Preparation method of mildew-proof plate

Abstract

The invention discloses a preparation method of a mildew-proof board, and relates to the technical field of building boards, and the preparation method comprises the following steps: step 1, preparation of mildew-proof glue: mixing quaternary ammonium salt modified chitosan and antibacterial particles in dipping glue to obtain a mildew-proof glue material; 2, composite sizing is conducted, specifically, a density board and a mildew-proof sizing material are mixed and compounded, and a composite blank is obtained; and 3, hot press molding is conducted, specifically, the composite blank is placed in a mold, and the finished mildew-proof plate is obtained through hot press compounding. Wherein the quaternary ammonium salt modified chitosan and the antibacterial particles account for 2-15% of the mass of the mildew-proof rubber material; and the mould-proof glue material accounts for 6-15% of the mass of the composite blank material. According to the preparation method, the quaternary ammonium salt modified chitosan and the antibacterial particles are mixed so as to synergistically improve the sterilization and mildew-proof performance with the antibacterial particles, the quaternary ammonium salt modified chitosan and the antibacterial particles are fully immersed into material gaps of the density board, the density board is firmly adhered during hot press molding, a completely-closed structure is formed in the density board, and the long-term, lasting and effective antibacterial and mildew-proof effects are achieved.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and in particular to a method for preparing a mildew-resistant building material. Background Technology

[0002] Medium-density fiberboard (MDF) is a type of engineered wood fiberboard. Its main component is wood fiber. It is formed by hot grinding, drying, gluing, laying, hot pressing, post-treatment, and sanding. It is an environmentally friendly alternative to solid wood furniture and building materials.

[0003] Chinese patent application CN117183033B discloses an antibacterial medium-density fiberboard and its manufacturing method. The antibacterial medium-density fiberboard and its manufacturing method include two parts: internal and external antibacterial treatment. Under the synergistic effect of natural antibacterial agents as the main component and inorganic antibacterial agents as the auxiliary component, the fibers in the board manufacturing process and the adhesives used for impregnating the surface decorative paper are simultaneously treated with antibacterial agents. This results in an antibacterial medium-density fiberboard with high antibacterial performance, no toxic decomposition products, environmental friendliness, and compliance with national standards for the basic physical properties of medium-density fiberboard.

[0004] However, when this antibacterial medium-density fiberboard is laminated with decorative paper impregnated with existing melamine resin adhesive, the antibacterial and mildew-proof functions are achieved by relying on the antibacterial effect of the melamine resin adhesive. However, when it is worn or cracked, the mildew-proof and antibacterial effects will be greatly reduced and the mildew-proof effect will be lost, which needs to be improved. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a method for preparing anti-mildew board, so as to achieve a long-lasting and effective antibacterial and anti-mildew effect. The specific solution is as follows: A method for preparing a mildew-resistant board includes the following steps: Step 1, Preparation of anti-mildew adhesive: Quaternary ammonium salt modified chitosan and antibacterial particles are mixed in impregnation adhesive to obtain anti-mildew adhesive material; Step 2, Composite Adhesive Application: Mix and bond the MDF material with the anti-mildew adhesive to obtain a composite preform; Step 3, Hot pressing: The composite blank is placed into the mold and hot-pressed to obtain the finished mildew-proof board; The quaternary ammonium salt modified chitosan and antibacterial particles account for 2-15% of the mass of the antifungal adhesive; the antifungal adhesive accounts for 6-15% of the mass of the composite preform.

[0006] Preferably, in step 1, the impregnating adhesive is urea-formaldehyde resin adhesive, phenolic resin adhesive, or phenolic-urea-formaldehyde resin adhesive.

[0007] Preferably, in step 2, the MDF material is composed of 60-80 parts by mass of wood fiber, 20-30 parts by mass of bamboo, and 5-20 parts by mass of wheat straw, which are then crushed, steamed at high temperature, ground under high pressure, and dried.

