Waterproof wax for artificial board as well as preparation method and application of waterproof wax

Abstract

The invention relates to the technical field of chemical engineering, in particular to waterproof wax for an artificial board and a preparation method and application thereof. The waterproof wax for the artificial board comprises the following components in percentage by weight: 40-43% of paraffin; 0.8 to 1.9 percent of a low molecular polymer; 0.4%-1.9% of a high-molecular polymer; 0.2%-0.9% of a cross-linking agent; 4%-6% of an emulsifier; and the balance of water. The waterproof wax is a product obtained by further homogenizing and dispersing a cross-linked product obtained by paraffin, a specific low-molecular polymer and a high-molecular polymer under the action of a cross-linking agent in the presence of an emulsifier with an HLB (Hydrophile-Lipophile Balance) value of 8-14. The waterproof wax has extremely high viscosity and can replace part of urea resin while playing a waterproof role, the use amount of the urea resin is reduced, and the mechanical strength and the waterproof effect of the finally obtained plate are obviously enhanced.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, specifically to a waterproof wax for engineered wood panels, its preparation method, and its application. Background Technology

[0002] In the processing of engineered wood products such as plywood, particleboard, and fiberboard, adhesives are used to bond the wood chips and fibers together to give the board sufficient strength. At the same time, an appropriate amount of waterproofing agent is added to ensure that the board has a certain degree of water resistance.

[0003] Currently, emulsified wax is commonly used as a waterproofing additive in the production of engineered wood products, applied together with adhesives. Urea-formaldehyde resin has advantages such as simple manufacturing, convenient use, and low cost, and has become the main adhesive in my country's engineered wood product production, accounting for more than 90% of the adhesives used in engineered wood products. However, urea-formaldehyde resin has a formaldehyde release problem during manufacturing and use, which has become the biggest problem in the application of engineered wood products. Existing methods to reduce formaldehyde release in engineered wood products mainly include the following categories: improving adhesives, post-processing of engineered wood products, and improving engineered wood product manufacturing processes. Among them, post-processing of engineered wood products and improving engineered wood product manufacturing processes will lead to complex processing techniques and significantly increased costs. While improving adhesives can reduce formaldehyde release to some extent, its reduction effect is extremely limited, and it will also complicate the preparation process of the adhesive and increase the cost of the adhesive.

[0004] Therefore, the research and development of a high-viscosity waterproof wax for engineered wood products is of great significance for reducing the amount of urea-formaldehyde resin used in engineered wood products and lowering the formaldehyde release from the products, while achieving a waterproof effect. Summary of the Invention

[0005] This invention provides a waterproof wax for engineered wood products. This waterproof wax has high viscosity and can partially replace urea-formaldehyde resin, reducing the amount of urea-formaldehyde resin used in the production of engineered wood products. It can also significantly enhance the mechanical strength and waterproof effect of the final engineered wood products.

[0006] The present invention also provides a method for preparing the above-mentioned waterproof wax for artificial boards, which is simple, low-cost and easy to implement.

[0007] The present invention also provides a type of engineered wood panel in which the amount of urea-formaldehyde resin used as an adhesive is small and the amount of formaldehyde released is low.

[0008] The present invention achieves the above-mentioned technical objectives through the following technical solutions:

[0009] A waterproof wax for engineered wood panels comprises the following components by weight percentage: paraffin wax 40-43%; low molecular weight polymer 0.8-1.9%; high molecular weight polymer 0.4%-1.9%; crosslinking agent 0.2%-0.9%; emulsifier 4%-6%; and the balance being water. The paraffin wax is fully refined or semi-refined paraffin wax; the low molecular weight polymer is one or more of polyethylene wax, polypropylene wax, polybutadiene, and polyvinyl chloride; the high molecular weight polymer is one or more of ethylene-vinyl acetate copolymer, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, and polyethylene terephthalate; the crosslinking agent is one or more of dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide; and the emulsifier has an HLB value of 8-14.

