A surface ink printing process for hollow boards

Abstract

The present application relates to the technical field of ink, in particular to a surface ink printing process of hollow plate. The present application firstly carries out hydrophobic modification on carboxymethyl chitosan, reacts carboxymethyl chitosan and linoleic acid to generate hydrophobic chitosan, then mixes the hydrophobic chitosan, sodium alginate, acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid, N,N-methylene bisacrylamide and kaolin, carries out polymerization reaction, grinds and sieves the product after reaction to obtain polymer coated kaolin. The polymer coated kaolin is mixed with water-based acrylic resin, water-based polyurethane resin, pigment carbon black and deionized water to obtain ink. The ink prepared by the present application is applied to the surface of the hollow plate, and after drying, an ink layer with smooth and flat surface and good antibacterial property can be formed.

Description

Technical Field

[0001] This invention relates to the field of ink technology, specifically to a surface ink printing process for hollow boards. Background Technology

[0002] Hollow core boards are a new type of material with a hollow structure, waterproof and shockproof, and typically require ink printing on their surface. Water-based inks, compared to other types of inks, have significantly lower volatile organic compound (VOC) content, are odorless and non-toxic, and exhibit excellent safety performance, making them harmless to operators' health and environmentally friendly. In existing technologies, inorganic components are usually added during ink production to adjust the ink's flowability and viscosity. These inorganic components include calcium carbonate, clay, silica, or kaolin. However, kaolin is difficult to disperse directly in ink, and due to differences in particle size, density, hydrophilicity, charge, and compatibility, direct addition can cause water-based inks to float, develop color variations, become incompatible, and have poor adhesion. Therefore, modification is necessary. Summary of the Invention

[0003] The purpose of this invention is to provide a surface ink printing process for hollow boards to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a surface ink printing process for hollow boards, comprising the following steps:

[0005] Step 1:

[0006] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0007] S12: Add linolenic acid to ethanol, then add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide to obtain a linolenic acid solution;

[0008] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 70-90℃, react for 4-5 hours, cool to 30-40℃ and continue to react for 8-12 hours, and dialyze the reactants with distilled water to obtain hydrophobic chitosan.

[0009] Step 2:

[0010] S21: Add sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8-9 with sodium hydroxide solution under ice water bath, cool and then add hydrophobic chitosan, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0011] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate as an initiator, heat to 70-80℃, and copolymerize for 2-3 hours; dry, pulverize, and sieve the reactant solution to obtain polymer-coated kaolin.

[0012] Step 3:

[0013] Waterborne acrylic resin, waterborne polyurethane resin, pigment carbon black, and deionized water are mixed and stirred at 40-60°C for 15-20 minutes. Polymer-coated kaolin is added and stirred at 15-25°C for 30-40 minutes to obtain composite ink.

[0014] Step 4:

[0015] Pour composite ink into one end of the screen printing plate and use a squeegee to move the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; after the hollow board is dried, remove it and let it cool.

[0016] Furthermore, in S12, the molar ratio of linolenic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide is 1:1.5:1.5.

[0017] Furthermore, in S13, carboxymethyl chitosan and linolenic acid are mixed in a weight ratio of 1:1.

[0018] Furthermore, in S21, the amount of each component in the crosslinking mixed solution, by weight, is 1-2 parts sodium alginate, 4-6 parts hydrophobic chitosan, 1-1.5 parts acrylic acid, 1-1.5 parts 2-acrylamido-2-methylpropanesulfonic acid, and 0.3-0.5 parts crosslinking agent N,N-methylenebisacrylamide.

[0019] Furthermore, in S22, the polymer-coated kaolin contains 55-65% polymer and 35-45% kaolin by weight percentage.

[0020] Furthermore, in S22, the polymer-coated kaolin has a mesh size of 500–1000 mesh.

[0021] Furthermore, in step 3, the content of each component in the composite ink, by weight, is 15-20 parts waterborne acrylic resin, 14-18 parts waterborne polyurethane resin, 8-12 parts pigment carbon black, 58-66 parts deionized water, and 4-6 parts polymer-coated kaolin.

[0022] Furthermore, in step 4, the drying temperature is 40–45°C, and the drying time is 20–30 min.

[0023] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: To improve the dispersion performance of kaolin in water-based inks, this invention modifies it through a polymerization reaction. First, carboxymethyl chitosan and linoleic acid are reacted to generate hydrophobic chitosan, introducing unsaturated double bonds into the chitosan. Then, the hydrophobic chitosan, sodium alginate, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, N,N-methylenebisacrylamide are mixed with kaolin. After the reaction, the product is pulverized and sieved to obtain polymer-coated kaolin. The polymer-coated kaolin is then mixed with water-based acrylic resin, water-based polyurethane resin, pigment carbon black, and deionized water to obtain the ink. In the polymer-coated kaolin, the hydrophobic chitosan not only provides antibacterial properties but also contains hydrophobic groups. These groups, along with hydrophilic groups such as sulfonic acid and carboxylic acid groups, act together to produce an amphiphilic surfactant-like effect, ensuring good dispersion performance of kaolin in the ink. In addition, the polymer has polar groups such as carboxyl groups, which have a good adsorption effect on pigment carbon black. They adsorb in the form of carbon black and form effective steric hindrance, thereby making the pigment carbon black uniformly dispersed in the ink.

