Moisture-proof treatment process for stainless steel lining paper and application

Abstract

According to the damp-proof treatment process and application of the stainless steel lining paper, a multi-dimensional damp-proof barrier is constructed through the steps of raw paper pretreatment, plasma surface activation, nano-composite damp-proof paint coating and gradient drying and curing. The binding force of the base paper and the coating is improved through plasma activation, the nanoparticles and the resin synergistically form a compact structure, and the moisture-proof effect can be enhanced through secondary coating or back coating. The treated lining paper is obviously optimized in moisture resistance and mechanical property, good in adaptability with stainless steel plates, capable of protecting the steel plates for a long time in a high-humidity environment, capable of effectively preventing the steel plates from being rusted when being suitable for packaging the stainless steel plates and capable of meeting the storage and transportation requirements of the stainless steel plates.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of backing paper processing, in particular to a stainless steel backing paper moisture-proof processing technology and application. BACKGROUND

[0002] In the process of storing and transporting stainless steel plates, backing paper is used to separate and protect them from surface scratches or rust.

[0003] Traditional stainless steel backing paper is mostly made of ordinary sulfate wood pulp paper, which only realizes basic moisture-proof through simple wax coating or sizing treatment. However, it has many defects: low surface activity leads to poor adhesion of the coating, which is prone to peeling; the single moisture-proof barrier is not dense enough, and moisture can easily penetrate, causing the stainless steel plate to rust; the mechanical properties are weak, and the paper is easily damaged during packaging or handling, which cannot provide long-term stable protection for the stainless steel plate.

[0004] Especially in high humidity environments, the moisture-proof failure of traditional backing paper is more prominent, which seriously affects the surface quality and value of the stainless steel plate. Therefore, there is an urgent need for a processing technology that can significantly improve the moisture-proof performance, enhance the adhesion of the coating, and ensure the mechanical stability. SUMMARY

[0005] The purpose of the present application is to provide a stainless steel backing paper moisture-proof processing technology and application to solve the technical problem that the existing traditional stainless steel backing paper is prone to moisture-proof deficiency and coating peeling, which affects the quality of the stainless steel plate.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A stainless steel backing paper moisture-proof processing technology, comprising the following steps:

[0008] (1) Pretreatment of raw paper: select sulfate wood pulp paper with a basis weight of 60-120 g / m² as the base paper, clean the surface impurities by ultrasonic cleaning with deionized water, and then dry it in a vacuum drying oven at 60-80℃ until the moisture content is ≤3%;

[0009] (2) Surface activation: place the pretreated base paper in a plasma treatment device, use a mixture of argon and oxygen gas (volume ratio 3:1), and treat it at a power of 150-250W and a vacuum degree of 50-100Pa for 30-90s to obtain a surface-activated base paper;

[0010] (3) Preparation of moisture-proof coating: mix nano-silicon dioxide and nano-zinc oxide according to a mass ratio of 1:0.5-2, add to a mixed solvent of ethanol and deionized water, the volume ratio of ethanol to deionized water is 1:1, ultrasonic dispersion for 30-60 min to form a nano-dispersion liquid; mix water-based polyurethane resin and polyvinylidene fluoride emulsion according to a mass ratio of 3:1, add 5%-15% of the nano-dispersion liquid based on the mass of the mixed resin, and then add 0.5%-2% of silane coupling agent KH-550 based on the total mass, stir for 2-4 h to obtain the moisture-proof coating;

[0011] (4) Coating treatment: use the dipping-coating and doctor-blade composite process to dip-coat the surface-activated base paper with the moisture-proof coating at a dipping speed of 2-5 m / min, and then control the wet film thickness to be 10-30 μm by a doctor blade to form a preliminary coating layer;

[0012] (5) Drying and curing: dry and cure the coated base paper at 80-100 ℃ for 3-5 min by hot air, and then at 120-150 ℃ for 2-3 min by infrared, and obtain the moisture-proof treated stainless steel lining paper after cooling to room temperature.

