Composition for manufacturing wood composite material containing kenaf, wood composite material using the same, and manufacturing method thereof

Abstract

This invention relates to a composition for manufacturing wood composite materials, a wood composite material using the same, and a method for manufacturing the same. More specifically, it relates to a composition for manufacturing wood composite materials comprising a thermoplastic resin, a silane compound of formula (1) comprising an acrylate moiety, and a biomass mixture comprising kenaf powder and wood flour; a wood composite material manufactured using the same; and a method for manufacturing the wood composite material. In formula (1), R1, R2, and R3 are each independently selected from C. 1‑6 Alkoxy, C 1‑6 Alkyl, halogen, C 1‑6 Alkylsiloxy, allyl and C 1‑6 The group consists of alkenyl groups; n is 0 to 15; R4 is C 1‑6 Alkyl group. Formula (1)

Description

Technical Field

[0001] This invention relates to a composition for manufacturing a wood composite material containing kenaf, a wood composite material using the same, and a method for manufacturing the same, and more specifically, to a composition for manufacturing a wood composite material containing kenaf with improved mechanical properties, a wood composite material using the same, and a method for manufacturing the same. Background Technology

[0002] Recently, in the construction industry, the demand for wood-based materials has been increasing due to the preference for the natural feel of wood. However, if wood is used directly, it is prone to deterioration, decay, rot, surface cracking, and breakage due to its weak resistance to heat, water, and mechanical impact, thus compromising its quality. Therefore, in order to maintain the natural beauty and usability of wood while improving its resistance to heat, water, and mechanical impact, wood composite materials have been explored. Wood-plastic composites, or WPC (short for Wood-Plastic-Combination, Wood-Polymer-Composite, etc.), are obtained by impregnating liquid-curing resins or polymeric monomers into wood and then curing it. They can bring out the characteristics of wood and improve its basic properties, and are therefore widely used in building materials and other fields.

[0003] On the other hand, this type of environmentally friendly, low-carbon new material, wood flour plastic, is made by combining natural wood flour with harmless olefin-based thermoplastic polymer resins through a special compounding process. It is easy to extrude and injection mold, and as a bio-based plastic raw material, it can reduce carbon dioxide emissions and achieve 100% recycling. It is an environmentally friendly material that combines the high-end natural texture of wood with the durability, water resistance, and processability of polymer resins. However, during extrusion and injection molding, the wood flour, which has low thermal stability, undergoes carbonization. During the cooling process of the molded product, the mechanical properties decrease due to the weakened interfacial adhesion between the plastic and the wood flour. Furthermore, the increased moisture content of the wood flour due to its hydrophilicity reduces its corrosion resistance. These are its limitations. To overcome these problems, highly toxic flame retardants, preservatives, fire retardants, and other chemical additives have been used, leading to endocrine disruptors and other environmental issues.

[0004] For example, Korean Patent Publication No. 10-2008-0103734 discloses a biocomposite material with improved mechanical strength, comprising a biodegradable polymer, a main material composed of cellulose-based natural materials, and a hydrolysis inhibitor. However, this technology requires the inclusion of hydrolysis inhibitors such as diisopropyl-phenyl isocyanate.

[0005] On the other hand, kenaf, a natural material, is an annual herbaceous plant of the Malvaceae family native to West Africa. It has a strong ability to absorb carbon dioxide from the air, contains a large amount of useful cellulose, and grows rapidly, reaching 3-4 meters in just six months, making it a promising material. The kenaf stem can be structurally divided into the epidermis and the core. The epidermis has a high cellulose content, yielding long and strong fibers, which has long been used for clothing, bags, ropes, etc. Globally, kenaf varieties are mainly divided into early-maturing varieties cultivated in high-latitude regions and late-maturing varieties cultivated in Africa, India, and the United States. In South Korea's climate, early-maturing varieties can be harvested for seeds, but the biomass yield is extremely low, only 40-60% of that of late-maturing varieties. While late-maturing varieties have high biomass yields, they cannot be harvested for seeds in mid-latitude temperate climates like South Korea, making continuous cultivation difficult. To improve this, the Korea Atomic Energy Research Institute (KAERI) has developed two mid-to-late maturing varieties, "Jangdae" and "Wandae," using radiation breeding technology. These varieties can be harvested for seeds and ensure biomass yields of over 80% of late-maturing varieties in the Korean climate. Currently, only "Jangdae" (National Seed Institute of Korea No. 4560), "Wandae" (National Seed Institute of Korea No. 9374), "Baekma" (National Seed Institute of Korea No. 5285), and "Chikbong" (National Seed Institute of Korea No. 5286), all developed by KAERI, have been registered as protected varieties of kenaf. KAERI has also applied for the "Wonbaek" variety (National Seed Institute of Korea Application No. 2023-72), which has enhanced salt tolerance and can be cultivated in tidal flats.