[0010] The waterproof wax is obtained by further homogenizing and dispersing the crosslinked products of paraffin wax, low molecular weight polymers, and high molecular weight polymers in the presence of an emulsifier.

[0011] The waterproof wax for engineered wood panels described above comprises the following components by weight percentage: paraffin wax 41-43%; low molecular weight polymer 1.4-1.9%; high molecular weight polymer 0.8%-1.9%; crosslinking agent 0.5%-0.9%; emulsifier 4%-6%; and the balance being water; wherein the emulsifier has an HLB value of 10-13.

[0012] The waterproof wax for engineered wood panels described above comprises the following components by weight percentage: paraffin wax 42-43%; low molecular weight polymer 1.8-1.9%; high molecular weight polymer 1.5-1.9%; crosslinking agent 0.8-0.9%; emulsifier 4-6%; and the balance being deionized water; wherein the emulsifier has an HLB value of 12.

[0013] The waterproof waxes used for engineered wood panels described above have low molecular weight polymers with a weight-average molecular weight of 300-10000 and high molecular weight polymers with a weight-average molecular weight of 1×10⁻⁶. 5 -3×10 5 .

[0014] The waterproof wax used for engineered wood panels mentioned above is paraffin wax No. 52, 54, 56, or 58, which is a semi-refined wax.

[0015] The waterproof wax for engineered wood panels described above uses a low-molecular-weight polymer that is one or a combination of polyethylene wax and polypropylene wax.

[0016] The waterproof wax for engineered wood panels described above uses a polymer that is one or more of the following: ethylene-vinyl acetate copolymer, cellulose acetate, and hydroxyethyl cellulose.

[0017] The waterproof wax for engineered wood panels described above uses dicumyl peroxide as a crosslinking agent.

[0018] The present invention also provides a method for preparing the above-mentioned waterproof wax for engineered wood panels, comprising the following preparation steps:

[0019] Under an inert gas atmosphere, paraffin wax is melted, and low-molecular-weight polymers, high-molecular-weight polymers, and crosslinking agents are added according to the above proportions and components to carry out a crosslinking reaction. After the crosslinking reaction is completed, water and emulsifiers are added, and the mixture is homogenized and dispersed to obtain the final product.

[0020] The present invention also provides a type of engineered wood panel, which is prepared by using the above-mentioned waterproof wax as a waterproofing agent and urea-formaldehyde resin as an adhesive.

[0021] The waterproof wax for engineered wood products provided by this invention has extremely high viscosity. While playing a waterproof role, it can replace part of the urea-formaldehyde resin, reducing the amount of urea-formaldehyde resin used. Moreover, the mechanical strength and waterproof effect of the resulting particleboard are significantly enhanced. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] Waterproofing wax and urea-formaldehyde resin are two indispensable raw materials in the production of engineered wood products. Due to the formaldehyde release problem of urea-formaldehyde resin, this invention aims to reduce the amount of formaldehyde released by increasing the viscosity of the waterproofing wax and reducing the amount of urea-formaldehyde resin used in the adhesive.

[0024] The waterproof wax for engineered wood panels provided by this invention comprises the following components by weight percentage: 40-43% paraffin wax, 0.8-1.9% low molecular weight polymer, 0.4%-1.9% high molecular weight polymer, 0.2%-0.9% crosslinking agent, 4%-6% emulsifier, and the balance being water; the paraffin wax is fully refined or semi-refined paraffin wax; the low molecular weight polymer is one or more of polyethylene wax, polypropylene wax, polybutadiene, and polyvinyl chloride; the high molecular weight polymer is one or more of ethylene-vinyl acetate copolymer, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, and polyethylene terephthalate; the crosslinking agent is selected from one or more of dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide; the emulsifier has an HLB value of 8-14; and the waterproof wax is a product obtained by further homogenizing and dispersing the crosslinked product obtained by paraffin wax, low molecular weight polymer, and high molecular weight polymer under the action of the crosslinking agent in the presence of the emulsifier.