[0013] The moisture-proof treatment process of the stainless steel lining paper has the advantages that the impurities are removed and the water content is controlled through the original paper pretreatment, which lays a stable foundation for the subsequent treatment; the surface activation treatment can improve the surface activity of the base paper and enhance the bonding force with the moisture-proof coating; the synergistic effect of the nano-particles and the resin in the moisture-proof coating can form a dense moisture-proof barrier; the dipping-coating and doctor-blade composite process combined with gradient drying and curing can ensure that the coating layer is uniform and fully cured, and the moisture-proof performance, mechanical properties and adaptability to the stainless steel plate of the lining paper are improved as a whole.

[0014] As a preferred scheme of the present application, the electrode spacing of the plasma treatment equipment in step (2) is 5-15 mm, and the running speed of the base paper during treatment is 10-20 m / min. By limiting the electrode spacing of the plasma treatment equipment and the running speed of the base paper, the uniformity and effectiveness of the plasma surface activation of the base paper can be ensured, and local insufficient activation or excessive activation caused by improper parameters can be avoided, further enhancing the bonding effect of the base paper and the coating layer.

[0015] As a preferred scheme of the present application, the particle size of the nano-silicon dioxide in step (3) is 10-50 nm, and the particle size of the nano-zinc oxide is 20-80 nm; the solid content of the water-based polyurethane resin is 30%-50%, and the solid content of the polyvinylidene fluoride emulsion is 40%-60%. By limiting the particle size of the nano-particles and the solid content of the resin, the nano-particles can be uniformly dispersed in the coating, and a good composite system is formed with the resin, improving the density and stability of the coating layer, and further enhancing the moisture-proof and breaking resistance of the lining paper

[0016] As a preferred scheme of the present application, the doctor blade in step (4) is a comma-shaped doctor blade, the included angle between the doctor blade and the base paper is 30-60°, and the doctor blade pressure is 0.1-0.3 MPa. With the above technical scheme, the doctor blade is a comma-shaped doctor blade, and the included angle between the doctor blade and the base paper and the doctor blade pressure are limited, so that the coating thickness can be accurately controlled, the uniformity of the coating can be ensured, the coating defects can be reduced, and the consistency of the surface quality and the moisture-proof performance of the backing paper can be improved.

[0017] As a preferred scheme of the present application, the air speed of the hot air drying in step (5) is 1-3 m / s, the infrared curing uses a medium-wave infrared lamp with a wavelength of 2-5 μm, and the irradiation intensity is 50-100 kW / m². With the above technical scheme, by limiting the air speed of the hot air drying and the lamp source parameters of the infrared curing, the gradual drying and curing of the coating can be realized, the cracking or insufficient drying of the coating caused by too fast drying can be avoided, the stability of the coating structure can be ensured, and the moisture-proof effect can be improved.

[0018] As a preferred scheme of the present application, it further includes a secondary coating step (6): a secondary doctor blade coating is performed on the surface of the backing paper obtained in step (5) using the same moisture-proof coating, the wet film thickness is 5-15 μm, and then the drying and curing process of step (5) is repeated, and the total coating thickness is controlled to be 15-45 μm. With the above technical scheme, by increasing the secondary coating step, the possible coating deficiency in the first coating can be compensated, the coating thickness can be increased, the moisture-proof barrier effect of the backing paper can be further enhanced, and the overall moisture-proof performance can be improved.

[0019] As a further scheme of the present application, in the moisture-proof coating for the secondary coating, the addition amount of the nano dispersion liquid is increased by 2%-5% compared with the first coating, and 1%-3% of polytetrafluoroethylene powder in total mass is added, and the particle size of the polytetrafluoroethylene powder is 1-5 μm. With the above technical scheme, by adjusting the addition amount of the nano dispersion liquid and introducing the polytetrafluoroethylene powder in the secondary coating, the wear resistance and smoothness of the coating can be enhanced, the compactness of the coating can be improved, the backing paper can be more durable in use, and the peeling from the stainless steel plate can be smoother.

