A formaldehyde-free high-strength furniture board and its preparation method

Abstract

This application discloses a formaldehyde-free, high-strength furniture board and its preparation method, belonging to the technical field of furniture board technology. By weight, the board comprises: 20-30 parts filler, 100-150 parts PVC resin, 40-50 parts plant powder, 2-3 parts stabilizer, 20-30 parts plasticizer, 1-3 parts lubricant, and 5-10 parts formaldehyde-free adhesive. Using PVC resin and plant powder as the base material, this furniture board possesses the appearance characteristics of solid wood. The formaldehyde-free adhesive effectively bonds the remaining components, improving the board's mechanical strength and environmental performance, enabling it to meet the requirements of various furniture products.

Description

Technical Field

[0001] This application relates to a formaldehyde-free high-strength home furnishing board and its preparation method, belonging to the field of home furnishing board technology. Background Technology

[0002] Existing engineered wood products require the addition of urea-formaldehyde resin as an adhesive to bond wood materials during the manufacturing process. Although urea-formaldehyde resin has good bonding performance, it continuously releases formaldehyde during use. Formaldehyde is a carcinogen, and long-term use of furniture made with formaldehyde will seriously endanger human health.

[0003] Solid wood panels can avoid this problem; however, their high production cost, susceptibility to warping, and high consumption of raw materials make them difficult to widely promote and use. Currently, PVC resin can be used to produce hard boards; however, these boards are easily affected by ultraviolet light, and their mechanical strength will decrease with long-term use. They are also not environmentally friendly and fail to meet people's desired appearance characteristics of solid wood. Summary of the Invention

[0004] To address the aforementioned issues, a formaldehyde-free, high-strength furniture board is provided. This board uses PVC resin and plant powder as its base materials, enabling it to possess the appearance characteristics of solid wood. The formaldehyde-free adhesive used tightly bonds the remaining components, improving the board's mechanical strength and environmental performance, thus allowing it to meet the requirements of various furniture products.

[0005] According to one aspect of this application, a formaldehyde-free high-strength home furnishing board is provided, comprising, by weight: 20-30 parts filler, 100-150 parts PVC resin, 40-50 parts plant powder, 2-3 parts stabilizer, 20-30 parts plasticizer, 1-3 parts lubricant, and 5-10 parts formaldehyde-free adhesive.

[0006] Boards made from PVC resin and plant powder as base materials have the appearance of solid wood, satisfying users' demand for the look of solid wood while reducing board deformation and raw material waste. The addition of fillers can improve the mechanical properties of the board, resulting in high-strength furniture boards that can be used to manufacture furniture products with high load-bearing capacity. Formaldehyde-free adhesives can bond the above raw materials together, improving the board's density, corrosion resistance, and moisture resistance, and there is no formaldehyde release during use, meeting the modern demand for environmentally friendly boards.

[0007] Optionally, the plasticizer is tributyl citrate, the lubricant is magnesium stearate and polyethylene wax, and the stabilizer is an organotin stabilizer.

[0008] Optionally, the molecular weight of the PVC resin is 30,000 to 50,000.

[0009] Optionally, the formaldehyde-free adhesive includes natural gums, polylactic acid, and a solvent, wherein the solvent accounts for 30-40% of the total weight of the formaldehyde-free adhesive, and the weight ratio of the natural gums to polylactic acid is 1:(2-5).

[0010] Preferably, the solvent is selected from at least one of water, ethanol, and acetone.

[0011] Natural resins and polylactic acid (PLA) exhibit good adhesion when mixed. Natural resins increase their affinity with plant powders, while PLA, being a biodegradable material, allows for the recycling of the board, further enhancing its environmental friendliness. Furthermore, the ester groups in PLA increase its polarity, thereby improving its compatibility with PVC resin. Therefore, when PLA and natural resins are used in combination, PLA can embed itself into the PVC molecular chain, increasing its adhesion to PVC and also acting as a plasticizer, improving the board's mechanical strength and heat resistance. Natural resins can encapsulate and bond the plant powders. Thus, the aforementioned formaldehyde-free adhesive enhances the bonding performance of other components and improves the board's strength and density.

[0012] Optionally, the polylactic acid has a molecular weight of 10,000 to 20,000.

