Anti-slip paper base for coating dies and method for manufacturing the same

Abstract

The application belongs to the technical field of papermaking, and particularly relates to an anti-skid paper base for a coating mold and a preparation method thereof. In order to solve the problem that the coating mold lacks effective anti-skid design in the prior art, the application provides an anti-skid paper base for a coating mold and a preparation method thereof. The anti-skid paper base is provided with a coating layer on the front and back surfaces of the base body. The front coating layer comprises a styrene-acrylic latex, a butadiene-styrene latex, a polyurethane resin and modified alkali lignin. The back coating layer is added with components such as nano-silicon dioxide and nano-calcium carbonate to improve the anti-skid performance. The preparation process involves steps such as wood pulp disintegration, chemical addition, molding spraying, glue dipping and drying, high-temperature cross-linking and groove modification, so that the final product has high strength, good air permeability and water resistance, and the friction coefficient is significantly improved.

Description

Technical Field

[0001] This application belongs to the field of papermaking technology, and specifically relates to an anti-slip paper base for coating molds and its preparation method. Background Technology

[0002] Coated abrasives, as a crucial industrial tool, are widely used in various fields such as automobile manufacturing, metal processing, furniture production, and electronic equipment assembly. Their basic structure involves fixing abrasive particles to a flexible or semi-rigid substrate using an adhesive, providing efficient grinding and polishing services for workpieces with various complex shapes. With the increasing demands for processing precision in modern manufacturing and the growing market demand for efficient, safe, and environmentally friendly products, the research and application of coated abrasives has become a significant focus of industrial attention.

[0003] The core of coated abrasives lies in their ability to flexibly adapt to different types of workpieces and maintain good performance during operation. This involves not only selecting suitable base materials to ensure sufficient mechanical strength and support, but also considering how to improve the product's wear resistance and tear resistance to extend its service life and reduce replacement frequency. Furthermore, coated abrasives should possess excellent water resistance in humid environments to prevent structural damage or performance degradation due to moisture intrusion. Simultaneously, to ensure user safety and improve work efficiency, coated abrasives must have a certain degree of anti-slip properties to prevent accidental slippage during handheld operation.

[0004] While existing coated abrasive technology has reached a high level in some aspects, there are still many problems to be solved in practical applications. Traditional coated abrasives mostly use paper, cloth, or synthetic fiber fabrics as substrates and natural rubber, animal glue, or synthetic resins as binders to fix the abrasive grains, but existing technologies still have some limitations.

[0005] Ordinary paper-based materials tend to lose hardness under wet conditions, affecting grinding performance; while cloth or synthetic fiber fabrics may wear or tear under high-intensity use, leading to a shortened product lifespan. Traditional binders are prone to failure under extreme temperature changes or contact with liquids, potentially causing abrasive grains to detach and reducing work efficiency. Especially in high-temperature and high-humidity environments, the performance stability of binders is a significant challenge. Furthermore, existing coated abrasives lack effective anti-slip designs, reducing operational safety and efficiency and increasing safety hazards. Current manufacturing processes still have room for improvement in achieving precise and uniform control over abrasive grain distribution and coating thickness. Drying techniques and surface finishing methods also have room for optimization; for example, traditional drying processes are time-consuming, impacting production efficiency; surface finishing techniques are relatively simple, making it difficult to create complex textures, limiting the product's aesthetics and anti-slip performance.

[0006] In conclusion, although coated abrasive technology has made some progress, there are still many problems that need to be solved in practical applications. Summary of the Invention

[0007] To address the lack of effective anti-slip design in existing coated abrasives, this application provides an anti-slip paper base for coated molds and its preparation method. The anti-slip paper base has a coating layer on both the front and back sides of the substrate, achieving excellent anti-slip effect.

[0008] This application provides an anti-slip paper base for coating molds, which includes the following structure in sequence: a front coating layer, a substrate, and a back coating layer, wherein the front coating layer and the back coating layer are attached to both sides of the substrate;

[0009] The front coating layer comprises the following components by weight:

[0010] 30-60 parts of styrene-acrylic latex, 30-60 parts of styrene-butadiene latex, 10-20 parts of polyurethane resin, and 3-7 parts of modified alkali lignin;

[0011] The substrate is paper-based;

[0012] The back coating layer comprises the following components by weight:

[0013] Styrene-acrylic latex 30-60 parts, styrene-butadiene latex 30-60 parts, nano silica 1-2 parts, nano calcium carbonate 2-12 parts, glycerin 1-2 parts, modified alkali lignin 3-7 parts, drying agent 1-2 parts.