[0008] Preferably: the pulverization yields powder particles with a particle size less than 0.8 mm; the high-temperature cooking is performed at a controlled temperature of 100°C for a cooking time of 30-60 minutes; the high-pressure grinding is performed at a controlled pressure of 0.2-0.4 kg / cm². 2 The process yields fine powder with a particle size of less than 0.2 mm; the drying process involves controlling the temperature at 120-130℃ and drying the fine powder to a moisture content of 13-25%.

[0009] Preferably, in step 3, the temperature of the hot-pressing composite is 150-180℃, the pressure is controlled at 40-80MPa, and the time is 3-10min.

[0010] Preferably, in step 1, the antibacterial particles are composed of zinc borate and one of zinc-based antibacterial particles or silver-based antibacterial particles in a mass ratio of 10:1-2; the zinc-based antibacterial particles are purchased from Guangzhou Aihaoer Anti-mildew and Antibacterial Technology Co., Ltd., and the silver-based antibacterial particles are purchased from Guangzhou Jiaxin Technology Co., Ltd.

[0011] Preferably, in step 1, the preparation method of the quaternary ammonium salt modified chitosan includes step ①, mixing chitosan, glacial acetic acid and deionized water at a mass ratio of 1:1:48, and stirring to obtain a chitosan solution; step ②, adding an initiator to the chitosan solution, adding a quaternary ammonium salt under nitrogen protection, and then stirring in a water bath at 70-85℃ for 3-5 hours to obtain a grafted mixture; step ③, adding sodium hydroxide to the grafted mixture and adjusting the pH to 11 to obtain a precipitate; and step ④, drying the precipitate under vacuum to obtain the finished quaternary ammonium salt modified chitosan.

[0012] Preferably, the initiator is composed of cerium ammonium nitrate and ammonium bisulfite in a mass ratio of 8-9:1-2.

[0013] Preferably, the concentration of the initiator is 0.036-0.042 mol / L, and the molar ratio of the amount of the quaternary ammonium salt added to the chitosan is 1-1.1:1.

[0014] Preferably, the quaternary ammonium salt is (Me)₂R₁R₂N. + Furthermore, R1 and R2 are Me and MeO-(C2H4O). n Any combination of -C2H4-, Me with phenyl, and Et with phenyl.

[0015] As can be seen from the above scheme, this application provides a method for preparing a mildew-resistant board, which has the following beneficial effects: 1. By mixing quaternary ammonium salt modified chitosan with antibacterial particles, the antibacterial and antifungal properties are enhanced in synergy with the antibacterial particles. It fully penetrates into the material pores of MDF and firmly adheres to MDF during hot pressing, forming a completely closed structure inside, thus achieving a long-lasting and effective antibacterial and antifungal effect. 2. By mixing impregnating adhesive with quaternary ammonium salt modified chitosan and antibacterial particles, the quaternary ammonium salt modified chitosan is effectively dispersed while the antibacterial particles are orderly dispersed in the impregnating adhesive. This promotes the combination of antibacterial particles with MDF material, thereby achieving effective antibacterial and mildew-proof effects while preventing external air from entering between MDF materials and affecting the antibacterial and mildew-proof effects. 3. By combining zinc borate with zinc-based or silver-based antibacterial particles, zinc borate not only has effective antibacterial properties but also works synergistically with zinc-based or silver-based antibacterial particles and quaternary ammonium salt-modified chitosan to achieve effective antibacterial and antifungal effects. At the same time, it promotes the synergistic enhancement of the structural strength of the antifungal board by zinc-based or silver-based antibacterial particles, so as to prevent cracking and affect the stability of the internal structure, thereby achieving effective antibacterial and antifungal effects. 4. By using a grafting reaction between quaternary ammonium salt and chitosan, quaternary ammonium salt modified chitosan with a grafting rate of more than 20% is obtained. This allows the quaternary ammonium salt modified chitosan to significantly improve the dispersion performance of antibacterial particles in the impregnating adhesive, while promoting effective structural integration with MDF material. This significantly improves the structural strength of MDF material after hot pressing, while achieving effective antibacterial and antifungal effects. Detailed Implementation

[0016] The technical solutions described below in conjunction with the embodiments of this application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0017] It should be mentioned that the zinc-based antibacterial particles were purchased from Guangzhou Aihaoer Anti-mildew and Antibacterial Technology Co., Ltd., and the silver-based antibacterial particles were purchased from Guangzhou Jiaxin Technology Co., Ltd.