[0006] Therefore, if wood composite materials with improved mechanical properties can be developed using kenaf without the need for harmful compounds, they are expected to be widely used in a variety of related fields. Summary of the Invention

[0007] (Technical issue)

[0008] One aspect of the present invention is to provide a composition for manufacturing wood composite materials, wherein a wood composite material with improved mechanical properties can be obtained by means of the composition.

[0009] Another aspect of the present invention is to provide a wood composite material with improved mechanical properties.

[0010] Another aspect of the present invention is to provide a method for manufacturing a wood composite material with improved mechanical properties.

[0011] (Technical Solution)

[0012] Therefore, according to one aspect of the present invention, a composition for manufacturing wood composite materials is provided, wherein, based on the weight of the whole composition, the composition for manufacturing wood composite materials comprises: 10 to 85% by weight of a thermoplastic resin; 0.1 to 20% by weight of a silane compound of formula (1) below, comprising an acrylate portion; and 10 to 85% by weight of a biomass mixture comprising kenaf powder and wood flour.

[0013] Equation (1)

[0014] According to another aspect of the present invention, a wood composite material manufactured using the wood composite material manufacturing composition of the present invention is provided.

[0015] According to another aspect of the present invention, a method for manufacturing a wood composite material is provided, the method comprising: mixing a thermoplastic resin, a silane compound of formula (1) containing an acrylate portion, and a biomass mixture containing kenaf powder and wood flour to manufacture a composition for manufacturing a wood composite material; heating and extruding the composition for manufacturing a wood composite material to form a shape; and irradiating the formed extrudate with an electron beam at a dose of 0.1 kGy to 50 kGy.

[0016] (Invention Effects)

[0017] According to the present invention, a wood composite material with improved mechanical properties such as tensile strength can be provided by utilizing radiation technology. Attached Figure Description

[0018] Figure 1 (a) shows wood composite compound pellets manufactured using the compositions for manufacturing wood composites of Comparative Manufacturing Examples 1 to 3. Figure 1 (b) shows a wood composite film sample.

[0019] Figure 2 The surface views of the wood powder used in Comparative Manufacturing Example 1 and the kenaf (complete and long) powder used in Comparative Manufacturing Examples 2 and 3 are shown using scanning electron microscopy.

[0020] Figure 3 The melt index, tensile strength, and impact strength of the wood composite compound pellets manufactured using the compositions for manufacturing wood composites of Comparative Manufacturing Examples 1 to 3 are shown, and the results are presented respectively. Figure 3 (a) to Figure 3 In (c).

[0021] Figure 4The results of scanning electron microscopy confirming the surface of wood composite material particles obtained using the compositions for manufacturing wood composite materials of comparative manufacturing examples 1 and 3, and manufacturing example 2 are shown.

[0022] Figure 5 The document shows the manufacturing process of environmentally friendly kenaf synthetic wood (WPC), which includes mixing, extrusion, and cutting processes, as well as photographs of WPC samples.

[0023] Figure 6 The graph shows the changes in physical properties of walnut composite wood (WPC) under electron beam irradiation, with the maximum bending load (N) on the left and the impact strength (KJ / m) on the right. 2 (Charts) Detailed Implementation

[0024] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention can be modified in many different ways, and the scope of the present invention is not limited to the embodiments described below.