[0014] This application also provides a method for preparing an anti-slip paper base for coating molds, comprising the following steps:

[0015] S1. Softwood and hardwood pulps are broken down to a break-down concentration of 5.0% to 4.0%, and then pulped using a pulper to a freeness of 30 to 40°SR to obtain broken-down wood pulp;

[0016] S2. Add defoamer, PAE wet strength agent, polyacrylamide and aluminum sulfate to the addition tank. Pump the beaten wood pulp obtained in S1 into the addition tank in advance and adjust the concentration to 3% to 3.5%. Perform internal sizing to obtain pulp.

[0017] S3. The pulp in step S2 is formed by a wire paper machine. After forming, starch is sprayed onto the wet end. Starch and alkyl ketene dimer sizing agent are sprayed onto the paper surface simultaneously on both sides to perform wire part sizing.

[0018] S4. After the mesh is sprayed with adhesive, it is pressed and then dried. The drying temperature is 90-130℃ and the time is 30-180s.

[0019] S5. After drying, add the dryer to the sizing machine for dry sizing, and then dry it again;

[0020] S6. After drying, the matrix is ​​obtained by calendering using a calender.

[0021] S7. Coating the front side of the calendered substrate, and then performing high-temperature crosslinking at 130℃~150℃ for 30~120s to obtain the front coating layer.

[0022] S8. Then, back coating is performed, followed by high-temperature crosslinking at 130℃~150℃ for 30~120s to obtain the back coating layer.

[0023] S9. Use a grooved roller to finish the paper;

[0024] S10. Use a winding device to wind the paper, and then package it to obtain the non-slip coated paper base.

[0025] Furthermore, in step S1, the weight ratio of softwood pulp to hardwood pulp is 5-8:2-5, preferably 7:3.

[0026] Furthermore, the PAE wet strength agent mentioned in step S2 is a polyamide-epoxychloropropane resin with a solid content of 12-13%, a viscosity of 35-70 cp, and a pH of 4-5.

[0027] Furthermore, the defoamer in step S2 is one or more of the following: emulsified silicone oil, higher carbon alcohol fatty acid ester complex, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether, or polydimethylsiloxane.

[0028] Furthermore, the starch in step S3 is cationic starch with a concentration of 2-6%, and the alkyl ketene dimer sizing agent is a cationic alkyl ketene dimer sizing agent with a concentration of 1-4%.

[0029] Furthermore, the impregnation of the dryer in step S5 uses an impregnation solution, and the raw material composition of the impregnation solution, by weight, is as follows:

[0030] 30-50 parts of styrene-acrylic latex, 40-60 parts of phenolic resin, 10-20 parts of polyvinyl alcohol, and 3-5 parts of hydroxypropyl methylcellulose.

[0031] Furthermore, the drying process described in step S5 is a combination of an infrared drying oven and a drying cylinder. The infrared drying oven reaches a temperature of 220-260°C, and the process involves instantaneous ultra-high temperature curing for 3-5 seconds, followed by drying in a drying oven at 90-140°C for 10-25 seconds.

[0032] Furthermore, by weight, step S2 contains 0.5 to 1 part of defoamer, 3 to 5 parts of PAE wet strength agent, 3 to 5 parts of polyacrylamide, and 6 to 10 parts of aluminum sulfate.

[0033] Furthermore, by weight, 2 to 6 parts of starch and 1 to 4 parts of alkyl ketene dimer sizing agent are used in step S3.

[0034] Furthermore, the drying agent is a fatty acid salt, ketone, ester, etc.

[0035] This application first involves mixing softwood pulp and hardwood pulp in a specific ratio and breaking them down to a specified concentration and freeness. This process ensures optimal bonding strength and air permeability between fibers, laying a solid foundation for subsequent processes. Softwood pulp provides excellent tensile strength and toughness, while the fine fibers of hardwood pulp fill the gaps between fibers, providing optimal air permeability and further enhancing the overall strength of the paper.

