Highly antibacterial and moisture-proof wood board for furniture and preparation method thereof

Abstract

The invention relates to the field of wood boards, in particular to a highly antibacterial and moisture-proof wood board for furniture and a preparation method thereof. Polyvinyl alcohol, a self-made aqueous branched polyurethane dispersed composite antibacterial agent with hydrophobic side chains and sodium silicate are selected for joint modification as green, environmentally friendly, and formaldehyde-free impregnation treatment modifiers, and a substrate is subjected to vacuum pressure impregnation treatment; a zinc-based organic porous skeleton is in situ generated on nanocellulose to obtain composite nanocellulose, and the composite nanocellulose is composited with flaky nanoamino clay with antibacterial and mildew-proof effects by electrostatic action to serve as a reinforcing support skeleton in a substrate layer and as a nano container for a high-efficiency, broad-spectrum, and low-toxic antibacterial agent, carboxylbenzisothiazolinone; amino-branched siloxane and glyceryl monostearate are used as hydrophobic modification components to synthesize an aqueous branched polyurethane with double hydrophobic side chains.

Description

Technical Field

[0001] The invention relates to the field of wood boards, in particular to a highly antibacterial and moisture-proof wood board for furniture and a preparation method thereof. Background Art

[0002] Wood boards are commonly used components in existing furniture decoration, and wooden furniture is very popular in the building materials market. However, logs directly used as furniture components have defects such as easy moisture absorption, easy breeding of bacteria, and poor corrosion resistance. The current market usually uses modifiers to treat wood boards to improve their antibacterial and moisture-proof properties.

[0003] In view of the defects of existing wood such as soft material, low strength, unstable size, flammability and perishability, the existing market often uses aldehyde resins, acetylation and other methods for impregnation treatment, but there is the problem of releasing toxic gases such as formaldehyde and acetic acid, which will endanger human health and the natural environment; the existing market usually uses inorganic silicon such as sodium silicate and silica sol for formaldehyde-free modification, but there are also problems such as low toughness, high hygroscopicity, and easy loss of modifiers; and in daily living, people frequently come into contact with furniture, and friction and contact with furniture are inevitable. The wear and stain resistance of furniture is also a hot topic for consumers. Summary of the invention

[0004] The object of the present invention is to provide a highly antibacterial and moisture-proof wood board for furniture and a preparation method thereof, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for preparing a highly antibacterial and moisture-proof wooden board for furniture comprises the following steps:

[0007] S1: preparing an antibacterial impregnation solution using a composite antibacterial agent, polyvinyl alcohol, aqueous branched polyurethane, sodium silicate, and deionized water;

[0008] S2: placing the substrate into an antibacterial impregnation liquid for vacuum pressure impregnation treatment, and then heating and drying to obtain a substrate layer;

[0009] S3: Protective coatings were prepared using composite antimicrobial agents, microsilica, ethyl acetate, and waterborne branched polyurethane;

[0010] S4: coating the protective coating onto the substrate layer and curing the coating to obtain a highly antibacterial and moisture-proof wood board for furniture.

[0011] Furthermore, the working conditions of the vacuum pressure impregnation treatment are: pressure of 1.5-2MPa, time of 10-12h; the working conditions of the temperature drying are: first air drying to 65-70% moisture content, then heating to 100°C and drying to absolute dryness.

[0012] Furthermore, the substrate is one of a poplar veneer, a bamboo board, and a rosewood board.

[0013] Furthermore, the antibacterial impregnation liquid is composed of: 3-5 parts of composite antibacterial agent, 1-4 parts of polyvinyl alcohol, 10-15 parts of water-based branched polyurethane, 10-20 parts of sodium silicate, and 70-80 parts of deionized water, in parts by mass.

[0014] Furthermore, the mass ratio of the composite antibacterial agent, micron silica, ethyl acetate, and water-based branched polyurethane in the protective coating is 4:1:75:8.

[0015] Furthermore, the size of the micronized silica is 50-150 μm.

[0016] Furthermore, the preparation of the composite antibacterial agent comprises the following steps:

[0017] (1) Mixing magnesium chloride hexahydrate and anhydrous ethanol, adding 3-aminopropyltriethoxysilane, stirring at 25° C. for 10-12 hours, centrifuging, washing with anhydrous ethanol for 3-5 times, drying, crushing, dispersing in distilled water, and ultrasonically treating for 3-5 minutes to obtain a nanoamino clay dispersion;

