Biological functional veneer artificial board containing herbal active substances

Abstract

The invention provides a biological functional facing artificial board containing herbal active substances. The biological functional facing artificial board comprises a base material layer with the thickness being 8-12 mm and a functional facing layer with the thickness being 50-80 microns. The base material layer is composed of a mixture of straw and bamboo fibers subjected to steam pretreatment and a bio-based adhesive, and the weight ratio of the straw to the bamboo fibers is 100: (15-20); the functional facing layer is prepared from the following materials in parts by weight: 45 to 55 parts of waterborne polyurethane resin, 10 to 15 parts of herbal active substance microcapsule powder, 30 to 40 parts of modified inorganic filler and 2 to 3 parts of polyethylene wax. According to the biological functional veneer artificial board containing the herbal active substances, the herbal active substances are embedded into the veneer layer after being microencapsulated through the veneer layer packaging technology instead of being directly mixed with the base material, so that uneven dispersion and processing damage are avoided, and meanwhile the function timeliness is prolonged through the slow release design.

Description

Technical Field

[0001] The invention relates to the technical field of artificial boards, and in particular to a biological functional facing artificial board containing herbal active substances. Background Art

[0002] As people's requirements for a healthier home environment continue to increase, traditional artificial boards can no longer meet the needs of the modern market. In recent years, researchers and manufacturers have begun to explore the introduction of herbal active substances into artificial boards to give them more biological functions. Biofunctional decorative artificial boards containing herbal active substances refer to artificial boards that, during the production process of artificial boards, use a specific process to add herbal active substances to the base material or finishing material of the artificial boards, thereby giving the artificial boards biological functions such as antibacterial, antiviral, and mildew resistance.

[0003] Herbal active substances refer to biologically active ingredients extracted from herbal plants. Introducing herbal active substances into artificial boards can not only improve the health performance of artificial boards, but also meet people's demand for green and environmentally friendly home products.

[0004] The herbal active substances are directly added to the base material of the artificial board, and are evenly distributed inside the artificial board through mixing, hot pressing and other processes. This method is simple and easy to implement, but the distribution of the herbal active substances in the artificial board may be uneven, resulting in differences in the biological functions of the artificial board. Especially in the direct addition method, the herbal active substances tend to gather in certain areas of the artificial board, but less in other areas. In addition, the herbal active substances are easily affected by external factors such as temperature and humidity during the production and processing of the artificial board and lose their activity. Especially in the impregnation method, the volatilization of the solvent and the high temperature during the processing may cause the decomposition or inactivation of the herbal active substances. Based on this, the present invention provides a biofunctional veneer artificial board containing herbal active substances. Summary of the invention

[0005] The purpose of the present invention is to provide a biofunctional facing artificial board containing herbal active substances. Through the facing layer encapsulation technology, the herbal active substances are microencapsulated and embedded in the facing layer, thereby avoiding uneven dispersion and processing damage, and at the same time extending the functional timeliness through the sustained release design.

[0006] In one aspect, the present invention provides a biofunctional facing artificial board containing herbal active substances, comprising a substrate layer with a thickness of 8-12 mm and a functional facing layer with a thickness of 50-80 μm;

[0007] The substrate layer is composed of a mixture of steam-pretreated straw and bamboo fiber and a bio-based adhesive in a weight ratio of 100:(15-20);

[0008] The functional finishing layer comprises the following materials in parts by weight: 45-55 parts of waterborne polyurethane resin, 10-15 parts of herbal active substance microcapsule powder, 30-40 parts of modified inorganic filler, and 2-3 parts of polyethylene wax.

[0009] Furthermore, the method for preparing the mixture of steam-pretreated straw and bamboo fiber comprises: crushing the straw and bamboo fiber in a weight ratio of 1:(3-4) to a length of 3-5 mm; and performing steam pretreatment at a temperature of 100-110° C. for 30-40 minutes.

[0010] Furthermore, the preparation method of the bio-based adhesive includes: mixing 100-110 parts of cassava starch and 400-450 parts of water, adding 3-4 parts of ammonium persulfate, oxidizing at 70-80°C for 50-70 minutes, heating to 90-100°C, stirring at 200-300rpm for 30-40 minutes, cooling to 45-55°C, adding 10-12 parts of tannic acid and 1-1.2 parts of borax for 40-50 minutes, and adjusting the pH to 6.5-7.0 to obtain the adhesive.