[0025] According to the present invention, a composition for manufacturing wood composite materials is provided, which utilizes radiation technology and applies a specific biomass combination to manufacture wood composite materials with improved mechanical properties.

[0026] More specifically, the wood composite material manufacturing composition of the present invention comprises: a thermoplastic resin; a silane compound of formula (1) below comprising an acrylate portion; and a biomass mixture comprising kenaf powder and wood flour.

[0027] Equation (1)

[0028] The kenaf used in this invention can be selected from at least one of early-maturing, mid-late-maturing, and late-maturing kenaf varieties, preferably late-maturing or mid-late-maturing varieties, such as Wantai or Changtai. The variety "Wantai" can be obtained through Korean National Seed Institute Variety Protection No. 9374, "Changtai" through National Seed Institute Variety Protection No. 4560, "Baima" through National Seed Institute No. 5285, "Chifeng" through National Seed Institute No. 5286, and "Yuanbai" through National Seed Institute Application No. 2023-72.

[0029] On the other hand, the kenaf can be kenaf that includes the core and the bark, i.e., the core and the bark. For example, powder obtained from the entire stem of kenaf can be used without separating the core and the bark.

[0030] There are no particular restrictions on the manufacturing method of kenaf powder. For example, kenaf powder can be manufactured by crushing seed oil or by-products remaining after seedling cultivation, including all by-products such as the core and bark, during the seed setting period of kenaf seeds.

[0031] This invention combines kenaf powder with wood flour, and the addition of kenaf powder results in a wood composite material with superior tensile strength. This can be explained by the fact that, based on the porous structure of kenaf, resin components can penetrate into the porous regions, thereby improving the physical properties.

[0032] In equation (1), R1, R2, and R3 are each independently chosen from C. 1-6 Alkoxy, C 1-6 Alkyl, halogen, C 1-6 Alkylsiloxy, allyl and C 1-6 The group consists of alkenyl groups; n is 0 to 15; R4 is C 1-6 alkyl.

[0033] At this time, the C 2-6 Alkyl means that it can contain unsaturated bonds.

[0034] More preferably, R1, R2 and R3 are each independently selected from the group consisting of methoxy, ethoxy, propoxy, butoxy, methyl, ethyl, propyl, butyl, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), methylsiloxy, trimethylsiloxy, ethylsiloxy, triethylsiloxy, propylsiloxy, tripropylsiloxy, butylsiloxy, tributylsiloxy, allyl and vinyl; n is 0 to 10; and R4 is methyl, ethyl, propyl or butyl.

[0035] For example, the silane compound of formula (1) can be a compound in which R1, R2 and R3 are independently selected from methoxy and ethoxy; n is an integer, for example from 1 to 5; and R4 is a methyl, ethyl or propyl compound.

[0036] More specifically, the silane compound of formula (1) may be one or more selected from the group consisting of 3-(trimethoxysilyl)propyl acrylate, 3-(chlorodimethylsilyl)propyl methacrylate, 3-[diethoxy(methyl)silyl]propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl acrylate, [dimethoxy(methyl)silyl]methyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-[tri(trimethylsiloxy)silyl]propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(methoxydimethylsilyl)propyl acrylate, 3-(triethoxysilyl)propyl methacrylate, 3-(triallylsilyl)propyl methacrylate, 3-(triallylsilyl)propyl methacrylate and (triethoxysilyl)methyl methacrylate.

[0037] The resin of the present invention is preferably a thermoformable resin. For example, the thermoplastic resin that can be used in the present invention may be one or more selected from the group consisting of polyethylene, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, and polypropylene, but is not limited thereto.