[0018] (2) mixing zinc nitrate hexahydrate and N,N-dimethylformamide, adding a mixture of 2-aminobenzimidazole, benzimidazole and methanol, keeping the mixture at 18-25° C. for 10-12 hours, adding nanocellulose, heating the mixture to 30-40° C. for 3-5 hours, centrifuging the mixture for 5-10 minutes, washing the mixture with ethanol, and drying the mixture to obtain composite nanocellulose; mixing the composite nanocellulose and deionized water, adding a nanoamino clay dispersion, and keeping the mixture at 35-40° C. for 1-2 hours to obtain amino clay composite nanocellulose;

[0019] (3) 1,2-Benzisothiazol-3-one, potassium hydroxide and distilled water are mixed, heated to 115°C, sodium chloroacetate aqueous solution is added, the temperature is kept for 12-16 hours, cooled to 18-25°C, filtered under reduced pressure, the pH is adjusted to 1, washed with water, anhydrous ethanol and acetone in sequence, and dried to obtain carboxybenzisothiazolinone; amino clay composite nanocellulose, deionized water and carboxybenzisothiazolinone are mixed, ultrasonically stirred for 1-2 hours, stirred at 18-25°C for 10-12 hours, centrifuged, washed and dried to obtain a composite antibacterial agent.

[0020] Further, the preparation of the waterborne branched polyurethane comprises the following steps:

[0021] 1) Under nitrogen protection, 3-aminopropyltriethoxysilane, isocyanatepropyltriethoxysilane and toluene are mixed, kept at 75-80° C. for 22-24 hours, rotary evaporated and dried to obtain a composite preparation; the composite preparation, ethanol and distilled water are mixed, the pH is adjusted to 10, kept at 55-60° C. for 3-4 hours under nitrogen protection, rotary evaporated and dried to obtain amino-branched siloxane;

[0022] 2) Mix polycaprolactone diol, dibutyltin dilaurate and isophorone diisocyanate, keep the temperature at 35-40°C for 20-30min, heat to 75-80°C, add 1,4-butanediol, keep the temperature for 2-3h, cool to 35-40°C, add a mixed solution of acetone and N-methyldiethanolamine, heat to 70-75°C and keep the temperature for 1-2h, cool to 40°C, add a mixed solution of acetone and amino-branched siloxane, continue to keep the temperature for 1h, heat to 65-70°C and keep the temperature for 2h, add glyceryl monostearate, heat to 75-80°C and keep the temperature for 2-3h, add ethanol, cool to 40°C, add a mixed solution of acetone and glacial acetic acid, add deionized water, and perform rotary evaporation to obtain water-based branched polyurethane.

[0023] Furthermore, the mass ratio of amino-branched siloxane to glyceryl monostearate is 0.5:12.

[0024] Beneficial effects of the present invention:

[0025] The invention provides a highly antibacterial and moisture-proof wooden board for furniture and a preparation method thereof, so as to prepare a green, environmentally friendly, flame-retardant, antifouling, highly antibacterial and moisture-proof wooden board.

[0026] In the present invention, one of poplar veneer, bamboo board and rosewood board is selected as the substrate. In order to improve the moisture resistance and flame retardancy of the substrate, sodium silicate is used to modify the wood. In order to improve the problems of low toughness, high hygroscopicity and easy loss of the modifier when sodium silicate is added alone, polyvinyl alcohol, a self-made aqueous branched polyurethane dispersed composite antibacterial agent with hydrophobic side chains and sodium silicate are selected for joint modification as a green, environmentally friendly, formaldehyde-free impregnation treatment modifier. The substrate is subjected to vacuum pressure impregnation treatment, which effectively improves the mechanical properties, antibacterial properties and flame retardancy of the substrate.

[0027] The nanocellulose is introduced into the present invention to play a toughening effect. In order to give the wood board high antibacterial and moisture-proof and flame-retardant properties, a zinc-based organic porous skeleton is in situ generated on the nanocellulose to obtain a composite nanocellulose. The composite nanocellulose is compounded with a flaky nanoamino clay having an antibacterial and mildew-proof effect by electrostatic action, and the composite nanocellulose is used as a reinforcing support skeleton in the substrate layer, and at the same time as a nano container for a highly efficient, broad-spectrum, low-toxic antibacterial agent, carboxylbenzisothiazolinone, thereby giving the wood board high antibacterial and flame-retardant moisture-proof properties, and making the wood board have long-lasting antibacterial and antifouling effects; at the same time, the multiple active sites in the composite antibacterial agent help it to bond with the composite antibacterial agent. The composite antibacterial agent is combined with other raw materials to make the composite antibacterial agent adhere to the wooden board permanently and firmly, while achieving the enhancement, toughness, moisture-proof and mildew-proof properties of the wooden board; at the same time, the zinc-based organic porous skeleton in the composite antibacterial agent not only serves as a nanocontainer, but its unique porous structure can effectively delay or inhibit the generation and emission of smoke; the porous metal compounds formed by pyrolysis during the combustion process will promote the formation of a carbon layer and inhibit the release of toxic gases. At the same time, the porous structure of the composite antibacterial agent in the carbon layer will complicate the release pathways of pyrolysis products and toxic gases, thereby inhibiting the spread of flames and gas emissions, thereby improving the flame retardancy of the wooden board.