[0025] This invention introduces low-molecular-weight polymers and high-molecular-weight polymers, which, under the action of a crosslinking agent, crosslink with some components of paraffin wax. The crosslinked product is then further emulsified to obtain a waterproof wax with high viscosity. When used in conjunction with urea-formaldehyde resin, this waterproof wax reduces the amount of urea-formaldehyde resin used in the production of engineered wood products, and significantly enhances the mechanical strength and waterproofing effect of the resulting boards. The added low-molecular-weight and high-molecular-weight polymers increase the content of high-carbon molecules in paraffin wax, increasing the internal friction during molecular motion, thus increasing intermolecular interaction forces and resistance during movement. The crosslinking agent reacts the main component of paraffin wax, straight-chain alkanes, with the high- and low-molecular-weight polymers, utilizing carbon-carbon double bonds to transform the straight-chain molecular structure into a three-dimensional network structure. Under the combined effect of these two factors, the viscosity and other properties of paraffin wax are improved.

[0026] Further research revealed that when the mass percentage of paraffin wax is 41-43%, the mass percentage of low-molecular-weight polymer is 1.4-1.9%, the mass percentage of high-molecular-weight polymer is 0.8%-1.9%, the mass percentage of crosslinking agent is 0.5%-0.9%, the mass percentage of emulsifier is 4%-6%, and the remainder is water, and the HLB value of the emulsifier is 10-13, the prepared waterproof wax for engineered wood products exhibits better viscosity and is more conducive to improving the mechanical properties and waterproofing effect of engineered wood products. The dosage of urea-formaldehyde resin in particleboard is 72 kg / m³. 3 The dosage of waterproof wax for engineered wood panels is 4 kg / m². 3 For example, the resulting board has an internal bonding strength of 1.4 MPa or higher, and a water absorption thickness expansion rate of 7.5% or lower. Compared with ordinary paraffin as a waterproofing agent, the internal bonding strength is increased by 2 times or more, and the water absorption thickness expansion rate is reduced by more than 30%.

[0027] When the mass percentage of paraffin wax is 42-43%, the mass percentage of low-molecular-weight polymer is 1.8-1.9%, the mass percentage of high-molecular-weight polymer is 1.5-1.9%, the mass percentage of crosslinking agent is 0.8-0.9%, the mass percentage of emulsifier is 4-6%, and the balance is deionized water, and the HLB value of the emulsifier is 12, the viscosity of the prepared waterproof wax for engineered wood products can be further improved. The dosage of urea-formaldehyde resin in each cubic meter of particleboard is 72 kg / m³. 3 The dosage of waterproof wax for engineered wood panels is 4 kg / m². 3 For example, the resulting board has an internal bonding strength of 1.6 MPa or higher, and a water absorption thickness expansion rate of 6.3% or lower. Compared with ordinary paraffin as a waterproofing agent, the internal bonding strength is increased by 2.3 times and the water absorption thickness expansion rate is reduced by more than 45%.

[0028] In this invention, the low molecular weight polymer is preferably a polymer with a weight average molecular weight of 300-10000, and the high molecular weight polymer is preferably a polymer with a weight average molecular weight of 1×10⁻⁶. 5 -3×10 5 Polymers.

[0029] Paraffin wax, as the main component, is a mixture of hydrocarbons with approximately 18-30 carbon atoms. It is obtained from lubricating oil fractions obtained by crude oil distillation through solvent refining, solvent dewaxing, or wax freezing crystallization and pressing dewaxing to produce wax paste, followed by deoiling and further refining. Depending on the degree of refining, paraffin wax can be divided into three types: fully refined paraffin wax, semi-refined paraffin wax, and crude paraffin wax. Each type of wax is further classified according to its melting point, generally in 2°C increments, into different grades, such as grades 52, 54, 56, and 58. In both molten and emulsified states, paraffin wax itself has a certain viscosity. In this invention, fully refined paraffin wax is superior to semi-refined paraffin wax. Considering performance and cost-effectiveness, semi-refined paraffin wax, such as grade 54 semi-refined paraffin wax, is usually chosen.