[0011] Furthermore, the preparation method of the herbal active substance microcapsule powder includes: emulsifying wormwood extract, lavender extract, gelatin-gum arabic and deionized water at a temperature of 45-55°C and a speed of 10000-12000 rpm, controlling the inlet temperature to 120-130°C and the outlet temperature to 70-80°C for spray drying to prepare the microcapsule powder.

[0012] Furthermore, the weight ratio of the wormwood extract, lavender extract, gelatin-gum arabic and deionized water is (2-3): (1-2): (6-8): (60-70).

[0013] Furthermore, the preparation method of the modified inorganic filler includes: mixing the calcium carbonate and diatomaceous earth mixed material and nano-silicon dioxide after calcination pretreatment, adding silane coupling agent KH-570, stirring and mixing at a speed of 300-400rpm and a temperature of 60-70°C for 2-3h to obtain an activated filler; immersing the activated filler in a chitosan aqueous solution, ultrasonically dispersing for 30-40min, and drying at 60-70°C to obtain the modified inorganic filler.

[0014] Furthermore, the calcination pretreatment step includes: crushing calcium carbonate and diatomaceous earth in a weight ratio of 1: (0.4-0.6) to a particle size of ≤500nm; and calcining at a temperature of 500-600°C for 1-2h.

[0015] Furthermore, the weight ratio of the calcium carbonate and diatomaceous earth mixed material after calcination pretreatment, nano silicon dioxide and silane coupling agent KH-570 is 100:5-9:1-2.

[0016] Furthermore, the weight ratio of the activated filler, chitosan and water is 1:(0.04-0.06):(2-3).

[0017] On the other hand, the present invention also provides a method for preparing a biofunctional facing artificial board containing herbal active substances, the steps comprising:

[0018] (1) Preparation of the substrate layer: adding a mixture of steam-pretreated straw and bamboo fiber with a moisture content of 8% to 10% and a bio-based adhesive to a twin-screw extruder for mixing, paving into a slab, hot pressing, trimming and polishing to obtain the substrate layer;

[0019] (2) Preparation of functional finishing layer: Aqueous polyurethane resin, herbal active substance microcapsule powder, modified inorganic filler and polyethylene wax are stirred and mixed at a rotation speed of 800-900 rpm for 30-40 min to obtain a mixed coating, and the mixed coating is sprayed on the surface of the substrate layer. After curing, the biofunctional finishing artificial board containing herbal active substances is obtained.

[0020] Furthermore, the hot pressing step includes: hot pressing at a pressure of 1-2 MPa and room temperature for 5-10 min; hot pressing at a pressure of 8-10 MPa and a temperature of 110-120° C. for 15-20 min.

[0021] Furthermore, the density of the substrate layer is 0.6-0.8 g / cm 3 .

[0022] Furthermore, the spray gun pressure during spraying is 0.3-0.5 MPa.

[0023] Furthermore, the curing step includes: drying with hot air at 80-90°C for 10-15 minutes, followed by drying at a wavelength of 365nm and an intensity of 80-90mW / cm 2 UV curing was performed for 30-40 seconds under the conditions.

[0024] The beneficial effects of the present invention are:

[0025] The present invention adopts a mixture of straw and bamboo fiber after steam pretreatment as the main body of the substrate layer, and introduces a bio-based adhesive modified by tannic acid, thereby achieving a dual improvement in the performance and environmental protection of the substrate layer. Among them, through steam pretreatment, the fiber structure of straw and bamboo fiber is optimized, and the bonding force between fibers is enhanced, thereby improving the overall strength and stability of the substrate layer. At the same time, the pretreatment process helps to remove impurities and volatile substances in the fiber and reduce the adverse effects in subsequent processing. In addition, tannic acid, as a natural polyphenol compound, its phenolic hydroxyl structure can undergo a cross-linking reaction with other components in the bio-based adhesive to form a denser cross-linked network. This not only enhances the cross-linking density of the adhesive, reduces the water absorption expansion rate of the substrate layer, but also gives the substrate layer excellent antibacterial properties. The phenolic hydroxyl structure of tannic acid can destroy the bacterial cell membrane, thereby effectively inhibiting bacterial growth and achieving long-term antibacterial.