[0038] Furthermore, the thermoplastic resins used in this invention include biodegradable resins. Additionally, one or more of the aforementioned thermoplastic resins may be mixed with one or more of the biodegradable resins mentioned below. The biodegradable resin may be, for example, a bioplastic, and more specifically includes: natural polymers produced in nature, such as polysaccharides, starch, gum, pectin, natural rubber, lignocellulose, cellulose, hemicellulose, etc.; bio-based polymers manufactured by polymerizing biomass-based monomers, such as polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoates (PHA), etc.; and biodegradable polymers polymerized from petroleum-based monomers, such as polyhydroxybutyrate (PHB), polycaprolactone (PCL), polybutylene succinate (PBS), poly-β-hydroxybutyrate (PHB), poly-β-hydroxyvalerate (PHV), polybutylene adipate / terephthalate (PBAT), polypropylene terephthalate (PTT), etc., and the thermoplastic resin of the present invention may use at least one of these.

[0039] On the other hand, the wood composite material manufacturing composition of the present invention preferably contains, based on the weight of the whole composition, 10 to 85% by weight of resin, 0.1 to 20% by weight of silane compound of formula (1) containing an acrylate portion, and 10 to 85% by weight of biomass mixture containing kenaf powder and wood flour, for example, 10 to 70% by weight of resin, 0.1 to 10% by weight of silane compound of formula (1) containing an acrylate portion, and 10 to 70% by weight of biomass mixture containing kenaf powder and wood flour.

[0040] When the resin content is below 10% by weight within the above range, the content of modified polymer in the composite material is small, resulting in insufficient mechanical properties. When it exceeds 85% by weight within the above range, the content of wood flour in the biomass mixture is insufficient compared to the polymer, resulting in insufficient performance of the wood composite material. On the other hand, when the silane compound of formula (1) is below 0.1% by weight within the above range, the degree of crosslinking between the biomass mixture and the polymer is low, resulting in problems in improving mechanical properties and hydrophobicity. When it exceeds 20% by weight within the above range, the crosslinking between the biomass mixture and the polymer is too high, resulting in decreased processability during hot pressing and injection molding. Furthermore, when the biomass mixture content is below 10% by weight within the above range, the content of the biomass mixture and / or wood flour is insufficient compared to the polymer, resulting in insufficient performance of the wood composite material. When it exceeds 85% by weight within the above range, the content of polymer in the composite material is small, resulting in insufficient mechanical properties.

[0041] Furthermore, the composition for manufacturing wood composite materials of the present invention may further comprise difunctional or trifunctional acrylic monomers. In this case, the trifunctional acrylic monomer exhibits a higher number of double bond ionizations in the acrylic moiety upon irradiation compared to the difunctional acrylic monomer, thereby increasing the bonding of the molecular chains and enhancing cross-linking.

[0042] For example, the bifunctional acrylic monomer may be one or more selected from the group consisting of 1-(acryloyloxy)-3-(methacryloyloxy)-2-propanol, 1,3-butanediol dimethacrylate, bis(4-methacryloylthiophenyl)sulfide, 1,9-bis(acryloyloxy)nonane, 1,4-bis(acryloyloxy)butane, 1,6-bis(acryloyloxy)hexane, 1,10-bis(acryloyloxy)decane, glycerol dimethacrylate, 1,6-bis(acryloyloxy)-2,2,3,3,4,4,5,5-octafluorohexane, diethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, 1,12-dodecanediol dimethacrylate, diethylene glycol dimethacrylate, bis(trimethylolpropane)tetraacrylate, and ethylene glycol dimethacrylate.

[0043] On the other hand, the trifunctional acrylic monomer may be one or more selected from the group consisting of 1,6-hexanediol dimethacrylate, 4,4'-isopropylidene dimethacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, nonanediol dimethacrylate, pentaerythritol tetraacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, tri(2-acryloyloxyethyl) isocyanurate, tripropylene glycol diacrylate, tetraethylene glycol dimethacrylate, and tetramethylene glycol dimethacrylate.

[0044] On the other hand, each part by weight of the biomass mixture contains 0.4 parts by weight and less than 2 parts by weight of the thermoplastic resin, for example, in a ratio of 2:5 to 5:2, or 2:3 to 3:2. Depending on the purpose of injection molding or extrusion, the ratio of thermoplastic resin to biomass mixture can be adjusted to 2:5 or 3:2 to 1:1, or 1:1 to 2:3 or 2:5. However, if each part by weight of the biomass mixture contains more than 2 parts by weight of thermoplastic resin, the manufacturing properties will be reduced due to decreased flowability and increased inhomogeneity of the mixture during injection molding and extrusion molding.

