Multi-layer composite plastic-wood plate and preparation method thereof

Abstract

The invention relates to the technical field of plates, and discloses a multi-layer composite plastic-wood plate and a preparation method thereof.The plastic-wood plate sequentially comprises a mildew-proof coating, a plastic-wood plate layer and a mildew-proof coating from top to bottom, the mildew-proof coating can endow the plate with good mildew-proof and antibacterial effects, the plastic-wood plate layer is prepared from wood powder and PVC powder as main raw materials, and the plastic-wood plate layer is prepared from wood powder and PVC powder as auxiliary raw materials. The board is formed by mixing and pressing a functional aid and the like which are used as additives, and the mechanical strength of the board can be effectively improved by adding the functional aid. Besides, the phosphorus-containing polyether sulphone macromolecular chain structure in the structure contains a carbon source, an acid source and a gas source at the same time, is a ternary integrated intumescent flame retardant, and can form an intumescent carbon layer to cover the outer side of the board when the board is combusted, so that the combustion cannot be continued, and the flame retardant property of the board can be greatly improved by adding a small amount of the flame retardant.

Description

Technical Field

[0001] The invention relates to the technical field of boards, and in particular to a multi-layer composite plastic-wood board and a preparation method thereof. Background Art

[0002] Plastic wood board is a new type of industrial standardized decorative environmentally friendly and energy-saving wood product manufactured by extrusion. It combines the advantages of wood and plastic to become a new type of composite material that is environmentally friendly, recyclable, non-toxic and pollution-free. In recent years, with the continuous advancement of technology, multi-layer plastic wood boards have gradually emerged in the market, and their unique advantages have brought many conveniences to the construction industry. Multi-layer plastic wood boards are particularly outstanding in hardness and durability. The inner layer of plastic plus wood powder structure provides solid support and stability for the board, while the outer layer of polymer coating can provide additional functionality for the plastic wood board, such as mildew and antibacterial. Therefore, compared with single-layer plastic wood boards, multi-layer plastic wood board products have more advantages in practical applications and can have a wider range of applications.

[0003] Although the functionality of plastic wood panels is relatively excellent, the frequent occurrence of fires in recent years has led consumers to have higher requirements for the flame retardant functionality of building materials. The flame retardant performance of plastic wood panels themselves is not excellent, and the halogens contained in the PVC structure will produce a large amount of toxic gases when burned, which not only harms the environment, but also poses a great threat to the safety of residents. Therefore, the development of plastic wood panels with excellent flame retardant performance has gradually become a key research and development direction. At present, the use of inorganic flame retardants such as antimony trioxide as additives is the main way to improve the flame retardant performance of plastic wood panels. However, inorganic flame retardants generally have poor flame retardant modification effects and are added in large amounts, which can easily have a negative impact on the mechanical properties of the panels. Therefore, there are still defects in practical applications. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the purpose of the present invention is to provide a multi-layer composite plastic-wood board and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A multi-layer composite plastic wood board, the plastic wood board comprises, from top to bottom, an anti-mildew coating, a plastic wood board layer, and an anti-mildew coating; the plastic wood board layer is made of raw materials including the following parts by weight:

[0007]

[0008] The preparation method of the plastic wood board layer is as follows:

[0009] Step 1: Weigh the raw materials of each component according to their weight, and then add them into a mixer, control the temperature to 100-120°C, stir at a speed of 1000-2000r / min, and stir mechanically to mix evenly to form a pre-mixed material;

[0010] Step 2: Under the conditions of temperature of 200-210°C and pressure of 20-30MPa, the mixed material is extruded and shaped to obtain the plastic wood board layer.

[0011] As a further solution of the present invention, the preparation method of the functional additive is as follows:

[0012] Step S1, dispersing potassium hexatitanate whiskers in anhydrous toluene, and then adding diisocyanate monomer to the formed dispersion. After the addition, nitrogen is introduced for protection, and the temperature is gradually increased to 70-80° C., and after heat treatment for 3-6 hours, the temperature is lowered and the material is discharged. The solid material is collected by centrifugation to obtain modified potassium titanate whiskers;

[0013] Step S2, adding the modified potassium titanate whisker into tetrahydrofuran, after uniform dispersion, adding the phosphorus-containing polyarylethersulfone and the catalyst, stirring evenly, controlling the temperature to 60-65° C., keeping warm and stirring for 4-8 hours, stopping heating, separating the solid material, and obtaining the functional additive.