[0028] In order to improve the moisture-proof and hydrophobic properties of wood, amino-branched siloxane and glyceryl monostearate are used as hydrophobic modification components to synthesize water-based branched polyurethane with double hydrophobic side chains; water-based branched polyurethane is added to the antibacterial impregnation liquid to improve the compatibility of various raw materials in the antibacterial impregnation liquid and protective coating. After impregnation treatment, part of sodium silicate, water-based branched polyurethane, and composite antibacterial agent can enter the cell wall of wood, and polyvinyl alcohol can form a cross-linking effect between water-based branched polyurethane and wood; under high temperature and hypoxic conditions, the surface of the substrate layer will be carbonized, delaying the transfer of heat and oxygen to the interior of the wood, thereby hindering the combustion of the wood, and greatly improving the flame retardancy and deformation resistance of the substrate layer.

[0029] In order to give the wood board a fluorine-free, anti-fouling and wear-resistant surface, the mass ratio of the composite antibacterial agent and micron silica is controlled in the protective coating based on water-based branched polyurethane, so that they can jointly build a dense multi-level micro-raised hydrophobic structure, giving the protective layer excellent self-cleaning ability and wear resistance. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back, etc., the directional indication is only used to explain a specific posture such as the relative position relationship between the components, the movement status, etc. If the specific posture changes, the directional indication will also change accordingly. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0032] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0033] Embodiment 1: A method for preparing a highly antibacterial and moisture-proof wood board for furniture, comprising the following steps:

[0034] S1: preparing an antibacterial impregnation solution using a composite antibacterial agent, polyvinyl alcohol, aqueous branched polyurethane, sodium silicate, and deionized water;

[0035] The composition of the antibacterial impregnation liquid is as follows: 3 parts of composite antibacterial agent, 1 part of polyvinyl alcohol, 10 parts of water-based branched polyurethane, 10 parts of sodium silicate, and 70 parts of deionized water, in parts by mass.

[0036] S2: placing the substrate into an antibacterial impregnation liquid for vacuum pressure impregnation treatment, and then heating and drying to obtain a substrate layer;

[0037] The working conditions of vacuum pressure impregnation treatment are: pressure of 1.5MPa, time of 12h; the working conditions of temperature drying are: first air drying to 65% moisture content, then heating to 100℃ and drying to absolute dryness;

[0038] The preparation of the composite antibacterial agent comprises the following steps:

[0039] (1) 3.62 mmol of magnesium chloride hexahydrate and 20 mL of anhydrous ethanol were mixed, 5.9 mmol of 3-aminopropyltriethoxysilane was added, the mixture was stirred at 25° C. for 10 h, centrifuged, washed with anhydrous ethanol three times, dried, crushed, dispersed in 50 mL of distilled water, and ultrasonically treated for 3 min to obtain a nanoamino clay dispersion;

[0040] (2) 1.5 g of zinc nitrate hexahydrate and 50 mL of N,N-dimethylformamide were mixed, and a mixture of 0.48 g of 2-aminobenzimidazole, 0.18 g of benzimidazole, and 25 mL of methanol was added, and the mixture was kept warm at 18°C ​​for 12 h, and 1 g of nanocellulose was added, and the mixture was heated to 30°C and kept warm for 5 h, and centrifuged at 8000 r / min for 5 min, washed with ethanol, and dried to obtain composite nanocellulose; 2 g of composite nanocellulose and 60 mL of deionized water were mixed, and 1 g of nanoamino clay dispersion was added, and the mixture was kept warm at 35°C for 2 h to obtain amino clay composite nanocellulose;

[0041] (3) 8 g 1,2-benzisothiazol-3-one, 3.5 g potassium hydroxide, and 50 mL distilled water were mixed, heated to 115° C., 10 mL of 10% sodium chloroacetate aqueous solution was added, the mixture was kept warm for 12 h, cooled to 18° C., filtered under reduced pressure, the pH was adjusted to 1, and the mixture was washed with water, anhydrous ethanol, and acetone in sequence, and dried to obtain carboxybenzisothiazolinone; 1.2 g amino clay composite nanocellulose, 25 mL deionized water, and 0.5 g carboxybenzisothiazolinone were mixed, ultrasonically stirred for 1 h, stirred at 18° C. for 12 h, centrifuged, washed, and dried to obtain a composite antibacterial agent;

[0042] The preparation of waterborne branched polyurethane comprises the following steps:

[0043] 1) Under nitrogen protection, 50 mmol 3-aminopropyl triethoxysilane, 50 mmol isocyanate propyl triethoxysilane, and 100 mL toluene were mixed, kept at 75° C. for 24 h, rotary evaporated, and dried to obtain a composite preparation; 25 mmol of the composite preparation, 50 mL of ethanol, and 30 mmol of distilled water were mixed, the pH was adjusted to 10, and under nitrogen protection, the mixture was kept at 55° C. for 4 h, rotary evaporated, and dried to obtain an amino-branched siloxane;

[0044] 2) 17g polycaprolactone diol, 0.9g dibutyltin dilaurate, 75g isophorone diisocyanate were mixed, kept at 35°C for 30min, heated to 75°C, 19g 1,4-butanediol was added, kept warm for 2h, cooled to 35°C, 200mL acetone and a mixed solution of 25g N-methyldiethanolamine were added, heated to 70°C and kept warm for 2h, cooled to 40°C, 100mL acetone and a mixed solution of 0.25g amino-branched siloxane were added, and kept warm for 1h, heated to 65°C and kept warm for 2h, 6g monostearate was added, heated to 75°C and kept warm for 3h, 100mL ethanol was added, cooled to 40°C, 300mL acetone and a mixed solution of 20g glacial acetic acid were added, 1L deionized water was added, and rotary evaporation was performed to obtain an aqueous branched polyurethane;

[0045] S3: Protective coatings were prepared using composite antimicrobial agents, microsilica, ethyl acetate, and waterborne branched polyurethane;

[0046] The mass ratio of the composite antimicrobial agent, micronized silica, ethyl acetate, and waterborne branched polyurethane in the protective coating is 4:1:75:8;

[0047] The size of micronized silica is 50 μm;

[0048] S4: coating the protective coating onto the substrate layer and curing the coating to obtain a highly antibacterial and moisture-proof wood board for furniture.

[0049] Embodiment 2: A method for preparing a highly antibacterial and moisture-proof wood board for furniture, comprising the following steps:

[0050] S1: preparing an antibacterial impregnation solution using a composite antibacterial agent, polyvinyl alcohol, aqueous branched polyurethane, sodium silicate, and deionized water;

[0051] The composition of the antibacterial impregnation liquid is as follows: 4 parts of composite antibacterial agent, 2 parts of polyvinyl alcohol, 11 parts of water-based branched polyurethane, 15 parts of sodium silicate, and 75 parts of deionized water, in parts by mass.

[0052] S2: placing the substrate into an antibacterial impregnation liquid for vacuum pressure impregnation treatment, and then heating and drying to obtain a substrate layer;

[0053] The working conditions of vacuum pressure impregnation treatment are: pressure 1.8MPa, time 11h; the working conditions of temperature drying are: first air drying to 68% moisture content, then heating to 100℃ and drying to absolute dryness;

[0054] The preparation of the composite antibacterial agent comprises the following steps:

[0055] (1) 3.62 mmol of magnesium chloride hexahydrate and 20 mL of anhydrous ethanol were mixed, 5.9 mmol of 3-aminopropyltriethoxysilane was added, the mixture was stirred at 25° C. for 11 h, centrifuged, washed 4 times with anhydrous ethanol, dried, crushed, dispersed in 50 mL of distilled water, and ultrasonically treated for 4 min to obtain a nanoamino clay dispersion;

[0056] (2) 1.5 g of zinc nitrate hexahydrate and 50 mL of N,N-dimethylformamide were mixed, and a mixture of 0.48 g of 2-aminobenzimidazole, 0.18 g of benzimidazole, and 25 mL of methanol was added, and the mixture was kept warm at 20° C. for 11 h, and 1 g of nanocellulose was added, and the mixture was heated to 35° C. and kept warm for 4 h, and centrifuged at 8000 r / min for 8 min, and washed with ethanol, and dried to obtain composite nanocellulose; 2 g of composite nanocellulose and 60 mL of deionized water were mixed, and 1 g of nanoamino clay dispersion was added, and the mixture was kept warm at 38° C. for 1.5 h to obtain amino clay composite nanocellulose;

[0057] (3) 8 g 1,2-benzisothiazol-3-one, 3.5 g potassium hydroxide, and 50 mL distilled water were mixed, heated to 115° C., 10 mL of 10% sodium chloroacetate aqueous solution was added, the mixture was kept warm for 14 h, cooled to 20° C., filtered under reduced pressure, the pH value was adjusted to 1, and the mixture was washed with water, anhydrous ethanol, and acetone in sequence, and dried to obtain carboxybenzisothiazolinone; 1.2 g amino clay composite nanocellulose, 25 mL deionized water, and 0.5 g carboxybenzisothiazolinone were mixed, ultrasonically stirred for 1.5 h, stirred at 20° C. for 11 h, centrifuged, washed, and dried to obtain a composite antibacterial agent;