[0024] It should be noted that during the preparation of polymer-coated kaolin, the polymer has a certain water absorption capacity, which causes it to swell after absorbing water, affecting the ink's fluidity. Simultaneously, it shrinks after drying, resulting in an uneven and defective film. During the polymer crosslinking process, kaolin particles physically fill the micropores of the network, making the micropores of the crosslinking network too narrow, reducing the polymer's water absorption and inhibiting its swelling, which affects ink performance. Therefore, controlling the mass of kaolin in polymer-coated kaolin to 35-45% achieves this effect. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The materials used in this invention and their sources are as follows: carboxymethyl chitosan is from Shanghai Yuanye Biotechnology Co., Ltd., product number S30948-500g; kaolin is from Xinze Kaolin, 6000 mesh; waterborne acrylic resin is from Shuaike Chemical, model SK6460; waterborne polyurethane resin is from Shuaike Chemical, product number SK9080D; and pigment carbon black is from Shaoxing Deke Carbon Black Co., Ltd., model DK201P.

[0027] Example 1: A surface ink printing process for hollow boards, comprising the following steps:

[0028] Step 1:

[0029] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0030] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0031] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 70℃, react for 4 hours, cool to 30℃ and continue to react for 8 hours, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0032] Step 2:

[0033] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0034] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 70℃, and copolymerize for 2 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 45% kaolin and 55% polymer.

[0035] Step 3:

[0036] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 40°C for 15 minutes. Then, 5g of polymer-coated kaolin is added and stirred at 15°C for 30 minutes to obtain the composite ink.

[0037] Step 4:

[0038] Pour composite ink into one end of the screen printing plate and use a squeegee to move the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 40°C to dry for 20 minutes, and then take it out to cool.

[0039] Example 2: A surface ink printing process for hollow boards, comprising the following steps:

[0040] Step 1:

[0041] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0042] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0043] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 80℃, react for 4.5h, cool to 35℃ and continue to react for 10h, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0044] Step 2:

[0045] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0046] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 75℃, and copolymerize for 2.5 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 45% kaolin and 55% polymer;

[0047] Step 3:

[0048] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 50°C for 18 minutes. Then, 5g of polymer-coated kaolin is added and stirred at 20°C for 35 minutes to obtain the composite ink.

[0049] Step 4:

[0050] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 42°C to dry for 25 minutes, and then take it out to cool.

[0051] Example 3: A surface ink printing process for hollow boards, comprising the following steps:

[0052] Step 1:

[0053] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0054] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0055] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 90℃, react for 5h, cool to 40℃ and continue to react for 12h, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0056] Step 2:

[0057] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0058] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 80℃, and copolymerize for 3 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 45% kaolin and 55% polymer;

[0059] Step 3:

[0060] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 60℃ for 20min. Then, 5g of polymer-coated kaolin is added and stirred at 25℃ for 40min to obtain composite ink.

[0061] Step 4:

[0062] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 45°C to dry for 30 minutes, and then take it out to cool.

[0063] Example 4: A surface ink printing process for hollow boards, comprising the following steps:

[0064] Step 1:

[0065] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0066] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0067] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 70℃, react for 4 hours, cool to 30℃ and continue to react for 8 hours, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0068] Step 2:

[0069] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0070] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 75℃, and copolymerize for 2.5 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 43% kaolin and 57% polymer;

[0071] Step 3:

[0072] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 55°C for 18 minutes. Then, 5g of polymer-coated kaolin is added and stirred at 22°C for 35 minutes to obtain the composite ink.

[0073] Step 4:

[0074] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 45°C to dry for 28 minutes, and then take it out to cool.

[0075] Example 5: A surface ink printing process for hollow boards, comprising the following steps:

[0076] Step 1:

[0077] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0078] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0079] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 90℃, react for 4.5h, cool to 40℃ and continue to react for 10h, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0080] Step 2:

[0081] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0082] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 75℃, and copolymerize for 2.5 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 40% kaolin and 60% polymer;

[0083] Step 3:

[0084] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 60°C for 15 minutes. Then, 5g of polymer-coated kaolin is added and stirred at 20°C for 35 minutes to obtain the composite ink.