[0014] As a further embodiment of the present invention, in step S1, the diisocyanate monomer is at least one of toluene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate.

[0015] As a further embodiment of the present invention, in step S2, the catalyst is any one of stannous octoate, dibutyltin dilaurate or dibutyltin diacetate.

[0016] As a further embodiment of the present invention, in step S2, the preparation method of the phosphorus-containing polyarylethersulfone is as follows:

[0017] Step SS1, adding polyarylethersulfone to 1,2-dichloroethane, stirring and mixing, then adding halogenated acylate and aluminum trichloride to the system, and stirring at a temperature of 40-50° C. for 3-5 hours to obtain halogenated polyarylethersulfone;

[0018] Step SS2, add the halogenated polyarylethersulfone to toluene, stir mechanically to mix evenly, then add 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and alkaline catalyst, after adding, pass nitrogen, exhaust the air, then increase the temperature to 70-80°C, keep stirring for 4-8h, to obtain phosphorus-containing polyarylethersulfone.

[0019] As a further embodiment of the present invention, in step SS1, the halogenated acylate is chloroacetyl chloride.

[0020] As a further embodiment of the present invention, in step S2, the alkaline catalyst is triethylamine.

[0021] As a further embodiment of the present invention, in step SS2, the mass ratio of the 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide to the halogenated polyarylethersulfone is 0.4-0.6:1.

[0022] As a further solution of the present invention, the rubber additive is at least one of EPDM rubber, natural rubber or polybutadiene rubber; the plasticizer is dioctyl phthalate; the stabilizer is a calcium zinc stabilizer; the lubricant is polyethylene wax or stearic acid; and the antioxidant is a phosphite antioxidant.

[0023] A method for preparing a multi-layer composite plastic-wood board comprises the following steps:

[0024] The first step is to dissolve chitosan in an acetic acid solution with a volume fraction of 1-3%, stir and mix, and prepare a chitosan solution with a mass fraction of 10-20%, and then mix it with an epoxy resin according to a volume ratio of 0.5-1:1, and mechanically stir to prepare an anti-mildew coating;

[0025] Step 2: Use a 360° rotating roller to evenly apply the anti-mildew paint on both sides of the plastic wood board layer, and control the coating amount to 100-150g / m 2 , forming an anti-mildew coating. After coating, cure it in a temperature environment of 100-120℃ for 4-8 hours and then take it out.

[0026] Beneficial effects of the present invention:

[0027] (1) The functional additive prepared by the present invention is a potassium hexatitanate whisker coated with a phosphorus-containing polyarylethersulfone macromolecular chain. On the one hand, the presence of the macromolecular chain enables the potassium hexatitanate whisker to form a mutually entangled cross-linked structure with the PVC molecular chain during the melt mixing process, effectively improving the interfacial affinity between the potassium hexatitanate whisker and PVC, which is beneficial to give full play to the advantages of the potassium hexatitanate whisker as an inorganic filler and improving the mechanical strength of the board. In addition, the phosphorus-containing polyarylethersulfone macromolecular chain structure contains a carbon source, an acid source and a gas source at the same time, which is a ternary intumescent flame retardant, and can form an intumescent carbon layer when the board burns, covering the outside of the board, so that the combustion cannot continue, thereby achieving a small amount of addition, which can greatly improve the flame retardant properties of the board.

[0028] (2) The plastic wood board of the present invention has a multi-layer structure, wherein the outer layer is an anti-mildew coating formed by curing an epoxy resin-based anti-mildew coating, and the anti-mildew coating contains a natural antibacterial agent chitosan, so the anti-mildew coating can exhibit good antibacterial properties and can effectively prevent bacteria from breeding and causing mildew.