[0045] The biomass mixture preferably contains wood flour and kenaf powder in a weight ratio of 40:60 to 30:70, for example, within such a range can ensure further improved tensile strength.

[0046] Furthermore, according to the present invention, a wood composite material manufactured using the composition for manufacturing wood composite materials of the present invention is provided, wherein the mechanical properties of the wood composite material of the present invention are improved, particularly the tensile strength is improved.

[0047] The wood composite material of the present invention can be manufactured by the following process.

[0048] More specifically, the method for manufacturing the wood composite material of the present invention includes the steps of: providing the above-described composition for manufacturing the wood composite material of the present invention using kenaf powder; heating and extruding the composition for manufacturing the wood composite material to form a shape; and irradiating the formed extrudate with an electron beam.

[0049] More specifically, the kenaf powder that can be used in this invention can be obtained by crushing the remaining core and bark after seed harvesting during the seed setting period of kenaf seeds, thereby obtaining kenaf powder in the range of 90 to 120 mesh for use.

[0050] After producing such kenaf powder, the kenaf powder is used to mix a thermoplastic resin, a silane compound of formula (1) containing an acrylate portion, and a biomass mixture containing kenaf powder and wood flour, thereby performing the step of manufacturing the wood composite material manufacturing composition of the present invention described above.

[0051] Subsequently, using this wood composite material manufacturing composition, a step of heating and extruding the wood composite material manufacturing composition to form a shape is performed.

[0052] The molding step is preferably performed within a temperature range of 170 to 250°C, and more preferably within a temperature range of 190 to 230°C. When the temperature of the molding step is below the aforementioned 170°C range, molding may not proceed smoothly. When the temperature exceeds the aforementioned 250°C range, the mechanical properties of the wood composite material may decrease due to the thermal decomposition of the polymer resin and the carbonization of the wood flour. On the other hand, the cutting step after molding can be performed after cooling, for example, cutting after cooling to a temperature of 40 to 80°C.

[0053] The electron beam irradiation step can be performed at a dose of 0.1 kGy or higher to less than 75 kGy. Preferably, the electron beam irradiation step is performed at a dose of 0.1 kGy to 50 kGy, for example, at a dose of 1 kGy or higher to 25 kGy or less than 25 kGy. When the dose is below the above range, the improvement in physical properties such as flexural strength may be insufficient; when the dose exceeds the above range, the wood composite material will decompose, and physical properties such as flexural strength will actually decrease.

[0054] Furthermore, the electron beam irradiation step is preferably performed at an electron beam energy of 1 to 9 MeV, for example, 1 to 5 MeV, and more preferably at an electron beam energy of 2 to 3 MeV. When the energy is below the above range, the improvement in physical properties such as bending strength may be insufficient; when the energy is above the above range, the wood composite material will decompose, and physical properties such as bending strength will decrease instead.

[0055] The present invention will now be described in more detail through specific embodiments. These embodiments are merely examples to aid in understanding the invention, and the scope of the invention is not limited thereto.

[0056] Implementation

[0057] Example

[0058] 1. Preparation of compositions for manufacturing wood composite materials

[0059] (1) Red sesame powder

[0060] After harvesting seeds (for oil and seedling cultivation) from the Korean National Seed Institute, the remaining core and outer skin of either "Jangdae" (Korean National Seed Institute Variety Protection No. 4560) or "Wandae" (Korean National Seed Institute Variety Protection No. 9374) obtained during the seed setting period are directly crushed without separating them, thereby obtaining kenaf powder in the range of 90 to 120 mesh.