[0036] Next, defoamers, PAE wet strength agents, polyacrylamide, and aluminum sulfate are added to the addition tank. The wet strength agent improves the wet strength of the paper and also makes the paper less prone to breakage during subsequent processes and sizing. The defoamer quickly removes fine air bubbles trapped between fibers, eliminates foam floating on the pulp surface, dissolves air in the pulp, and eliminates large bubbles on the water surface, thus reducing the impact of air bubbles on the process, preventing the formation of voids, reducing paper breaks, ensuring the loss of fibers and wet-end chemicals, resulting in better paper uniformity and significantly improved quality. Polyacrylamide improves the dewatering performance of the pulp, increases the retention rate of fine fibers and fillers, and reduces raw material consumption. Aluminum sulfate significantly improves the paper's water resistance and impermeability, increases the retention rate of fine fibers and fillers, improves the filtration performance of the pulp, thereby improving the paper's uniformity and strength.

[0037] Subsequently, the paper formed by the fourdrinier paper machine is sprayed with cationic starch and alkyl ketene dimer sizing agent before pressing. This treatment method improves the retention rate of alkyl ketene dimers more effectively than traditional in-pulp addition, thereby enhancing the sizing effect and significantly improving the physical strength of the paper. This application uses a combination of infrared drying oven and drying cylinder. The infrared drying oven reaches a temperature of 220–260°C, first performing instantaneous ultra-high temperature curing, followed by drying in the drying cylinder at 90–140°C. By continuously adjusting the drying curve and optimizing these conditions, the binder can be fully cured, improving the overall structural strength of the sandpaper. Comparative tests show that paper dried using this method has a tensile strength 3–5% higher and a tear resistance more than 5% higher than normal paper.

[0038] The impregnation process uses a specially formulated impregnation solution containing styrene-acrylic latex, phenolic resin, polyvinyl alcohol, and hydroxypropyl methylcellulose (HMCMC). These substances work together on the paper surface to form a strong and elastic protective film, enhancing not only the paper's abrasion resistance and heat resistance but also its excellent adhesion. Cellulose acts as a toughening agent to improve the paper's toughness, while HMCMC acts as a highly efficient binder to improve the sandpaper's adhesion, making it more durable and stable. Furthermore, HMCMC improves the sandpaper's suspension properties, preventing the abrasive particles from settling and agglomerating during manufacturing, thus ensuring the smoothness and consistency of the sandpaper surface. The film-forming properties of HMCMC effectively improve the abrasion resistance and heat resistance of the sandpaper, extending its service life, and its excellent water retention helps control the drying speed and hardness of the sandpaper.

[0039] The coating formulation used in the front coating layer contains styrene-acrylic latex, styrene-butadiene latex, polyurethane resin, and modified alkali lignin. Polyurethane resin is a high-molecular-weight material with high strength, tear resistance, and abrasion resistance. It can undergo a self-crosslinking reaction at high temperatures to form a thermoplastic elastomer, exhibiting good wear resistance and yellowing resistance. The addition of modified alkali lignin to the coating improves the hydrophilicity and reactivity of the coating surface. Alkali lignin has a low relative molecular mass and high polydispersity; its main structural units include syringyl, guaiacol, and p-hydroxyphenyl. Upon pyrolysis at high temperatures, guaiacol and methoxycatechol fully bind with the fibers, improving anti-slip performance. The back coating layer also contains nano-silica, nano-calcium carbonate, glycerin, modified alkali lignin, and a drying agent. The nano-calcium carbonate has a particle size of 0.01 micrometers to 0.1 micrometers, which is significantly smaller than ordinary calcium carbonate, resulting in good compatibility with latex. The nano-silica has a particle size of 10 to 15 nanometers. Its particles are small in size, have many micropores, a large specific surface area, and good dispersibility.

[0040] Nanomaterials such as nano-calcium carbonate and nano-silica were added to the coating as anti-slip particles, improving the anti-slip performance of the paper. These nanomaterials, after modification, were combined with an aqueous emulsion to form a composite coated anti-slip paper with a high coefficient of friction. Experiments showed that when the mass ratio of nano-silica to nano-calcium carbonate was 1:7, with 1 part nano-silica, 7 parts nano-calcium carbonate, and 2 parts glycerol, and the drying temperature was 70℃, the prepared composite anti-slip paper achieved a static friction coefficient of 0.802, exhibiting excellent anti-slip performance.

