Preparation method of composite filler reinforced polyurethane adhesive shaving board

Abstract

The invention relates to a composite filler reinforced polyurethane adhesive shaving board and a preparation method thereof. A polyurethane adhesive is prepared from raw materials including polyol, isocyanate, filler and paraffin emulsion. The filler is a blend of kaolin and microcrystalline cellulose, the kaolin is helpful to improve the mechanical properties of the adhesive through physical filling and chemical effects, and the microcrystalline cellulose and the polyurethane adhesive generate strong hydrogen bond interaction to form a tight network structure. And the mechanical strength of the polyurethane adhesive shaving board is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite material synthesis and particleboard technology, and particularly relates to a particleboard using a polyurethane adhesive reinforced by composite fillers and a preparation method thereof. BACKGROUND

[0002] Particleboard is a board prepared by using agricultural and forestry residues such as small-diameter timber and branch timber as raw materials, and by applying adhesive or other additives under the condition of heating and pressing. Particleboard is widely used in the furniture manufacturing and building decoration industries due to its uniform structure, good processing performance, stable performance, no radiation, and easy processing. At present, the traditional particleboard processing industry mainly uses aldehyde adhesive, but it faces the risk of high formaldehyde release and easy harm to human body. With the national promotion of green production, the demand for carbon reduction of wooden products in the "double carbon" strategy, and the improvement of environmental awareness, polyurethane adhesive is favored due to its environmental friendliness. Polyurethane adhesive is an organic polymer material containing urethane groups or isocyanate segments in the molecular chain, which is generated by the reaction of polyol and biomass polyol. Polyurethane adhesive raw materials are non-toxic and solvent-free, and will not produce harmful volatile organic compounds (VOCs) in the use process. Therefore, polyurethane adhesive can replace aldehyde adhesive in the wood-based panel industry to solve the problem of formaldehyde release and effectively reduce the negative impact on the environment. Compared with aldehyde adhesive, the board prepared by polyurethane adhesive has better chemical resistance, heat resistance and mechanical strength, so that polyurethane adhesive has attracted widespread attention in the wood-based panel industry.

[0003] However, polyurethane adhesive still has problems such as insufficient adhesion and limited cohesive strength in processing and application, which limits its large-scale application to some extent. Current research work generally focuses on enhancing the bonding performance of polyurethane adhesive by designing new polyols and their modifications. However, due to the low profit of the wood-based panel industry and the high cost of chemical modification, most of the researches only stay in the laboratory stage, and it is difficult to realize large-scale industrial development.

[0004] Based on the above problem analysis, the present application learns from the design concept of composite materials, introduces fillers with specific activity and structural characteristics, utilizes the synergistic effect of chemical bonding and physical filling between the fillers and the polyurethane adhesive matrix, realizes the significant improvement of the bonding performance, and at the same time, considers the process feasibility and cost benefit. The effectiveness of this concept is partly supported by research. The basic structural unit of clay inorganic fillers is a rigid skeleton composed of periodic stacking, which has a large specific surface area. Microcrystalline cellulose is a rod-shaped crystal with a length of 60-180 nm and a width of 3-15 nm, with a length-diameter ratio distribution of 8-20, and has a high crystallinity. The molecular chain has a large number of hydroxyl functional groups, and the molecular chain is rich in a large number of hydroxyl functional groups, which can form a firm urethane covalent bond with the polar groups such as amino and carbonyl on the polyurethane molecular chain, expand the molecular chain, and promote the crosslinking performance. By introducing kaolin and microcrystalline cellulose composite fillers, on the one hand, the adhesive bonding performance and mechanical strength of the adhesive itself are enhanced, and on the other hand, the crosslinking performance of the adhesive and the wood substrate is enhanced, and the overall mechanical properties of the particle board are enhanced in many ways. However, due to the easy agglomeration of inorganic fillers in the adhesive matrix, the dispersibility of the inorganic fillers in the polyurethane system is poor, which often restricts the effective play of the reinforcing effect of the adhesive. Therefore, the present application provides a polyurethane adhesive reinforced by composite fillers and a preparation method thereof. By adjusting the molar ratio of the fillers, the dispersion state and interface bonding behavior of the fillers in the matrix are optimized, the agglomeration of the fillers is inhibited, and the synergistic reinforcing effect is fully played, so that a polyurethane adhesive with high bonding strength and good environmental adaptability is obtained. The polyurethane adhesive of the present application can be applied to the production process of particle board, and the overall mechanical properties of the board are significantly improved. The preparation method has simple process and controllable conditions, and has good industrial application prospect. SUMMARY