[0029] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 This is the infrared analysis spectrum of phosphorus-containing polyarylethersulfone. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Preparation Example

[0034] Preparation of functional additives:

[0035] Step S1, dispersing 3.5 g of potassium hexatitanate whiskers in anhydrous toluene, and then adding 1.2 g of toluene-2,4-diisocyanate to the formed dispersion. After the addition, nitrogen protection is introduced, and the temperature is gradually increased to 75° C. After heat treatment for 4 hours, the temperature is lowered and the material is discharged. The solid material is collected by centrifugation to obtain modified potassium titanate whiskers;

[0036] According to the hydrochloric acid-di-n-butylamine titration test method, the percentage of isocyanate groups of the modified potassium hexatitanate whiskers was tested. 0.5 g was taken as a sample, and the concentration of the hydrochloric acid standard solution was 0.5 mol / L. The test results showed that the percentage of isocyanate groups was 3.75%.

[0037] Step S2, add 2.8g of modified potassium titanate whiskers to tetrahydrofuran, and after uniform dispersion, add 4.5g of phosphorus-containing polyarylethersulfone and 0.2g of dibutyltin dilaurate, stir evenly, control the temperature to 60°C, keep warm and stir for 6h, stop heating, separate the solid material, and prepare a functional additive.

[0038] The functional additive was titrated using the same titration test method, and the results showed that the percentage of isocyanate groups was 0.81%. It is speculated that the principle of the above technical solution is: first, the potassium titanate whisker is surface-modified using the diisocyanate monomer toluene-2,4-diisocyanate to obtain a modified potassium titanate whisker containing an isocyanate group, and then, under the catalysis of dibutyltin dilaurate, it undergoes further amine esterification reaction with the substituted hydroxyl group in the phosphorus-containing polyarylethersulfone structure, resulting in a large amount of isocyanate groups being consumed, and the phosphorus-containing polyarylethersulfone macromolecular chain is grafted onto the surface of the potassium hexatitanate whisker to obtain the functional additive.

[0039] The preparation method of phosphorus-containing polyarylethersulfone is as follows:

[0040] Step SS1, adding 1.5 g of polyarylethersulfone to 1,2-dichloroethane, stirring to mix, then adding 0.4 g of chloroacetyl chloride and 0.1 g of aluminum chloride to the system, and stirring at 40° C. for 4 h to obtain halogenated polyarylethersulfone;

[0041] Step SS2, add 1.2 g of halogenated polyarylethersulfone to toluene, stir mechanically to mix evenly, then add 0.5 g of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and triethylamine, after adding, pass nitrogen, exhaust the air, then raise the temperature to 75 ° C, keep stirring for 6 hours, to obtain phosphorus-containing polyarylethersulfone.

[0042] Figure 1 This is the infrared analysis spectrum of phosphorus-containing polyarylethersulfone, where 3301cm -1 The absorption peak at 3000 cm is the characteristic absorption peak of the hydroxyl group that does not participate in the reaction in the structure of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide. -1 ~3100cm -1 The absorption peak at 1741 cm is the carbon-hydrogen absorption peak of the benzene ring skeleton. -1 The absorption peak at 1098 cm is the characteristic absorption peak of carbonyl C=O. -1 The absorption peak appearing at is the characteristic absorption peak of the ether bond produced by the substitution reaction.

[0043] Example 1

[0044] Preparation of plastic wood board layer:

[0045] Step 1: Add 18 parts of wood flour, 36 parts of PVC powder, 3 parts of light calcium, 2.4 parts of functional additives, 5 parts of EPDM rubber, 4 parts of dioctyl phthalate, 5 parts of calcium zinc stabilizer, 2 parts of polyethylene wax and 1 part of phosphite into a mixer according to weight parts, control the temperature to 100°C, the stirring rate to 1000r / min, and mechanically stir and mix evenly to form a pre-mixed material;

[0046] Step 2: Under the conditions of temperature of 200°C and pressure of 30MPa, the mixed material is extruded and shaped to obtain the plastic wood board layer.

[0047] The functional auxiliary agent used is the functional auxiliary agent prepared in the preparation example, and the same applies to the following.

