the amount of washed kaolin is 1.2 to 1.5 times that of styrene-butadiene latex.

6. The layered paper-based composite film according to claim 1, characterized in that, The paper base layer with a basic barrier coating undergoes high-temperature calendering treatment, resulting in a printed surface roughness of less than 1.2μm.

7. The layered paper-based composite film according to claim 1, characterized in that, The thickness of the plasma-enhanced chemical vapor deposition silicon oxide layer is 50~100 nm; the coating weight of the basic barrier functional coating on each side is a, 25≥a≥10 g / m 2 / noodle.

8. A lamination composite processing system, characterized in that, It includes a base paper coating unit, a calender, a plasma-enhanced chemical vapor deposition equipment, and a multilayer film composite unit arranged in sequence.

9. A lamination composite processing system according to claim 8, characterized in that, The base paper coating unit is a coating machine used to coat the base paper with a basic barrier functional coating; the deposition equipment includes plasma-enhanced chemical vapor deposition equipment; the multilayer film composite unit includes a solvent-free composite machine.

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