[0005] To solve the problems of the existing polyurethane adhesive particle board, the present application aims to provide a polyurethane adhesive particle board reinforced by composite fillers and a preparation method thereof, and to improve the shear strength of the polyurethane adhesive and the mechanical properties such as the internal bonding strength and the static bending strength of the polyurethane adhesive particle board.

[0006] The present application is achieved by the following technical scheme: the first aspect of the present application provides a polyurethane adhesive, characterized in that it comprises the following components: polyol, isocyanate, filler and paraffin emulsion; wherein the filler is a mixture of kaolin and microcrystalline cellulose, the particle size of kaolin is 300-600 nm; the diameter distribution of microcrystalline cellulose is about 10-90 µm, and the length size distribution is about 20-200 µm; the mass ratio of kaolin and microcrystalline cellulose is (1:1)~(3:1).

[0007] Preferably, the polyurethane adhesive comprises the following components: polyol 23 wt.%-28 wt.%, isocyanate 45 wt.%-54 wt.%, filler 6 wt.%-20 wt.%, paraffin emulsion 12 wt.%-14 wt.%; preferably, the mass ratio of kaolin and microcrystalline cellulose is (1:1)-(3:1); particularly preferably, 2:1.

[0008] Microcrystalline cellulose (MCC) is a product of natural cellulose acid hydrolysis to the limit degree of polymerization, which is composed of glucose units connected by β-1, 4-glucoside bonds. These linear cellulose chains are intertwined together as microfibers in plant cell walls. Microcrystalline cellulose has no fibrous nature, but has very strong fluidity. The crystalline phase and quasi-crystalline phase belong to the cellulose structure, and the cellulose chains exhibit a highly ordered arrangement, which makes it have high strength and stability, unexpectedly, the use of microcrystalline cellulose in combination with kaolin in the polyurethane adhesive system achieves unexpected technical effects.

[0009] Preferably, the polyol is glycerol, the glycerol has a hydroxyl value of about 1800 mg KOH / g, and a molecular weight of 92.

[0010] Preferably, the isocyanate is polymethylene polyphenyl isocyanate, the isocyanate content is 30%-35%, and the molecular weight is 250.

[0011] Preferably, the microcrystalline cellulose has a diameter distribution of about 10-90 µm and a length size distribution of about 20-200 µm.

[0012] Preferably, the microcrystalline cellulose has a limit degree of polymerization (LODP) of 15-75.

[0013] The second aspect of the present application provides a method for preparing a shaving board, characterized by comprising the following steps: (1) Dehydrating glycerol by rotary evaporation; (2) Drying the coarse shavings at 80 ℃ for 30 min, and the water content is 6%-8%; (3) Drying the filler composed of kaolin and microcrystalline cellulose at 120-130 ℃ for 60 min to obtain a filler mixture; (4) Adding glycerol, kaolin and microcrystalline cellulose filler, and paraffin emulsion into a reaction kettle, stirring uniformly, making the filler uniformly dispersed in glycerol and paraffin emulsion, and uniformly applying to the surface of the shavings by a spray gun; (5) using a spray gun to uniformly spray the polymethylene polyphenyl isocyanate on the shaving surface, to obtain the polyurethane adhesive shaving rough material reinforced by the composite filler; drying the rough material to a water content of 9%-12%, and then carrying out the laying and pre-pressing of the shaving board blank in a formed mold frame, and finally carrying out hot pressing and curing in a hot press, to obtain the shaving board; The polyurethane adhesive is composed of polyol, isocyanate and filler, and the total mass of the polyurethane adhesive is 100%, wherein the polyurethane adhesive comprises 20 wt.%-24 wt.% of polyol, 50 wt.%-60 wt.% of isocyanate, 6 wt.%-20 wt.% of filler and 12 wt.%-14 wt.% of paraffin emulsion; wherein the filler is a mixture of kaolin and microcrystalline cellulose, the particle size of the kaolin is 300-600 nm, the diameter distribution of the microcrystalline cellulose is about 10-90 µm, and the length size distribution is about 20-200 µm; and the mass ratio of the kaolin to the microcrystalline cellulose is (1:1)~(3:1).

