A method for producing an antistatic oriented strand board

Abstract

The application provides a preparation method of an antistatic oriented strand board, and belongs to the technical field of strand boards; the preparation method comprises the steps of preparing antistatic particles, impregnation, drying, gluing, paving, hot-pressing, and post-treatment; the preparation of the antistatic particles comprises the steps of pretreatment of graphene oxide, modified zinc oxide, and mixing; in the mixing step, the pretreated graphene oxide is placed in toluene, stirred uniformly, then the modified zinc oxide is added and stirred, the stirring time is 33-38 min, the stirring speed is 210-230 rpm, after the stirring is completed, the temperature is increased to 70-74 DEG C, triethylamine is added, the addition rate is controlled to be 2.0-2.4 mL / min, after the addition is completed, the reaction is carried out at 70-74 DEG C for 6.5-6.8 h, after the reaction is completed, the antistatic particles are prepared through filtration, washing, and drying; the antistatic oriented strand board prepared by the method has good and long-lasting antistatic performance, high mechanical performance, and excellent ultraviolet resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of particle boards, and particularly relates to a preparation method of an antistatic oriented particle board. Background Art

[0002] Oriented strand board is one of the new varieties of particle board. When the particles are laid out, the upper and lower surface layers of the oriented strand board arrange the glue-mixed particles longitudinally according to their fiber direction, while the core layer particles are arranged transversely to form a three-layer structural slab, which is then hot-pressed into an oriented strand board. The shape of this particle board requires a longer length and is slightly thicker than that of ordinary particle board. There are two methods of directional laying: mechanical orientation and electrostatic orientation. The former is suitable for directional laying of large particles, and the latter is suitable for directional laying of fine particles. The directional laying of oriented strand board makes it have higher strength in a certain direction, and it is often used as a structural material instead of plywood.

[0003] Because oriented strand board has a relatively uniform structure and good processing performance, it can be used for decorative purposes such as indoor furniture, flooring, and interior doors. It is also a raw material for the construction industry, train and car carriage manufacturing.

[0004] The existing technology for preparing oriented strand boards usually focuses on improving the bending elastic modulus, enhancing the static bending strength, etc., and generally does not involve antistatic properties, which limits the use of oriented strand boards.

[0005] For example, CN114800763A discloses a method for preparing high-strength particleboard, which includes the steps of lignin modification, ultrafine calcium carbonate modification, glue making, glue mixing, particle paving and microwave hot pressing; specifically, it is disclosed that enzymatic lignin is first modified using acrylic acid, itaconic acid and an initiator to obtain modified lignin, and ultrafine calcium carbonate is modified using a silane coupling agent and sodium stearate to obtain modified ultrafine calcium carbonate, and then diphenylmethane diisocyanate, polyacrylate, modified lignin and modified ultrafine calcium carbonate are mixed in proportion to obtain composite glue, and then the particles are treated with a pretreatment agent prepared with sodium stearate and sodium chloride, and then the composite glue and particles are mixed to obtain glue-mixed particles, and then the glue-mixed particles are paved to obtain a slab, and then the slab is microwave-heated and pressed into a plate to obtain a high-strength particleboard.

[0006] The patented particleboard preparation method can heat the oriented particle board continuously, quickly and evenly, thereby improving the strength performance of the product. However, its antistatic performance is poor, which affects the overall performance of the particleboard.

[0007] In order to improve the antistatic properties of oriented strand board, the applicant added antistatic agents in the early stage of research and development, but there are the following problems:

[0008] 1. The antistatic agent is easily lost, making the antistatic performance not lasting;

[0009] 2. Excessive use of antistatic agents will affect the strength of oriented strand board;

[0010] 3. The moisture resistance of the oriented strand board produced is poor, and its strength performance drops sharply under ultraviolet irradiation. Summary of the Invention

[0011] In order to solve the technical problems existing in the prior art, the present invention provides a method for preparing an antistatic oriented strand board, which has excellent and long-lasting antistatic performance, good strength performance, and excellent UV resistance.

[0012] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0013] A method for preparing an antistatic oriented strand board includes the steps of preparing antistatic particles, impregnation, drying, gluing, paving, hot pressing, and post-processing. The specific operations are as follows:

[0014] 1. Preparation of antistatic particles

[0015] (1) Graphene oxide pretreatment

[0016] A. Decentralized processing

[0017] The graphene oxide was placed in deionized water, polyvinyl pyrrolidone and octadecyl dimethyl benzyl ammonium chloride were added, and ultrasonic treatment was performed, with the ultrasonic time being 23-27 minutes, the ultrasonic power being 127-140W, and the ultrasonic frequency being 35-40kHz. After the ultrasonic treatment, the mixture was filtered and washed, and dried at 78-82°C for 8.8-9.2 hours to obtain dispersed graphene oxide;

[0018] The mass ratio of the graphene oxide, deionized water, polyvinyl pyrrolidone and octadecyldimethylbenzyl ammonium chloride is 7.2-7.6:60-65:0.7-0.9:0.8-1.2;

[0019] B. Secondary processing

[0020] The dispersed graphene oxide and tetrahydrofuran are placed in a reaction vessel and stirred for 30-34 minutes at a stirring speed of 242-257 rpm. After the stirring is completed, nitrogen is introduced, hexachlorocyclotriphosphazene and triethylamine are added, and the temperature is raised from 0.8-1.2° C. to 73-77° C. for reflux reaction for 12.0-13.0 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain pretreated graphene oxide.

[0021] The mass volume ratio of the dispersed graphene oxide, tetrahydrofuran, hexachlorocyclotriphosphazene and triethylamine is 5.4-5.8 g:95-110 mL:11.8-12.2 g:19.7-20.3 g;

[0022] (2) Preparation of modified zinc oxide

[0023] A. Primary modification

[0024] The zinc oxide is placed in an ethanol solution and ball milled for 30-34 minutes at a ball milling speed of 104-116 rpm, a ball milling temperature of 43-47° C., and a ball-to-material ratio of 4-6:1. After the ball milling is completed, the solution is transferred to a sealed container, an amination reagent is added, and the solution is stirred evenly. The temperature is raised to 70-73° C., the pressure is controlled at 1.4-1.6 MPa, and the solution is allowed to stand for 6.3-6.7 hours. After the standing period, the solution is filtered, washed, and dried to obtain primary modified zinc oxide.