[0061] (2) Compositions for manufacturing wood composite materials

[0062] Manufacturing Example 1

[0063] A composition for manufacturing wood composite materials is prepared by mixing 9 kg of polyethylene, 0.1 kg of 3-(trimethoxysilyl)propyl methacrylate (hereinafter referred to as 'TMPMA') and 1 kg of a biomass mixture containing wood flour obtained from Doil Ecotech and the sesame powder obtained in 1.(1) above at room temperature.

[0064] At this point, by changing the weight ratio of wood flour to kenaf powder to 100:0, 90:10, 70:30, 50:50, 40:60, 30:70, 10:90, and 0:100, a composition for manufacturing wood composite materials was produced.

[0065] Manufacturing Example 2

[0066] Except for using long-tailed red hemp powder instead of whole-tailed red hemp powder, a wood composite material manufacturing composition was manufactured using the same process as in Manufacturing Example 1.

[0067] Comparative Manufacturing Example 1

[0068] A wood composite material manufacturing composition was manufactured using the same process as in Manufacturing Example 1, except that only wood flour was used instead of kenaf powder.

[0069] Comparative Manufacturing Example 2

[0070] Except for the absence of wood flour and the use of only sesame powder, a wood composite material manufacturing composition was manufactured using the same process as in Manufacturing Example 1.

[0071] Comparative Manufacturing Example 3

[0072] Except that no wood flour is used, only long-tailed red sesame powder is used, a wood composite material manufacturing composition was manufactured using the same process as in Manufacturing Example 2.

[0073] 2. Manufacturing of wood composite materials

[0074] (1) Manufacturing of wood composite material pellets

[0075] The wood composite material obtained in step 1.(2) above is continuously extruded at 190°C using a Brabender (Lab-station), cooled to 40 to 80°C during the process, and cut into lengths of 2 to 6 mm and diameters of 2 to 4 mm, thereby extruding into cylindrical masterbatch about 5 mm long. Then, the wood composite material is obtained by irradiating it with an electron beam of 10 kGy using an electron beam accelerator (2.5 MeV).

[0076] The resulting wood composite compound pellets are shown in Figure 1 In (a).

[0077] (2) Fabrication of wood composite film samples

[0078] The wood composite material manufacturing composition obtained in 1.(2) above was melt-mixed using an intermittent melt mixer equipped with a roller blade rotor (HAAKE PolyDrive Rheomix 600, Thermo Electron Corporation, Germany). The mixture was then hot-pressed for 4 minutes at a temperature of 185°C and a pressure of 3000psi using a hydraulic hot press to produce a film (sheet) sample. The sample was then irradiated with an electron beam of 10kGy using an electron beam accelerator (2.5 MeV).

[0079] The wood composite film sample obtained therefrom is shown in Figure 1 In (b).

[0080] 3. Confirmation of the physical properties of wood composite materials

[0081] (1) Surface Analysis

[0082] 1) Surface analysis of wood flour and kenaf powder

[0083] The surfaces of wood flour and long-platform and whole-platform sesame powder were observed using a scanning electron microscope, and the results are as follows: Figure 2 As shown, surface analysis of wood powder (wood flour) and kenaf powder confirmed that wood powder has a smooth surface, while kenaf powder exhibits a rough surface due to the rupture of vessel pits. This demonstrates that the difference in surface structure can improve physical properties when melt-mixed with polymers.

[0084] 2) Surface analysis of wood composite materials

[0085] When the weight ratio of wood flour to kenaf (long-stacked) powder is 30:70, the surface of the wood composite material particles obtained using the compositions for manufacturing wood composite materials of Manufacturing Example 2, Comparative Manufacturing Example 1, and 3 is examined using a scanning electron microscope, and the results are shown below. Figure 4 middle.

[0086] like Figure 4 As shown, when kenaf powder is included, components such as resin enter the porous structure, thereby improving adhesion and physical properties. Therefore, when a mixture of wood flour and kenaf is used, the physical properties can complement each other, resulting in a more ideal outcome.

[0087] (2) Physical property evaluation

[0088] 1) Melt index

[0089] After heating the temperature of the cylinder bore to 210°C, the material is placed into the cylinder, the piston with applied load is placed in place, and the discharge volume from the bore is cut off after 5 minutes. After another minute, it is cut off, and the discharge rate (g / 10min) is calculated.