[0014] The reaction rate of glycerol and isocyanate is too fast, which can cause the viscosity of the system to increase rapidly, thereby affecting the sizing effect. Surprisingly, the filler of the present application can promote the uniform dispersion of the filler in the system after being premixed with glycerol, thereby obtaining stable and ideal sizing effect.

[0015] In the shaving board, the mass ratio of the shaving to the polyurethane adhesive is 140-160:14-16.

[0016] The solid content of the paraffin emulsion is 30%, and the oil content is 45%.

[0017] In the hot pressing process, the hot pressing temperature is 120-135℃, the hot pressing pressure is 1.0-1.5 MPa, and the hot pressing time is 5 minutes.

[0018] The sizing amount is 5-6 wt.%, the hot pressing temperature is 120-135℃, the hot pressing pressure is 1.6-3.0 MPa, and the hot pressing time is 5 minutes.

[0019] The present application has the following beneficial effects due to the above technical solutions: 1.The present application provides a preparation of kaolin and microcrystalline cellulose filler composite reinforced polyurethane adhesive and its application in particle board. Kaolin is abundant in production and low in price. As an inorganic filler, it can fill the pores on the surface of wood, increase the contact area between the adhesive and the matrix, and improve the shear strength of the interface through chemical or physical interaction, thereby improving the mechanical properties. Microcrystalline cellulose is a short rod-shaped micrometer particle with a large number of hydroxyl groups on its surface. As an organic filler, it reacts with isocyanate in the polyurethane prepolymer to form a firm chemical bond. Kaolin and microcrystalline cellulose filler play a role through physical filling and chemical bonding mechanisms, significantly improving the shear strength of the polyurethane adhesive.

[0020] 2.The present application is mainly applied to particle board. During the synthesis of polyurethane adhesive, the molecular weight of isocyanate is about 250, which can easily penetrate into the porous wood substrate. Isocyanate has strong polarity and activity, and reacts with the active groups of wood, thereby forming a firm chemical bond between the wood and the adhesive layer and improving the bonding performance.

[0021] 3.The present application uses environmentally friendly bio-based glycerol as a polyol. The multiple hydroxyl groups in the molecule can react with isocyanate to form a polyurethane network with high shear strength without using a catalyst. To overcome the defect that the viscosity of the adhesive increases due to the rapid reaction between glycerol and isocyanate, affecting the adhesive quality, the present application solves the process problem of adhesive application by pre-mixing glycerol with kaolin and microcrystalline cellulose and then spraying the adhesive in batches.

[0022] 4.The preparation process of the present application is simple, easy to mass produce, and conducive to industrial application and popularization. The development of new high-strength particle board can reduce wood consumption, control production costs, and cope with rising raw material prices. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The infrared analysis chart of Example 1. DETAILED DESCRIPTION

[0024] The present application will be further described in conjunction with the following examples, but the embodiments of the present application are not limited thereto.

[0025] In the examples of the present application, the specific conditions are not specified, and the conventional conditions or the conditions recommended by the manufacturer are used. The raw materials, reagents, etc. used without specifying the manufacturer are all conventional products that can be purchased on the market.

[0026] The materials involved in the following examples can be obtained from commercial channels.

[0027] Performance test: (1) Particle size: detected by a laser particle size analyzer, according to the test method provided in “ISO13320-2020”; (2) Hydroxyl value: according to the method for determining the content of isocyanate groups (NCO) in polyurethane prepolymer provided in “HG / T2409-2023”; Plywood tensile test conditions: AGS-X universal material testing machine was used to prepare samples according to “GB / T17657-2013”, and the mechanical properties were determined.

