Flame-retardant composite wood board and method for manufacturing the same

Abstract

The application discloses a fire-retardant composite wood board and a preparation method thereof. The preparation method of the composite wood board comprises the following steps: immersing single-layer wood boards in an aqueous solution containing a first fire retardant and dicyandiamide, drying the single-layer wood boards, and then bonding and pressing the single-layer wood boards by using an adhesive to obtain the fire-retardant composite wood board. The first fire retardant is prepared by the following steps: S1, reacting 1,2-bis(chlorodimethylsilyl)ethane with syringaldehyde in a first organic solvent to obtain an intermediate A; S2, reacting the intermediate A with tyrosine in a second organic solvent to obtain an intermediate B; and S3, mixing and reacting the intermediate B and phosphorous acid to obtain the first fire retardant. The first fire retardant can form a covalent bond with the wood board, and the fire-retardant property of the treated wood board is significantly improved. Meanwhile, the second fire retardant in the adhesive can achieve a synergistic effect with the first fire retardant impregnated on the wood board, so that the prepared composite wood board has an ultimate oxygen index of more than 60%.

Description

Technical Field

[0001] This invention relates to the field of composite wood panel technology, and more particularly to flame-retardant composite wood panels and their preparation methods. Background Technology

[0002] With the acceleration of modern urbanization, the scale of buildings is constantly expanding, especially the increase in the number of high-rise buildings and public buildings such as shopping malls, hospitals, schools, and office buildings, making building fire safety a significant public safety issue. Traditional wood, as a flammable material, is extremely prone to causing disasters in fires. The rapid spread of fire poses a great safety hazard, and in many major fire accidents, the flammable nature of wood as a building material has led to the rapid spread of fire and heavy losses.

[0003] The flame-retardant properties of flame-retardant wood are related to the performance and dosage of the flame retardant, as well as its distribution within the wood. The effects of flame-retardant treatment on wood strength, hygroscopicity, etc., depend on the type, acidity / alkalinity, and processing conditions of the flame retardant used. The purpose of this invention is to provide a flame-retardant composite wood board with good flame-retardant properties. Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a flame-retardant composite wood board and its preparation method, which has excellent flame-retardant properties.

[0005] The method for preparing flame-retardant composite wood panels proposed in this invention comprises the following steps: immersing a single-layer wood panel in an aqueous solution containing a first flame retardant and dicyandiamide, drying it, and then bonding and pressing multiple single-layer wood panels together with an adhesive to obtain a flame-retardant composite wood panel;

[0006] The structural formula of the first flame retardant is as follows:

[0007]

[0008] Preferably, the mass ratio of the first flame retardant, dicyandiamide, and water is 1:0.01-0.1:20-30; the impregnation temperature is 60-70℃, and the time is 10-20 min; the drying temperature is 35-55℃.

[0009] Preferably, the method for preparing the first flame retardant includes the following steps:

[0010] S1: 1,2-bis(chlorodimethylsilyl)ethane reacts with eugenol in a first organic solvent to prepare intermediate A;

[0011] S2: Intermediate A is reacted with tyrosine in a second organic solvent to obtain intermediate B;

[0012] S3: Intermediate B and phosphorous acid are mixed and reacted to obtain the first flame retardant.

[0013] Preferably, the molar ratio of 1,2-bis(chlorodimethylsilyl)ethane to eugenol in S1 is 1:2-3; the first solvent is one of tetrahydrofuran, n-hexane, and n-octane; the reaction temperature is 60-80℃, and the reaction time is 1-5h.

[0014] Preferably, the molar ratio of intermediate A to tyrosine in S2 is 1:2-3; the second solvent is one of ethanol, acetone and isopropanol; the reaction temperature is 60-80℃ and the reaction time is 1-5h.

[0015] Preferably, the molar ratio of intermediate B to phosphorous acid in S3 is 1:2-2.5; the reaction temperature is 105-115℃, and the reaction time is 1-5h.

[0016] Preferably, the adhesive further includes a second flame retardant, which is prepared by dispersing triethylamine and phytic acid in N,N-dimethylformamide, and then adding cobalt nitrate, cerium nitrate and hexadecyl(2-acetyl)dimethylammonium chloride to react and obtain the second flame retardant.