[0018] The preparation method of the anti-mildew board of this application will be described in detail below.

[0019] A method for preparing a mildew-resistant board includes the following steps: Step 1, Preparation of anti-mildew adhesive: Quaternary ammonium salt modified chitosan and antibacterial particles are mixed in impregnation adhesive to obtain anti-mildew adhesive material, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles in anti-mildew adhesive material is 2-15%; Step 2, Composite Adhesive Application: Mix and bond the MDF material with the anti-mildew adhesive to obtain a composite blank, with the anti-mildew adhesive accounting for 6-15% of the mass of the composite blank; Step 3, Hot pressing: Place the composite blank into the mold and hot press to obtain the finished mildew-proof board. The hot pressing temperature is 150-180℃, the pressure is controlled at 40-80MPa, and the time is 3-10min.

[0020] The impregnating adhesive is urea-formaldehyde resin adhesive, phenolic resin adhesive, or phenolic-urea-formaldehyde resin adhesive.

[0021] MDF (Medium-Density Fiberboard) is composed of 60-80 parts by weight of wood fiber, 20-30 parts by weight of bamboo, and 5-20 parts by weight of wheat straw, which are crushed, cooked at high temperature, and ground under high pressure before drying. The crushing process produces powder particles with a diameter of less than 0.8 mm. The high-temperature cooking is carried out at a controlled temperature of 100℃ for 30-60 minutes. The high-pressure grinding is carried out at a controlled pressure of 0.2-0.4 kg / cm². 2 The process yields fine powder with a particle size of less than 0.2 mm. Drying is performed at a controlled temperature of 120-130℃, drying the fine powder until its moisture content reaches 13-25%.

[0022] It should be mentioned that the antibacterial particles in the embodiments of this application are composed of zinc borate and one of zinc-based antibacterial particles or silver-based antibacterial particles in a mass ratio of 10:1-2.

[0023] Furthermore, the preparation method of quaternary ammonium salt modified chitosan in the embodiments of this application includes the following steps: Step ①: Chitosan, glacial acetic acid and deionized water are mixed at a mass ratio of 1:1:48 and stirred to obtain a chitosan solution; Step ②: An initiator is added to the chitosan solution, and quaternary ammonium salt is added under nitrogen protection, followed by stirring in a water bath at 70-85℃ for 3-5 hours to obtain a grafted mixture; Step ③: Sodium hydroxide is added to the grafted mixture and the pH is adjusted to 11 to obtain a precipitate; Step ④: The precipitate is vacuum dried to obtain the finished quaternary ammonium salt modified chitosan.

[0024] The initiator consists of cerium ammonium nitrate and ammonium bisulfite in a mass ratio of 8-9:1-2. The concentration of the initiator is 0.036-0.042 mol / L, and the molar ratio of the quaternary ammonium salt to chitosan is 1-1.1:1. The quaternary ammonium salt is (Me)₂R₁R₂N. + Furthermore, R1 and R2 are Me and MeO-(C2H4O). n Any combination of -C2H4-, Me with phenyl, and Et with phenyl.

[0025] Therefore, the grafting reaction between the quaternary ammonium salt and chitosan will achieve a grafting rate of more than 20%, and the obtained quaternary ammonium salt modified chitosan will significantly improve its compatibility with the impregnating adhesive, thus dispersing it orderly in the impregnating adhesive and achieving a synergistic effect and containing antibacterial particles. In addition, the quaternary ammonium salt modified chitosan will enhance the adhesive ability of the impregnating adhesive, thereby strengthening the structural strength and sealing performance of the anti-mildew board prepared by this method.