[0058] The preparation of waterborne branched polyurethane comprises the following steps:

[0059] 1) Under nitrogen protection, 50 mmol 3-aminopropyl triethoxysilane, 50 mmol isocyanate propyl triethoxysilane, and 100 mL toluene were mixed, kept at 78° C. for 23 h, rotary evaporated, and dried to obtain a composite preparation; 25 mmol of the composite preparation, 50 mL of ethanol, and 30 mmol of distilled water were mixed, the pH was adjusted to 10, and under nitrogen protection, the mixture was kept at 58° C. for 3.5 h, rotary evaporated, and dried to obtain amino-branched siloxane;

[0060] 2) 17g polycaprolactone diol, 0.9g dibutyltin dilaurate, 75g isophorone diisocyanate were mixed, kept at 38°C for 25min, heated to 78°C, 19g 1,4-butanediol was added, kept warm for 2.5h, cooled to 38°C, 200mL acetone and a mixture of 25g N-methyldiethanolamine were added, heated to 73°C and kept warm for 1.5h, cooled to 40°C, 100mL acetone and a mixture of 0.25g amino-branched siloxane were added, and kept warm for 1h, heated to 68°C and kept warm for 2h, 6g glyceryl monostearate was added, heated to 78°C and kept warm for 2.5h, 100mL ethanol was added, cooled to 40°C, 300mL acetone and a mixture of 20g glacial acetic acid were added, 1L deionized water was added, and rotary evaporation was performed to obtain an aqueous branched polyurethane;

[0061] S3: Protective coatings were prepared using composite antimicrobial agents, microsilica, ethyl acetate, and waterborne branched polyurethane;

[0062] The mass ratio of the composite antimicrobial agent, micronized silica, ethyl acetate, and waterborne branched polyurethane in the protective coating is 4:1:75:8;

[0063] The size of micronized silica is 50 μm;

[0064] S4: coating the protective coating onto the substrate layer and curing the coating to obtain a highly antibacterial and moisture-proof wood board for furniture.

[0065] Embodiment 3: A method for preparing a highly antibacterial and moisture-proof wood board for furniture, comprising the following steps:

[0066] S1: preparing an antibacterial impregnation solution using a composite antibacterial agent, polyvinyl alcohol, aqueous branched polyurethane, sodium silicate, and deionized water;

[0067] The composition of the antibacterial impregnation liquid is as follows: 5 parts of composite antibacterial agent, 4 parts of polyvinyl alcohol, 15 parts of water-based branched polyurethane, 20 parts of sodium silicate, and 80 parts of deionized water, in parts by mass.

[0068] S2: placing the substrate into an antibacterial impregnation liquid for vacuum pressure impregnation treatment, and then heating and drying to obtain a substrate layer;

[0069] The working conditions of vacuum pressure impregnation treatment are: pressure 2MPa, time 10h; the working conditions of temperature drying are: first air drying to 70% moisture content, then heating to 100℃ and drying to absolute dryness;

[0070] The preparation of the composite antibacterial agent comprises the following steps:

[0071] (1) 3.62 mmol of magnesium chloride hexahydrate and 20 mL of anhydrous ethanol were mixed, 5.9 mmol of 3-aminopropyltriethoxysilane was added, the mixture was stirred at 25° C. for 12 h, centrifuged, washed with anhydrous ethanol for 5 times, dried, crushed, dispersed in 50 mL of distilled water, and ultrasonically treated for 5 min to obtain a nanoamino clay dispersion;

[0072] (2) 1.5 g of zinc nitrate hexahydrate and 50 mL of N,N-dimethylformamide were mixed, and a mixture of 0.48 g of 2-aminobenzimidazole, 0.18 g of benzimidazole, and 25 mL of methanol was added, and the mixture was kept at 25° C. for 10 h, and 1 g of nanocellulose was added, and the mixture was heated to 40° C. and kept for 3 h, and the mixture was centrifuged at 8000 r / min for 10 min, and the mixture was washed with ethanol and dried to obtain composite nanocellulose; 2 g of composite nanocellulose and 60 mL of deionized water were mixed, and 1 g of nanoamino clay dispersion was added, and the mixture was kept at 40° C. for 1 h to obtain amino clay composite nanocellulose;