[0030] The study also found that when the low molecular weight polymer is selected from one or a combination of polyethylene wax and polypropylene wax, the waterproofing effect and viscosity of the waterproofing wax are better. For example, in some specific embodiments, the low molecular weight polymer selected is polyethylene wax with a weight average molecular weight of 500-1000 and a melting temperature of 90-110°C.

[0031] When any one or more combinations of ethylene-vinyl acetate copolymer, hydroxyethyl cellulose, and cellulose acetate are selected, the waterproofing effect and viscosity of the waterproof wax are better. For example, in some specific embodiments, the polymer selected is an ethylene-vinyl acetate copolymer with a vinyl acetate (VA) content of 12-24% and a melt heating temperature of 120-130°C.

[0032] The role of crosslinking agents is to transform linear or slightly branched macromolecules into a three-dimensional network structure, thereby improving properties such as strength. Different crosslinking agents have different crosslinking effects; when dicumyl peroxide is used, the degree of crosslinking reaction is relatively easy to control.

[0033] Emulsifiers function to form a stable emulsion from two or more immiscible components. An emulsifier is a surfactant with both hydrophilic and lipophilic groups in its molecule. The hydrophilicity or lipophilicity of an emulsifier is typically expressed using the "hydrophilic-lipophilic balance value (HLB value)." Different emulsifiers have different HLB values, and a suitable emulsifier must be selected to obtain a stable emulsion. In this invention, using an emulsifier with an HLB value of 8-14 ensures the stability of the emulsion system. Furthermore, using an HLB value of 10-13 provides even better system stability. For example, in some specific embodiments, the emulsifier is a compound of Span 80 and Tween 20.

[0034] In addition, it is understood that any emulsifier that can be compounded to obtain an HLB value within the above range is applicable to this application, and is not limited to Span 80 and Tween 20.

[0035] The present invention also provides a method for preparing the above-mentioned waterproof wax for engineered wood products. It is understood that the above-mentioned waterproof wax for engineered wood products can be obtained by conventional methods, namely, first melting paraffin wax, then adding low molecular weight polymer, high molecular weight polymer and crosslinking agent to carry out crosslinking reaction; after the crosslinking reaction is completed, water and emulsifier are added, and after homogenization and dispersion, the product is obtained.

[0036] Further research revealed that when paraffin wax is melted in an inert gas atmosphere, followed by the addition of low-molecular-weight polymers, high-molecular-weight polymers, and crosslinking agents for a crosslinking reaction, and then routinely emulsified and homogenized, the resulting waterproof wax for engineered wood panels exhibits higher viscosity.

[0037] The present invention also provides a type of engineered wood panel, which is prepared by using the above-mentioned waterproof wax as a waterproofing agent and urea-formaldehyde resin as an adhesive.

[0038] The waterproof wax for engineered wood panels of the present invention will be further described in detail below with reference to specific embodiments.

[0039] Raw material source: No. 54 semi-refined paraffin wax, kinematic viscosity (100℃) is 3.733 mm. 2 ·s -1 The following materials were purchased from PetroChina Fushun Petrochemical Company: polyethylene wax (weight average molecular weight 500-1000) purchased from PetroChina Daqing Petrochemical Company; polypropylene wax (weight average molecular weight 500-900) purchased from Sinopec Qilu Petrochemical Company; and ethylene-vinyl acetate copolymer, with vinyl acetate (VA) comprising 19% by mass (weight average molecular weight 1.2×10⁻⁶). 5 -1.4×10 5 The product was purchased from Mitsui, Japan; hydroxyethyl cellulose (weight average molecular weight 1.1 × 10⁻⁶) was also included. 5 -1.3×10 5 Hydroxypropyl cellulose (weight average molecular weight 1.1 × 10⁻⁶) 5 -1.3×10 5 The first product was purchased from Henan Jinshuo Technology Co., Ltd.; the second product was purchased from Jinan Shuangying Chemical Co., Ltd.