[0025] The particle size of the zinc oxide is 175-185 nm;

[0026] The mass concentration of the ethanol solution is 50-54%;

[0027] The mass ratio of the zinc oxide, ethanol solution, and amination reagent is 10.1-10.5:115-125:2.7-3.0;

[0028] The amination agent is a mixture of 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate, and the mass ratio of the 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate is 0.8-1.2:0.6-0.8:1.1-1.4;

[0029] B. Deep modification

[0030] Add ethanol solution and tartaric acid to a reaction vessel, stir evenly, then add primary modified zinc oxide at a rate of 0.4-0.6 g / min. After the addition is complete, perform ultrasonic treatment for 13-17 minutes, an ultrasonic power of 94-98 W, and an ultrasonic frequency of 30-35 kHz. After the ultrasonic treatment is completed, heat to 80-84° C. at a rate of 0.4-0.6° C. / min, react with stirring for 18-22 hours, and filter and dry after the reaction is completed to obtain modified zinc oxide.

[0031] The mass concentration of the ethanol solution is 38-43%;

[0032] The mass volume ratio of the ethanol solution, tartaric acid, and primary modified zinc oxide is 95-105 mL: 5.0-5.3 g: 3.5-3.8 g;

[0033] (3) Mixed

[0034] The pretreated graphene oxide was placed in toluene and stirred evenly, and then the modified zinc oxide was added and stirred for 33-38 minutes at a stirring speed of 210-230 rpm. After the stirring was completed, the temperature was raised to 70-74°C, and triethylamine was added at a rate of 2.0-2.4 mL / min. After the addition was completed, the mixture was reacted at 70-74°C for 6.5-6.8 hours. After the reaction was completed, the mixture was filtered, washed, and dried to obtain antistatic particles.

[0035] The mass ratio of the pretreated graphene oxide, toluene, modified zinc oxide, and triethylamine is 1.8-2.2 g: 37-42 mL: 3.6-3.8 g: 21-25 mL.

[0036] 2. Impregnation

[0037] The surface wood shavings and the core wood shavings are placed in an antistatic compound, stirred evenly, and then immersed for 13-18 minutes at a temperature of 36-40° C. After the immersion is completed, the immersed surface wood shavings and the immersed core wood shavings are respectively obtained;

[0038] The surface shavings are 35-38 mm long, 4.3-4.7 mm wide, and 0.20-0.25 mm thick, and are made from poplar shavings.

[0039] The core material is 40-44 mm long, 4.8-5.2 mm wide, and 0.22-0.28 mm thick and is made of pine wood chips;

[0040] The mass ratio of the surface wood chips raw material to the antistatic composite agent is 5.3-5.6:18-20;

[0041] The mass ratio of the core layer wood chips raw material to the antistatic agent is 4.1-4.3:21-25;

[0042] The raw material components of the antistatic composite are 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide, and the mass ratio of the 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide is 86-90:18-22:3.7-4.3:3.0-3.4:8.3-8.7.

[0043] 3. Drying

[0044] The impregnated surface wood chips and the impregnated core wood chips are dried using flue gas at 348-354° C. respectively to make the moisture content 2.3-2.7%, thereby obtaining dried surface wood chips and dried core wood chips.

[0045] 4. Sizing

[0046] Adhesive is applied to the dried surface wood chips and the dried core wood chips by mechanical mixing method to prepare the sized surface wood chips and the sized core wood chips;

[0047] The surface glue application amount is 2.5-3.0%, and the glue application amount is based on the mass ratio of absolute dry glue to absolute dry wood shavings;

[0048] The amount of glue applied to the core layer is 2.1-2.5%, and the amount applied is based on the mass ratio of absolute glue to absolute dry wood shavings;

[0049] The preparation method of the adhesive comprises the following steps: mixing 32-37 g of isocyanate glue and 4.0-4.4 g of nano-titanium dioxide, stirring evenly, adding 1.8-2.2 g of paraffin wax, 1.2-1.4 g of diacetyl tartaric acid monoglyceride and 1.6-1.8 g of sodium oleate, and homogenizing the mixture. The homogenization time is 4.5-5.5 minutes, and the homogenization pressure is 4.4-4.8 MPa. After the homogenization is completed, the adhesive is obtained.

[0050] 5. Paving

[0051] The glued core layer wood chips are paved through a five-layer paving head to obtain a core layer material, and then the glued surface layer materials are paved on the upper and lower surfaces of the core layer material to obtain a slab;

[0052] The core layer material is a three-layer structure, which is composed of a core layer upper surface layer, a core layer middle layer, and a core layer lower surface layer from top to bottom, wherein the core layer middle layer is paved horizontally, and the core layer upper surface layer and the core layer lower surface layer are paved vertically;

[0053] The surface shavings of the surface material after gluing during paving are arranged longitudinally;

[0054] The mass ratio of the core layer material to the surface layer material is 7.3-7.7:2.3-2.7;

[0055] In the core layer material, the mass ratio of the core layer upper surface layer, the core layer middle layer, and the core layer lower surface layer is 1:0.8-1.2:1;

[0056] The mass ratio of the upper layer to the lower layer of the surface material is 1:0.8-1.2.

[0057] 6. Hot pressing

[0058] The slab is compacted by a pre-press, and then cut into the required slab width by a slab trimming saw to obtain a sawn slab, which is then hot pressed by a continuous flat press. The hot pressing temperatures are 232-237°C, 218-224°C, 216-222°C, 198-202°C, and 167-173°C, respectively. The hot pressing factor is 5.8-6.2s / mm, and the pressures are 1.3-1.5MPa, 1.2-1.4MPa, 0.8-1.0MPa, 0.4-0.6MPa, and 0.7-0.9MPa, respectively. After the hot pressing is completed, a plain board is obtained.