[0041] Adding glycerin as a binder to the coating adjusts its viscosity and also improves its anti-slip properties. When the mass fraction of nano-calcium carbonate is 4%, the static friction coefficient meets the standard requirements, but the coating viscosity is 120 mPa·s, higher than the suitable viscosity (20–100 mPa·s) widely used in industrial production. Glycerin reduces the coating viscosity. Experiments showed that with a glycerin mass fraction of 2%, the anti-slip paper prepared had a static friction coefficient of 0.707, and the coating viscosity was 78.50 mPa·s. This setting provides the best friction performance.

[0042] A drier is a substance that accelerates the drying of a coating film. Its function is to speed up the oxidation, polymerization, and drying of the coating, achieving rapid drying. It reduces the flow rate of liquid on the paper surface, thus reducing leveling. Reduced leveling makes the coating more textured, preventing a smooth coating surface and reducing friction. Water-based driers can reduce the surface tension of water, making it easier for water in the coating to detach from the surface. This allows moisture on the coating surface to be more easily absorbed and evaporated by the air, thus promoting the drying process. Secondly, water-based driers can increase the evaporation rate of the solvent, thereby removing moisture from the coating surface more quickly.

[0043] Finally, grooved finishing rollers replace traditional soft pressure rollers, creating unique textures on the product surface, enhancing friction and aesthetics, while also providing some anti-counterfeiting features. Soft pressure rollers are primarily made of cast iron or stainless steel; if the material is too hard, it can damage the coating on the surface and reduce friction. Grooved finishing rollers, on the other hand, add patterns to a steel roller, creating a textured surface that enhances the product's three-dimensionality, increases friction, improves aesthetics, and provides some anti-counterfeiting properties. Detailed Implementation

[0044] The following specific embodiments further illustrate the technical solution and effects of the present invention. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0045] The equipment used in the preparation method of this invention can all be equipment known in the art. Unless otherwise specified, all raw materials used in this invention are commercially available.

[0046] The PAE wet strength agent is a polyamide-epoxychloropropane resin with a solid content of 12-13%, a viscosity of 35-70 cp, and a pH of 4-5; the modified alkali lignin is a sulfonated modified alkali lignin produced by Guangzhou Fengsen New Materials Co., Ltd., model MN-1; the alkyl ketene dimer sizing agent is cationic, produced by Zhejiang Chuanhua Huayang Chemical Co., Ltd.; the defoamer is a high carbon alcohol fatty acid ester complex produced by Zhejiang Chuanhua Huayang Chemical Co., Ltd.; and the drying agent is produced by Shandong Qilin Chemical Co., Ltd., model DOP.

[0047] Example 1

[0048] This application provides an anti-slip paper base for coating molds, comprising the following structures in sequence: a front coating layer, a substrate, and a back coating layer, wherein the front coating layer and the back coating layer are attached to both sides of the substrate, and the preparation method includes the following steps:

[0049] S1. Softwood and hardwood pulps are broken down to a break-down concentration of 5.0%, with a weight ratio of softwood pulp to hardwood pulp of 8:5. The pulps are then beaten to a freeness of 40°SR using a refiner to obtain the beaten wood pulp.

[0050] S2. Add 1 part defoamer, 4 parts PAE wet strength agent, 4 parts polyacrylamide, and 8 parts aluminum sulfate to the addition tank. Pump the beaten wood pulp obtained in S1 into the addition tank in advance and adjust the concentration to 3 wt%. Perform internal sizing to obtain the pulp.

[0051] S3. The pulp in step S2 is formed by a long wire paper machine. After forming, starch is sprayed onto the wet end. Four parts of starch and three parts of alkyl ketene dimer sizing agent are sprayed onto the paper surface on both sides at the same time to perform wire part sizing.

[0052] S4. After the mesh is sprayed with adhesive, it is pressed and then dried at a temperature of 90℃ for 180 seconds.

[0053] S5. Add the glue to the glue applicator for dry impregnation. The glue solution includes 30 parts by weight of styrene-acrylic latex, 60 parts of phenolic resin, 10 parts of polyvinyl alcohol, and 5 parts of hydroxypropyl methylcellulose. Then dry it by using a combination of infrared drying oven and drying cylinder. The infrared drying oven temperature reaches 240℃. First, it is instantaneously cured at ultra-high temperature for 4 seconds, and then the oven temperature is 100℃ for 20 seconds.