[0013] Optionally, the polylactic acid (PLA) is PLA that has been surface-modified with polyvinyl alcohol (PVA) and aminosilane. Surface modification of PLA with PVA and aminosilane has two advantages: first, it increases the hydrophilicity of PLA, thereby enhancing its compatibility with plant powders and fillers, and improving its adhesion to these materials, facilitating the uniform adhesion and fixation of plant powders and fillers within the PVC molecular chain; second, it allows the PLA surface to contain more hydroxyl and amino groups, enabling the formation of hydrogen bonds in the board material, thus improving the board's mechanical strength and temperature resistance, meeting the requirements for high-temperature furniture boards.

[0014] Optionally, polylactic acid is immersed in a mixed solution containing polyvinyl alcohol and aminosilane for at least 2 hours, and then the polylactic acid is removed, washed and dried to obtain surface-modified polylactic acid.

[0015] Optionally, in the mixed solution, the concentration of polyvinyl alcohol is 2-4 wt%, and the concentration of aminosilane is 1-3 wt%. The solvent in the mixed solution is selected from at least one of methanol, ethanol, and ethylene glycol.

[0016] The concentration and soaking time of the above substances facilitate the adsorption of polyvinyl alcohol and aminosilane on the surface of polylactic acid, increase the loading of polyvinyl alcohol and aminosilane, and enable the two substances to be uniformly loaded on the surface of polylactic acid, thereby improving the uniformity of polylactic acid modification and allowing polylactic acid to exert its best effect.

[0017] Optionally, the formaldehyde-free adhesive further includes silicone resin and a curing agent, wherein the weight ratio of the natural gum, silicone resin and curing agent is 1:(2-4):(0.2-0.3).

[0018] Preferably, the curing agent is selected from at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0019] The addition of the aforementioned silicone resin has several advantages. First, it further improves the adhesion of formaldehyde-free adhesives to other components, thereby increasing the density and strength of the board. Second, the silicone resin increases the compatibility between plant powder, fillers, and PVC resin. Under the action of the curing agent, the silicone resin cross-links, confining the plant powder and fillers not only between the molecular chains of PVC but also uniformly confining the molecular chains of plant powder, fillers, and PVC between the molecular chains of silicone resin, thus improving the uniformity of the board's performance. Third, the molecular chains of silicone resin and PVC resin interpenetrate to form a dense polymer network. This network can entangle and unentangle under the action of plasticizers, stabilizers, and lubricants, thereby improving the board's resistance to deformation and extending its service life while increasing its strength.

[0020] Furthermore, after the polylactic acid is modified with amino silane, the surface of the polylactic acid also contains amino groups. These amino groups can crosslink with the silicone resin during the preparation of the board, thereby connecting the molecular chains of polylactic acid and silicone resin, increasing the length and crosslinking density of the polymer molecular chains in the board, reducing the porosity of the board surface, and thus improving the board's peel resistance, moisture resistance and corrosion resistance.

[0021] Optionally, the filler is selected from any one or more of titanium dioxide, silicon dioxide, aluminum hydroxide, cellulose nanocrystals, and microcrystalline cellulose.

[0022] Preferably, the filler is selected from cellulose nanocrystals and microcrystalline cellulose in a weight ratio of 3:1. These two substances can not only play a reinforcing role, but also play a lubricating role, which facilitates the mixing of components in the board, improves the fluidity of the material, and thus improves the formability of the board.

[0023] Optionally, the filler is a filler that has been surface modified with benzotriazole and imidazole. The filler is placed in an ethanol solution containing benzotriazole and imidazole and treated at 40-50°C for 3-5 hours. After that, the filler is taken out, washed and dried to obtain the surface-modified filler.

[0024] After modification, the filler surface is loaded with benzotriazole and imidazole. These two substances improve the affinity between the filler and the adhesive, allowing the filler to be uniformly dispersed in PVC resin and plant powder substrates, avoiding agglomeration and reducing the probability of localized damage to the board. At the same time, the amino groups in these two substances can form chemical bonds with the molecular chains of silicone resin during crosslinking, further improving the compatibility of the filler with formaldehyde-free adhesives. Furthermore, the nitrogen atoms and amino groups in benzotriazole and imidazole can further increase the number of hydrogen bonds in the board, thereby improving the board's resistance to deformation. The carbon-nitrogen double bonds and nitrogen-nitrogen double bonds contained therein can also increase the polarity of the filler, thus playing a role in plasticizing and toughening PVC resin.