[0028] Shear strength test of polyurethane adhesive reinforced by composite fillers: using poplar single board as the object board, samples were prepared according to “GB / T17657-2013”, 10 samples per group. AGS-X universal material testing machine was used to determine the shear strength of polyurethane adhesive reinforced by composite fillers according to “GB / T17657-2013”.

[0029] Shaving board tensile test conditions: CMT electronic universal testing machine was used to prepare samples according to the P2 requirements in “GB / T4897-2015” standard, and the internal bonding strength, static bending strength, elastic modulus, water absorption rate and water absorption swelling rate of the shaving board reinforced by the composite fillers were determined.

[0030] CMT electronic universal testing machine was used to prepare samples according to the P2 requirements in “GB / T4897-2015” standard, and the water absorption rate and water absorption swelling rate of the shaving board reinforced by the composite fillers were determined by immersing in 20℃ water bath for 2h.

[0031] Example 1 (1) 20 g of glycerol was dehydrated and dried by rotary evaporation to prevent foaming of glycerol and polymethylene polyphenyl isocyanate, and 3 wt.% of kaolin and 3 wt.% of microcrystalline cellulose fillers were dried at 120-130℃ for 60 min. The glycerol, kaolin and microcrystalline cellulose fillers and 10 g of paraffin emulsion were added to the reaction kettle and stirred uniformly to disperse the fillers uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and a spray gun was used to uniformly apply them to the surface of the shavings during stirring to obtain coarse materials and uniformly apply them to the surface of the shaving board.

[0032] (2) 60 g of polymethylene polyphenyl isocyanate (molar ratio of isocyanate NCO to polyol OH R = 1.3) was uniformly applied to the surface of the shavings by a spray gun, and the coarse materials were dried to a moisture content of 9%-12%. The shaving board blank was laid and pre-pressed in a formed mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive shaving board with a composite filler content of 6 wt.%.

[0033] Example 2 (1) 20 g of glycerol, 5 wt.% of kaolin, 5 wt.% of microcrystalline cellulose filler and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the fillers uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and the prepolymer was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a shavings crude material.

[0034] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, and the crude material was dried to a moisture content of 9%-12%. The shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a composite filler content of 10 wt.%.

[0035] Example 3 (1) 20 g of glycerol, 10 wt.% of kaolin, 5 wt.% of microcrystalline cellulose filler and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the fillers uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and the prepolymer was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a shavings crude material.

[0036] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, and the crude material was dried to a moisture content of 9%-12%. The shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a composite filler content of 15 wt.%.

[0037] Example 4 (1) 20 g of glycerol, 15 wt.% of kaolin, 5 wt.% of microcrystalline cellulose filler and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the fillers uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and the prepolymer was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a shavings crude material.

[0038] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, and the crude material was dried to a moisture content of 9%-12%. The shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a composite filler content of 20 wt.%.

[0039] Comparative Example 1 (1) 20 g of glycerol and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle. The coarse shavings were put into a glue mixer, and the prepolymer was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a crude material and uniformly applied to the surface of the particle board by a spray gun.

[0040] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, the coarse material was dried to a moisture content of 9-12%, and the shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a glyceryl polyurethane adhesive particle board.

[0041] Comparative Example 2 (1) 20 g of glycerol, 5 wt.% of kaolin filler, and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the filler uniformly in the glycerol and paraffin emulsion. The coarse shavings were placed in a glue mixer, and the glycerol was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a coarse material and uniformly applied to the surface of the particle board by a spray gun.

[0042] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, the coarse material was dried to a moisture content of 9-12%, and the shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a kaolin filler content of 5 wt.%.

[0043] Comparative Example 3 (1) 20 g of glycerol, 10 wt.% of kaolin filler, and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the filler uniformly in the glycerol and paraffin emulsion. The coarse shavings were placed in a glue mixer, and the glycerol was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a coarse material and uniformly applied to the surface of the particle board by a spray gun.