[0040] Evaluation and analysis methods: The viscosity of paraffin wax is expressed as kinematic viscosity (100℃), in accordance with standard GB / T265; the strength of the board is expressed as internal bonding strength, in accordance with standard GB / T 17657; the water resistance of the board is expressed as water absorption thickness swelling rate, in accordance with standard GB / T 17657.

[0041] Example 1

[0042] A waterproof wax for engineered wood panels is prepared from the following raw materials by weight percentage: 40.5% semi-refined paraffin wax No. 54, 0.8% polyethylene wax, 0.4% ethylene-vinyl acetate copolymer, 0.2% dicumyl peroxide, 4% compound emulsifier (Span 80: Tween 20 = 37:63, HLB = 12.0), and the balance being deionized water. The preparation method is as follows:

[0043] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0044] (2) Add ethylene-vinyl acetate copolymer to the solution in step (1), continue heating and melting at 115°C and stir for 30 min to obtain a homogeneous solution;

[0045] (3) Add dicumyl peroxide to the solution from step (2), heat and stir at 130°C for 10 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 10.592 mm. 2 ·s -1 ;

[0046] (4) Add deionized water and compound emulsifier to the modified paraffin obtained in step (3), emulsify it for 30 minutes at 135℃ and 0.5MPa by passing it through a homogenizer at 2500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0047] Example 2

[0048] A waterproof wax for engineered wood panels is prepared from the following raw materials by weight percentage: 40.1% semi-refined paraffin wax No. 54, 1.3% polyethylene wax, 0.4% ethylene-vinyl acetate copolymer, 0.2% dicumyl peroxide, 4% compound emulsifier (Span 80: Tween 20 = 53:47, HLB = 10.0), and the balance being deionized water. The preparation method is as follows:

[0049] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0050] (2) Add ethylene-vinyl acetate copolymer to the solution in step (1), continue heating and melting at 115°C and stirring for 30 min to obtain a homogeneous solution;

[0051] (3) Add dicumyl peroxide to the solution from step (2), heat and stir at 130°C for 10 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 14.289 mm. 2 ·s-1 ;

[0052] (4) Add deionized water and compound emulsifier to the modified paraffin obtained in step (3), emulsify it for 30 minutes at 135℃ and 0.5MPa by passing it through a homogenizer at 2500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0053] Example 3

[0054] A waterproof wax for engineered wood panels is prepared from the following raw materials by weight percentage: 42.3% No. 54 semi-refined paraffin wax, 1.4% polyethylene wax, 0.9% ethylene-vinyl acetate copolymer, 0.5% dicumyl peroxide, 4% compound emulsifier (Span 80: Tween 20 = 37:63, HLB = 12.0), and the balance being deionized water. The preparation method is as follows:

[0055] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0056] (2) Add ethylene-vinyl acetate copolymer to the solution in step (1), continue heating at 120°C to melt, and stir for 30 min to obtain a homogeneous solution;

[0057] (3) Add dicumyl peroxide to the solution from step (2), heat and stir at 135°C for 12 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 25.963 mm. 2 ·s -1 ;

[0058] (4) Add deionized water and compound emulsifier to the modified paraffin obtained in step (3), emulsify it for 30 minutes at 140℃ and 0.7MPa by passing it through a homogenizer at 3500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0059] Example 4

[0060] A waterproof wax for engineered wood panels is prepared from the following raw materials by weight percentage: 41.6% semi-refined paraffin wax No. 54, 1.8% polyethylene wax, 0.9% ethylene-vinyl acetate copolymer, 0.7% dicumyl peroxide, 4% compound emulsifier (Span 80: Tween 20 = 33:67, HLB = 12.5), and the balance being deionized water. The preparation method is as follows:

[0061] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0062] (2) Add ethylene-vinyl acetate copolymer to the solution in step (1), continue heating at 120°C to melt, and stir for 30 min to obtain a homogeneous solution;