[0048] Example 2

[0049] Preparation of plastic wood board layer:

[0050] Step 1: Add 20 parts of wood flour, 38 parts of PVC powder, 5 parts of light calcium, 3 parts of functional additives, 6 parts of natural rubber, 5 parts of dioctyl phthalate, 8 parts of calcium zinc stabilizer, 3 parts of polyethylene wax and 1.5 parts of phosphite into a mixer according to weight parts, control the temperature to 110°C, the stirring rate to 1500r / min, and mechanically stir and mix evenly to form a mixed pre-material;

[0051] Step 2: Under the conditions of a temperature of 210° C. and a pressure of 25 MPa, the mixed material is extruded and shaped to obtain a plastic wood board layer.

[0052] Example 3

[0053] Preparation of plastic wood board layer:

[0054] Step 1: Add 25 parts of wood flour, 40 parts of PVC powder, 6 parts of light calcium, 3.5 parts of functional additives, 10 parts of polybutadiene rubber, 8 parts of dioctyl phthalate, 10 parts of calcium zinc stabilizer, 4 parts of polyethylene wax and 2 parts of phosphite into a mixer according to weight parts, control the temperature to 120°C, stir at a speed of 2000r / min, and mix evenly with mechanical stirring to form a pre-mixed material;

[0055] Step 2: Under the conditions of a temperature of 210° C. and a pressure of 20 MPa, the mixed material is extruded and shaped to obtain a plastic wood board layer.

[0056] Comparative Example 1

[0057] Preparation of plastic wood board layer:

[0058] Step 1: Add 20 parts of wood flour, 38 parts of PVC powder, 5 parts of light calcium, 3 parts of potassium hexatitanate whiskers, 6 parts of natural rubber, 5 parts of dioctyl phthalate, 8 parts of calcium zinc stabilizer, 3 parts of polyethylene wax and 1.5 parts of phosphite into a mixer according to weight parts, control the temperature to 110°C, the stirring rate to 1500r / min, and mix them evenly with mechanical stirring to form a pre-mixed material;

[0059] Step 2: Under the conditions of a temperature of 210° C. and a pressure of 25 MPa, the mixed material is extruded and shaped to obtain a plastic wood board layer.

[0060] Comparative Example 2

[0061] Preparation of plastic wood board layer:

[0062] Step 1: Add 20 parts of wood flour, 38 parts of PVC powder, 5 parts of light calcium, 3 parts of phosphorus-containing polyarylethersulfone, 6 parts of natural rubber, 5 parts of dioctyl phthalate, 8 parts of calcium zinc stabilizer, 3 parts of polyethylene wax and 1.5 parts of phosphite into a mixer according to weight parts, control the temperature to 110°C, the stirring rate to 1500r / min, and mix them evenly with mechanical stirring to form a pre-mixed material;

[0063] Step 2: Under the conditions of a temperature of 210° C. and a pressure of 25 MPa, the mixed material is extruded and shaped to obtain a plastic wood board layer.

[0064] The phosphorus-containing polyarylethersulfone is the phosphorus-containing polyarylethersulfone prepared in the preparation example.

[0065] Test Case

[0066] Various performance tests were performed on the wood-plastic board layers in the embodiments and comparative examples, and the results are recorded in Table 1:

[0067] Table 1 - Test results

[0068] Compressive strength / MPa Limiting oxygen index / % Example 1 26.8 33.4 Example 2 27.3 33.5 Example 3 27.1 33.1 Comparative Example 1 24.0 25.7 Comparative Example 2 19.7 32.8

[0069] The compressive strength test reference standard is GB / T 1041-2008; the limiting oxygen index test method reference standard is GB / T406.2-2009.

[0070] Analysis shows that the use of the functional additives prepared in the preparation example as additives can make the plastic wood board layer have excellent mechanical strength and flame retardant properties.

[0071] After the functional additives were replaced with unmodified potassium hexatitanate whiskers, on the one hand, due to interface problems, the potassium hexatitanate whiskers could not be evenly dispersed, making it difficult to effectively exert their advantages as inorganic additives, so the mechanical strength was significantly reduced. In addition, the phosphorus-containing polyarylethersulfone macromolecular chain was lost and the ternary intumescent flame retardant was not contained, resulting in a significant reduction in the flame retardancy of the sheet layer. After the functional additives were replaced with phosphorus-containing polyarylethersulfone, the reinforcing effect of the potassium hexatitanate whiskers was lost, and the mechanical strength of the material was greatly reduced.

