Flame-retardant composite board and preparation method thereof

Abstract

The invention discloses a flame-retardant composite wood board and a preparation method thereof.The preparation method of the composite wood board comprises the following steps that single-layer wood boards are soaked in an aqueous solution containing a first flame retardant and dicyandiamide, after drying, the multiple single-layer wood boards are bonded and pressed through an adhesive, and the flame-retardant composite wood board is prepared; the preparation method of the first flame retardant comprises the following steps: S1: 1, reacting 2-bis (chlorodimethylsilyl) ethane with syringaldehyde in a first organic solvent to prepare an intermediate A; s2, reacting the intermediate A with tyrosine in a second organic solvent to prepare an intermediate B; s3, the intermediate B and phosphorous acid are mixed for a reaction, and the first flame retardant is prepared. The first flame retardant can form covalent bond combination with the wood board, so that the flame retardant property of the treated wood is remarkably improved; and meanwhile, the second flame retardant in the adhesive and the first flame retardant impregnated on the wood board can achieve a synergistic promotion effect, so that the limit oxygen index of the prepared composite wood board is up to 60% or above.

Description

Technical Field

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

[0002] With the acceleration of the modern urbanization process, 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 has made building fire safety an important public safety issue. As a flammable material, traditional wood is extremely likely to cause disasters in fires. The fast spread speed of fires brings great potential safety hazards. In many major fire accidents, the flammable characteristics of wood as a building material have led to rapid fire spread and heavy losses.

[0003] The flame-retardant performance of flame-retardant wood is related to the performance and dosage of the flame retardant, and also related to the distribution state of the flame retardant in the wood. The influence of flame-retardant treatment on the strength, moisture absorption, etc. of wood depends on the type, acid-base property of the used flame retardant and the treatment process conditions. The purpose of the present invention is to provide a flame-retardant composite wood board with good flame-retardant performance. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes a flame-retardant composite wood board and a preparation method thereof, which have excellent flame-retardant performance.

[0005] The preparation method of the flame-retardant composite wood board proposed by the present invention is as follows: impregnate a single-layer wood board in an aqueous solution containing a first flame retardant and dicyandiamide, and after drying, bond and press a plurality of single-layer wood boards through an adhesive to obtain a flame-retardant composite wood board;

[0006] Among them, 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 °C, the time is 10 - 20 min; the drying temperature is 35 - 55 °C.

[0009] Preferably, the preparation method of the first flame retardant is as follows:

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

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

[0012] S3: Mix and react intermediate B and phosphorous acid to obtain the first flame retardant.

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

[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 °C, and the reaction time is 1-5 h.

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

[0016] Preferably, the binder further comprises a second flame retardant, and 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 cetyl(2-acetoxy)dimethylammonium chloride are added for reaction to obtain the second flame retardant.

[0017] Preferably, the mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate and cetyl(2-acetoxy)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 binder.

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

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

[0020] The beneficial technical effects of the present invention:

[0021] (1) The first flame retardant prepared from 1,2-bis(chlorodimethylsilyl)ethane, syringaldehyde, tyrosine and phosphorous acid in the present invention has excellent flame retardant performance, and under the catalysis of dicyandiamide during the impregnation process of the wood board, the first flame retardant can form a covalent bond with the wood board, significantly improving the flame retardant performance of the treated wood.

[0022] (2) The binder of the present invention further comprises a second flame retardant. In the preparation method, the structure of the second flame retardant is guided by cetyl(2-acetoxy)dimethylammonium chloride, so that the second flame retardant can achieve a synergistic promotion effect with the first flame retardant impregnated on the wood board. Specific Embodiments

[0023] The following further illustrates the present invention with specific embodiments.

[0024] The raw materials used in the embodiments of the present invention are all commercially available, and the binder selected is a commercially available phenolic resin binder.

[0025] Example 1

[0026] The preparation method of the flame-retardant composite wood board proposed by the present invention is as follows: impregnate a single-layer wood board in an aqueous solution containing a first flame retardant and dicyandiamide, and after drying, bond and press multiple single-layer wood boards through an adhesive to obtain a flame-retardant composite wood board;

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

[0028] The preparation method of the first flame retardant is as follows:

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

[0030]

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

[0032]

[0033] S3: Mix and react intermediate B and phosphorous acid to obtain the first flame retardant, and the structural formula of the first flame retardant is:

[0034]

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

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

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

[0038] The adhesive also includes a second flame retardant, and the second flame retardant and the adhesive are uniformly mixed. The preparation method of the second flame retardant is as follows: disperse triethylamine and phytic acid in N,N-dimethylformamide, and then add cobalt nitrate, cerium nitrate and cetyl(2-acetoxy)dimethylammonium chloride for reaction to obtain the second flame retardant.

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

[0040] The reaction temperature is 80 °C and the time is 9 h.