[0063] (3) Add dicumyl peroxide to the solution from step (2), heat and stir at 135°C for 15 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 29.359 mm. 2 ·s -1 ;

[0064] (4) Add deionized water and compound emulsifier to the modified paraffin obtained in step (3), emulsify it for 30 minutes at 140℃ and 0.7MPa by passing it through a homogenizer at 3500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0065] Example 5

[0066] A waterproof wax for engineered wood panels is prepared from the following raw materials by weight percentage: 42.3% No. 54 semi-refined paraffin wax, 1.9% polyethylene wax, 1.9% ethylene-vinyl acetate copolymer, 0.9% dicumyl peroxide, 6% compound emulsifier (Span 80: Tween 20 = 33:67, HLB = 12.5), and the balance being deionized water. The preparation method is as follows:

[0067] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0068] (2) Add ethylene-vinyl acetate copolymer to the solution in step (1), continue heating and melting at 130°C and stirring for 30 min to obtain a homogeneous solution;

[0069] (3) Add dicumyl peroxide to the solution from step (2), heat and stir at 140°C for 16 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 44.774 mm. 2 ·s -1 ;

[0070] (4) Add deionized water and compound emulsifier to the modified paraffin obtained in step (3), emulsify it for 40 minutes at 145℃ and 0.7MPa using a homogenizer at 4500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0071] Example 6

[0072] The difference between this embodiment and embodiment 5 is that steps (1)-(3) are carried out in an air atmosphere during preparation.

[0073] The modified paraffin obtained in step (3) has a kinematic viscosity (100℃) of 40.263 mm. 2 ·s -1 .

[0074] Example 7

[0075] The difference between this embodiment and Embodiment 5 is that an equal mass fraction of polypropylene wax is used instead of polyethylene wax.

[0076] The modified paraffin obtained in step (3) has a kinematic viscosity (100℃) of 41.556 mm. 2 ·s -1 .

[0077] Example 8

[0078] The difference between this embodiment and Embodiment 5 is that an equal mass of hydroxyethyl cellulose is used to replace the ethylene-vinyl acetate copolymer.

[0079] The modified paraffin obtained in step (3) has a kinematic viscosity (100℃) of 40.863 mm. 2 ·s -1 .

[0080] Example 9

[0081] The difference between this embodiment and Embodiment 5 is that an equal mass of hydroxypropyl cellulose is used to replace the ethylene-vinyl acetate copolymer.

[0082] The modified paraffin obtained in step (3) has a kinematic viscosity (100℃) of 37.405 mm. 2 ·s -1 .

[0083] Example 10

[0084] The difference between this embodiment and Embodiment 5 is that benzoyl peroxide is used in place of dicumyl peroxide in equal parts by mass.

[0085] The modified paraffin obtained in step (3) has a kinematic viscosity (100℃) of 36.952 mm. 2 ·s -1 .

[0086] Comparative Example 1

[0087] The main difference between this comparative example and Example 2 is that the components do not contain the crosslinking agent dicumyl peroxide. Specifically, it is prepared from the following raw materials by weight percentage: 40.3% of No. 54 semi-refined paraffin wax, 1.3% of polyethylene wax, 0.4% of ethylene-vinyl acetate copolymer, 4% of compound emulsifier (Span 80: Tween 20 = 53:47, HLB = 10.0), and the balance being deionized water. The preparation method is as follows:

[0088] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0089] (2) Add ethylene-vinyl acetate copolymer to the solution from step (1), continue heating to 115°C to melt, and stir for 1 hour to obtain modified paraffin wax with a kinematic viscosity (100°C) of 7.852 mm. 2 ·s -1 ;

[0090] (3) Add deionized water and compound emulsifier to the modified paraffin obtained in step (2), emulsify it for 25 minutes at 130℃ and 0.5MPa using a homogenizer at 2500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0091] Comparative Example 2

[0092] The main difference between this comparative example and Example 2 is that the components do not contain ethylene-vinyl acetate copolymer. Specifically, it is prepared from the following raw materials by weight percentage: 40.5% of No. 54 semi-refined paraffin wax, 1.3% of polyethylene wax, 0.2% of dicumyl peroxide, 4% of a compound emulsifier (Span 80: Tween 20 = 53:47, HLB = 10.0), with the balance being deionized water. The preparation method is as follows:

[0093] (1) Heat the paraffin raw material to melt under a nitrogen atmosphere. After the solution becomes clear, add polyethylene wax to it and heat and stir at 105°C until both are completely melted.