[0026] The present invention embeds the herbal active substances into a functional finishing layer after microencapsulation, prolongs the functional timeliness through a sustained-release design, and avoids the problems of uneven dispersion and processing damage. Among them, gelatin-gum arabic is used as the wall material, and herbal active substances such as wormwood extract and lavender extract are encapsulated in microcapsules. This microcapsule structure can effectively protect heat-sensitive herbal ingredients and prevent them from being inactivated during processing and storage. At the same time, the sustained-release effect of the microcapsule enables the herbal active substances to be continuously released, extending the timeliness of the antibacterial, deodorizing and other functions of the functional finishing layer. By controlling the wall material thickness, porosity and other parameters of the microcapsule, the release rate of the herbal active substances can be adjusted to achieve a sustained-release effect. This design not only improves the performance stability of the functional finishing layer, but also reduces the waste and environmental pollution caused by the rapid release of active substances.

[0027] The present invention adopts inorganic fillers that are calcined and modified with chitosan to synergistically improve the filler-resin interface bonding force and antibacterial durability. Among them, calcium carbonate and diatomaceous earth are calcined pre-treated to form a porous structure. This porous structure not only increases the specific surface area of ​​the filler, which is conducive to the adsorption of adhesives and other components, but also improves the activity of the filler. The microcracks and pores generated during the calcination process help to relieve stress concentration and improve the deformation resistance of the substrate layer. The activated filler is immersed in a chitosan aqueous solution so that the chitosan coating is covered on the filler surface. Chitosan, as a natural polymer compound, has good antibacterial properties and biocompatibility. Its coating can further enhance the antibacterial durability of the filler and improve the interface bonding force between the filler and the resin. This synergistic effect enables the functional finishing layer to have good antibacterial properties while maintaining excellent performance.

[0028] The present invention realizes an efficient and environmentally friendly production process by optimizing the preparation process of the substrate layer and the functional finishing layer. A twin-screw extruder is used to evenly mix the steam-pretreated straw and bamboo fiber mixture with a bio-based adhesive, and then the mixture is paved into a slab for hot pressing. This process not only improves production efficiency, but also ensures the uniformity and compactness of the substrate layer. During the hot pressing process, the performance of the substrate layer can be further optimized by controlling parameters such as pressure, temperature and time. In addition, raw materials such as water-based polyurethane resin, herbal active substance microcapsule powder, modified inorganic filler and polyethylene wax are stirred and mixed evenly and then sprayed on the surface of the substrate layer for curing. This spraying process not only achieves uniform coverage of the functional finishing layer, but also avoids problems such as uneven coating and sagging that may occur in traditional coating processes. During the curing process, the surface bonding strength and surface crack resistance of the functional finishing layer can be further improved by controlling the conditions of hot air drying and UV curing. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described clearly and completely below. 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.

[0030] The raw materials in the present invention are: waterborne polyurethane resin model BW-8700, purchased from Zibo Baowei New Material Technology Co., Ltd., polyethylene wax model P903666, purchased from MacLean Reagent, wormwood extract purchased from Xi'an Tianbao Biotechnology Co., Ltd., and lavender extract purchased from Fufeng Snot Biotechnology Co., Ltd.

[0031] Example 1

[0032] This embodiment provides a biofunctional facing artificial board containing herbal active substances, comprising a substrate layer with a thickness of 10 mm and a functional facing layer with a thickness of 65 μm;

[0033] The substrate layer is composed of a mixture of steam-pretreated straw and bamboo fiber in a weight ratio of 100:17 and a bio-based adhesive;

[0034] The functional finishing layer comprises the following materials in parts by weight: 50 parts of waterborne polyurethane resin, 12 parts of herbal active substance microcapsule powder, 35 parts of modified inorganic filler, and 2.5 parts of polyethylene wax;

[0035] The method for preparing the mixture of straw and bamboo fiber after steam pretreatment includes: crushing the straw and bamboo fiber in a weight ratio of 1:3.5 to a length of 4 mm; performing steam pretreatment at a temperature of 105° C. for 35 minutes;