[0054] S6. After drying, the matrix is ​​obtained by calendering using a calender.

[0055] S7. The coating on the front side of the calendered substrate includes 30 parts of styrene-acrylic latex, 60 parts of styrene-butadiene latex, 10 parts of polyurethane resin and 7 parts of modified alkali lignin by weight. Then, it is subjected to high-temperature crosslinking at 130℃ for 120s to obtain the front coating layer.

[0056] S8. Then, the back coating is carried out. The coating consists of 30 parts of styrene-acrylic latex, 60 parts of styrene-butadiene latex, 1 part of nano silica, 7 parts of nano calcium carbonate, 2 parts of glycerin, 3 parts of modified alkali lignin, and 2 parts of drying agent by weight. The coating is then cross-linked at 150°C for 30 seconds to obtain the back coating layer.

[0057] S9. Use a grooved roller to finish the paper;

[0058] S10. Use a winding device to wind the paper, and then package it to obtain the non-slip coated paper base.

[0059] Example 2

[0060] This application provides an anti-slip paper base for coating molds, comprising the following structures in sequence: a front coating layer, a substrate, and a back coating layer, wherein the front coating layer and the back coating layer are attached to both sides of the substrate, and the preparation method includes the following steps:

[0061] S1. Softwood and hardwood pulps are broken down to a break-down concentration of 4.0%, with a weight ratio of softwood pulp to hardwood pulp of 5:2. The pulps are then beaten to a freeness of 30°SR using a refiner to obtain the beaten wood pulp.

[0062] S2. Add 0.5 parts of defoamer, 5 parts of PAE wet strength agent, 3 parts of polyacrylamide, and 6 parts of aluminum sulfate to the addition tank. Pump the beaten wood pulp obtained in S1 into the addition tank in advance and adjust the concentration to 3.5 wt%. Perform internal sizing to obtain the pulp.

[0063] S3. The pulp in step S2 is formed by a long wire paper machine. After forming, starch is sprayed onto the wet end. Two parts of starch and one part of alkyl ketene dimer sizing agent are sprayed onto the paper surface on both sides at the same time to perform wire part sizing.

[0064] S4. After the mesh is sprayed with adhesive, it is pressed and then dried at a temperature of 130℃ for 30 seconds.

[0065] S5. Add the glue to the glue applicator for dry glue impregnation. The glue impregnation solution includes 50 parts by weight of styrene-acrylic latex, 40 parts of phenolic resin, 20 parts of polyvinyl alcohol, and 3 parts of hydroxypropyl methylcellulose. Then dry it by using a combination of infrared drying oven and drying cylinder. The infrared drying oven temperature reaches 260℃, and it is first instantaneously cured at ultra-high temperature for 5 seconds, followed by drying in the oven at 90℃ for 25 seconds.

[0066] S6. After drying, the matrix is ​​obtained by calendering using a calender.

[0067] S7. The coating on the front side of the calendered substrate is made of 60 parts by weight of styrene-acrylic latex, 30 parts by weight of styrene-butadiene latex, 20 parts by weight of polyurethane resin and 3 parts by weight of modified alkali lignin. Then, the coating is cross-linked at 150°C for 30 seconds to obtain the front coating layer.

[0068] S8. Then, the back coating is carried out. The coating consists of 60 parts of styrene-acrylic latex, 30 parts of styrene-butadiene latex, 2 parts of nano silica, 2 parts of nano calcium carbonate, 2 parts of glycerin, 7 parts of modified alkali lignin, and 1 part of drying agent by weight. The coating is then subjected to high-temperature cross-linking at 130°C for 120 seconds to obtain the back coating layer.

[0069] S9. Use a grooved roller to finish the paper;

[0070] S10. Use a winding device to wind the paper, and then package it to obtain the non-slip coated paper base.

[0071] Example 3

[0072] This application provides an anti-slip paper base for coating molds, comprising the following structures in sequence: a front coating layer, a substrate, and a back coating layer, wherein the front coating layer and the back coating layer are attached to both sides of the substrate, and the preparation method includes the following steps:

[0073] S1. Softwood and hardwood pulps are broken down to a break-down concentration of 3.5%, with a weight ratio of softwood pulp to hardwood pulp of 7:3. The pulps are then beaten to a freeness of 35°SR using a refiner to obtain the beaten wood pulp.