[0073] (3) 8 g 1,2-benzisothiazol-3-one, 3.5 g potassium hydroxide, and 50 mL distilled water were mixed, heated to 115° C., 10 mL of 10% sodium chloroacetate aqueous solution was added, the mixture was kept warm for 16 h, cooled to 18° C., filtered under reduced pressure, the pH value was adjusted to 1, and the mixture was washed with water, anhydrous ethanol, and acetone in sequence, and dried to obtain carboxybenzisothiazolinone; 1.2 g amino clay composite nanocellulose, 25 mL deionized water, and 0.5 g carboxybenzisothiazolinone were mixed, ultrasonically stirred for 2 h, stirred at 25° C. for 10 h, centrifuged, washed, and dried to obtain a composite antibacterial agent;

[0074] The preparation of waterborne branched polyurethane comprises the following steps:

[0075] 1) Under nitrogen protection, 50 mmol 3-aminopropyl triethoxysilane, 50 mmol isocyanate propyl triethoxysilane, and 100 mL toluene were mixed, kept at 80° C. for 22 h, rotary evaporated, and dried to obtain a composite preparation; 25 mmol of the composite preparation, 50 mL of ethanol, and 30 mmol of distilled water were mixed, the pH was adjusted to 10, and under nitrogen protection, the mixture was kept at 60° C. for 3 h, rotary evaporated, and dried to obtain amino-branched siloxane;

[0076] 2) 17g of polycaprolactone diol, 0.9g of dibutyltin dilaurate, and 75g of isophorone diisocyanate were mixed, kept at 40°C for 20min, heated to 80°C, 19g of 1,4-butanediol was added, kept warm for 3h, cooled to 40°C, 200mL of acetone and a mixed solution of 25g of N-methyldiethanolamine were added, heated to 75°C and kept warm for 1h, cooled to 40°C, 100mL of acetone and a mixed solution of 0.25g of amino-branched siloxane were added, and kept warm for 1h, heated to 70°C and kept warm for 2h, 6g of glyceryl monostearate were added, heated to 80°C and kept warm for 2h, 100mL of ethanol was added, cooled to 40°C, 300mL of acetone and a mixed solution of 20g of glacial acetic acid were added, 1L of deionized water was added, and rotary distillation was performed to obtain an aqueous branched polyurethane;

[0077] S3: Protective coatings were prepared using composite antimicrobial agents, microsilica, ethyl acetate, and waterborne branched polyurethane;

[0078] The mass ratio of the composite antimicrobial agent, micronized silica, ethyl acetate, and waterborne branched polyurethane in the protective coating is 4:1:75:8;

[0079] The size of micronized silica is 50 μm;

[0080] S4: coating the protective coating onto the substrate layer and curing the coating to obtain a highly antibacterial and moisture-proof wood board for furniture.

[0081] Comparative Example 1: Taking Example 3 as the control group, 20 parts of sodium silicate and 80 parts of deionized water were used to replace the antibacterial impregnation liquid, and the other processes were normal.

[0082] Comparative Example 2: Taking Example 3 as the control group, carboxybenzisothiazolinone was used to replace the composite antibacterial agent, and the other processes were normal.

[0083] Comparative Example 3: Taking Example 3 as the control group, the composite antibacterial agent was replaced by a nano-amino clay dispersion, and the other processes were normal.

[0084] Comparative Example 4: Taking Example 3 as the control group, nanocellulose was used to replace the composite antibacterial agent, and other processes were normal.

[0085] Comparative Example 5: Example 3 was used as the control group, amino-branched siloxane was not prepared, and other processes were normal.

[0086] Comparative Example 6: Taking Example 3 as the control group, the aqueous branched polyurethane was replaced with aqueous polyurethane (001: Langfang Wanteng Anticorrosion Materials Co., Ltd.), and the other processes were normal.

[0087] The base plate used in the embodiment and the comparative example is a poplar board, which is a fast-growing poplar with an age of 16 years, taken from a tree with a round and straight trunk without obvious appearance defects and flaws such as an elliptical trunk, with a breast diameter range of 31 cm and a height of 1-6 m from the base. After lumbering, it is dried to a moisture content of 10%, pressed and planed for use;

[0088] In the examples and comparative examples, the thickness of the substrate layer is 20 mm, and the thickness of the protective coating is 500 μm.

[0089] Source of raw materials:

[0090] Nanocellulose (100nm): Jinjinle Chemical Co., Ltd.; 1,2-Benzisothiazol-3-one 2634-33-5: Hubei Jusheng Technology Co., Ltd.; Polyvinyl alcohol P139545, sodium silicate S302432, magnesium chloride hexahydrate M116331, 3-aminopropyltriethoxysilane A107148, zinc nitrate hexahydrate Z111703, N,N-dimethylformamide D111999, 2-aminobenzimidazole A104845, benzimidazole B106095, sodium chloroacetate S1 08371, triethoxypropylsilane T106834, polycaprolactone diol P478032, dibutyltin dilaurate D100274, isophorone diisocyanate I109582, 1,4-butanediol B110391, N-methyldiethanolamine M105603, glyceryl monostearate G196240, micronized silica S433676: Aladdin reagent; anhydrous ethanol, methanol, potassium hydroxide, acetone, toluene, glacial acetic acid, ethyl acetate, analytical grade: Sinopharm reagent.