[0036] The preparation method of the bio-based adhesive comprises: mixing 105 parts of cassava starch and 425 parts of water, adding 3.5 parts of ammonium persulfate, performing oxidation reaction at 75°C for 60 minutes, heating to 95°C, stirring continuously at 250 rpm for 35 minutes, cooling to 50°C, adding 11 parts of tannic acid and 1.1 parts of borax, reacting for 45 minutes, and adjusting the pH to 6.8 to obtain the bio-based adhesive;

[0037] The preparation method of the herbal active substance microcapsule powder comprises: emulsifying wormwood extract, lavender extract, gelatin-arabic gum and deionized water at a temperature of 50°C and 11000rpm at a high speed, controlling the inlet temperature to 125°C and the outlet temperature to 75°C for spray drying to prepare the microcapsule powder; the weight ratio of the wormwood extract, lavender extract, gelatin-arabic gum and deionized water is 2.5:1.5:7:65;

[0038] The preparation method of the modified inorganic filler comprises: crushing calcium carbonate and diatomaceous earth in a weight ratio of 1:0.5 to a particle size of 500nm; calcining at a temperature of 550°C for 1.5h; mixing the calcium carbonate and diatomaceous earth mixed material after calcination pretreatment and nano-silicon dioxide, adding silane coupling agent KH-570, stirring and mixing at a speed of 350rpm and a temperature of 65°C for 2.5h to obtain an activated filler; immersing the activated filler in a chitosan aqueous solution, ultrasonically dispersing for 35min, and drying at 65°C to obtain the filler; the weight ratio of the calcium carbonate and diatomaceous earth mixed material after calcination pretreatment, nano-silicon dioxide and silane coupling agent KH-570 is 100:7:1.5; the weight ratio of the activated filler, chitosan and water is 1:0.05:2.5;

[0039] The preparation method of the biofunctional veneer artificial board containing herbal active substances comprises the following steps:

[0040] (1) Preparation of substrate layer: A mixture of steam-pretreated straw and bamboo fiber with a moisture content of 9% and a bio-based adhesive were added to a twin-screw extruder, mixed, and laid into a slab. After hot pressing, trimming and polishing, the density was 0.7 g / cm 3 The substrate layer;

[0041] (2) Preparation of functional finishing layer: Aqueous polyurethane resin, herbal active substance microcapsule powder, modified inorganic filler and polyethylene wax were stirred and mixed at a speed of 850 rpm for 35 min to obtain a mixed coating, and the mixed coating was sprayed on the surface of the substrate layer at a spray gun pressure of 0.4 MPa, and hot air dried at 85°C for 12 min, and then heated at a wavelength of 365 nm and an intensity of 85 mW / cm 2 After UV curing for 35 seconds under the above conditions, the biofunctional veneer artificial board containing herbal active substances is obtained.

[0042] Example 2

[0043] This embodiment provides a biofunctional facing artificial board containing herbal active substances, comprising a substrate layer with a thickness of 8 mm and a functional facing layer with a thickness of 50 μm;

[0044] The substrate layer is composed of a mixture of steam-pretreated straw and bamboo fiber and a bio-based adhesive in a weight ratio of 100:15;

[0045] The functional finishing layer comprises the following materials in parts by weight: 45 parts of waterborne polyurethane resin, 10 parts of herbal active substance microcapsule powder, 30 parts of modified inorganic filler, and 2 parts of polyethylene wax;

[0046] The method for preparing the mixture of straw and bamboo fiber after steam pretreatment comprises: crushing the straw and bamboo fiber in a weight ratio of 1:3 to a length of 3 mm; performing steam pretreatment at a temperature of 100° C. for 30 minutes;

[0047] The preparation method of the bio-based adhesive comprises: mixing 100 parts of cassava starch and 400 parts of water, adding 3 parts of ammonium persulfate, carrying out oxidation reaction at 70°C for 50 minutes, heating to 90°C, stirring continuously at 200 rpm for 30 minutes, cooling to 45°C, adding 10 parts of tannic acid and 1 part of borax to react for 40 minutes, and adjusting the pH to 6.5 to obtain the bio-based adhesive;

[0048] The preparation method of the herbal active substance microcapsule powder comprises: emulsifying wormwood extract, lavender extract, gelatin-arabic gum and deionized water at a temperature of 45°C and 10000 rpm at a high speed, controlling the inlet temperature at 120°C and the outlet temperature at 70°C for spray drying to prepare the microcapsule powder; the weight ratio of the wormwood extract, lavender extract, gelatin-arabic gum and deionized water is 2:1:6:60;