[0026] Example 1 A method for preparing a mildew-resistant board includes the following steps: Step 1, Preparation of anti-mildew adhesive: Quaternary ammonium salt modified chitosan and antibacterial particles are mixed in impregnation adhesive to obtain anti-mildew adhesive material, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles in anti-mildew adhesive material is 2%, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles is 1:1. Step 2, Composite Adhesive Application: Mix and bond the MDF material with the anti-mildew adhesive to obtain a composite blank, wherein the anti-mildew adhesive accounts for 6% of the mass of the composite blank; Step 3, Hot pressing: Place the composite blank into the mold and hot press to obtain the finished mildew-proof board. The hot pressing temperature is 150℃, the pressure is controlled at 40MPa, and the time is 10min.

[0027] The impregnating adhesive is a phenolic resin adhesive.

[0028] The MDF (Medium-Density Fiberboard) material is composed of 60 parts by weight of wood fiber, 20 parts by weight of bamboo, and 5 parts by weight of wheat straw, which are crushed, cooked at high temperature, and ground under high pressure before drying. The crushing process yields powder particles with a diameter of less than 0.8 mm. The high-temperature cooking is performed at a controlled temperature of 100℃ for 30 minutes. The high-pressure grinding is performed at a controlled pressure of 0.2 kg / cm². 2 The process yields fine powder with a particle size of less than 0.2 mm. Drying is carried out at a controlled temperature of 120°C, and the fine powder is dried to a moisture content of 13%.

[0029] It should be mentioned that the antibacterial particles in the embodiments of this application are composed of zinc borate and zinc-based antibacterial particles in a mass ratio of 10:1.

[0030] Furthermore, the preparation method of quaternary ammonium salt modified chitosan in the embodiments of this application includes the following steps: Step ①: Chitosan, glacial acetic acid and deionized water are mixed at a mass ratio of 1:1:48 and stirred to obtain a chitosan solution; Step ②: An initiator is added to the chitosan solution, and quaternary ammonium salt is added under nitrogen protection, followed by stirring in a 70°C water bath for 3 hours to obtain a grafted mixture; Step ③: Sodium hydroxide is added to the grafted mixture and the pH is adjusted to 11 to obtain a precipitate; Step ④: The precipitate is vacuum dried to obtain the finished quaternary ammonium salt modified chitosan.

[0031] The initiator consists of cerium ammonium nitrate and ammonium bisulfite in a mass ratio of 8:1. The concentration of the initiator is 0.036 mol / L, and the molar ratio of the quaternary ammonium salt to chitosan is 1:1. The quaternary ammonium salt is (Me)₂R₁R₂N. + Furthermore, R1 and R2 are Me and MeO-(C2H4O). n -C2H4.

[0032] Example 2 A method for preparing a mildew-resistant board includes the following steps: Step 1, Preparation of anti-mildew adhesive: Quaternary ammonium salt modified chitosan and antibacterial particles are mixed in impregnation adhesive to obtain anti-mildew adhesive material, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles in anti-mildew adhesive material is 8%, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles is 1.1:1; Step 2, Composite Adhesive Application: Mix and bond the MDF material with the anti-mildew adhesive to obtain a composite blank, wherein the anti-mildew adhesive accounts for 10% of the mass of the composite blank; Step 3, Hot pressing: Place the composite blank into the mold and hot press to obtain the finished mildew-proof board. The hot pressing temperature is 160℃, the pressure is controlled at 50MPa, and the time is 5min.

[0033] The impregnating adhesive is a phenolic urea-formaldehyde resin adhesive.