[0091] Performance Test:

[0092] Bending performance: refer to ASTMD790, use universal mechanical testing machine for three-point bending performance test, the diameter of support shaft and load rod are 10mm, the loading speed is 2mm / min, the wood board is prepared into a specimen with a length of 1000mm and a width of 100mm, and the ratio of span to thickness is 20:1; Hydrophobicity: 4μL water droplet is used for water contact angle test; Antibacterial performance: Escherichia coli is used as the strain, and the plate method is used for testing; Flame retardant performance: refer to the flame retardant grade of vertical burning test in UL-94; Formaldehyde emission: refer to GB18580-2017 for determination; specific data are shown in Table 1;

[0093] Table 1

[0094]

[0095]

[0096] The invention provides a highly antibacterial and moisture-proof wooden board for furniture and a preparation method thereof, so as to prepare a green, environment-friendly, flame-retardant, antifouling, highly antibacterial and moisture-proof wooden board.

[0097] Comparing Example 3 with Comparative Example 1, the present invention selects polyvinyl alcohol, a homemade aqueous branched polyurethane dispersed composite antibacterial agent with a hydrophobic side chain, and sodium silicate for joint modification as a green, environmentally friendly, formaldehyde-free impregnation treatment modifier, and performs vacuum pressure impregnation treatment on the substrate, thereby effectively improving the mechanical properties, antibacterial properties, and flame retardant properties of the substrate.

[0098] Comparing Example 3 with Comparative Example 2, Comparative Example 3 and Comparative Example 4, the nanocellulose introduced in the present invention has a toughening effect. In order to give the wood board high antibacterial property and moisture-proof and flame-retardant property, a zinc-based organic porous skeleton is in situ generated on the nanocellulose to obtain a composite nanocellulose. The composite nanocellulose is compounded with a flaky nanoamino clay having an antibacterial and mildew-proof effect by electrostatic action, and the composite nanocellulose is used as a reinforcing support skeleton in the substrate layer, and at the same time as a nano-container of a high-efficiency, broad-spectrum, low-toxic antibacterial agent, carboxylbenzisothiazolinone, thereby giving the wood board high antibacterial property and flame-retardant and moisture-proof property, so that the wood board has a long-lasting antibacterial and antifouling effect; at the same time, the composite antibacterial agent The multiple active sites of the composite antibacterial agent help it to combine with other raw materials, so that the composite antibacterial agent can be firmly attached to the wooden board for a long time, while achieving the enhanced toughness, moisture-proof and mildew-proof properties of the wooden board; at the same time, the zinc-based organic porous skeleton in the composite antibacterial agent not only serves as a nanocontainer, but its unique porous structure can effectively delay or inhibit the generation and emission of smoke; the porous metal compounds formed by pyrolysis during the combustion process will promote the formation of a carbon layer and inhibit the release of toxic gases. At the same time, the porous structure of the composite antibacterial agent in the carbon layer will complicate the release pathways of pyrolysis products and toxic gases, thereby inhibiting the spread of flames and gas emissions, thereby improving the flame retardancy of the wooden board.

[0099] Example 3 is compared with Comparative Examples 5 and 6. In order to improve the moisture-proof and hydrophobic properties of wood, amino-branched siloxane and glyceryl monostearate are used as hydrophobic modification components to synthesize an aqueous branched polyurethane with a double hydrophobic side chain; the aqueous branched polyurethane is added to the antibacterial impregnation liquid to improve the compatibility of the raw materials in the antibacterial impregnation liquid and the protective coating. After the impregnation treatment, part of the sodium silicate, the aqueous branched polyurethane, and the composite antibacterial agent can enter the cell wall of the wood, and polyvinyl alcohol can form a cross-linking effect between the aqueous branched polyurethane and the wood; the surface of the substrate layer is carbonized under high temperature and hypoxic conditions, delaying the transfer of heat and oxygen to the interior of the wood, thereby hindering the combustion of the wood, and greatly improving the flame retardancy and deformation resistance of the substrate layer; in order to give the wood board a fluorine-free, anti-fouling and wear-resistant surface, in the protective coating based on the aqueous branched polyurethane, the mass ratio of the composite antibacterial agent to micron silicon dioxide is controlled so that it can build a dense multi-level micro-protrusion hydrophobic structure, giving the protective layer excellent self-cleaning ability and wear resistance.