[0049] The preparation method of the modified inorganic filler comprises: crushing calcium carbonate and diatomaceous earth in a weight ratio of 1:0.4 to a particle size of 450nm; calcining at a temperature of 500°C for 1h; mixing the calcium carbonate and diatomaceous earth mixed material after calcination pretreatment and nano-silicon dioxide, adding silane coupling agent KH-570, stirring and mixing at a speed of 300rpm and a temperature of 60°C for 2h to obtain an activated filler; immersing the activated filler in a chitosan aqueous solution, ultrasonically dispersing for 30min, and drying at 60°C to obtain the filler; the weight ratio of the calcium carbonate and diatomaceous earth mixed material after calcination pretreatment, nano-silicon dioxide and silane coupling agent KH-570 is 100:5:1; the weight ratio of the activated filler, chitosan and water is 1:0.04:2;

[0050] The preparation method of this bio-functional veneered artificial board containing herbal active substances comprises the following steps:

[0051] (1) Preparation of the base material layer: Mix the mixture of steam-pretreated straw and bamboo fibers with a moisture content of 8% and a bio-based adhesive in a twin-screw extruder, lay them into a board blank, and obtain a base material layer with a density of 0.6 g / cm 3 after hot pressing and edge trimming and polishing;

[0052] (2) Preparation of the functional veneer layer: Stir and mix aqueous polyurethane resin, herbal active substance microcapsule powder, modified inorganic filler, and polyethylene wax at a rotation speed of 800 rpm for 30 min to obtain a mixed coating. Spray the mixed coating on the surface of the base material layer, with the spray gun pressure being 0.3 MPa, dry it in hot air at 80 °C for 10 min, and then carry out UV curing for 30 s under the conditions of a wavelength of 365 nm and an intensity of 80 mW / cm 2 to obtain the bio-functional veneered artificial board containing herbal active substances.

[0053] Example 3

[0054] This example provides a bio-functional veneered artificial board containing herbal active substances, which includes a base material layer with a thickness of 12 mm and a functional veneer layer with a thickness of 80 μm;

[0055] The base material layer is composed of a mixture of steam-pretreated straw and bamboo fibers with a weight ratio of 100:20 and a bio-based adhesive;

[0056] The functional veneer layer is composed of the following materials by weight: 55 parts of aqueous polyurethane resin, 15 parts of herbal active substance microcapsule powder, 40 parts of modified inorganic filler, and 3 parts of polyethylene wax;

[0057] Among them, the preparation method of the mixture of steam-pretreated straw and bamboo fibers includes: crushing and pulverizing straw and bamboo fibers with a weight ratio of 1:4 to a length of 5 mm; carrying out steam pretreatment at a temperature of 110 °C for 40 min;

[0058] The preparation method of the bio-based adhesive includes: mixing 110 parts of cassava starch and 450 parts of water, adding 4 parts of ammonium persulfate, carrying out an oxidation reaction at 80 °C for 70 min, raising the temperature to 100 °C, continuously stirring at 300 rpm for 40 min, cooling to 55 °C, adding 12 parts of tannic acid and 1.2 parts of borax and reacting for 50 min, and adjusting the pH to 7.0 to obtain it;

[0059] The preparation method of the microcapsule powder of the herb active substance includes: high-speed emulsifying wormwood extract, lavender extract, gelatin - gum arabic and deionized water at a temperature of 55°C and 12,000 rpm, and controlling the inlet temperature at 130°C and the outlet temperature at 80°C for spray drying to obtain the microcapsule powder; the weight ratio of wormwood extract, lavender extract, gelatin - gum arabic and deionized water is 3:2:8:70;

[0060] The preparation method of the modified inorganic filler includes: crushing calcium carbonate and diatomite with a weight ratio of 1:0.6 to a particle size of 500 nm; calcining at a temperature of 600°C for 2 h; mixing the pre - calcined calcium carbonate and diatomite mixture and nano - silica, and then adding silane coupling agent KH - 570, and stirring and mixing at a rotation speed of 400 rpm and a temperature of 70°C for 3 h to obtain the activated filler; impregnating the activated filler in a chitosan aqueous solution, ultrasonic dispersing for 40 min, and drying at 70°C to obtain it; the weight ratio of the pre - calcined calcium carbonate and diatomite mixture, nano - silica and silane coupling agent KH - 570 is 100:9:2; the weight ratio of the activated filler, chitosan and water is 1:0.06:3;