[0034] The MDF (Medium-Density Fiberboard) material is composed of 70 parts by weight of wood fiber, 25 parts by weight of bamboo, and 10 parts by weight of wheat straw, which are crushed, cooked at high temperature, and ground under high pressure before drying. The crushing process yields powder particles with a diameter of less than 0.8 mm. The high-temperature cooking is performed at a controlled temperature of 100℃ for 45 minutes. The high-pressure grinding is performed at a controlled pressure of 0.3 kg / cm². 2 The process yields fine powder with a particle size of less than 0.2 mm. Drying is carried out at a controlled temperature of 125°C, and the fine powder is dried to a moisture content of 20%.

[0035] It should be mentioned that the antibacterial particles in the embodiments of this application are composed of zinc borate and zinc-based antibacterial particles in a mass ratio of 20:3.

[0036] Furthermore, the preparation method of quaternary ammonium salt modified chitosan in the embodiments of this application includes the following steps: Step ①: Chitosan, glacial acetic acid and deionized water are mixed in a mass ratio of 1:1:48 and stirred to obtain a chitosan solution; Step ②: An initiator is added to the chitosan solution, and quaternary ammonium salt is added under nitrogen protection, followed by stirring in an 80°C water bath for 4 hours to obtain a grafted mixture; Step ③: Sodium hydroxide is added to the grafted mixture and the pH is adjusted to 11 to obtain a precipitate; Step ④: The precipitate is vacuum dried to obtain the finished quaternary ammonium salt modified chitosan.

[0037] The initiator consists of cerium ammonium nitrate and ammonium bisulfite in a mass ratio of 4:1. The concentration of the initiator is 0.040 mol / L, and the molar ratio of the quaternary ammonium salt to chitosan is 1.1:1. The quaternary ammonium salt is (Me)₂R₁R₂N. + Furthermore, R1 and R2 are Me and phenyl, respectively.

[0038] Example 3 A method for preparing a mildew-resistant board includes the following steps: Step 1, Preparation of anti-mildew adhesive: Quaternary ammonium salt modified chitosan and antibacterial particles are mixed in impregnation adhesive to obtain anti-mildew adhesive material, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles in anti-mildew adhesive material is 15%, and the mass ratio of quaternary ammonium salt modified chitosan to antibacterial particles is 1.2:1. Step 2, Composite Adhesive Application: Mix and bond the MDF material with the anti-mildew adhesive to obtain a composite blank, wherein the anti-mildew adhesive accounts for 15% of the mass of the composite blank; Step 3, Hot pressing: Place the composite blank into the mold and hot press to obtain the finished mildew-proof board. The hot pressing temperature is 180℃, the pressure is controlled at 80MPa, and the time is 3min.

[0039] The impregnating adhesive is a phenolic resin adhesive.

[0040] The MDF (Medium-Density Fiberboard) material is composed of 80 parts by weight of wood fiber, 30 parts by weight of bamboo, and 20 parts by weight of wheat straw, which are crushed, cooked at high temperature, and ground under high pressure before drying. The crushing process yields powder particles with a diameter of less than 0.8 mm. The high-temperature cooking is performed at a controlled temperature of 100℃ for 60 minutes. The high-pressure grinding is performed at a controlled pressure of 0.4 kg / cm². 2 The process yields fine powder with a particle size of less than 0.2 mm. Drying is carried out at a controlled temperature of 130℃, and the fine powder is dried to a moisture content of 25%.

[0041] It should be mentioned that the antibacterial particles in the embodiments of this application are composed of zinc borate and silver-based antibacterial particles in a mass ratio of 5:1.

[0042] Furthermore, the preparation method of quaternary ammonium salt modified chitosan in the embodiments of this application includes the following steps: Step ①: Chitosan, glacial acetic acid and deionized water are mixed in a mass ratio of 1:1:48 and stirred to obtain a chitosan solution; Step ②: An initiator is added to the chitosan solution, and quaternary ammonium salt is added under nitrogen protection, followed by stirring in an 85°C water bath for 5 hours to obtain a grafted mixture; Step ③: Sodium hydroxide is added to the grafted mixture and the pH is adjusted to 11 to obtain a precipitate; Step ④: The precipitate is vacuum dried to obtain the finished quaternary ammonium salt modified chitosan.