[0025] Optionally, the molar ratio of benzotriazole to imidazole is (1-3):1, and the concentration of benzotriazole in the ethanol solution is 1-1.5 mol / L.

[0026] The above molar ratio and concentration facilitate the modification of fillers by benzotriazole and imidazole, improve the uniformity of the distribution of the two substances on the filler surface, and enable carbon-nitrogen double bonds and nitrogen-nitrogen double bonds to work synergistically to achieve the best plasticizing and toughening effect.

[0027] According to another aspect of this application, a method for preparing formaldehyde-free high-strength furniture boards as described in any of the above claims is provided, comprising the following steps:

[0028] (1) Mix PVC resin, filler, stabilizer and plasticizer to obtain a premix;

[0029] (2) The premixed material is then mixed with plant powder, lubricant and formaldehyde-free adhesive to obtain the material to be extruded;

[0030] (3) The material to be extruded is placed in a twin-screw extruder, melt-blended, extruded and dried to obtain the formaldehyde-free high-strength home furnishing board.

[0031] Optionally, the melt blending temperature in step (3) is 120-130℃ and the extrusion molding temperature is 150-170℃.

[0032] The above preparation steps first involve mixing PVC resin, filler, stabilizer, and plasticizer components to obtain a premix, which allows the filler to be uniformly dispersed in the PVC resin. Then, plant powder, lubricant, and formaldehyde-free adhesive are mixed to obtain the material to be extruded. With the help of formaldehyde-free adhesive and lubricant, the plant powder and premix can be mixed evenly, increasing the contact area between the components and facilitating their bonding during extrusion, thereby obtaining high-strength furniture boards.

[0033] The beneficial effects of this application include, but are not limited to:

[0034] 1. The formaldehyde-free high-strength furniture board according to this application uses a formaldehyde-free adhesive to tightly bond the remaining components, improve the mechanical strength of the board, and prevent the furniture board from releasing formaldehyde during use, thus meeting the requirements of environmental protection and safety.

[0035] 2. The formaldehyde-free high-strength home furnishing board of this application uses plant powder as raw material to achieve resource recycling and reuse. Its appearance has the characteristics of solid wood, which can not only meet the user's demand for the appearance of solid wood, but also reduce the deformation of the board and the waste of raw materials. Detailed Implementation

[0036] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0038] Example 1

[0039] This embodiment relates to a formaldehyde-free high-strength furniture board and its preparation method. By weight, the board comprises: 15 parts titanium dioxide, 5 parts microcrystalline cellulose, 100 parts PVC resin (molecular weight of 30,000), 40 parts plant powder, 2 parts organotin stabilizer, 20 parts tributyl citrate, 0.5 parts magnesium stearate, 0.5 parts polyethylene wax, and 5 parts formaldehyde-free adhesive. The formaldehyde-free adhesive is composed of natural gum, polylactic acid, and ethanol. The molecular weight of polylactic acid is 10,000, and ethanol accounts for 30% of the total weight of the formaldehyde-free adhesive. The weight ratio of natural gum to polylactic acid is 1:2.

[0040] The preparation method of this board includes the following steps:

[0041] (1) A premix was prepared by mixing PVC resin, titanium dioxide, microcrystalline cellulose, organotin stabilizer and tributyl citrate.

[0042] (2) The premixed material is then mixed with plant powder, magnesium stearate, polyethylene wax and formaldehyde-free adhesive to obtain the material to be extruded.

[0043] (3) The material to be extruded is placed in a twin-screw extruder, melt-blended at 120°C for 10 min, extruded and dried at 150°C to obtain the formaldehyde-free high-strength home furnishing board.

[0044] Example 2

[0045] This embodiment relates to a formaldehyde-free high-strength furniture board and its preparation method. By weight, the board comprises: 22.5 parts cellulose nanocrystals, 7.5 parts microcrystalline cellulose, 150 parts PVC resin (molecular weight of 50,000), 50 parts plant powder, 3 parts organotin stabilizer, 30 parts tributyl citrate, 2 parts magnesium stearate, 1 part polyethylene wax, and 10 parts formaldehyde-free adhesive. The formaldehyde-free adhesive is composed of natural gum, polylactic acid, and ethanol. The molecular weight of polylactic acid is 20,000, and ethanol accounts for 40% of the total weight of the formaldehyde-free adhesive. The weight ratio of natural gum to polylactic acid is 1:5.