[0061] The preparation method of this bio - functional veneered wood - based panel containing herb active substances includes the following steps:

[0062] (1) Preparation of the substrate layer: Mix the mixture of steam - pretreated straw and bamboo fiber with a moisture content of 10% and a bio - based adhesive and add them to a twin - screw extruder, lay them into a board blank, and obtain a substrate layer with a density of 0.8 g / cm 3 after hot - pressing and trimming and polishing;

[0063] (2) Preparation of the functional veneer layer: Stir and mix aqueous polyurethane resin, microcapsule powder of herb active substance, modified inorganic filler and polyethylene wax at a rotation speed of 900 rpm for 40 min to obtain a mixed coating, spray the mixed coating on the surface of the substrate layer, with the spray gun pressure of 0.5 MPa, dry in hot air at 90°C for 15 min, and then carry out UV curing for 40 s under the conditions of a wavelength of 365 nm and an intensity of 90 mW / cm 2 to obtain the bio - functional veneered wood - based panel containing herb active substances.

[0064] Example 4

[0065] This example provides a bio - functional veneered wood - based panel containing herb active substances, including a substrate layer with a thickness of 8 mm and a functional veneer layer with a thickness of 80 μm;

[0066] The substrate layer is composed of a mixture of steam - pretreated straw and bamboo fiber with a weight ratio of 100:15 and a bio - based adhesive;

[0067] The functional decorative layer comprises the following materials by weight: 45 parts of waterborne polyurethane resin, 15 parts of herb active substance microcapsule powder, 30 parts of modified inorganic filler, and 3 parts of polyethylene wax;

[0068] Among them, the preparation method of the mixture of steam-pretreated straw and bamboo fiber includes: crushing straw and bamboo fiber with a weight ratio of 1:3 to a length of 5 mm; performing steam pretreatment at a temperature of 100 °C for 40 min;

[0069] The preparation method of the bio-based adhesive includes: mixing 100 parts of cassava starch and 450 parts of water, adding 3 parts of ammonium persulfate, performing an oxidation reaction at 80 °C for 50 min, raising the temperature to 100 °C, continuously stirring at 200 rpm for 40 min, adding 12 parts of tannic acid and 1 part of borax after cooling to 45 °C and reacting for 50 min, and adjusting the pH to 6.5 to obtain it;

[0070] The preparation method of the herb active substance microcapsule powder includes: high-speed emulsifying wormwood extract, lavender extract, gelatin-arabic gum, and deionized water at a temperature of 55 °C and 10,000 rpm, and controlling the inlet temperature at 130 °C and the outlet temperature at 70 °C for spray drying to prepare microcapsule powder; the weight ratio of wormwood extract, lavender extract, gelatin-arabic gum, and deionized water is 3:2:6:70;

[0071] The preparation method of the modified inorganic filler includes: crushing calcium carbonate and diatomite with a weight ratio of 1:0.4 to a particle size of 500 nm; calcining at a temperature of 600 °C for 1 h; mixing the calcium carbonate and diatomite mixed material after calcination pretreatment and nano-silica, adding silane coupling agent KH-570, and stirring and mixing at a rotation speed of 400 rpm and a temperature of 60 °C for 3 h to obtain activated filler; impregnating the activated filler in a chitosan aqueous solution, ultrasonically dispersing for 30 min, and drying at 70 °C to obtain it; the weight ratio of the calcium carbonate and diatomite mixed material after calcination pretreatment, nano-silica, and silane coupling agent KH-570 is 100:5:2; the weight ratio of activated filler, chitosan, and water is 1:0.04:3;

[0072] The preparation method of this bio-functional decorative wood-based panel containing herb active substances includes the following steps:

[0073] (1) Preparation of the base material layer: adding the mixture of steam-pretreated straw and bamboo fiber with a moisture content of 8% and the bio-based adhesive into a twin-screw extruder for mixing, paving into a board blank, hot pressing, trimming and polishing to obtain a base material layer with a density of 0.8 g / cm 3 ;

[0074] (2) Preparation of the functional decorative layer: Mix aqueous polyurethane resin, microcapsule powder of herbal active substances, modified inorganic filler, and polyethylene wax under stirring at a rotation speed of 800 rpm for 40 min to obtain a mixed coating. Spray the mixed coating on the surface of the substrate layer with a spray gun pressure of 0.3 MPa, and dry it with hot air at 90 °C for 10 min. Subsequently, perform UV curing for 30 s under the conditions of a wavelength of 365 nm and an intensity of 90 mW / cm 2 to obtain the bio-functional decorative artificial board containing herbal active substances.