[0020] As a preferred scheme of the present application, it further includes a back coating treatment step (7): a layer of paraffin emulsion with a thickness of 2-5 μm is coated on the non-coated surface of the base paper, dried at 60-80 °C for 1-2 min, the solid content of the paraffin emulsion is 10%-20%, and the paraffin emulsion is composed of microcrystalline wax with a melting point of 50-70 °C and an emulsifier at a mass ratio of 9:1. With the above technical scheme, the back coating treatment is performed on the non-coated surface of the base paper to form an additional moisture-proof layer, which can further block the moisture from the back of the base paper, and cooperates with the front coating to comprehensively improve the overall moisture-proof ability of the backing paper.

[0021] As a preferred scheme of the present application, the 24h water absorption rate of the moisture-proof treated stainless steel lining paper is ≤5%, the burst strength is ≥3.5kPa, the air permeability is ≤10mL / (min·cm²), and the peeling force with the stainless steel plate is 0.5-1.5N / 25mm. By limiting the performance of the moisture-proof treated lining paper, the effects brought by the foregoing process are comprehensively reflected, so that the lining paper has good moisture-proof property, mechanical strength, air permeability and adaptability to the stainless steel plate, and meets the use requirements of the stainless steel packaging.

[0022] The present application also provides an application of the stainless steel lining paper in stainless steel plate packaging. The stainless steel plate is a cold-rolled stainless steel plate with a thickness of 0.1-2mm, and the lining paper is wrapped around the stainless steel plate in a winding manner. After storage in an environment with a temperature of 20-30℃ and a relative humidity of 60%-80%, the surface of the stainless steel plate is free of rust and water marks. By using the stainless steel lining paper prepared by the foregoing process in specific stainless steel plate packaging, the excellent moisture-proof property of the lining paper can be utilized to effectively protect the stainless steel plate during storage, so that rusting and water marks of the stainless steel plate caused by moisture are avoided, and the surface quality of the stainless steel plate is ensured.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1. The moisture-proof property is significantly improved. The adhesion of the coating is enhanced by plasma activation, and the dense structure of the nano-composite coating forms a multi-dimensional moisture-proof barrier to effectively block the intrusion of moisture, solving the problem that the traditional lining paper is prone to rusting of the stainless steel plate due to moisture.

[0025] 2. The mechanical property is optimized. The coating and the base paper are tightly combined to synergistically improve the burst strength and tear resistance of the lining paper, so that the lining paper is not easy to be damaged during packaging, transportation and storage, and long-term stable protection is ensured.

[0026] 3. The use adaptability is enhanced. The surface of the coating is smooth and the peeling force is moderate, so that the lining paper can be tightly combined with the stainless steel plate to prevent displacement, and can be easily peeled off when unpacking to avoid leaving residues or scratching the surface of the steel plate.

[0027] 4. The environmental adaptability is widened. The treated lining paper can maintain good performance in a high-humidity environment, prolong the storage period of the stainless steel plate, and reduce the quality loss caused by environmental factors. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0029] Figure 1 This is a flowchart of an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0031] In the description of the embodiments of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0032] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present invention should be understood according to the specific circumstances.

[0033] Reference Figure 1 The present invention provides a moisture-proof treatment process for stainless steel lining paper, which includes the following five embodiments:

[0034] Standard procedure:

[0035] (1) Pretreatment of base paper: Sulfate wood pulp paper with a basis weight of 60-120 g / m² is selected as base paper. After ultrasonic cleaning with deionized water to remove surface impurities, it is dried in a vacuum drying oven at 60-80℃ until the moisture content is ≤3%;

[0036] (2) Surface activation: The pretreated base paper is placed in a plasma treatment device and treated with a mixture of argon and oxygen (volume ratio 3:1) for 30 to 90 seconds under the conditions of power 150 to 250W and vacuum degree 50 to 100Pa to obtain surface activated base paper.