[0044] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, the coarse material was dried to a moisture content of 9-12%, and the shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a kaolin filler content of 10 wt.%.

[0045] Comparative Example 4 (1) 20 g of glycerol, 15 wt.% of kaolin filler, and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the filler uniformly in the glycerol and paraffin emulsion. The coarse shavings were placed in a glue mixer, and the glycerol was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a coarse material and uniformly applied to the surface of the particle board by a spray gun.

[0046] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, the coarse material was dried to a moisture content of 9-12%, and the shavings board blank was laid and pre-pressed in a shaped mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive particle board with a kaolin filler content of 15 wt.%.

[0047] Comparative Example 5 (1) 20 g of glycerol, 5 wt.% of microcrystalline cellulose filler and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the filler uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and the glue was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a coarse material which was uniformly applied to the surface of the shaving board by a spray gun.

[0048] (2) 60 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, and the coarse material was dried to a moisture content of 9%-12%. The laying and pre-pressing of the shaving board blank were carried out in a formed mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive shaving board with a microcrystalline cellulose filler content of 5 wt.%.

[0049] Comparative Example 6 (1) 20 g of glycerol, 10 wt.% of kaolin and 5 wt.% of bacterial cellulose filler and 10 g of paraffin emulsion were stirred uniformly in a reaction kettle to disperse the filler uniformly in the glycerol and paraffin emulsion. The coarse shavings were put into a glue mixer, and the glue was uniformly applied to the surface of the shavings by a spray gun during stirring to obtain a coarse material which was uniformly applied to the surface of the shaving board by a spray gun.

[0050] (2) 38 g of polymethylene polyphenyl isocyanate was uniformly applied to the surface of the shavings by a spray gun, and the coarse material was dried to a moisture content of 9%-12%. The laying and pre-pressing of the shaving board blank were carried out in a formed mold frame, and finally hot-pressed in a hot press to obtain a polyurethane adhesive shaving board with a kaolin and bacterial cellulose composite filler content of 15 wt.%.

[0051] The test results of the wood board shear performance of the polyurethane adhesives described in Examples 1-4 and Comparative Examples 1-6 are shown in Table 1: As can be seen from Table 1 and Figure 1 the infrared analysis diagram, the shear strength of Examples 1-4 is significantly improved compared with the comparative examples. Kaolin as an inorganic filler is introduced into the polyurethane adhesive, and its particles can fill the small voids in the polyurethane adhesive, improve the density of the adhesive, and reduce the bubbles and cracks in the adhesive by physical filling, thereby helping to improve the mechanical properties of the adhesive. Through Figure 1 infrared spectroscopy analysis, the C-O stretching vibration is at 1050 cm -1 , which is the characteristic peak of ester polyol. Since the amount of polyol added in each group of samples remains the same, the spectrum in this region does not change significantly, indicating that the filler does not affect the basic segment structure of the polyol. 1611 cm -1 and 1511 cm -1The absorption bands at 3402 cm -1 The broad absorption peak at 2270 cm -1 The characteristic absorption peak of -NCO at 2260 cm -1 The absorption bands at 1723 cm -1 The absorption bands at 1723 cm -1 The absorption bands at 1723 cm

[0052] The internal bond strength of the particleboard made from the polyurethane adhesives of Examples 1-4 and Comparative Examples 1-6 was tested and the results are shown in Table 2: As shown in Table 2, the internal bond strength of the sample with 10 wt.% kaolin and 3 wt.% microcrystalline cellulose composite fillers (Example 3) was improved compared to the comparative examples. The internal bond strength of the adhesive increased first and then decreased with the increase of the content of kaolin. This is mainly because too much kaolin will cause agglomeration in the adhesive, which will weaken the adhesion of the adhesive, thereby affecting the bonding strength of the adhesive and the particleboard. Therefore, it is important to balance the amount of kaolin and microcrystalline cellulose composite fillers to maintain the performance of the adhesive and effectively improve the internal bond strength of the particleboard.