[0046] The preparation method of this board includes the following steps:

[0047] (1) A premix was prepared by mixing PVC resin, cellulose nanocrystals, microcrystalline cellulose, organotin stabilizer and tributyl citrate.

[0048] (2) The premixed material is then mixed with plant powder, magnesium stearate, polyethylene wax and formaldehyde-free adhesive to obtain the material to be extruded.

[0049] (3) The material to be extruded is placed in a twin-screw extruder, melt-blended at 130°C for 10 min, extruded and dried at 170°C to obtain the formaldehyde-free high-strength home furnishing board.

[0050] Example 3

[0051] The difference between this embodiment and Embodiment 2 is that the polylactic acid is polylactic acid that has been surface-modified with polyvinyl alcohol and aminosilane. The specific modification steps are as follows:

[0052] Polylactic acid was placed in an ethanol solution containing polyvinyl alcohol and aminosilane, wherein the concentration of polyvinyl alcohol was 4 wt% and the concentration of aminosilane was 3 wt%. After soaking for 2 hours, the polylactic acid was removed, washed with ethanol and dried to obtain surface-modified polylactic acid.

[0053] The remaining components and preparation methods are the same as in Example 2, resulting in formaldehyde-free high-strength home furnishing boards.

[0054] Example 4

[0055] The difference between this embodiment and Embodiment 2 is that the polylactic acid is polylactic acid that has been surface-modified with polyvinyl alcohol and aminosilane. The specific modification steps are as follows:

[0056] Polylactic acid was placed in an ethanol solution containing polyvinyl alcohol and aminosilane, wherein the concentration of polyvinyl alcohol was 2 wt% and the concentration of aminosilane was 1 wt%. After soaking for 2 hours, the polylactic acid was removed, washed with ethanol and dried to obtain surface-modified polylactic acid.

[0057] The remaining components and preparation methods are the same as in Example 2, resulting in formaldehyde-free high-strength home furnishing boards.

[0058] Example 5

[0059] The difference between this embodiment and Embodiment 3 is that the formaldehyde-free adhesive also includes silicone resin and a curing agent. The weight ratio of natural gum, silicone resin and curing agent is 1:2:0.2. The curing agent is ethylenediamine. The remaining components and preparation methods are the same as in Embodiment 3, resulting in formaldehyde-free high-strength home furnishing boards.

[0060] Example 6

[0061] The difference between this embodiment and Embodiment 3 is that the formaldehyde-free adhesive also includes silicone resin and a curing agent. The weight ratio of natural gum, silicone resin and curing agent is 1:4:0.3. The curing agent is diethylenetriamine. The remaining components and preparation methods are the same as in Embodiment 3, resulting in formaldehyde-free high-strength home furnishing boards.

[0062] Example 7

[0063] The difference between this embodiment and Example 6 is that the filler is a filler that has been surface modified with benzotriazole and imidazole. The filler is placed in an ethanol solution containing benzotriazole and imidazole, with the concentration of benzotriazole being 1 mol / L and the concentration of imidazole being 1 mol / L. The solution is treated at 40°C for 5 hours. After that, the filler is taken out, washed, and dried to obtain the surface-modified filler.

[0064] The remaining components and preparation methods are the same as in Example 6, resulting in formaldehyde-free high-strength home furnishing boards.

[0065] Example 8

[0066] The difference between this embodiment and Embodiment 6 is that the filler is a filler that has been surface modified with benzotriazole and imidazole. The filler is placed in an ethanol solution containing benzotriazole and imidazole, with the concentration of benzotriazole being 1.5 mol / L and the concentration of imidazole being 0.5 mol / L. The solution is treated at 50°C for 3 hours. After that, the filler is taken out, washed, and dried to obtain the surface-modified filler.

[0067] The remaining components and preparation methods are the same as in Example 6, resulting in formaldehyde-free high-strength home furnishing boards.

[0068] Example 9

[0069] The difference between this embodiment and Embodiment 3 is that the filler is a filler that has been surface modified with benzotriazole and imidazole. The filler is placed in an ethanol solution containing benzotriazole and imidazole, with a concentration of 1.5 mol / L for benzotriazole and a concentration of 0.5 mol / L for imidazole. The solution is treated at 50°C for 3 hours. After that, the filler is removed, washed, and dried to obtain the surface-modified filler.