[0074] S2. Add 0.5 parts of defoamer, 3 parts of PAE wet strength agent, 5 parts of polyacrylamide, and 10 parts of aluminum sulfate to the addition tank. Pump the beaten wood pulp obtained in S1 into the addition tank in advance and adjust the concentration to 3.5 wt%. Perform internal sizing to obtain the pulp.

[0075] S3. The pulp in step S2 is formed by a long wire paper machine. After forming, starch is sprayed onto the wet end. Six parts of starch and four parts of alkyl ketene dimer sizing agent are sprayed onto the paper surface on both sides at the same time to perform wire part sizing.

[0076] S4. After the mesh is sprayed with adhesive, it is pressed and then dried at a temperature of 110℃ for 100 seconds.

[0077] S5. Add the glue to the glue applicator for dry impregnation. The glue solution includes 40 parts by weight of styrene-acrylic latex, 50 parts of phenolic resin, 15 parts of polyvinyl alcohol, and 4 parts of hydroxypropyl methylcellulose. Then dry it using a combination of infrared drying oven and drying cylinder. The infrared drying oven reaches a temperature of 220℃, and first instantaneous ultra-high temperature curing is performed for 5 seconds. Then the oven temperature is 140℃ for 15 seconds.

[0078] S6. After drying, the matrix is ​​obtained by calendering using a calender.

[0079] S7. The coating on the front side of the calendered substrate is made of 50 parts by weight of styrene-acrylic latex, 50 parts by weight of styrene-butadiene latex, 15 parts by weight of polyurethane resin and 5 parts by weight of modified alkali lignin. Then, the coating is cross-linked at 140°C for 80 seconds to obtain the front coating layer.

[0080] S8. Then, the back coating is carried out. The coating consists of 50 parts by weight of styrene-acrylic latex, 50 parts by weight of styrene-butadiene latex, 2 parts by weight of nano silica, 12 parts by weight of nano calcium carbonate, 1 part by weight of glycerin, 5 parts by weight of modified alkali lignin, and 1 part by weight of drying agent. The coating is then subjected to high-temperature cross-linking at 140°C for 80 seconds to obtain the back coating layer.

[0081] S9. Use a grooved roller to finish the paper;

[0082] S10. Use a winding device to wind the paper, and then package it to obtain the non-slip coated paper base.

[0083] The preparation method of Comparative Example 1 is the same as that of Example 1, but no modified alkali lignin is added to the coatings applied to both sides.

[0084] The preparation method of Comparative Example 2 is the same as that of Example 1, but the drying in step S5 is done in an oven instead of an infrared drying oven, with the temperature set at 100°C.

[0085] The preparation method of Comparative Example 3 is the same as that of Example 1, but double-sided coating is not performed, and only the back coating layer is retained.

[0086] The preparation method of Comparative Example 4 is the same as that of Example 1, but double-sided coating is not performed, and only the front coating layer is retained.

[0087] The products obtained from the examples and comparative examples were subjected to performance testing:

[0088] (1) Air permeability test:

[0089] By comparing air permeability, the permeability of paper to air or other gases under different pressures can be evaluated. The standard method of GB / T 22901-2008 is adopted: this method measures the average airflow rate through a unit area sample per unit time under a unit pressure difference, expressed in micrometers per pascal-second.

[0090] (2) Roughness test:

[0091] The method used is GB / T 2679.4-1994, "Determination of Roughness of Paper and Paperboard," also known as the air leakage method. This method is based on the principle of measuring the airflow between the paper surface and the metal ring under specific pressure. The rougher the paper surface, the greater the airflow, and the higher the roughness value.

[0092] (3) Water resistance test:

[0093] The QB / T 1668-1992 Cobb Absorbency Tester Method is adopted. The Cobb Absorbency Tester Method is a precise method for measuring the water absorption of paper and paperboard. It calculates the surface water absorption value by measuring the mass change of paper after absorbing water under specific conditions.

[0094] (4) Leveling test:

[0095] The leveling process of paper coating refers to the process by which the coating, after being applied, slowly flows across the paper surface due to surface tension, gradually forming a smooth plane. Typically, the paper is tilted at a 45° angle, and a drop of water is placed using a dropper to test the width of the water as it flows across the paper surface.

[0096] The test results are shown in the table below.