[0059] 7. Post-processing

[0060] Oriented strand board is produced by cutting the raw boards into pieces, turning them over for cooling, storing them for aging, cutting them into specifications, inspecting and grading them, and packaging them for storage.

[0061] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0062] 1. The present invention first performs a dispersion treatment on graphene oxide, which can better avoid the agglomeration of graphene and enhance the dispersion performance. Then, hexachlorocyclotriphosphazene is used for secondary treatment. Under the catalytic action of triethylamine, the hydroxyl groups of graphene oxide can react with hexachlorocyclotriphosphazene, and hexachlorocyclotriphosphazene is grafted on the surface of graphene oxide. The obtained pretreated graphene oxide has good stability. In the step of preparing modified zinc oxide, aminosilane coupling agent is first used to perform primary modification on zinc oxide, so that the primary modified oxide Zinc oxide is present as particles that are individually dispersed and have amino groups grafted onto their surfaces. Tartaric acid is then used for a condensation acylation reaction. Finally, after a mixing step, the P-Cl groups of the pretreated graphene oxide react with the -NH2 of the modified zinc oxide to produce antistatic particles. The zinc oxide and graphene oxide present a cross-linked network structure with strong and stable bonding. The antistatic particles are used in the impregnation and sizing steps, have good compatibility with other ingredients, and exhibit excellent homogeneity, effectively enhancing the antistatic and mechanical properties of the oriented strand board. The antistatic properties are long-lasting and the mechanical properties are stable.

[0063] 2. The antistatic oriented strand board prepared by the method of the present invention has a density of 0.84-0.89 g / cm 3 ;

[0064] 3. The antistatic oriented strand board prepared by the method of the present invention has a parallel static bending strength of 46.7-47.4 MPa, a vertical static bending strength of 30.6-31.2 MPa, an internal bonding strength of 0.84-0.92 MPa, and a parallel elastic modulus of 4885-4894 MPa;

[0065] 4. The antistatic oriented strand board prepared by the method of the present invention has good and lasting antistatic performance and a resistivity of 3.25-3.32×107 Ω / cm;

[0066] 5. The antistatic oriented strand board prepared by the method of the present invention is placed under a strength of 610W / cm 2 The samples were irradiated with ultraviolet light for 5 days and then placed under an intensity of 820W / cm 2 The samples were irradiated with ultraviolet light for 5 days and then placed under an intensity of 450W / cm 2 After irradiation under ultraviolet light for 5 days, the parallel static bending strength was measured again and was 44.0-45.2MPa, the vertical static bending strength was 28.5-29.4MPa, and the parallel elastic modulus was 4631-4703MPa. DETAILED DESCRIPTION

[0067] In order to more clearly understand the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described.

[0068] Example 1

[0069] 1. Preparation of antistatic particles

[0070] (1) Graphene oxide pretreatment

[0071] A. Decentralized processing

[0072] 7.4 g of graphene oxide was placed in 63 g of deionized water, 0.8 g of polyvinyl pyrrolidone and 1.0 g of octadecyldimethylbenzyl ammonium chloride were added, and ultrasonic treatment was performed for 25 min, the ultrasonic power was 132 W, and the ultrasonic frequency was 37 kHz. After the ultrasonic treatment, the mixture was filtered and washed, and dried at 80° C. for 9.0 h to obtain dispersed graphene oxide;

[0073] B. Secondary processing

[0074] 5.6 g of dispersed graphene oxide and 100 mL of tetrahydrofuran were placed in a reaction vessel and stirred for 32 min at a stirring speed of 250 rpm. After the stirring was completed, nitrogen was introduced, 12.0 g of hexachlorocyclotriphosphazene and 20.0 g of triethylamine were added, and the temperature was raised from 1.0° C. to 75° C. for reflux reaction for 12.5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated graphene oxide;

[0075] (2) Preparation of modified zinc oxide

[0076] A. Primary modification

[0077] 10.3 g of zinc oxide was placed in 120 g of ethanol solution and ball milled for 32 min at a speed of 110 rpm, a temperature of 45° C., and a ball-to-material ratio of 5:1. After the ball milling was completed, the solution was transferred to a sealed container, 2.9 g of an amination reagent was added, and the solution was stirred evenly. The temperature was raised to 71° C., the pressure was controlled at 1.5 MPa, and the solution was allowed to stand for 6.5 h. After the standing period, the solution was filtered, washed, and dried to obtain primary modified zinc oxide.

[0078] The particle size of the zinc oxide is 180 nm;

[0079] The mass concentration of the ethanol solution is 52%;

[0080] The amination agent is a mixture of 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate, and the mass ratio of the 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate is 1.0:0.7:1.2;

[0081] B. Deep modification

[0082] 100 mL of ethanol solution and 5.1 g of tartaric acid were added to the reaction vessel, and after stirring evenly, 3.7 g of primary modified zinc oxide was added at a rate of 0.5 g / min. After the addition was completed, ultrasonic treatment was performed for 15 min, the ultrasonic power was 96 W, and the ultrasonic frequency was 33 kHz. After the ultrasonic treatment was completed, the temperature was raised to 82° C. at a rate of 0.5° C. / min, and the reaction was stirred for 20 h. After the stirring reaction was completed, the mixture was filtered and dried to obtain modified zinc oxide.

[0083] The mass concentration of the ethanol solution is 40%;

[0084] (3) Mixed

[0085] 2.0 g of pretreated graphene oxide was placed in 40 mL of toluene and stirred evenly. Then, 3.7 g of modified zinc oxide was added and stirred for 35 min at a stirring speed of 220 rpm. After stirring, the temperature was raised to 72 ° C. 23 mL of triethylamine was added at a rate of 2.2 mL / min. After the addition was completed, the mixture was reacted at 72 ° C for 6.7 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain antistatic particles.