[0043] The initiator consists of cerium ammonium nitrate and ammonium bisulfite in a mass ratio of 9:2. The concentration of the initiator is 0.042 mol / L, and the molar ratio of the quaternary ammonium salt to chitosan is 1.1:1. The quaternary ammonium salt is (Me)₂R₁R₂N. + Furthermore, R1 and R2 are Et and phenyl.

[0044] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that Comparative Example 1 did not add quaternary ammonium salt modified chitosan.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that Comparative Example 2 uses chitosan instead of quaternary ammonium salt modified chitosan.

[0046] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that Comparative Example 3 uses quaternized chitosan powder, which was purchased from Beijing Jieershuang High Technology Co., Ltd.

[0047] The following tests were conducted on the above embodiments and comparative examples, and the test results are shown in Table 1.

[0048] The test was conducted based on JIS Z2801:2000 "Detection and Evaluation of Antibacterial Properties of Antimicrobial Products" and ASTM G21-96 "Determination of Antifungal Resistance of Synthetic Polymer Materials".

[0049] The antibacterial rate was determined using standard PE plastic sheets as a control material. Both the submitted material and the control material had dimensions of 50 mm. 50mm.

[0050] Bacterium 1 is Escherichia coli, Bacterium 2 is Staphylococcus aureus, and Bacterium 3 is Candida albicans.

[0051] Table 1. Results of Antibacterial and Antifungal Tests

[0052] As shown in Table 1 above, the quaternary ammonium salt modified chitosan in this application embodiment does not show a significant improvement in overall antibacterial rate compared to Comparative Example 3. However, this was only tested under a one-day (24-hour) test standard. Long-term use will lead to significant differences in the data, demonstrating that the technical solution of this application significantly improves the antibacterial rate compared to using quaternary ammonium salt modified chitosan powder. Meanwhile, compared to Comparative Example 2 and Comparative Example 1, the modified chitosan, due to the grafting of quaternary ammonium salt, exhibits improved antibacterial properties. Furthermore, the difference in the type of quaternary ammonium salt affects the bonding effect of the quaternary ammonium salt modified chitosan with the MDF material after mixing with antibacterial particles, thus influencing the antibacterial and anti-mold ability of the anti-mold board prepared by this method.

[0053] In summary, this application provides a method for preparing an anti-mold board. This method involves mixing quaternary ammonium salt-modified chitosan with antibacterial particles to synergistically enhance the antibacterial and anti-mold properties. The mixture fully penetrates the pores of the MDF material and firmly adheres to the MDF during hot pressing, forming a completely closed internal structure, thus achieving a long-lasting and effective antibacterial and anti-mold effect. Simultaneously, by mixing the impregnating adhesive with the quaternary ammonium salt-modified chitosan and antibacterial particles, the quaternary ammonium salt-modified chitosan is effectively dispersed while the antibacterial particles are orderly dispersed in the impregnating adhesive, promoting the binding of the antibacterial particles with the MDF material. This achieves an effective antibacterial and anti-mold effect while preventing external air from entering the MDF material and affecting the antibacterial and anti-mold effect. In the formulation of antibacterial particles, zinc borate is combined with zinc-based or silver-based antibacterial particles. This allows zinc borate to effectively combat bacteria and, in conjunction with the zinc-based or silver-based antibacterial particles and quaternary ammonium salt-modified chitosan, achieve effective antibacterial and antifungal effects. Simultaneously, the zinc-based or silver-based antibacterial particles synergistically enhance the structural strength of the antifungal board, preventing cracking and ensuring internal structural stability, thus achieving effective antibacterial and antifungal effects. Furthermore, the quaternary ammonium salt-modified chitosan, obtained through a grafting reaction between quaternary ammonium salt and chitosan, achieves a grafting rate greater than 20%. This significantly improves the dispersion performance of antibacterial particles in the impregnating adhesive while promoting effective structural integration with the MDF material. This significantly enhances the structural strength of the MDF material after hot pressing, achieving effective antibacterial and antifungal effects.