[0097]

Claims

1. A mold coated anti-skid paper base, characterized in that: sequentially comprising the following structures: a front coating layer, a base and a back coating layer, the front coating layer and the back coating layer being attached to both sides of the base; the front coating layer comprises the following components by weight fraction: 30-60 parts of styrene-acrylic latex, 30-60 parts of butadiene-styrene latex, 10-20 parts of polyurethane resin, and 3-7 parts of modified alkali lignin; the base is a paper base; the back coating layer comprises the following components by weight fraction: 30-60 parts of styrene-acrylic latex, 30-60 parts of butadiene-styrene latex, 1-2 parts of nano-silicon dioxide, 2-12 parts of nano-calcium carbonate, 1-2 parts of glycerol, 3-7 parts of modified alkali lignin, and 1-2 parts of a quick-drying agent, the weight fraction ratio of the nano-silicon dioxide to the nano-calcium carbonate being 1:7; the modified alkali lignin is sulfonated modified alkali lignin; and a preparation method of the mold coated anti-skid paper base, comprising the following steps: S1, disintegrating coniferous wood pulp and broadleaf wood pulp at a disintegration mass concentration of 5.0%-4.0%, and beating the disintegrated wood pulp to a beating degree of 30-40°SR by a beater to obtain beaten wood pulp; S2, adding the beaten wood pulp obtained in S1 into a dosing tank, adjusting the mass concentration to 3%-3.5%, and adding a defoaming agent, PAE wet strength agent, polyacrylamide and aluminum sulfate into the dosing tank to perform in-pulp sizing to obtain pulp; S3, forming the pulp obtained in step S2 by a long net paper machine, spraying starch in a wet part after forming, and spraying the starch and alkyl ketene dimer sizing agent onto the paper surface at the same time to perform web spraying; S4, after the web spraying, performing pressing and then drying at a temperature of 90-130℃ for 30-180s; S5, adding a sizing machine to perform dry part impregnation, the dry part impregnation using a sizing liquid, the sizing liquid comprising the following raw materials by weight fraction: 30-50 parts of styrene-acrylic latex, 40-60 parts of phenolic resin, 10-20 parts of polyvinyl alcohol, and 3-5 parts of hydroxypropyl methyl cellulose; after the impregnation, performing drying by a combination of an infrared drying box and a drying cylinder, the infrared drying box being heated to a temperature of 220-260℃, and being instantaneously super-high-temperature solidified for 3-5s, and then being dried in a subsequent oven at a temperature of 90-140℃ for 10-25s; S6, performing calendering by a calender to obtain the base; S7, coating the front surface of the calendered base, and then performing high-temperature crosslinking at 130-150℃ for 30-120s to obtain the front coating layer; S8, then performing back coating, and then performing high-temperature crosslinking at 130-150℃ for 30-120s to obtain the back coating layer; S9, using a grooved roller to modify the paper; S10, using a winding device to wind and package to obtain the anti-skid coated paper base. 2.The mold coated anti-skid paper base according to claim 1, characterized in that: the weight ratio of the coniferous wood pulp to the broadleaf wood pulp in step S1 is 5-8:2-5. 3.The mold coated anti-skid paper base according to claim 1, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The PAE wet strength agent in step S2 is polyamide-epichlorohydrin resin, the solid content of the wet strength agent is 12-13%, the viscosity is 35-70 cp, and the pH is 4-5.

4. The anti-skid paper base for coating mold according to claim 1, wherein: The defoaming agent in step S2 is one or more of emulsified silicone oil, high-carbon alcohol fatty acid ester compound, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylamine ether, polyoxypropylene glycerol ether, and polydimethylsiloxane.

5. The anti-skid paper base for coating mold according to claim 1, wherein: The defoaming agent is 0.5-1 parts, the PAE wet strength agent is 3-5 parts, the polyacrylamide is 3-5 parts, and the aluminum sulfate is 6-10 parts by weight.

6. The anti-skid paper base for coating mold according to claim 1, wherein: The starch in step S3 is cationic starch, and the concentration is 2-6 wt%; the alkyl ketene dimer sizing agent is cationic alkyl ketene dimer sizing agent, and the concentration is 1-4 wt%.

7. The anti-skid paper base for coating mold according to claim 1, wherein: The starch is 2-6 parts, and the alkyl ketene dimer sizing agent is 1-4 parts by weight.

Images