[0086] 2. Impregnation

[0087] The surface wood shavings and the core wood shavings are placed in an antistatic compound, stirred evenly, and then immersed for 15 minutes at a temperature of 38°C. After the immersion, the immersed surface wood shavings and the immersed core wood shavings are obtained respectively.

[0088] The surface shavings are 36 mm long, 4.5 mm wide and 0.23 mm thick and are made from poplar shavings.

[0089] The core material is 42 mm long, 5.0 mm wide and 0.25 mm thick and is made of pine wood chips;

[0090] The mass ratio of the surface wood shavings raw material to the antistatic compound is 5.4:19;

[0091] The mass ratio of the core layer wood chips to the antistatic agent is 4.2:23;

[0092] The raw material components of the antistatic composite are 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide, and the mass ratio of the 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide is 88:20:4.0:3.2:8.5.

[0093] 3. Drying

[0094] The impregnated surface wood chips and the impregnated core wood chips were dried using flue gas at 350° C. to make the moisture content 2.5%, thereby obtaining dried surface wood chips and dried core wood chips.

[0095] 4. Sizing

[0096] Adhesive is applied to the dried surface wood chips and the dried core wood chips by mechanical mixing method to prepare the sized surface wood chips and the sized core wood chips;

[0097] The surface sizing amount is 2.7%, and the sizing amount is based on the mass ratio of absolute dry glue to absolute dry wood shavings;

[0098] The amount of glue applied to the core layer is 2.3%, and the amount applied is based on the mass ratio of absolute glue to absolute dry wood shavings;

[0099] The adhesive is prepared by mixing 35 g of isocyanate glue and 4.2 g of nano-titanium dioxide, stirring evenly, adding 2.0 g of paraffin, 1.3 g of diacetyl tartaric acid monoglyceride and 1.7 g of sodium oleate for homogenization, wherein the homogenization time is 5.0 min and the homogenization pressure is 4.6 MPa. After the homogenization is completed, the adhesive is obtained.

[0100] 5. Paving

[0101] The glued core layer wood chips are paved through a five-layer paving head to obtain a core layer material, and then the glued surface layer materials are paved on the upper and lower surfaces of the core layer material to obtain a slab;

[0102] The core layer material is a three-layer structure, which is composed of a core layer upper surface layer, a core layer middle layer, and a core layer lower surface layer from top to bottom, wherein the core layer middle layer is paved horizontally, and the core layer upper surface layer and the core layer lower surface layer are paved vertically;

[0103] The surface shavings of the surface material after gluing during paving are arranged longitudinally;

[0104] The mass ratio of the core layer material to the surface layer material is 7.5:2.5;

[0105] In the core layer material, the mass ratio of the core layer upper surface layer, the core layer middle layer, and the core layer lower surface layer is 1:1:1;

[0106] The mass ratio of the upper and lower layers of the surface material is 1:1.

[0107] 6. Hot pressing

[0108] The slab is compacted by a pre-press and then cut into the required slab width by a slab trimming saw to obtain a sawn slab. The slab is hot pressed by a continuous flat press. The hot pressing temperatures are 235°C, 220°C, 220°C, 200°C, and 170°C, respectively. The hot pressing factor is 6s / mm, and the pressures are 1.4MPa, 1.3MPa, 0.9MPa, 0.5MPa, and 0.8MPa, respectively. After the hot pressing is completed, a plain board is obtained.

[0109] 7. Post-processing

[0110] Oriented strand board is produced by cutting the raw boards into pieces, turning them over for cooling, storing them for aging, cutting them into specifications, inspecting and grading them, and packaging them for storage.

[0111] Example 2

[0112] 1. Preparation of antistatic particles

[0113] (1) Graphene oxide pretreatment

[0114] A. Decentralized processing

[0115] 7.2 g of graphene oxide was placed in 60 g of deionized water, 0.7 g of polyvinyl pyrrolidone and 0.8 g of octadecyldimethylbenzyl ammonium chloride were added, and ultrasonic treatment was performed for 23 min, the ultrasonic power was 127 W, and the ultrasonic frequency was 35 kHz. After the ultrasonic treatment, the mixture was filtered and washed, and dried at 78 ° C for 8.8 h to obtain dispersed graphene oxide;

[0116] B. Secondary processing

[0117] 5.4 g of dispersed graphene oxide and 95 mL of tetrahydrofuran were placed in a reaction vessel and stirred for 30 min at a stirring speed of 242 rpm. After the stirring was completed, nitrogen was introduced, 11.8 g of hexachlorocyclotriphosphazene and 19.7 g of triethylamine were added, and the temperature was raised from 0.8° C. to 73° C. for reflux reaction for 12.0 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated graphene oxide;

[0118] (2) Preparation of modified zinc oxide

[0119] A. Primary modification

[0120] 10.1 g of zinc oxide was placed in 115 g of ethanol solution and ball milled for 30 min at a speed of 104 rpm, a temperature of 43° C., and a ball-to-material ratio of 4:1. After the ball milling was completed, the solution was transferred to a sealed container, 2.7 g of an amination reagent was added, and the solution was stirred evenly. The temperature was raised to 70° C., the pressure was controlled at 1.4 MPa, and the solution was allowed to stand for 6.3 h. After the standing period, the solution was filtered, washed, and dried to obtain primary modified zinc oxide.

[0121] The particle size of the zinc oxide is 175 nm;

[0122] The mass concentration of the ethanol solution is 50%;

[0123] The amination agent is a mixture of 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate, and the mass ratio of the 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate is 0.8:0.6:1.1;

[0124] B. Deep modification

[0125] Add 95 mL of ethanol solution and 5.0 g of tartaric acid to the reaction container, stir evenly, then add 3.5 g of primary modified zinc oxide at a rate of 0.4 g / min. After the addition is complete, perform ultrasonic treatment for 13 min, an ultrasonic power of 94 W, and an ultrasonic frequency of 30 kHz. After the ultrasonic treatment is completed, heat to 80° C. at a rate of 0.4° C. / min, react with stirring for 18 h, and filter and dry to obtain modified zinc oxide.