[0085] Step 4:

[0086] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 45°C to dry for 25 minutes, and then take it out to cool.

[0087] Example 6: A surface ink printing process for hollow boards, comprising the following steps:

[0088] Step 1:

[0089] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0090] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0091] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 70℃, react for 5h, cool to 35℃ and continue to react for 11h, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0092] Step 2:

[0093] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0094] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 80℃, and copolymerize for 2 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 35% kaolin and 65% polymer.

[0095] Step 3:

[0096] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 60℃ for 20min. Then, 5g of polymer-coated kaolin is added and stirred at 25℃ for 30min to obtain composite ink.

[0097] Step 4:

[0098] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 45°C to dry for 20 minutes, and then take it out to cool.

[0099] Comparative Example 1: Kaolin was added directly, and the other parameters were the same as in Example 1.

[0100] Step 1:

[0101] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 40℃ for 15min. Then, 5g of kaolin is added and stirred at 15℃ for 30min to obtain the composite ink.

[0102] Step 2:

[0103] Pour composite ink into one end of the screen printing plate and use a squeegee to move the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 40°C to dry for 20 minutes, and then take it out to cool.

[0104] Comparative Example 2: No hydrophobic chitosan was added, and the other parameters were the same as in Example 2.

[0105] Step 1:

[0106] S11: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8.5 with sodium hydroxide solution under ice water bath, cool and add 1.2g of acrylic acid and 1g of 2-acrylamido-2-methylpropanesulfonic acid to obtain a cross-linked mixed solution;

[0107] S12: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 75℃, and copolymerize for 2.5 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 45% kaolin and 55% polymer.

[0108] Step 2:

[0109] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 50°C for 18 minutes. Then, 5g of polymer-coated kaolin is added and stirred at 20°C for 35 minutes to obtain the composite ink.

[0110] Step 3:

[0111] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 42°C to dry for 25 minutes, and then take it out to cool.

[0112] Comparative Example 3: The polymer content in the polymer-coated kaolin was increased, while the other parameters were the same as in Example 3.

[0113] Step 1:

[0114] S11: Dissolve carboxymethyl chitosan in deionized water to obtain a carboxymethyl chitosan solution;

[0115] S12: Add 1 mol of linolenic acid to ethanol, then add 1.5 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 mol of N-hydroxysuccinimide to obtain a linolenic acid solution;

[0116] S13: Add linolenic acid solution to carboxymethyl chitosan solution, heat to 90℃, react for 5h, cool to 40℃ and continue to react for 12h, dialyze the reactants with distilled water to obtain hydrophobic chitosan, wherein the mass ratio of carboxymethyl chitosan to linolenic acid is 1:1;

[0117] Step 2:

[0118] S21: Add 1g of sodium alginate to deionized water, mix and stir into a paste, adjust the pH to 8 with sodium hydroxide solution under ice water bath, cool and then add 4g of hydrophobic chitosan, 1.2g of acrylic acid, 1g of 2-acrylamido-2-methylpropanesulfonic acid and 0.5g of crosslinking agent N,N-methylenebisacrylamide to obtain a crosslinked mixed solution.

[0119] S22: Add kaolin to the crosslinking mixture, stir evenly, then add potassium persulfate (3.5% of the total monomer mass) as initiator, heat to 80℃, and copolymerize for 3 hours; dry, pulverize, and sieve the reactant solution to obtain kaolin coated with polymer with a mesh size of 500; by weight percentage, 20% kaolin and 80% polymer;

[0120] Step 3:

[0121] By weight, 20g of waterborne acrylic resin, 18g of waterborne polyurethane resin, 12g of pigment carbon black and 66g of deionized water are mixed and stirred at 60℃ for 20min. Then, 5g of polymer-coated kaolin is added and stirred at 25℃ for 40min to obtain composite ink.

[0122] Step 4:

[0123] Pour composite ink into one end of the screen printing plate and use a squeegee to push the composite ink to the other end; continue to push the squeegee back and forth to allow the composite ink to pass through the mesh and enter the surface of the hollow board to form an ink layer; move the hollow board to an environment with a temperature of 45°C to dry for 30 minutes, and then take it out to cool.

[0124] experiment:

[0125] The antibacterial properties of the composite inks prepared in Examples 1-6 and Comparative Examples 1-3 were tested: the composite inks were coated on the bottom of a petri dish, dried, and then Escherichia coli bacterial solution was added. The dishes were incubated at 37°C for 24 hours, and the antibacterial rate was calculated.

[0126] Observe the morphology of the ink layer on the surface of the hollow board prepared in Examples 1-6 and Comparative Examples 1-3 after drying. If the ink layer morphology is smooth and flat, it indicates that the ink has good flow properties; if the ink layer morphology has pits, air holes, etc., it indicates that the flow properties are poor.