[0094] (2) Add dicumyl peroxide to the solution from step (1), heat and stir at 130°C for 10 hours to obtain modified paraffin with a kinematic viscosity (100°C) of 7.025 mm. 2 ·s -1 ;

[0095] (3) Add deionized water and compound emulsifier to the modified paraffin obtained in step (2), emulsify it for 30 minutes at 140℃ and 0.7MPa by passing it through a homogenizer at 2500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0096] Comparative Example 3

[0097] The main difference between this comparative example and Example 2 is that the components do not contain polyethylene wax. Specifically, it is prepared from the following raw materials by weight percentage: 41.4% of No. 54 semi-refined paraffin wax, 0.4% of ethylene-vinyl acetate copolymer, 0.2% of dicumyl peroxide, 4% of a compound emulsifier (Span 80: Tween 20 = 53:47, HLB = 10.0), with the balance being deionized water. The preparation method is as follows:

[0098] (1) The paraffin raw material was heated and melted under a nitrogen atmosphere. After the solution became clear, ethylene-vinyl acetate copolymer was added to it. The solution was heated and melted at 115°C and stirred for 30 minutes to obtain a homogeneous solution.

[0099] (2) Add dicumyl peroxide to the solution from step (1), heat and stir at 130°C for 10 hours to obtain high-viscosity modified paraffin with a kinematic viscosity (100°C) of 9.369 mm. 2 ·s -1 ;

[0100] (3) Add deionized water and compound emulsifier to the modified paraffin obtained in step (2), emulsify it for 25 minutes at 135℃ and 0.5MPa using a homogenizer at 2500r / min, and then cool it down to room temperature to obtain waterproof wax for artificial boards.

[0101] Comparative Example 4

[0102] The difference between this comparative example and the above-mentioned embodiment is that 42% of No. 54 semi-refined paraffin wax was melted and directly mixed with deionized water and 4% of compound emulsifier (Span 80: Tween 20 = 53:47, HLB = 10.0). After emulsification at 135°C and 0.5MPa through a homogenizer at 2500r / min for 25min, the mixture was cooled to room temperature to obtain a waterproof wax for engineered wood panels.

[0103] Experimental Example

[0104] The waterproof wax for engineered wood products prepared in the above embodiments and comparative examples were used to prepare particleboard according to the following methods: Wood shavings, urea-formaldehyde resin (purchased from Xinlai Plastic Synthetic Materials Additives Factory), and waterproof wax for engineered wood products were mixed. The resulting mixture was then subjected to laying, pre-pressing, and hot-pressing (temperature 200℃, pressure 3.0MPa) treatments to finally obtain particleboard. The amount of urea-formaldehyde resin used per cubic meter of particleboard was 72 kg / m³. 3 The dosage of waterproof wax for engineered wood panels is 4 kg / m². 3 Simultaneously, particleboard without the addition of the waterproof wax for engineered wood products of this invention is prepared, wherein the amount of urea-formaldehyde resin used per cubic meter of particleboard is 80 kg / m³. 3 The strength and waterproof performance of the above boards were tested (GB / T17657), and the results are shown in Table 1.