[0075] Comparative Example 1

[0076] In the preparation of the bio-based adhesive in Comparative Example 1, the addition of tannic acid was cancelled, and the others were the same as in Example 1.

[0077] Comparative Example 2

[0078] In Comparative Example 2, the herbal microcapsule powder in the functional decorative layer was replaced with unembedded herbal extract powder, that is, the microcapsule powder of herbal active substances was replaced with an equal weight ratio of mugwort extract and lavender extract of 2.5:1.5; the others were the same as in Example 1.

[0079] Comparative Example 3

[0080] In Comparative Example 3, gelatin - arabic gum was replaced with an equal amount of sodium alginate - chitosan composite wall material, and the others were the same as in Example 1.

[0081] Comparative Example 4

[0082] In Comparative Example 4, calcium carbonate and diatomite were replaced with an equal amount of kaolin and bentonite, and the others were the same as in Example 1.

[0083] Comparative Example 5

[0084] In Comparative Example 5, the modified inorganic filler used an uncalcined calcium carbonate / diatomite mixture, and the others were the same as in Example 1.

[0085] Comparative Example 6

[0086] In Comparative Example 6, the chitosan impregnation step of the modified inorganic filler was omitted, and the others were the same as in Example 1.

[0087] Test Example: Explore the properties of the artificial boards prepared in the foregoing Examples 1 - 4 and Comparative Examples 1 - 6, and conduct the following tests:

[0088] Surface bond strength and surface crack resistance: The test method refers to GB / T17657 - 2013;

[0089] Surface condition: Observe the surface condition of the artificial board specimens;

[0090] Water resistance: Referring to GB / T 17657-2013, the sample was soaked for 24 h, the thickness change was measured, and the swelling rate was calculated;

[0091] Antibacterial performance test: Referring to LY / T 1926-2020, the inhibition rates of each wood-based panel against Staphylococcus aureus, Escherichia coli, and Candida albicans were tested. Referring to GB / T 16422.2-2014, a xenon lamp aging chamber was used to simulate 1-year natural light irradiation, and then the inhibition rates against Staphylococcus aureus, Escherichia coli, and Candida albicans were tested.

[0092] The test results are shown in Tables 1 and 2 below:

[0093] Table 1

[0094]

[0095]

[0096] Table 2

[0097]

[0098] Combining the above data, the swelling rate of Comparative Example 1 was significantly higher than that of Example 1, and the antibacterial performance decreased significantly. Tannic acid not only enhances the crosslinking density of the adhesive (reducing water absorption and swelling), but its phenolic hydroxyl structure has a destructive effect on the bacterial cell membrane, which is the core contributor to the antibacterial function. The swelling rate and surface crack problems of Comparative Example 2 indicate that the unembedded herbal extract is prone to moisture absorption and has poor compatibility with the resin; the antibacterial performance of Comparative Example 3 is lower than that of Example 1 but better than that of the unembedded group, indicating that the wall material type affects the protection effect of the active substance. The gelatin-arabic gum system shows better performance in slow-release stability and process adaptability. Comparative Example 4 has a rough surface and a swelling rate of 11.2%, indicating that the pore structure of calcium carbonate / diatomite is more conducive to adsorbing the adhesive; the swelling rate of Comparative Example 5 is as high as 15.0% because no porous structure is formed, verifying the necessity of calcination for filler activation; the antibacterial performance of Comparative Example 6 is lower than that of Example 1 but higher than that of the unmodified group, indicating that the chitosan coating is crucial for long-term antibacterial.