[0126] The mass concentration of the ethanol solution is 38%;

[0127] (3) Mixed

[0128] 1.8 g of pretreated graphene oxide was placed in 37 mL of toluene and stirred evenly. Then, 3.6 g of modified zinc oxide was added and stirred for 33 min at a stirring speed of 210 rpm. After stirring, the temperature was raised to 70°C and 21 mL of triethylamine was added at a rate of 2.0 mL / min. After the addition was completed, the mixture was reacted at 70°C for 6.5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain antistatic particles.

[0129] 2. Impregnation

[0130] The surface wood shavings and the core wood shavings are placed in an antistatic compound, stirred evenly, and then immersed for 13 minutes at a temperature of 36°C. After the immersion, the immersed surface wood shavings and the immersed core wood shavings are obtained respectively.

[0131] The surface shavings are 35 mm long, 4.3 mm wide and 0.20 mm thick and are made from poplar shavings.

[0132] The core material is 40 mm long, 4.8 mm wide and 0.22 mm thick and is made of pine wood chips;

[0133] The mass ratio of the surface wood chips raw material to the antistatic compound is 5.3:18;

[0134] The mass ratio of the core layer wood chips to the antistatic agent is 4.1:21;

[0135] The raw material components of the antistatic composite are 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide, and the mass ratio of the 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide is 86:18:3.7:3.0:8.3.

[0136] 3. Drying

[0137] The impregnated surface wood chips and the impregnated core wood chips were dried using flue gas at 348° C. to achieve a moisture content of 2.3%, thereby obtaining dried surface wood chips and dried core wood chips.

[0138] 4. Sizing

[0139] Adhesive is applied to the dried surface wood chips and the dried core wood chips by mechanical mixing method to prepare the sized surface wood chips and the sized core wood chips;

[0140] The surface sizing amount is 2.5%, and the sizing amount is based on the mass ratio of absolute dry glue to absolute dry wood shavings;

[0141] The amount of glue applied to the core layer is 2.1%, and the amount applied is based on the mass ratio of absolute glue to absolute dry wood shavings;

[0142] The adhesive is prepared by mixing 32 g of isocyanate glue and 4.0 g of nano-titanium dioxide, stirring evenly, adding 1.8 g of paraffin, 1.2 g of diacetyl tartaric acid monoglyceride and 1.6 g of sodium oleate for homogenization, wherein the homogenization time is 4.5 min and the homogenization pressure is 4.8 MPa. After the homogenization is completed, the adhesive is obtained.

[0143] 5. Paving

[0144] The glued core layer wood chips are paved through a five-layer paving head to obtain a core layer material, and then the glued surface layer materials are paved on the upper and lower surfaces of the core layer material to obtain a slab;

[0145] The core layer material is a three-layer structure, which is composed of a core layer upper surface layer, a core layer middle layer, and a core layer lower surface layer from top to bottom, wherein the core layer middle layer is paved horizontally, and the core layer upper surface layer and the core layer lower surface layer are paved vertically;

[0146] The surface shavings of the surface material after gluing during paving are arranged longitudinally;

[0147] The mass ratio of the core layer material to the surface layer material is 7.3:2.7;

[0148] In the core layer material, the mass ratio of the core layer upper surface layer, the core layer middle layer, and the core layer lower surface layer is 1:1.2:1;

[0149] The mass ratio of the upper layer to the lower layer of the surface material is 1:0.8.

[0150] 6. Hot pressing

[0151] The slab is compacted by a pre-press and then cut into the required slab width by a slab trimming saw to obtain a sawn slab. The slab is hot pressed by a continuous flat press. The hot pressing temperatures are 232°C, 218°C, 216°C, 198°C, and 167°C, respectively. The hot pressing factor is 5.8s / mm, and the pressures are 1.3MPa, 1.2MPa, 0.8MPa, 0.4MPa, and 0.7MPa, respectively. After the hot pressing is completed, a plain board is obtained.

[0152] 7. Post-processing

[0153] Oriented strand board is produced by cutting the raw boards into pieces, turning them over for cooling, storing them for aging, cutting them into specifications, inspecting and grading them, and packaging them for storage.

[0154] Example 3

[0155] 1. Preparation of antistatic particles

[0156] (1) Graphene oxide pretreatment

[0157] A. Decentralized processing

[0158] 7.6 g of graphene oxide was placed in 65 g of deionized water, 0.97 g of polyvinyl pyrrolidone and 1.2 g of octadecyldimethylbenzyl ammonium chloride were added, and ultrasonic treatment was performed for 27 min, the ultrasonic power was 140 W, and the ultrasonic frequency was 40 kHz. After the ultrasonic treatment, the mixture was filtered and washed, and dried at 82 ° C for 9.2 h to obtain dispersed graphene oxide;

[0159] B. Secondary processing

[0160] 5.8 g of dispersed graphene oxide and 110 mL of tetrahydrofuran were placed in a reaction vessel and stirred for 34 min at a stirring speed of 257 rpm. After the stirring was completed, nitrogen was introduced, 12.2 g of hexachlorocyclotriphosphazene and 20.3 g of triethylamine were added, and the temperature was raised from 1.2° C. to 77° C. for reflux reaction for 13.0 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated graphene oxide;

[0161] (2) Preparation of modified zinc oxide

[0162] A. Primary modification

[0163] 10.5 g of zinc oxide was placed in 125 g of ethanol solution and ball milled for 34 min at a speed of 116 rpm, a temperature of 47° C., and a ball-to-material ratio of 6:1. After the ball milling was completed, the solution was transferred to a sealed container, 3.0 g of an amination reagent was added, and the solution was stirred evenly. The temperature was raised to 73° C., the pressure was controlled at 1.6 MPa, and the solution was allowed to stand for 6.7 h. After the standing period, the solution was filtered, washed, and dried to obtain primary modified zinc oxide.