[0041] Example 2

[0042] The preparation method of the flame-retardant composite wood board proposed by the present invention is as follows: Immerse the single-layer wood board in an aqueous solution containing the first flame retardant and dicyandiamide, and after drying, bond and press multiple single-layer wood boards through an adhesive to obtain the flame-retardant composite wood board;

[0043] The mass ratio of the first flame retardant, dicyandiamide and water is 1:0.01:20; the immersion temperature is 60 °C and the time is 10 min; the drying temperature is 35 °C.

[0044] The preparation method of the first flame retardant is as follows:

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

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

[0047] S3: Mix and react intermediate B and phosphorous acid to obtain the first flame retardant.

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

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

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

[0051] The binder also includes a second flame retardant, and the preparation method of the second flame retardant is as follows: Disperse triethylamine and phytic acid in N,N-dimethylformamide, and then add cobalt nitrate, cerium nitrate and cetyl(2-acetoxy)dimethylammonium chloride to react to obtain the second flame retardant.

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

[0053] The temperature of the reaction is 70 °C and the time is 6 h.

[0054] Example 3

[0055] The preparation method of the flame-retardant composite wood board proposed by the present invention is as follows: Immerse the single-layer wood board in an aqueous solution containing a first flame retardant and dicyandiamide, and after drying, bond and press multiple single-layer wood boards through an adhesive to obtain the flame-retardant composite wood board;

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

[0057] The preparation method of the first flame retardant is as follows:

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

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

[0060] S3: Mix and react intermediate B and phosphorous acid to obtain the first flame retardant.

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

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

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

[0064] The adhesive also includes a second flame retardant. The preparation method of the second flame retardant is as follows: Disperse triethylamine and phytic acid in N,N-dimethylformamide, and then add cobalt nitrate, cerium nitrate and cetyl(2-acetoxy)dimethylammonium chloride for reaction to obtain the second flame retardant.

[0065] The mass ratio of triethylamine, phytic acid, cobalt nitrate, cerium nitrate and cetyl(2-acetoxy)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 temperature of the reaction is 70 °C and the time is 6 h.

[0067] Comparative Example 1

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

[0069] Comparative Example 2

[0070] The single-layer wooden boards in this solution were not impregnated with the solution containing the first flame retardant. After directly bonding and pressing multiple single-layer wooden boards through the adhesive, a composite wooden board was prepared.

[0071] The adhesive includes 6% of the second flame retardant, and the preparation method of the second flame retardant is the same as that in Example 1.

[0072] Comparative Example 3

[0073] The single-layer wooden boards in this solution were not impregnated with the solution containing the first flame retardant. After directly bonding and pressing multiple single-layer wooden boards through the adhesive, a composite wooden board was prepared.

[0074] The adhesive includes 6% of the first flame retardant, and the preparation method of the first flame retardant is the same as that in Example 1.

[0075] According to GB / T 2406-93, the flame retardant properties of the composite wooden boards prepared in Examples 1-3 and Comparative Examples 1-3 were measured by an automatic oxygen index measuring instrument, and the test results are shown in Table 1.

[0076] Table 1 Test Results of Flame Retardant Properties

[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] It can be seen from the test results of Examples 1-3 that the limiting oxygen index of the composite wooden board prepared by the present invention reaches more than 60%, and it has excellent flame retardant properties. It can be seen from the test results of Comparative Example 2 and Comparative Example 3 that when the wooden board is not impregnated with the first flame retardant, the flame retardant effects of the first flame retardant and the second flame retardant in the adhesive are not very different. And it can be seen from the test results of Example 1 and Comparative Example 1 that when the wooden board is impregnated with the first flame retardant, the flame retardant property of the composite wooden board prepared by adding the second flame retardant to the adhesive (Example 1) is significantly better than that of the composite wooden board prepared by adding the first flame retardant to the adhesive (Comparative Example 1), indicating that the second flame retardant in the adhesive and the first flame retardant impregnated in the wooden board have a synergistic and promoting effect on the flame retardant effect.

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

Claims

1. A method for preparing a flame retardant composite wood board, characterized in that: The method comprises the following steps: immersing a single-layer wood board in an aqueous solution containing a first flame retardant and dicyandiamide, and after drying, bonding and pressing a plurality of single-layer wood boards with an adhesive to obtain a flame-retardant composite wood board; Wherein, the structural formula of the first flame retardant is as follows: 。 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 immersion temperature is 60-70°C, the time is 10-20 minutes; and the drying temperature is 35-55°C.

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

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

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

7. The method for preparing the flame-retardant composite wood board according to claim 1, characterized in that: The adhesive also includes a second flame retardant, and 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-acetoxy) dimethyl ammonium chloride are added to react to obtain the second flame retardant.

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

9. The method for preparing the flame-retardant composite wood board according to claim 7, characterized in that: The reaction temperature is 70-90°C and the reaction time is 6-12h.

10. A flame retardant composite wood board prepared by the method according to any one of claims 1 to 9.

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