[0037] (3) Preparation of moisture-proof coating: mix nano-silicon dioxide and nano-zinc oxide according to a mass ratio of 1:0.5-2, add to a mixed solvent of ethanol and deionized water, the volume ratio of ethanol to deionized water is 1:1, ultrasonic dispersion for 30-60 min to form a nano-dispersion liquid; mix water-based polyurethane resin and polyvinylidene fluoride emulsion according to a mass ratio of 3:1, add 5%-15% of the nano-dispersion liquid based on the mass of the mixed resin, and then add 0.5%-2% of silane coupling agent KH-550 based on the total mass, stir for 2-4 h to obtain the moisture-proof coating;

[0038] (4) Coating treatment: use the dipping-coating and doctor-blade composite process to dip-coat the surface-activated base paper with the moisture-proof coating at a dipping speed of 2-5 m / min, and then control the wet film thickness to be 10-30 μm by a doctor blade to form a preliminary coating layer;

[0039] (5) Drying and curing: dry and cure the coated base paper in a hot air drying oven at 80-100 ℃ for 3-5 min, and then in an infrared curing oven at 120-150 ℃ for 2-3 min, and then cool to room temperature to obtain the moisture-proof treated stainless steel liner paper.

[0040] Example 1: standard process example

[0041] Technical solution: strictly follow the standard steps. The base paper is selected as a sulfite wood pulp paper with a basis weight of 80 g / m², which is dried in a vacuum drying oven at 65 ℃ to a moisture content of 2.5%; the plasma treatment power is 200 W, the vacuum degree is 80 Pa, and the treatment time is 60 s; the mass ratio of nano-silicon dioxide to nano-zinc oxide in the moisture-proof coating is 1:1, and the nano-dispersion liquid addition amount is 10% of the mass of the mixed resin; the dipping speed is 3 m / min, and the wet film thickness is controlled to be 20 μm; first dry at 85 ℃ for 4 min, and then cure at 130 ℃ for 2.5 min.

[0042] Technical effect: comprehensively improve the moisture-proof performance of the stainless steel liner paper, the base paper and the coating layer are firmly combined, the coating layer is dense and uniform, and has good mechanical properties and adaptability to the stainless steel plate.

[0043] Working principle: the pretreatment of the base paper removes impurities and moisture, providing a stable foundation for subsequent treatment. The plasma activation increases the active sites on the surface of the base paper, making the coating more easily attached and combined. The nano-particles in the moisture-proof coating fill the gaps between the resins, forming a tight moisture-proof structure. Dipping-coating and doctor-blade ensure uniform coating of the coating layer, and gradient drying allows the coating layer to be fully cured.

[0044] Experimental data: water absorption rate (24 h) is 4.5%, burst strength is 3.8 kPa, air permeability is 8 mL / (min·cm²), and the peeling force from the stainless steel plate is 1.2 N / 25 mm. After being stored for 3 months in an environment with a temperature of 25 ℃ and a relative humidity of 70%, there is no rust and water mark on the surface of the stainless steel plate.

[0045] Example 2: Optimization of plasma parameters example:

[0046] Technical solution: On the basis of standard steps, adjust the electrode spacing of the plasma treatment equipment to 10 mm, the base paper running speed to 15 m / min, and the rest of the steps and parameters are the same as in Example 1.

[0047] Technical effect: Enhance the uniformity and effectiveness of the base paper surface activation, further improve the base paper and coating adhesion, and improve the moisture resistance and overall performance of the base paper.

[0048] Working principle: Suitable electrode spacing makes the plasma distribution more uniform, and the base paper running speed ensures that each part is subjected to plasma for an appropriate time, fully activating the base paper surface and promoting better bonding with the coating.