[0054] The terms “first,” “second,” “third,” “fourth,” etc., used in this application (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, or apparatus.

[0055] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0056] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for producing a mold resistant board, characterized by, It comprises the following steps: Step 1, antifungal glue preparation: mixing quaternary ammonium salt modified chitosan and antibacterial particles in impregnated glue to obtain antifungal glue; Step 2, composite sizing: mixing density board material with antifungal glue to obtain composite blank; Step 3, hot pressing forming: placing the composite blank into the mold to obtain finished antifungal board through hot pressing; The mass ratio of quaternary ammonium salt modified chitosan and antibacterial particles to the antifungal glue is 2-15%; The mass ratio of the antifungal glue to the composite blank is 6-15%; The preparation method of the quaternary ammonium salt modified chitosan comprises the following steps: ①, mixing chitosan, glacial acetic acid and deionized water in a mass ratio of 1:1:48 to obtain a chitosan solution by stirring; ②, adding an initiator to the chitosan solution, adding quaternary ammonium salt under nitrogen protection, and then treating with 70-85℃ water bath stirring for 3-5h to obtain a grafting mixture; ③, adding sodium hydroxide to the grafting mixture and adjusting the pH to 11 to obtain a precipitate; ④, vacuum drying the precipitate to obtain finished quaternary ammonium salt modified chitosan.

2. The method of claim 1, wherein the method further comprises: In step 1, the impregnated glue is urea-formaldehyde resin glue, phenol-formaldehyde resin glue or phenol-formaldehyde urea-formaldehyde resin glue.

3. The method of claim 1, wherein the method further comprises: In step 2, the density board material is composed of 60-80 parts of wood fiber, 20-30 parts of bamboo and 5-20 parts of wheat straw, which are crushed, high-temperature cooked, high-pressure ground and then dried; the high-temperature cooking is controlled at a temperature of 100℃ for 30-60 minutes; and the high-pressure grinding is controlled at a pressure of 0.2-0.4 kg / cm 2 . ​ 4. The method of claim 3, wherein the fungicide plate is prepared by the steps of: (a) preparing a mixture of the fungicide and the binder; (b) applying the mixture to the surface of the plate; and (c) drying the mixture. The powder particles with a particle size of less than 0.8mm are obtained by crushing; the fine powder with a particle size of less than 0.2mm is obtained by high-pressure grinding; the drying is controlled at a temperature of 120-130℃ to dry the fine powder to a water content of 13-25%.

5. The method of claim 1, wherein the method further comprises: In step 3, the temperature of the hot pressing is 150-180℃, and the pressure is controlled at 40-80MPa for 3-10min. ​ 6. The method of claim 1, wherein the method further comprises: In step 1, the antibacterial particles are composed of zinc borate and zinc-based or silver-based antibacterial particles in a mass ratio of 10:1-2. ​ 7. The method of claim 1, wherein the method further comprises: The initiator is composed of cerium nitrate and ammonium bisulfite in a mass ratio of 8-9:1-2. ​ 8. The method of claim 1, wherein the method further comprises: The concentration of the initiator is 0.036-0.042mol / L, and the molar ratio of the addition amount of the quaternary ammonium salt to the chitosan is 1-1.1:

1. ​ 9. The method of claim 1, wherein the method further comprises: the quaternary ammonium salt is (Me)2R1R2N + ; and R1 is Me and R2 is MeO-(C2H4O) n -C2H4-; or R1 is Me and R2 is phenyl; or R1 is Et and R2 is phenyl. ​

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