[0105] Table 1 Comparison of the application performance of waterproof wax for wood-based panels

[0106]

[0107]

[0108] The results above show that as the viscosity of the modified paraffin wax in the waterproof wax for engineered wood products increases, both the strength and waterproof performance of the particleboard improve. This indicates that the waterproof wax helps bond the wood fibers together and provides a good waterproofing effect. Compared to boards without the waterproof wax of this invention, the amount of urea-formaldehyde resin used in the preparation process of boards without the waterproof wax is 80 kg / m³. 3 In the example, the amount of urea-formaldehyde resin used in the preparation of the wood-based panel with added waterproof wax was 72 kg / m³. 3 By comparing the strength and water resistance data of the boards, it can be seen that the strength and water resistance of the boards are improved after adding the waterproof wax for artificial boards of this invention.

[0109] In summary, this invention demonstrates that replacing part of the urea-formaldehyde resin with waterproof wax in engineered wood panels not only reduces the amount of urea-formaldehyde resin used, but also enhances the mechanical strength and waterproofing effect of the resulting panels.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waterproof wax for engineered wood panels, characterized in that, Includes the following components by weight percentage: Paraffin 40-43%; Low molecular weight polymers: 0.8-1.9%; Polymer content: 0.4%-1.9%; Crosslinking agent 0.2%-0.9%; Emulsifier 4%-6%; The remainder is water; The paraffin wax is fully refined or semi-refined paraffin wax; the low molecular weight polymer is one or more of polyethylene wax, polypropylene wax, polybutadiene, and polyvinyl chloride; the high molecular weight polymer is one or more of ethylene-vinyl acetate copolymer, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, and polyethylene terephthalate; the crosslinking agent is one or more of dicumyl peroxide, benzoyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide; and the emulsifier has an HLB value of 8-14. The waterproof wax is obtained by further homogenizing and dispersing the crosslinked products of paraffin wax, low molecular weight polymers, and high molecular weight polymers in the presence of an emulsifier.

2. The waterproof wax for engineered wood panels according to claim 1, characterized in that, Includes the following components by weight percentage: Paraffin 41-43%; Low molecular weight polymers: 1.4-1.9%; Polymer content: 0.8%-1.9%; Crosslinking agent 0.5%-0.9%; Emulsifier 4%-6%; The remainder is water; The HLB value of the emulsifier is 10-13.

3. The waterproof wax for engineered wood panels according to claim 1, characterized in that, Includes the following components by weight percentage: Paraffin 42-43%; Low molecular weight polymers: 1.8-1.9%; Polymer content: 1.5-1.9%; Crosslinking agent 0.8-0.9%; Emulsifier 4-6%; The remainder is deionized water; The emulsifier has an HLB value of 12.

4. The waterproof wax for engineered wood panels according to any one of claims 1-3, characterized in that, Low molecular weight polymers have a weight-average molecular weight of 300-10000, while high molecular weight polymers have a weight-average molecular weight of 1×10⁻⁶. 5 -3×10 5 .

5. The waterproof wax for engineered wood panels according to any one of claims 1-3, characterized in that, The paraffin wax is semi-refined wax of grades 52, 54, 56, and 58.

6. The waterproof wax for engineered wood panels according to any one of claims 1-3, characterized in that, The low molecular weight polymer is one or a combination of two of polyethylene wax and polypropylene wax.

7. The waterproof wax for engineered wood panels according to any one of claims 1-3, characterized in that, The polymer is one or more of the following: ethylene-vinyl acetate copolymer, cellulose acetate, and hydroxyethyl cellulose.

8. The waterproof wax for engineered wood panels according to any one of claims 1-3, characterized in that, The crosslinking agent is dicumyl peroxide.

9. The method for preparing the waterproof wax for engineered wood panels according to any one of claims 1-8, characterized in that, The preparation steps include the following: Under an inert gas atmosphere, paraffin wax is melted, and low molecular weight polymer, high molecular weight polymer and crosslinking agent are added according to the proportions and components described in any one of claims 1-8 to carry out a crosslinking reaction; after the crosslinking reaction is completed, water and emulsifier are added, and the mixture is homogenized and dispersed to obtain the final product.

10. A type of engineered wood panel, characterized in that, It is prepared using the waterproof wax described in any one of claims 1-8 as a waterproofing agent and urea-formaldehyde resin as an adhesive.

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