[0127]

[0128]

[0129] Conclusions: Data from Examples 1-6 and Comparative Examples 1-3 show that the ink prepared by this invention has good antibacterial and flow properties. When used to prepare hollow fiberboard, it can improve the anti-corrosion performance of the hollow fiberboard, and the ink layer on the surface of the hollow fiberboard is smooth, flat, and aesthetically pleasing. The results of Example 1 and Comparative Example 1 indicate that polymer coating of kaolin not only improves the dispersibility of kaolin in the ink, resulting in better ink flow, but also imparts antibacterial properties to the ink. The results of Example 2 and Comparative Example 2 indicate that the addition of hydrophobic chitosan not only improves the antibacterial properties of the polymer but also makes the synthesized polymer amphiphilic, improving the dispersion performance of kaolin and pigment carbon black in the ink, thus resulting in a smooth and flat ink layer morphology. The results of Example 3 and Comparative Example 3 indicate that when the kaolin content in the polymer-coated kaolin decreases, the water absorption of the polymer-coated kaolin increases, leading to a decrease in ink printing performance and wrinkles in the ink layer.

[0130] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A surface ink printing process of a hollow board, characterized by: The method comprises the following steps: Step 1: S11: sodium alginate is added to deionized water, mixed and stirred into a paste, and the pH is adjusted to 8-9 with sodium hydroxide solution under ice water bath, and then hydrophobic chitosan, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and crosslinking agent N,N-methylene bisacrylamide are added to obtain a crosslinking mixed solution; S12: kaolin is added to the crosslinking mixed solution, stirred uniformly, and then initiator potassium persulfate is added, and the temperature is raised to 70-80 DEG C, and the copolymerization reaction is carried out for 2-3 h; the reaction solution is dried, crushed and sieved to obtain polymer-coated kaolin; Step 2: The aqueous acrylic resin, the aqueous polyurethane resin, the pigment carbon black and the deionized water are mixed, stirred at 40-60 DEG C for 15-20 min, and then the polymer-coated kaolin is added and stirred at 15-25 DEG C for 30-40 min to obtain a composite ink; Step 3: The composite ink is poured into one end of a silk screen printing plate, and a squeegee is used to push the composite ink to the other end; the squeegee is continuously pushed back and forth to make the composite ink pass through the mesh and form an ink layer on the surface of the hollow plate; the hollow plate is dried at 40-45 DEG C for 20-30 min, and then taken out and cooled to obtain a finished product; In step 1, the hydrophobic chitosan is prepared by the following method: carboxymethyl chitosan is dissolved in deionized water to obtain a carboxymethyl chitosan solution; linolenic acid is added to ethanol, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide are added to obtain a linolenic acid solution; the linolenic acid solution is added to the carboxymethyl chitosan solution, heated to 70-90 DEG C, reacted for 4-5 h, cooled to 30-40 DEG C and continued to react for 8-12 h, and the reaction product is dialyzed with distilled water to obtain hydrophobic chitosan; In S12, in the polymer-coated kaolin, the amount of each component is 55-65% polymer and 35-45% kaolin by weight percentage.

2. A process for printing ink on the surface of a hollow board according to claim 1, characterized in that: In the linolenic acid solution, the molar ratio of linolenic acid, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide is 1:1.5:1.

5.

3. A process for printing ink on the surface of a hollow board according to claim 1, characterized in that: In the preparation of hydrophobic chitosan, carboxymethyl chitosan and linolenic acid are reacted at a weight ratio of 1:

1.

4. The process for printing ink on the surface of a hollow board according to claim 1, wherein: In S11, in the crosslinking mixed solution, the amount of each component is 1-2 parts of sodium alginate, 4-6 parts of hydrophobic chitosan, 1-1.5 parts of acrylic acid, 1-1.5 parts of 2-acrylamido-2-methylpropanesulfonic acid and 0.3-0.5 parts of crosslinking agent N,N-methylene bisacrylamide by weight fraction.

5. A process for printing ink on the surface of a hollow board according to claim 1, characterized in that: In S12, the mesh size of the polymer-coated kaolin is 500-1000 mesh.

6. A process for printing ink on the surface of a hollow board according to claim 1, characterized in that: In step 2, the content of each component in the composite ink is 15-20 parts of aqueous acrylic resin, 14-18 parts of aqueous polyurethane resin, 8-12 parts of pigment carbon black, 58-66 parts of deionized water and 4-6 parts of polymer-coated kaolin by weight fraction.

7. A process for printing ink on the surface of a hollow board according to claim 1, characterized in that: In step 3, a protective layer is coated on the surface of the finished product; the protective layer is polytetrafluoroethylene with a thickness of 50-500 microns.

8. A hollow plate prepared by the surface ink printing process of the hollow plate according to any one of claims 1-7.

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