[0099] Finally, it should be noted that the above examples are only used to illustrate the present invention and do not limit the technical solutions described in the present invention; those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced; and all technical solutions and their improvements that do not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims

1. A biofunctional facing artificial board containing herbal active substances, characterized in that: It includes a substrate layer with a thickness of 8-12 mm and a functional finishing layer with a thickness of 50-80 μm; The substrate layer is composed of a mixture of steam-pretreated straw and bamboo fiber and a bio-based adhesive in a weight ratio of 100:(15-20); The functional finishing layer comprises the following materials in parts by weight: 45-55 parts of waterborne polyurethane resin, 10-15 parts of herbal active substance microcapsule powder, 30-40 parts of modified inorganic filler, and 2-3 parts of polyethylene wax.

2. The biofunctional facing artificial board containing herbal active substances according to claim 1, characterized in that: The method for preparing the mixture of steam-pretreated straw and bamboo fiber comprises: crushing the straw and bamboo fiber in a weight ratio of 1:(3-4) to a length of 3-5 mm; and performing steam pretreatment at a temperature of 100-110° C. for 30-40 minutes.

3. The biofunctional facing artificial board containing herbal active substances according to claim 1, characterized in that: The preparation method of the bio-based adhesive comprises: mixing 100-110 parts of cassava starch and 400-450 parts of water, adding 3-4 parts of ammonium persulfate, carrying out oxidation reaction at 70-80° C. for 50-70 minutes, heating to 90-100° C., stirring continuously at 200-300 rpm for 30-40 minutes, cooling to 45-55° C., adding 10-12 parts of tannic acid and 1-1.2 parts of borax for reaction for 40-50 minutes, and adjusting the pH to 6.5-7.0 to obtain the bio-based adhesive.

4. The biofunctional facing artificial board containing herbal active substances according to claim 1, characterized in that: The preparation method of the herbal active substance microcapsule powder comprises: emulsifying wormwood extract, lavender extract, gelatin-arabic gum and deionized water at a temperature of 45-55°C and a speed of 10000-12000 rpm, and spray drying the mixture at an inlet temperature of 120-130°C and an outlet temperature of 70-80°C to prepare the microcapsule powder.

5. The biofunctional facing artificial board containing herbal active substances according to claim 3, characterized in that: The weight ratio of the wormwood extract, lavender extract, gelatin-gum arabic and deionized water is (2-3): (1-2): (6-8): (60-70).

6. The biofunctional facing artificial board containing herbal active substances according to claim 1, characterized in that: The preparation method of the modified inorganic filler comprises: mixing a calcined pre-treated calcium carbonate and diatomaceous earth mixed material with nano silicon dioxide, adding a silane coupling agent KH-570, stirring and mixing for 2-3 hours at a rotation speed of 300-400 rpm and a temperature of 60-70° C. to obtain an activated filler; immersing the activated filler in a chitosan aqueous solution, ultrasonically dispersing for 30-40 minutes, and drying at 60-70° C. to obtain the modified inorganic filler.

7. The biofunctional facing artificial board containing herbal active substances according to claim 6, characterized in that: The calcination pretreatment step includes: crushing calcium carbonate and diatomaceous earth in a weight ratio of 1: (0.4-0.6) to a particle size of ≤500nm; and calcining at a temperature of 500-600°C for 1-2h.

8. The biofunctional facing artificial board containing herbal active substances according to claim 6, characterized in that: The weight ratio of the calcined pretreated calcium carbonate and diatomaceous earth mixed material, nano silicon dioxide and silane coupling agent KH-570 is 100:5-9:1-2.

9. The biofunctional facing artificial board containing herbal active substances according to claim 6, characterized in that: The weight ratio of the activated filler, chitosan and water is 1:(0.04-0.06):(2-3).

10. A method for preparing a biofunctional facing artificial board containing herbal active substances according to any one of claims 1 to 9, characterized in that the steps include: (1) Preparation of the substrate layer: adding a mixture of steam-pretreated straw and bamboo fiber with a moisture content of 8% to 10% and a bio-based adhesive to a twin-screw extruder for mixing, paving into a slab, hot pressing, trimming and polishing to obtain the substrate layer; (2) Preparation of functional finishing layer: Aqueous polyurethane resin, herbal active substance microcapsule powder, modified inorganic filler and polyethylene wax are stirred and mixed at a rotation speed of 800-900 rpm for 30-40 min to obtain a mixed coating, and the mixed coating is sprayed on the surface of the substrate layer. After curing, the biofunctional finishing artificial board containing herbal active substances is obtained.

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