[0090] 2) Tensile strength

[0091] According to ASTM D638, this test uses a UTM (Universal Testing Machine) to evaluate the most basic mechanical properties of materials (tensile strength, elongation, and modulus of elasticity). A dumbbell-shaped standard tensile specimen is fixed to clamps on both sides and stretched at a constant speed. The SS curve and the tensile strength, elongation, and modulus of elasticity obtained under stress-strain conditions are measured.

[0092] 3) Impact strength

[0093] According to ASTM D256, the Izod (cantilever beam) impact test is a test to measure the resistance of a specimen to high-speed loads. One end of a standard bending specimen is fixed, and the other end is struck with a hammer from the notched direction until it breaks. The impact value is then measured.

[0094] Based on the above evaluation methods, the melt index, tensile strength, and impact strength of the wood composite compound pellets manufactured using the compositions for manufacturing wood composites in Comparative Manufacturing Examples 1 to 3 were confirmed, and the results are shown below. Figure 3 (a) to Figure 3 In (c), the results confirmed that the physical properties of kenaf were further improved when using the finished powder.

[0095] On the other hand, by changing the weight ratio of wood flour to kenaf powder to 100:0, 90:10, 70:30, 50:50, 40:60, 30:70, 10:90, and 0:100, the tensile strength of the 2.(2) wood composite film samples made using the wood flour of Manufacturing Example 2 and Longtai kenaf powder was compared and confirmed with the case without electron beam irradiation as a control group. The results are shown in Table 1 below.

[0096] [Table 1]

[0097]

[0098] The results confirm that tensile strength increases significantly when irradiated with an electron beam, especially when the weight ratio of wood flour to kenaf is 40:60 to 30:70, the tensile strength is excellent.

[0099] 4. Preparation and property confirmation of environmentally friendly red jute synthetic wood (WPC) prototypes

[0100] (1) Manufacturing of synthetic wood (WPC)

[0101] like Figure 5 As shown, environmentally friendly synthetic wood (WPC) was manufactured through a mixing, extrusion, and cutting process, comprising 29.7% by weight polyethylene, 0.3% by weight 3-(trimethoxysilyl)propyl methacrylate (hereinafter referred to as 'TMPMA'), 60% by weight wood flour powder, and 10% by weight long-tailed kenaf biomass powder. The resulting synthetic wood was irradiated with an electron beam of a total dose of 20 kGy, and recognized testing was conducted to confirm the quality compliance of the electron-irradiated kenaf synthetic wood.

[0102] At this time, the test method was carried out according to KS F 3230:2020, and the results are shown in Table 2 below.

[0103] [Table 2] Quality compliance test results of synthetic wood containing kenaf (WPC)

[0104]

[0105] As can be confirmed in Table 2 above, the synthetic wood made from kenaf according to the present invention has physical properties such as impact strength, maximum bending load, bending creep deformation, impact resistance (room temperature / low temperature), warping resistance, screw holding force, anti-slip property (CSR), water absorption (weight change), freeze-thaw (maximum bending load change rate), linear thermal expansion coefficient, flame retardancy, and specific gravity that are suitable as synthetic wood. Furthermore, no formaldehyde release or harmful heavy metals such as arsenic, cadmium, chromium, lead, and mercury were detected, and it was confirmed to be chemically safe.

[0106] (2) Confirmation of physical properties of synthetic wood (WPC)

[0107] To improve the physical properties of the synthetic wood containing kenaf in this invention, the synthetic wood was irradiated with an electron beam (20 kGy) and its physical intensity changes were analyzed. The results are presented below. Figure 6 The result is as follows. Figure 6 It can be confirmed that by irradiating with an electron beam, the maximum bending load (N) of kenaf synthetic wood increased from 3,465 to 3,715, an increase of approximately 7%; the impact strength (KJ / m) also increased. 2 The value increased from 3.3 to 3.5, an increase of about 6%, indicating that electron beam irradiation can improve the physical properties of synthetic wood.