[0070] The remaining components and preparation methods are the same as in Example 3, resulting in formaldehyde-free high-strength home furnishing boards.

[0071] Example 10

[0072] The difference between this embodiment and Example 3 is that epoxy silane is used instead of amino silane. The remaining components and preparation methods are the same as in Example 3, resulting in formaldehyde-free high-strength home furnishing boards.

[0073] Example 11

[0074] The difference between this embodiment and Embodiment 6 is that the weight ratio of natural resin, polylactic acid, silicone resin and curing agent is 1:10:2:0.3. The remaining components and preparation methods are the same as in Embodiment 6, resulting in formaldehyde-free high-strength home furnishing boards.

[0075] Example 12

[0076] The difference between this embodiment and Example 9 is that ethylenediamine is used instead of imidazole, while the other components and preparation methods are the same as in Example 9, resulting in formaldehyde-free high-strength home furnishing boards.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that urea-formaldehyde resin is used instead of formaldehyde-free adhesive. All other components and preparation methods are the same as in Example 1, resulting in formaldehyde-free high-strength home furnishing boards.

[0079] Test Example 1

[0080] Mechanical properties of the boards prepared in the above examples and comparative examples were tested at room temperature. Warpage, cold resistance, heat aging resistance, heating dimensional change rate, water immersion dimensional change rate, odor classification and flame retardancy were tested according to QBT 51402017. The cold resistance, heat aging resistance and flame retardancy of Examples 1-12 and Comparative Example 1 were all qualified. The results are shown in Table 1 below.

[0081] Table 1

[0082]

[0083] Test Example 2

[0084] The plates prepared in the above embodiments and comparative examples were heat-treated at 80℃ for 72 hours, and then mechanical properties were tested. The results are shown in Table 2 below. After soaking the plates in 10% NaOH solution and 10% hydrochloric acid solution for 10 days, the appearance color and peeling of the plates were observed. The results are shown in Table 2 below.

[0085] Table 2

[0086]

[0087]

[0088] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A formaldehyde-free, high-strength furniture board, characterized in that, By weight, the board comprises: 20-30 parts filler, 100-150 parts PVC resin, 40-50 parts plant powder, 2-3 parts stabilizer, 20-30 parts plasticizer, 1-3 parts lubricant, and 5-10 parts formaldehyde-free adhesive. The formaldehyde-free adhesive comprises natural gum, polylactic acid (PLA), and a solvent. The solvent accounts for 30-40% of the total weight of the formaldehyde-free adhesive. The weight ratio of the natural gum to PLA is 1:(2-5). The PLA is surface-modified with polyvinyl alcohol (PVA) and aminosilane. The PLA is immersed in a mixed solution containing PVA and aminosilane for at least 2 hours. After that, the PLA is removed, washed, and dried to obtain surface-modified PLA. In the mixed solution, the concentration of PVA is 2-4 wt%, and the concentration of aminosilane is 1-3 wt%. The filler is selected from any one or more of titanium dioxide, silicon dioxide, aluminum hydroxide, cellulose nanocrystals, and microcrystalline cellulose. The filler is a filler that has been surface modified with benzotriazole and imidazole. The filler is placed in an ethanol solution containing benzotriazole and imidazole and treated at 40-50℃ for 3-5 hours. After that, the filler is taken out, washed and dried to obtain the surface-modified filler. The molar ratio of benzotriazole to imidazole is (1-3):

1. The concentration of benzotriazole in the ethanol solution is 1-1.5 mol / L.

2. The formaldehyde-free high-strength home furnishing board according to claim 1, characterized in that, The formaldehyde-free adhesive also includes silicone resin and a curing agent, wherein the weight ratio of the natural gum, silicone resin and curing agent is 1:(2-4):(0.2-0.3).

3. The method for preparing formaldehyde-free high-strength furniture boards according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Mix PVC resin, filler, stabilizer and plasticizer to obtain a premix; (2) The premixed material is then mixed with plant powder, lubricant and formaldehyde-free adhesive to obtain the material to be extruded; (3) The material to be extruded is placed in a twin-screw extruder, melt-blended, extruded and dried to obtain the formaldehyde-free high-strength home furnishing board.

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