[0100] The above descriptions are only embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the present invention specification under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a highly antibacterial and moisture-proof wooden board for furniture, characterized in that: The following steps are involved: S1: preparing an antibacterial impregnation solution using a composite antibacterial agent, polyvinyl alcohol, aqueous branched polyurethane, sodium silicate, and deionized water; S2: placing the substrate into an antibacterial impregnation liquid for vacuum pressure impregnation treatment, and then heating and drying to obtain a substrate layer; S3: Preparing protective coatings using composite antimicrobial agents, micronized silica, ethyl acetate, and waterborne branched polyurethane; S4: applying the protective coating onto the substrate layer and curing the coating to obtain a highly antibacterial and moisture-proof wood board for furniture; The preparation of the composite antibacterial agent comprises the following steps: (1) Mixing magnesium chloride hexahydrate and anhydrous ethanol, adding 3-aminopropyltriethoxysilane, stirring at 25° C. for 10-12 hours, centrifuging, washing with anhydrous ethanol for 3-5 times, drying, crushing, dispersing in distilled water, and ultrasonically treating for 3-5 minutes to obtain a nano amino clay dispersion; (2) mixing zinc nitrate hexahydrate and N,N-dimethylformamide, adding a mixture of 2-aminobenzimidazole, benzimidazole and methanol, keeping the mixture at 18-25° C. for 10-12 hours, adding nanocellulose, heating the mixture to 30-40° C. for 3-5 hours, centrifuging the mixture for 5-10 minutes, washing the mixture with ethanol, and drying the mixture to obtain composite nanocellulose; mixing the composite nanocellulose and deionized water, adding a nanoamino clay dispersion, and keeping the mixture at 35-40° C. for 1-2 hours to obtain amino clay composite nanocellulose; (3) 1,2-benzisothiazol-3-one, potassium hydroxide and distilled water are mixed, heated to 115°C, sodium chloroacetate aqueous solution is added, the mixture is kept warm for 12-16 hours, cooled to 18-25°C, filtered under reduced pressure, the pH value is adjusted to 1, washed with water, anhydrous ethanol and acetone in sequence, and dried to obtain carboxybenzisothiazolinone; amino clay composite nanocellulose, deionized water and carboxybenzisothiazolinone are mixed, ultrasonically stirred for 1-2 hours, stirred at 18-25°C for 10-12 hours, centrifuged, washed and dried to obtain a composite antibacterial agent; The preparation of waterborne branched polyurethane comprises the following steps: 1) Under nitrogen protection, 3-aminopropyltriethoxysilane, isocyanatepropyltriethoxysilane and toluene are mixed, kept at 75-80° C. for 22-24 hours, rotary evaporated and dried to obtain a composite preparation; the composite preparation, ethanol and distilled water are mixed, the pH is adjusted to 10, kept at 55-60° C. for 3-4 hours under nitrogen protection, rotary evaporated and dried to obtain amino-branched siloxane; 2) Mix polycaprolactone diol, dibutyltin dilaurate and isophorone diisocyanate, keep the temperature at 35-40°C for 20-30min, heat to 75-80°C, add 1,4-butanediol, keep the temperature for 2-3h, cool to 35-40°C, add a mixed solution of acetone and N-methyldiethanolamine, heat to 70-75°C and keep the temperature for 1-2h, cool to 40°C, add a mixed solution of acetone and amino-branched siloxane, continue to keep the temperature for 1h, heat to 65-70°C and keep the temperature for 2h, add glyceryl monostearate, heat to 75-80°C and keep the temperature for 2-3h, add ethanol, cool to 40°C, add a mixed solution of acetone and glacial acetic acid, add deionized water, and perform rotary evaporation to obtain water-based branched polyurethane.

2. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: The working conditions of vacuum pressure impregnation treatment are: pressure of 1.5-2MPa, time of 10-12h; the working conditions of temperature drying are: first air drying to 65-70% moisture content, then heating to 100°C and drying to absolute dryness.

3. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: The base plate is one of poplar veneer, bamboo board and rosewood board.

4. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: The antibacterial impregnation liquid is composed of 3-5 parts of composite antibacterial agent, 1-4 parts of polyvinyl alcohol, 10-12 parts of water-based branched polyurethane, 10-20 parts of sodium silicate and 70-80 parts of deionized water in parts by mass.

5. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: The mass ratio of the composite antibacterial agent, micron silicon dioxide, ethyl acetate and water-based branched polyurethane in the protective coating is 4:1:75:

8.

6. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: The size of micronized silica is 50-150 μm.

7. The method for preparing a highly antibacterial and moisture-proof wood board for furniture according to claim 1, characterized in that: In the preparation of water-based branched polyurethane, the mass ratio of amino-branched siloxane to glyceryl monostearate is 0.5:

12.

8. A highly antibacterial and moisture-proof wood board for furniture, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 7.

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