[0053] The modulus of rupture and elastic modulus of the particleboard made from the polyurethane adhesives of Examples 1-4 and Comparative Examples 1-6 were tested and the results are shown in Table 3: The water absorption thickness expansion rate test results of the polyurethane adhesive particle board described in embodiments 1-4 and comparative examples 1-6 are shown in Table 4: As can be seen from Tables 2, 3 and 4, the bonding strength of the prepared particle board can reach 0.72 MPa, the static bending strength can reach 12.16 MPa, the elastic modulus can reach 2592 MPa, and the 2 h water absorption expansion rate is 3%, which can meet the requirements of the furniture type particle board (P2 type) under dry state specified in GB / T 4897-2015.

[0054] In comparative example 6, the problems such as difficulty in dispersing, easy to agglomerate and extremely strong hygroscopicity of bacterial cellulose affect the preparation of polyurethane adhesive and particle board.

[0055] Although the general concept, specific implementation and test of the present application are described in detail above, it is obvious for those skilled in the art to make some modifications or improvements on the basis of the present application. Therefore, these modifications or improvements made without changing the original meaning of the present application are considered to be within the protection scope of the present application.

Claims

1. A polyurethane adhesive for particle board, characterized by comprising: The polyol is glycerol, the glycerol hydroxyl value is 1800-2000 mg KOH / g.

2. The polyurethane adhesive according to claim 1, characterized in that, The isocyanate is polymethylene polyphenyl isocyanate, the isocyanate content is 30%-35%, and the molecular weight is 250.

3. The polyurethane adhesive according to claim 1, wherein The diameter distribution of the microcrystalline cellulose is 10-90 µm, and the length size distribution is 20-200 µm.

4. The polyurethane adhesive according to claim 1, wherein Preferably, the limiting degree of polymerization (LODP) of the microcrystalline cellulose is 15-75. The method comprises the following steps:

5. A method of producing a particle board, characterized in that, (1) The glycerol is subjected to dehydration drying treatment by a rotary evaporation method; (2) The coarse shavings are dried at 80 ℃ for 30 min, and the water content is 6%-8%; (3) The kaolin and microcrystalline cellulose fillers are dried at 120-130 ℃ for 60 min to obtain a filler mixture; (4) The glycerol, kaolin and microcrystalline cellulose fillers and the paraffin emulsion are added into a reaction kettle, stirred uniformly, so that the fillers are uniformly dispersed in the glycerol and the paraffin emulsion, and the shavings are uniformly applied to the surface of the shavings by a spray gun; (5) The polymethylene polyphenyl isocyanate is uniformly applied to the surface of the shavings by a spray gun, and the polyurethane adhesive shavings raw material reinforced by the composite fillers is obtained; the shavings are dried to a water content of 9%-12%, and the shavings board blank is laid and pre-pressed in a formed mold frame, and finally hot-pressed in a hot press, and the shavings board is obtained. The polyurethane adhesive comprises, based on 100% of the total mass of the polyurethane adhesive composed of a polyol, an isocyanate and a filler: 23 wt.%-28 wt.% of the polyol, 45 wt.%-54 wt.% of the isocyanate, 6 wt.%-20 wt.% of the filler, and 12 wt.%-14 wt.% of the paraffin emulsion; wherein the filler is a mixture of kaolin and microcrystalline cellulose, the particle size of the kaolin is 200-350 nm, the diameter distribution of the microcrystalline cellulose is about 10-90 µm, and the length size distribution is about 20-200 µm. In the shavings board, the mass ratio of the shavings to the polyurethane adhesive is 140-160:14-16.

6. The preparation method according to claim 5, characterized in that, The paraffin emulsion has a solid content of 30% and an oil content of 45%.

7. The preparation method according to claim 5, characterized in that, In the hot pressing process, the hot pressing temperature is 120-135 ℃, the hot pressing pressure is 1.0-1.5 MPa, and the hot pressing time is 5 min.

8. The method of claim 5, wherein, The sizing amount is 5-6 wt.%, the hot pressing temperature is 120-135 ℃, the hot pressing pressure is 1.6-3.0 MPa, and the hot pressing time is 5 min.

9. Use according to claim 9, characterized in that, ​

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