[0017] Preferably, the mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate, and hexadecyl(2-acetic acid)dimethylammonium chloride is 10:10-20:1-3:1-3:0.1-0.3; the second flame retardant accounts for 4-8% of the total mass of the adhesive.

[0018] Preferably, the reaction temperature is 70-90℃ and the reaction time is 6-12h.

[0019] The flame-retardant composite wood board prepared by the method proposed in this invention.

[0020] Beneficial technical effects of the present invention:

[0021] (1) The first flame retardant prepared by the present invention using 1,2-bis(chlorodimethylsilyl)ethane, eugenol, tyrosine and phosphorous acid has excellent flame retardant properties. Furthermore, under the catalytic action of dicyandiamide during the impregnation process of wood boards, the first flame retardant can form covalent bonds with the wood boards, which significantly improves the flame retardant properties of the treated wood.

[0022] (2) The adhesive of the present invention also includes a second flame retardant, which is structured by hexadecyl(2-acetyl)dimethylammonium chloride in the preparation method, so that the second flame retardant can achieve a synergistic promoting effect with the first flame retardant impregnated on the wood board. Detailed Implementation

[0023] The present invention will be further explained below with reference to specific embodiments.

[0024] All raw materials used in the embodiments of the present invention are commercially available, and the adhesive is a commercially available phenolic resin adhesive.

[0025] Example 1

[0026] The method for preparing flame-retardant composite wood panels proposed in this invention comprises the following steps: immersing a single-layer wood panel in an aqueous solution containing a first flame retardant and dicyandiamide, drying it, and then bonding and pressing multiple single-layer wood panels together with an adhesive to obtain a flame-retardant composite wood panel;

[0027] The mass ratio of the first flame retardant, dicyandiamide, and water is 1:0.05:25; the impregnation temperature is 65℃ for 15 minutes; and the drying temperature is 45℃.

[0028] The steps for preparing the first flame retardant are as follows:

[0029] S1: 1,2-bis(chlorodimethylsilyl)ethane reacts with eugenol in a first organic solvent to prepare intermediate A, the structural formula of which is:

[0030]

[0031] S2: Intermediate A is reacted with tyrosine in a second organic solvent to obtain intermediate B, the structural formula of which is:

[0032]

[0033] S3: Intermediate B and phosphorous acid are mixed and reacted to obtain the first flame retardant. The structural formula of the first flame retardant is as follows:

[0034]

[0035] In S1, the molar ratio of 1,2-bis(chlorodimethylsilyl)ethane to eugenol is 1:2.2; the first solvent is tetrahydrofuran; the reaction temperature is 70℃ and the reaction time is 3h.

[0036] In S2, the molar ratio of intermediate A to tyrosine is 1:2.2; the second solvent is anhydrous ethanol; the reaction temperature is 70℃ and the reaction time is 3h.

[0037] In S3, the molar ratio of intermediate B to phosphorous acid is 1:2.2; the reaction temperature is 108℃ and the reaction time is 3h.

[0038] The adhesive also includes a second flame retardant. The second flame retardant and the adhesive are mixed evenly. The preparation method of the second flame retardant is as follows: triethylamine and phytic acid are dispersed in N,N-dimethylformamide, and then cobalt nitrate, cerium nitrate and hexadecyl(2-acetic acid)dimethylammonium chloride are added to react and the second flame retardant is obtained.

[0039] The mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate, and hexadecyl(2-acetic acid)dimethylammonium chloride is 10:15:2:2:0.2; the second flame retardant accounts for 6% of the total mass of the adhesive.

[0040] The reaction was carried out at a temperature of 80℃ for 9 hours.

[0041] Example 2

[0042] The method for preparing flame-retardant composite wood panels proposed in this invention comprises the following steps: immersing a single-layer wood panel in an aqueous solution containing a first flame retardant and dicyandiamide, drying it, and then bonding and pressing multiple single-layer wood panels together with an adhesive to obtain a flame-retardant composite wood panel;

[0043] The mass ratio of the first flame retardant, dicyandiamide, and water is 1:0.01:20; the impregnation temperature is 60℃ for 10 minutes; and the drying temperature is 35℃.