[0164] The particle size of the zinc oxide is 185 nm;

[0165] The mass concentration of the ethanol solution is 54%;

[0166] The amination agent is a mixture of 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate, and the mass ratio of the 3-diethylenetriaminopropyl trimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate is 1.2:0.8:1.4;

[0167] B. Deep modification

[0168] 105 mL of ethanol solution and 5.3 g of tartaric acid were added to the reaction vessel, and after stirring evenly, 3.8 g of primary modified zinc oxide was added at a rate of 0.6 g / min. After the addition was completed, ultrasonic treatment was performed for 17 min, the ultrasonic power was 98 W, and the ultrasonic frequency was 35 kHz. After the ultrasonic treatment was completed, the temperature was raised to 84 ° C at a rate of 0.6 ° C / min, and the reaction was stirred for 22 h. After the stirring reaction was completed, the mixture was filtered and dried to obtain modified zinc oxide;

[0169] The mass concentration of the ethanol solution is 43%;

[0170] (3) Mixed

[0171] 2.2 g of pretreated graphene oxide was placed in 42 mL of toluene and stirred evenly. Then, 3.8 g of modified zinc oxide was added and stirred for 38 min at a stirring speed of 230 rpm. After stirring, the temperature was raised to 74 ° C. 25 mL of triethylamine was added at a rate of 2.4 mL / min. After the addition was completed, the mixture was reacted at 74 ° C for 6.8 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain antistatic particles.

[0172] 2. Impregnation

[0173] The surface wood shavings and the core wood shavings are placed in an antistatic compound, stirred evenly, and then immersed for 18 minutes at a temperature of 40°C. After the immersion, the immersed surface wood shavings and the immersed core wood shavings are obtained respectively.

[0174] The surface shavings are 38 mm long, 4.7 mm wide and 0.25 mm thick and are made from poplar shavings.

[0175] The core material is 44 mm long, 5.2 mm wide and 0.28 mm thick and is made of pine wood chips;

[0176] The mass ratio of the surface wood chips raw material to the antistatic composite agent is 5.6:20;

[0177] The mass ratio of the core layer wood chips to the antistatic agent is 4.3:25;

[0178] The raw material components of the antistatic composite are 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide, and the mass ratio of the 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide is 90:22:4.3:3.4:8.7.

[0179] 3. Drying

[0180] The impregnated surface wood chips and the impregnated core wood chips were dried using flue gas at 354° C. to achieve a moisture content of 2.7%, thereby obtaining dried surface wood chips and dried core wood chips.

[0181] 4. Sizing

[0182] Adhesive is applied to the dried surface wood chips and the dried core wood chips by mechanical mixing method to prepare the sized surface wood chips and the sized core wood chips;

[0183] The surface sizing amount is 3.0%, and the sizing amount is based on the mass ratio of absolute dry glue to absolute dry wood shavings;

[0184] The amount of glue applied to the core layer is 2.5%, and the amount applied is based on the mass ratio of absolute glue to absolute dry wood shavings;

[0185] The adhesive is prepared by mixing 37 g of isocyanate glue and 4.4 g of nano-titanium dioxide, stirring evenly, adding 2.2 g of paraffin, 1.4 g of diacetyl tartaric acid monoglyceride and 1.8 g of sodium oleate for homogenization, wherein the homogenization time is 5.5 min and the homogenization pressure is 4.4 MPa. After the homogenization is completed, the adhesive is obtained.

[0186] 5. Paving

[0187] The glued core layer wood chips are paved through a five-layer paving head to obtain a core layer material, and then the glued surface layer materials are paved on the upper and lower surfaces of the core layer material to obtain a slab;

[0188] The core layer material is a three-layer structure, which is composed of a core layer upper surface layer, a core layer middle layer, and a core layer lower surface layer from top to bottom, wherein the core layer middle layer is paved horizontally, and the core layer upper surface layer and the core layer lower surface layer are paved vertically;

[0189] The surface shavings of the surface material after gluing during paving are arranged longitudinally;

[0190] The mass ratio of the core layer material to the surface layer material is 7.7:2.3;

[0191] In the core layer material, the mass ratio of the core layer upper surface layer, the core layer middle layer, and the core layer lower surface layer is 1:0.8:1;

[0192] The mass ratio of the upper and lower layers of the surface material is 1:1.2.

[0193] 6. Hot pressing

[0194] The slab is compacted by a pre-press and then cut into the required slab width by a slab trimming saw to obtain a sawn slab. The slab is hot pressed by a continuous flat press. The hot pressing temperatures are 237°C, 224°C, 222°C, 202°C, and 173°C, respectively. The hot pressing factor is 6.2s / mm, and the pressures are 1.5MPa, 1.4MPa, 1.0MPa, 0.6MPa, and 0.9MPa, respectively. After the hot pressing is completed, a plain board is obtained.

[0195] 7. Post-processing

[0196] Oriented strand board is produced by cutting the raw boards into pieces, turning them over for cooling, storing them for aging, cutting them into specifications, inspecting and grading them, and packaging them for storage.

[0197] Comparative Example 1

[0198] Based on Example 1, the changes are as follows: in the step of preparing antistatic particles,

[0199] (1) Omitting the secondary treatment step of the graphene oxide pretreatment step;

[0200] (2) In the step of preparing modified zinc oxide, the deep modification step is omitted;

[0201] (3) In the mixing step, the pretreated graphene oxide is replaced by the dispersed graphene oxide in equal amounts, and the modified zinc oxide is replaced by the primary modified zinc oxide in equal amounts;

[0202] The rest of the operations are the same.