[0072] A multi-layer composite plastic-wood board is prepared by using the plastic-wood board layer prepared in Example 2, which specifically includes the following steps:

[0073] The first step is to dissolve chitosan in an acetic acid solution with a volume fraction of 2%, stir and mix, and prepare a chitosan solution with a mass fraction of 15%, and then mix it with an epoxy resin at a volume ratio of 0.6:1, and mechanically stir to prepare an anti-mildew coating;

[0074] Step 2: Use a 360° rotating roller to evenly apply the anti-mildew paint on both sides of the plastic wood board layer, and control the coating amount to 120g / m 2 , forming an anti-mildew coating. After coating, cure it in a temperature environment of 100°C for 6 hours and then take it out.

[0075] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-layer composite wood-plastic board, characterized in that: The plastic wood board includes, from top to bottom, an anti-mildew coating, a plastic wood board layer, and an anti-mildew coating; the plastic wood board layer is made of raw materials including the following parts by weight: The preparation method of the plastic wood board layer is as follows: Step 1: Weigh the raw materials of each component according to their weight, and then add them into a mixer, control the temperature to 100-120°C, stir at a speed of 1000-2000r / min, and stir mechanically to mix evenly to form a pre-mixed material; Step 2: Under the conditions of temperature of 200-210°C and pressure of 20-30MPa, the mixed material is extruded and shaped to obtain the plastic wood board layer.

2. A multi-layer composite wood-plastic board according to claim 1, characterized in that: The preparation method of the functional additive is as follows: Step S1, using a diisocyanate monomer to perform surface modification on potassium hexatitanate whiskers to obtain modified potassium titanate whiskers; Step S2: Under the action of a catalyst, the modified potassium titanate whiskers are further grafted and modified using phosphorus-containing polyarylethersulfone to obtain a functional additive.

3. A multi-layer composite wood-plastic board according to claim 2, characterized in that: In step S1, the diisocyanate monomer is at least one of toluene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate.

4. The multi-layer composite wood-plastic board according to claim 2, characterized in that: In step S2, the catalyst is any one of stannous octoate, dibutyltin dilaurate or dibutyltin diacetate.

5. The multi-layer composite wood-plastic board according to claim 2, characterized in that: In step S2, the preparation method of the phosphorus-containing polyarylethersulfone is as follows: Step SS1, using a halogenated acylate to perform Friedel-Crafts acylation modification on poly(arylethersulfone) to obtain a halogenated poly(arylethersulfone); Step SS2: Under the action of a basic catalyst, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide is used to replace the halogenated polyarylethersulfone to obtain the phosphorus-containing polyarylethersulfone.

6. The multi-layer composite wood-plastic board according to claim 5, characterized in that: In step SS1, the halogenated acylate is chloroacetyl chloride.

7. The multi-layer composite wood-plastic board according to claim 5, characterized in that: In step S2, the alkaline catalyst is triethylamine.

8. The multi-layer composite wood-plastic board according to claim 5, characterized in that: In step SS2, the mass ratio of the 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide to the halogenated polyarylethersulfone is 0.4-0.6:

1.

9. The multi-layer composite wood-plastic board according to claim 1, characterized in that: The rubber additive is at least one of EPDM rubber, natural rubber or polybutadiene rubber; the plasticizer is dioctyl phthalate; the stabilizer is calcium zinc stabilizer; the lubricant is polyethylene wax or stearic acid; and the antioxidant is a phosphite antioxidant.

10. A method for preparing a multi-layer composite plastic-wood board, characterized in that: The following steps are involved: The first step is to dissolve chitosan in an acetic acid solution with a volume fraction of 1-3%, stir and mix, and prepare a chitosan solution with a mass fraction of 10-20%, and then mix it with an epoxy resin according to a volume ratio of 0.5-1:1, and mechanically stir to prepare an anti-mildew coating; Step 2: Use a 360° rotating roller to evenly apply the anti-mildew paint on both sides of the plastic wood board layer, and control the coating amount to 100-150g / m 2 , forming an anti-mildew coating. After coating, cure it in a temperature environment of 100-120℃ for 4-8 hours and then take it out.

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