[0044] The steps for preparing the first flame retardant are as follows:

[0045] S1: 1,2-bis(chlorodimethylsilyl)ethane reacts with eugenol in a first organic solvent to prepare intermediate A;

[0046] S2: Intermediate A is reacted with tyrosine in a second organic solvent to obtain intermediate B;

[0047] S3: Intermediate B and phosphorous acid are mixed and reacted to obtain the first flame retardant.

[0048] In S1, the molar ratio of 1,2-bis(chlorodimethylsilyl)ethane to eugenol is 1:2; the first solvent is tetrahydrofuran; the reaction temperature is 60℃ and the reaction time is 1h.

[0049] In S2, the molar ratio of intermediate A to tyrosine is 1:2; the second solvent is anhydrous ethanol; the reaction temperature is 60℃ and the reaction time is 5h.

[0050] In S3, the molar ratio of intermediate B to phosphorous acid is 1:2; the reaction temperature is 105℃ and the reaction time is 5h.

[0051] The adhesive also includes a second flame retardant, which is prepared as follows: triethylamine and phytic acid are dispersed in N,N-dimethylformamide, and then cobalt nitrate, cerium nitrate and hexadecyl(2-acetic acid)dimethylammonium chloride are added to react and the second flame retardant is obtained.

[0052] The mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate, and hexadecyl(2-acetyl)dimethylammonium chloride is 10:10:1:1:0.1; the second flame retardant accounts for 4% of the total mass of the adhesive.

[0053] The reaction was carried out at a temperature of 70°C for 6 hours.

[0054] Example 3

[0055] The method for preparing flame-retardant composite wood panels proposed in this invention comprises the following steps: immersing a single-layer wood panel in an aqueous solution containing a first flame retardant and dicyandiamide, drying it, and then bonding and pressing multiple single-layer wood panels together with an adhesive to obtain a flame-retardant composite wood panel;

[0056] The mass ratio of the first flame retardant, dicyandiamide, and water is 1:0.1:30; the impregnation temperature is 70℃ for 20 minutes; and the drying temperature is 55℃.

[0057] The steps for preparing the first flame retardant are as follows:

[0058] S1: 1,2-bis(chlorodimethylsilyl)ethane reacts with eugenol in a first organic solvent to prepare intermediate A;

[0059] S2: Intermediate A is reacted with tyrosine in a second organic solvent to obtain intermediate B;

[0060] S3: Intermediate B and phosphorous acid are mixed and reacted to obtain the first flame retardant.

[0061] In S1, the molar ratio of 1,2-bis(chlorodimethylsilyl)ethane to eugenol is 1:3; the first solvent is tetrahydrofuran; the reaction temperature is 80℃ and the reaction time is 1h.

[0062] In S2, the molar ratio of intermediate A to tyrosine is 1:3; the second solvent is anhydrous ethanol; the reaction temperature is 80℃ and the reaction time is 1h.

[0063] In S3, the molar ratio of intermediate B to phosphorous acid is 1:2.5; the reaction temperature is 115℃ and the reaction time is 1h.

[0064] The adhesive also includes a second flame retardant, which is prepared as follows: triethylamine and phytic acid are dispersed in N,N-dimethylformamide, and then cobalt nitrate, cerium nitrate and hexadecyl(2-acetic acid)dimethylammonium chloride are added to react and the second flame retardant is obtained.

[0065] The mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate, and hexadecyl(2-acetic acid)dimethylammonium chloride is 10:20:3:3:0.3; the second flame retardant accounts for 8% of the total mass of the adhesive.

[0066] The reaction was carried out at a temperature of 70°C for 6 hours.

[0067] Comparative Example 1

[0068] The adhesive in this solution includes 6% of a first flame retardant, which is uniformly mixed with the adhesive, and all other conditions are the same as in Example 1.

[0069] Comparative Example 2

[0070] In this method, the single-layer wood panels are not impregnated with a solution containing the first flame retardant. Multiple single-layer wood panels are directly bonded and pressed together with an adhesive to obtain a composite wood panel.

[0071] The adhesive includes 6% of a second flame retardant, which is prepared in the same way as in Example 1.

[0072] Comparative Example 3

[0073] In this method, the single-layer wood panels are not impregnated with a solution containing the first flame retardant. Multiple single-layer wood panels are directly bonded and pressed together with an adhesive to obtain a composite wood panel.