[0203] Comparative Example 2

[0204] Based on Example 1, the changes are as follows: in the step of preparing the antistatic particles,

[0205] (1) Omitting the dispersion step of the graphene oxide pretreatment step;

[0206] (2) In the primary modification step of preparing modified zinc oxide, octylphenol polyoxyethylene ether and glyceryl monostearate in the amination reagent were replaced with 52 wt% ethanol solution in equal amounts;

[0207] (3) In the gluing step, diacetyl tartaric acid monoglyceride and sodium oleate in the adhesive are replaced with isocyanate glue in equal amounts;

[0208] The rest of the operations are the same.

[0209] Performance testing

[0210] The properties of the oriented strand boards prepared in Examples 1-3 and Comparative Examples 1-2 were tested as follows:

[0211] 1. Strength performance

[0212]

[0213] 2. Antistatic properties

[0214]

[0215] 3. UV resistance

[0216] The oriented strand boards prepared in Examples 1-3 and Comparative Examples 1-2 were placed on a plate with a strength of 610 W / cm 2 The samples were irradiated with ultraviolet light for 5 days and then placed under an intensity of 820W / cm 2 The samples were irradiated with ultraviolet light for 5 days and then placed under an intensity of 450W / cm 2 After irradiation under ultraviolet light for 5 days, the strength performance was tested again. The results are as follows:

[0217]

[0218] Both graphene oxide and zinc oxide have good antistatic properties, but they have poor dispersibility and poor compatibility with components such as isocyanate glue, which affects the comprehensive performance of particleboard. The present invention first disperses the graphene oxide, which can better avoid the agglomeration of graphene and enhance the dispersion performance. Then, hexachlorocyclotriphosphazene is used for secondary treatment. Under the catalytic action of triethylamine, the hydroxyl groups of the graphene oxide can react with hexachlorocyclotriphosphazene, and hexachlorocyclotriphosphazene is grafted on the surface of the graphene oxide. The obtained pretreated graphene oxide has good stability. In the step of preparing modified zinc oxide, first Zinc oxide is primarily modified with an aminosilane coupling agent, so that the primary modified zinc oxide presents particles that are individually dispersed and have amino groups grafted on the surface. Tartaric acid is then used for a condensation acylation reaction. Finally, after a mixing step, the P-Cl group of the pretreated graphene oxide reacts with the -NH2 of the modified zinc oxide to prepare antistatic particles. The zinc oxide and graphene oxide present a cross-linked network structure with strong and stable bonding. The antistatic particles are used in the impregnation and sizing steps, have good compatibility with other ingredients, and are excellent in homogeneity, effectively enhancing the antistatic and mechanical properties of the oriented strand board, and have long-lasting antistatic properties and stable mechanical properties.

[0219] In Comparative Example 1, in the mixing step, the pretreated graphene oxide is replaced by dispersed graphene oxide in equal amounts, and the modified zinc oxide is replaced by primary modified zinc oxide in equal amounts. The bonding force between the graphene oxide and the primary modified zinc oxide is poor, and a relatively stable network structure cannot be formed, which affects the antistatic and mechanical properties of the particleboard, and the ultraviolet radiation resistance is poor. In Comparative Example 2, the dispersion treatment step of the graphene pretreatment step is omitted. When hexachlorocyclotriphosphazene is used for secondary treatment, the grafting of the graphene oxide is insufficient. In the primary modification step of the modified zinc oxide, the modification of the aminosilane coupling agent is also insufficient, resulting in uneven reaction in the mixing step, affecting the structural uniformity of the antistatic particles. In addition, in the sizing step, the diacetyl tartaric acid monoglyceride and sodium oleate in the adhesive are replaced by isocyanate glue in equal amounts, which leads to the dispersibility and wetting properties of the adhesive, and ultimately leads to poor mechanical properties and stability of the oriented strand board.

[0220] Unless otherwise specified, all ratios and percentages described in the present invention are by mass.

[0221] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an antistatic oriented strand board, characterized in that: The preparation method includes the steps of preparing antistatic particles, impregnation, drying, sizing, paving, hot pressing and post-processing; The preparation of antistatic particles comprises graphene oxide pretreatment, zinc oxide modification and mixing steps; The graphene oxide pretreatment step includes a dispersion treatment step and a secondary treatment step; The dispersion treatment step comprises placing graphene oxide in deionized water, adding polyvinyl pyrrolidone and octadecyl dimethyl benzyl ammonium chloride, and performing ultrasonic treatment, wherein the ultrasonic time is 23-27 minutes, the ultrasonic power is 127-140W, and the ultrasonic frequency is 35-40kHz. After the ultrasonic treatment, the resultant is filtered and washed, and dried at 78-82°C for 8.8-9.2 hours to obtain dispersed graphene oxide; The secondary treatment step comprises placing dispersed graphene oxide and tetrahydrofuran in a reaction vessel and stirring for 30-34 minutes at a stirring speed of 242-257 rpm. After the stirring is completed, nitrogen is introduced, hexachlorocyclotriphosphazene and triethylamine are added, the temperature is raised to 73-77° C., and a reflux reaction is carried out for 12.0-13.0 hours. After the reaction is completed, the pretreated graphene oxide is obtained by filtering, washing, and drying. The modified zinc oxide includes a primary modification step and a deep modification step; The zinc oxide is placed in an ethanol solution and ball milled for 30-34 minutes at a ball milling speed of 104-116 rpm, a ball milling temperature of 43-47° C., and a ball-to-material ratio of 4-6:

1. After the ball milling is completed, the solution is transferred to a sealed container, an amination reagent is added, and the solution is stirred evenly. The temperature is raised to 70-73° C., the pressure is controlled at 1.4-1.6 MPa, and the solution is allowed to stand for 6.3-6.7 hours. After the standing period, the solution is filtered, washed, and dried to obtain primary modified zinc oxide. The amination agent is a mixture of 3-diethylenetriaminopropyltrimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate; The deep modification step comprises adding an ethanol solution and tartaric acid to a reaction container, stirring evenly, adding primary modified zinc oxide at a rate of 0.4-0.6 g / min, performing ultrasonic treatment after the addition is completed, the ultrasonic time being 13-17 minutes, the ultrasonic power being 94-98 W, and the ultrasonic frequency being 30-35 kHz, and after the ultrasonic treatment is completed, heating to 80-84° C. at a rate of 0.4-0.6° C. / min, stirring and reacting for 18-22 hours, and filtering and drying after the stirring reaction is completed to obtain modified zinc oxide; The mixing step comprises placing the pretreated graphene oxide in toluene, stirring evenly, adding modified zinc oxide and stirring for 33-38 minutes at a stirring speed of 210-230 rpm, raising the temperature to 70-74° C. after the stirring is completed, adding triethylamine at a rate of 2.0-2.4 mL / min, reacting at 70-74° C. for 6.5-6.8 hours, filtering, washing, and drying after the reaction is completed to obtain antistatic particles; The impregnation step comprises placing the surface layer wood shavings and the core layer wood shavings in an antistatic compound, stirring them evenly, and then impregnating them; The raw materials of the antistatic composite agent are 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide, and the mass ratio of the 90wt% ethanol solution, antistatic particles, sodium dodecylbenzenesulfonate, carboxymethyl cellulose and silicon dioxide is 86-90:18-22:3.7-4.3:3.0-3.4:8.3-8.

7.

2. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: In the graphene oxide pretreatment step, in the dispersion treatment step, the mass ratio of the graphene oxide, deionized water, polyvinyl pyrrolidone and octadecyldimethylbenzyl ammonium chloride is 7.2-7.6:60-65:0.7-0.9:0.8-1.2; In the secondary treatment step, the mass volume ratio of the dispersed graphene oxide, tetrahydrofuran, hexachlorocyclotriphosphazene and triethylamine is 5.4-5.8 g:95-110 mL:11.8-12.2 g:19.7-20.3 g.

3. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: In the primary modification step, the particle size of the zinc oxide is 175-185 nm; The mass concentration of the ethanol solution is 50-54%; The mass ratio of the zinc oxide, ethanol solution, and amination reagent is 10.1-10.5:115-125:2.7-3.0; The mass ratio of the 3-diethylenetriaminopropyltrimethoxysilane, octylphenol polyoxyethylene ether and glyceryl monostearate is 0.8-1.2:0.6-0.8:1.1-1.

4.

4. The method for preparing an antistatic oriented strand board according to claim 1, wherein: In the deep modification step, the mass concentration of the ethanol solution is 38-43%; The mass volume ratio of the ethanol solution, tartaric acid, and primary modified zinc oxide is 95-105 mL: 5.0-5.3 g: 3.5-3.8 g.

5. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: In the mixing step, the mass volume ratio of the pretreated graphene oxide, toluene, modified zinc oxide, and triethylamine is 1.8-2.2 g:37-42 mL:3.6-3.8 g:21-25 mL.

6. The method for preparing an antistatic oriented strand board according to claim 1, wherein: In the impregnation step, the impregnation time is 13-18 minutes and the impregnation temperature is 36-40°C; The mass ratio of the surface wood chips raw material to the antistatic composite agent is 5.3-5.6:18-20; The mass ratio of the core layer wood chips raw material to the antistatic agent is 4.1-4.3:21-25.

7. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: The gluing step comprises applying the adhesive to the dried surface wood chips and the dried core wood chips by mechanically mixing the adhesive, thereby obtaining the gluing surface wood chips and the gluing core wood chips; The amount of glue applied to the surface wood chips is 2.5-3.0%, and the amount of glue applied is based on the mass ratio of absolute glue to absolute dry wood chips; The glue application amount of the core layer wood chips is 2.1-2.5%, and the application amount is based on the mass ratio of absolute dry glue to absolute dry wood chips.

8. The method for preparing an antistatic oriented strand board according to claim 7, characterized in that: The preparation method of the adhesive comprises the following steps: mixing 32-37 g of isocyanate glue and 4.0-4.4 g of nano-titanium dioxide, stirring evenly, adding 1.8-2.2 g of paraffin wax, 1.2-1.4 g of diacetyl tartaric acid monoglyceride and 1.6-1.8 g of sodium oleate, and homogenizing the mixture. The homogenization time is 4.5-5.5 minutes, and the homogenization pressure is 4.4-4.8 MPa. After the homogenization is completed, the adhesive is obtained.

9. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: The paving step comprises paving the core layer shavings after gluing through a five-layer paving head to obtain a core layer material, and then paving the surface layer material after gluing on the upper and lower surfaces of the core layer material to obtain a slab; The core layer material is a three-layer structure, which is composed of a core layer upper surface layer, a core layer middle layer, and a core layer lower surface layer from top to bottom, wherein the core layer middle layer is paved horizontally, and the core layer upper surface layer and the core layer lower surface layer are paved vertically; The surface shavings of the surface material after gluing during paving are arranged longitudinally; The mass ratio of the core layer material to the surface layer material is 7.3-7.7:2.3-2.7; In the core layer material, the mass ratio of the core layer upper surface layer, the core layer middle layer, and the core layer lower surface layer is 1:0.8-1.2:1; The mass ratio of the upper layer to the lower layer of the surface material is 1:0.8-1.

2.

10. The method for preparing an antistatic oriented strand board according to claim 1, characterized in that: The hot pressing forming steps are as follows: compacting the slab through a pre-press, and then cutting it into the required slab width through a slab trimming saw to obtain a sawn slab, and hot pressing the slab using a continuous flat press. The hot pressing temperatures are 232-237°C, 218-224°C, 216-222°C, 198-202°C, and 167-173°C, respectively. The hot pressing factor is 5.8-6.2s / mm, and the pressures are 1.3-1.5MPa, 1.2-1.4MPa, 0.8-1.0MPa, 0.4-0.6MPa, and 0.7-0.9MPa, respectively. After the hot pressing is completed, a plain board is obtained.

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