[0049] Experimental data: Water absorption rate (24h) reduced to 4.2%, bursting strength increased to 4.0kPa, air permeability 7mL / (min·cm²), and stainless steel plate peeling force 1.3N / 25mm. Under the same storage conditions, the surface of the stainless steel plate is in good condition and shows no signs of moisture.

[0050] Example 3: Adjusting nanoparticle and resin parameters example:

[0051] Technical solution: Nanometer silicon dioxide particle size 30nm, nanometer zinc oxide particle size 50nm, water-based polyurethane resin solid content 40%, polyvinylidene fluoride emulsion solid content 50%, and the rest of the steps and parameters are the same as in Example 1.

[0052] Technical effect: Optimize the dispersion of nanoparticles in the coating, form a more stable composite system with the resin, improve the coating density and stability, and enhance the moisture resistance and mechanical properties of the base paper.

[0053] Working principle: Nanoparticles of specific particle size are more easily dispersed uniformly in the resin, and work together to fill the internal pores of the coating, improving the structural stability and moisture resistance of the coating.

[0054] Experimental data: Water absorption rate (24h) 4.0%, bursting strength 4.2kPa, air permeability 6mL / (min·cm²), and stainless steel plate peeling force 1.35N / 25mm. After 3 months of storage test, the surface of the stainless steel plate shows no adverse phenomena caused by moisture.

[0055] Example 4: Improve the doctor blade coating process example:

[0056] Technical solution: Doctor blade coating uses a comma doctor blade, the doctor blade and base paper angle is 45°, the doctor blade coating pressure is 0.2MPa, and the rest of the steps and parameters are the same as in Example 1.

[0057] Technical effect: Accurately control the coating thickness, ensure the uniformity of the coating, reduce coating defects, and improve the consistency of the surface quality and moisture resistance performance of the base paper.

[0058] Working principle: the appropriate angle of the scraper and the scraping pressure make the paint evenly distributed on the base paper, ensuring consistent coating thickness and improving coating quality and moisture-proof effect stability.

[0059] Experimental data: water absorption rate (24h) 4.3%, burst resistance 4.1kPa, air permeability 7.5mL / (min·cm²), and peeling force from stainless steel plate 1.32N / 25mm. In the storage experiment, the surface of the stainless steel plate remained in good condition.

[0060] Example 5: increase the back coating treatment example:

[0061] Technical scheme: on the basis of the standard steps, after completing the front coating treatment, back coating treatment is carried out. A layer of paraffin emulsion (solid content 15%, composed of microcrystalline wax with a melting point of 60℃ and emulsifier at a mass ratio of 9:1) with a thickness of 3μm is coated on the non-coated surface of the base paper, dried at 70℃ for 1.5min, and the remaining steps and parameters are the same as in Example 1.

[0062] Technical effect: blocking moisture from entering from the back of the base paper, cooperating with the front coating, and comprehensively improving the overall moisture-proof ability of the backing paper.

[0063] Working principle: the paraffin emulsion forms a moisture-proof layer on the back of the base paper, which together with the front coating layer blocks moisture, reducing the effect of moisture on the stainless steel plate.

[0064] Experimental data: water absorption rate (24h) 3.8%, burst resistance 4.3kPa, air permeability 5.5mL / (min·cm²), and peeling force from stainless steel plate 1.4N / 25mm. After 3 months of storage, the surface of the stainless steel plate is bright and new, without any signs of moisture.

[0065] In summary, the moisture-proof treatment process and application of the stainless steel backing paper provided by the present application have the following working principle:

[0066] The moisture-proof treatment process of the stainless steel backing paper achieves efficient moisture-proof through multi-link synergistic effect:

[0067] 1. Pretreatment and activation: the raw paper is cleaned and dried to remove impurities and excess moisture, providing a clean and stable base for subsequent treatment; plasma treatment uses high-energy particles to bombard the surface of the paper, introducing active groups and increasing roughness, greatly improving the bonding ability of the base paper and the moisture-proof coating.