[0074] The adhesive contains 6% of a first flame retardant, which is prepared in the same way as in Example 1.

[0075] According to GB / T 2406-93, the flame retardant properties of the composite wood panels prepared in Examples 1-3 and Comparative Examples 1-3 were determined using an automatic oxygen index tester. The test results are shown in Table 1.

[0076] Table 1 Flame retardant performance test results

[0077] Group Oxygen index (%) Example 1 65.1 Example 2 62.4 Example 3 63.8 Comparative Example 1 49.6 Comparative Example 2 28.5 Comparative Example 3 31.7

[0078] The test results of Examples 1-3 show that the composite wood board prepared by this invention has a limiting oxygen index of over 60%, exhibiting excellent flame retardant properties. The test results of Comparative Examples 2 and 3 show that when the wood board is not impregnated with the first flame retardant, the flame retardant effects of the first and second flame retardants in the adhesive are not significantly different. However, the test results of Examples 1 and 1 show that when the wood board is impregnated with the first flame retardant, the composite wood board prepared by adding the second flame retardant to the adhesive (Example 1) exhibits significantly better flame retardant properties than the composite wood board prepared by adding the first flame retardant to the adhesive (Comparative Example 1). This indicates that the second flame retardant in the adhesive and the first flame retardant impregnated in the wood board have a synergistic effect in promoting flame retardant performance.

[0079] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application. The scope of this application is defined by the appended claims and their equivalents, all of which should be included within the protection scope of this application.

Claims

1. A method for preparing flame-retardant composite wood panels, characterized in that, The method steps are as follows: a single-layer wood board is immersed in an aqueous solution containing a first flame retardant and dicyandiamide. After drying, multiple single-layer wood boards are bonded and pressed together with an adhesive to obtain a flame-retardant composite wood board. The structural formula of the first flame retardant is as follows: ； The adhesive also includes a second flame retardant, which is prepared as follows: triethylamine and phytic acid are dispersed in N,N-dimethylformamide, and then cobalt nitrate, cerium nitrate and hexadecyl(2-acetyl)dimethylammonium chloride are added and reacted to obtain the second flame retardant.

2. The method for preparing the flame-retardant composite wood board according to claim 1, characterized in that, The mass ratio of the first flame retardant, dicyandiamide, and water is 1:0.01-0.1:20-30; the impregnation temperature is 60-70℃, and the time is 10-20 minutes; the drying temperature is 35-55℃.

3. The method for preparing the flame-retardant composite wood board according to claim 1, characterized in that, The steps for preparing the first flame retardant are as follows: S1: 1,2-bis(chlorodimethylsilyl)ethane reacts with eugenol in a first organic solvent to prepare intermediate A; S2: Intermediate A is reacted with tyrosine in a second organic solvent to obtain intermediate B; S3: Intermediate B and phosphorous acid are mixed and reacted to obtain the first flame retardant.

4. The method for preparing the flame-retardant composite wood board according to claim 3, characterized in that, In S1, the molar ratio of 1,2-bis(chlorodimethylsilyl)ethane to eugenol is 1:2-3; the first solvent is one of tetrahydrofuran, n-hexane, and n-octane; the reaction temperature is 60-80℃, and the reaction time is 1-5h.

5. The method for preparing the flame-retardant composite wood board according to claim 3, characterized in that, In S2, the molar ratio of intermediate A to tyrosine is 1:2-3; the second solvent is one of ethanol, acetone, and isopropanol; the reaction temperature is 60-80℃, and the reaction time is 1-5h.

6. The method for preparing the flame-retardant composite wood board according to claim 3, characterized in that, In S3, the molar ratio of intermediate B to phosphorous acid is 1:2-2.5; the reaction temperature is 105-115℃, and the reaction time is 1-5h.

7. The method for preparing the flame-retardant composite wood board according to claim 1, characterized in that, The mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate, and hexadecyl(2-acetic acid)dimethylammonium chloride is 10:10-20:1-3:1-3:0.1-0.3; the second flame retardant accounts for 4-8% of the total mass of the adhesive.

8. The method for preparing the flame-retardant composite wood board according to claim 1, characterized in that, The reaction temperature is 70-90℃, and the reaction time is 6-12 hours.

9. Flame-retardant composite wood panels prepared by the method according to any one of claims 1-8.

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