[0108] The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. It will be obvious to those skilled in the art that various modifications and variations can be made without departing from the technical concept of the present invention as described in the claims.

Claims

1. A composition for manufacturing wood composite materials, wherein, based on the weight of the entire composition, the composition for manufacturing wood composite materials comprises: 10 to 85% by weight of thermoplastic resin; The silane compound of formula (1) below, comprising 0.1 to 20% by weight of the acrylate portion; as well as A biomass mixture comprising 10 to 85% by weight of kenaf powder and wood flour. Equation (1) In equation (1), R1, R2, and R3 are each independently chosen from C. 1-6 Alkoxy, C 1-6 Alkyl, halogen, C 1-6 Alkylsiloxy, allyl and C 1-6 Groups composed of alkenyl groups; n is between 0 and 15; R4 is a C1-6 alkyl group.

2. The composition for manufacturing wood composite materials according to claim 1, wherein, Each part by weight of biomass mixture contains 0.4 to 2 parts by weight of the thermoplastic resin.

3. The composition for manufacturing wood composite materials according to claim 1, wherein, The biomass mixture comprises wood flour and kenaf powder in a weight ratio of 40:60 to 30:

70.

4. The composition for manufacturing wood composite materials according to claim 1, wherein, The kenaf is selected from at least one of the following groups: Changtai (Korea National Seed Institute No. 4560), Wantai (Korea National Seed Institute No. 9374), Baekma (Korea National Seed Institute No. 5285), Chibong (Korea National Seed Institute No. 5286), and Wonbaek (Korea National Seed Institute Application No. 2023-72).

5. The composition for manufacturing wood composite materials according to claim 1, wherein, The kenaf comprises a core and an outer layer.

6. The composition for manufacturing wood composite materials according to claim 1, wherein, The thermoplastic resin is selected from one or more of the group consisting of polyethylene, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene, and polypropylene.

7. The composition for manufacturing wood composite materials according to claim 1, wherein, The silane compound of formula (1) is a compound in which R1, R2 and R3 are independently selected from methoxy and ethoxy; n is 1 to 5; and R4 is methyl, ethyl or propyl.

8. The composition for manufacturing wood composite materials according to claim 1, wherein, The silane compound of formula (1) is selected from one or more of the group consisting of 3-(trimethoxysilyl)propyl acrylate, 3-(chlorodimethylsilyl)propyl methacrylate, 3-[diethoxy(methyl)silyl]propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl acrylate, [dimethoxy(methyl)silyl]methyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate, 3-[tri(trimethylsiloxy)silyl]propyl methacrylate, 3-[dimethoxy(methyl)silyl]propyl methacrylate, 3-(methoxydimethylsilyl)propyl acrylate, 3-(triethoxysilyl)propyl methacrylate, 3-(triallylsilyl)propyl methacrylate, 3-(triallylsilyl)propyl methacrylate and (triethoxysilyl)methyl methacrylate.

9. The composition for manufacturing wood composite materials according to claim 1, further comprising: Difunctional or trifunctional acrylic monomers.

10. A method for manufacturing a wood composite material, the method comprising: The step of mixing a thermoplastic resin, a silane compound of formula (1) containing an acrylate portion, and a biomass mixture containing kenaf powder and wood flour to manufacture a composition for manufacturing wood composite materials according to any one of claims 1 to 9; The step of heating and extruding the composition for manufacturing the wood composite material to form a shape; and The step of irradiating the formed extruded material with an electron beam at a dose of 0.1 kGy to 50 kGy.

11. The method for manufacturing the wood composite material according to claim 10, wherein, The molding process is carried out in a temperature range of 170 to 250°C.

12. The method for manufacturing wood composite material according to claim 10, wherein, The step of irradiating with an electron beam is performed at an electron beam energy of 1 to 9 MeV.

13. A wood composite material, manufactured by irradiating a heated extruded article of the wood composite material manufacturing composition according to any one of claims 1 to 9 with an electron beam dose of 0.1 kGy or more but less than 75 kGy.

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