[0068] 2. Composite coating construction: the nanoparticles (silicon dioxide, zinc oxide, etc.) and resin (water-based polyurethane, polyvinylidene fluoride, etc.) in the moisture-proof coating form a synergistic structure, the nanoparticles fill the gaps between the resin, and a dense physical barrier is constructed to block the penetration of moisture; the resin provides flexibility and adhesion of the coating, ensuring the integrity of the barrier.

[0069] 3. Precise coating and curing: The dip-coating and blade-coating combined process ensures uniform coverage of the coating, gradient drying (hot air + infrared) avoids cracking or bubbling of the coating due to rapid drying, and fully cures the coating to form a stable moisture-proof structure; secondary coating or back coating treatment further enhances the moisture-proof effect by increasing the coating thickness, optimizing the composition, or adding a back moisture-proof layer.

[0070] Technical effects:

[0071] 1. Significant improvement in moisture resistance: The coating adhesion is enhanced through plasma activation, combined with the dense structure of the nano-composite coating, forming a multi-dimensional moisture-proof barrier that effectively blocks moisture intrusion, solving the problem of rusting of stainless steel plates due to traditional backing paper moisture.

[0072] 2. Optimization of mechanical properties: The coating tightly bonds with the base paper, synergistically improving the bursting strength and tear resistance of the backing paper, making it less prone to damage during packaging, transportation, and storage, ensuring long-term stable protection.

[0073] 3. Enhanced suitability for use: The coating surface is smooth and has moderate peel strength, allowing it to tightly adhere to the stainless steel plate to prevent displacement, and easily peel off when unpacked, avoiding residual or scratching the steel plate surface.

[0074] 4. Widened environmental adaptability: The treated backing paper maintains good performance in high humidity environments, extending the storage period of stainless steel plates and reducing quality loss due to environmental factors.

[0075] Method of use:

[0076] 1. Preparation of backing paper: Prepare moisture-proof stainless steel backing paper according to the above process (secondary coating or back coating treatment can be selected according to requirements) to ensure uniform and damage-free coating.

[0077] 2. Packaging operation: Place the stainless steel plate flat, cover the prepared backing paper on the surface of the steel plate, and wrap or stack the backing paper to completely cover the steel plate, ensuring that the backing paper tightly adheres to the steel plate without wrinkles or gaps.

[0078] 3. Storage and transportation: The packaged stainless steel plate can be stored in a conventional warehouse environment (temperature 20-30℃, relative humidity 60%-80%), and during transportation, avoid violent collisions that may damage the backing paper. Slowly peel off the backing paper when unpacking.

[0079] Through the above process and method of use, the moisture-proof stainless steel backing paper can provide comprehensive and long-term protection for stainless steel plates, meeting the high-performance requirements of the stainless steel industry for packaging materials.

[0080] The above shows and describes the basic principles of the present application, the above is only the preferred embodiment of the present application, and does not limit the present application, the above embodiment and the description in the specification only illustrate the principles of the present application, any modification, equivalent replacement and improvement within the scope of the present application, etc. should be included in the protection scope of the present application.

Claims

1. A moisture-proof treatment process for stainless steel liner paper, characterized in that... Includes the following steps: (1) Pretreatment of base paper: Sulfate wood pulp paper with a basis weight of 60-120 g / m² is selected as base paper. After ultrasonic cleaning with deionized water to remove surface impurities, it is dried in a vacuum drying oven at 60-80℃ until the moisture content is ≤3%; (2) Surface activation: The pretreated base paper is placed in a plasma treatment device and treated with a mixture of argon and oxygen in a volume ratio of 3:1 for 30 to 90 seconds under the conditions of power of 150 to 250W and vacuum of 50 to 100Pa to obtain surface activated base paper. (3) Preparation of moisture-proof coating: Nano-silica and nano-zinc oxide are mixed at a mass ratio of 1:0.5-2 and added to a mixed solvent of ethanol and deionized water with a volume ratio of 1:

1. The mixture is ultrasonically dispersed for 30-60 min to form a nano-dispersion. Waterborne polyurethane resin and polyvinylidene fluoride emulsion are mixed at a mass ratio of 3:

1. 5%-15% of the nano-dispersion is added to the mixture, and 0.5%-2% of the total mass of silane coupling agent KH-550 is added. The mixture is stirred for 2-4 h to obtain the moisture-proof coating. (4) Coating treatment: The dip-coating-scraping composite process is adopted. The surface-activated base paper is first dipped in the moisture-proof coating at a dipping speed of 2-5 m / min. Then, the wet film thickness is controlled to be 10-30 μm by the scraper to form a preliminary coating. (5) Drying and curing: The coated base paper is first dried in hot air at 80-100℃ for 3-5 minutes, then cured in infrared at 120-150℃ for 2-3 minutes, and then cooled to room temperature to obtain moisture-proof stainless steel backing paper.

2. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: The electrode spacing of the plasma processing equipment in step (2) is 5-15 mm, and the base paper running speed is 10-20 m / min during processing.

3. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: The nano-silica in step (3) has a particle size of 10-50 nm and the nano-zinc oxide has a particle size of 20-80 nm; the solid content of the waterborne polyurethane resin is 30%-50% and the solid content of the polyvinylidene fluoride emulsion is 40%-60%.

4. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: The comma-shaped scraper is used for scraping in step (4), with the angle between the scraper and the base paper being 30-60° and the scraping pressure being 0.1-0.3MPa.

5. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: The hot air drying speed in step (5) is 1-3 m / s, and the infrared curing uses a medium-wave infrared lamp with a wavelength of 2-5 μm and an irradiation intensity of 50-100 kW / m². 2 .

6. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: It also includes step (6) secondary coating: the same moisture-proof coating is used to coat the backing paper surface obtained in step (5) a second time, with a wet film thickness of 5-15μm, and then the drying and curing process of step (5) is repeated, with the total coating thickness controlled at 15-45μm.

7. The moisture-proof treatment process for stainless steel liner paper according to claim 6, characterized in that: In the second-coating moisture-proof coating, the amount of nano-dispersion added is increased by 2% to 5% compared with the first coating, and 1% to 3% of polytetrafluoroethylene micro powder is added, wherein the particle size of the polytetrafluoroethylene micro powder is 1-5 μm.

8. The moisture-proof treatment process for stainless steel liner paper according to claim 1, characterized in that: It also includes step (7) back coating treatment: a layer of paraffin emulsion with a thickness of 2-5μm is coated on the uncoated side of the base paper and dried at 60-80℃ for 1-2 minutes. The solid content of the paraffin emulsion is 10%-20%, and it is composed of microcrystalline wax with a melting point of 50-70℃ and emulsifier in a mass ratio of 9:

1.

9. The moisture-proof treatment process for stainless steel liner paper according to any one of claims 1-8, characterized in that: The moisture-proof stainless steel liner paper has a 24-hour water absorption rate of ≤5%, a burst strength of ≥3.5kPa, an air permeability of ≤10mL / (min·cm²), and a peel force to the stainless steel plate of 0.5~1.5N / 25mm.

10. The application of stainless steel liner paper prepared by the moisture-proof treatment process described in any one of claims 1-9 in the packaging of stainless steel plates, characterized in that: The stainless steel plate is a cold-rolled stainless steel plate with a thickness of 0.1 to 2 mm. The lining paper is wrapped around the stainless steel plate by a winding method. After being stored for 3 months in an environment with a temperature of 20-30℃ and a relative humidity of 60% to 80%, the surface of the stainless steel plate is free of rust and watermarks.

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