A flame-retardant composite board and its preparation method

Abstract

The present invention discloses a flame-retardant composite board, which comprises a glass fiber layer, a flame-retardant layer and a rock wool layer; the flame-retardant layer is arranged between the glass fiber layer and the rock wool layer; by mass, the flame-retardant layer comprises 25-35 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 22-28 parts of polybenzimidazole-modified biphenyl polyimide, 8-12 parts of polybutylene terephthalate, 28-32 parts of kaolin and 3-8 parts of polydimethylsiloxane. The composite board obtained by the present invention has high tensile strength, good sound absorption effect and excellent flame retardancy.

Description

Technical Field

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

[0002] A composite board is a new type of building material. Currently, most composite boards are of a sandwich structure with a three-layer structure. Since the composite board is made of a combination of multiple different boards and can take into account the advantages of various boards at the same time, it is widely popular.

[0003] Existing rock wool composite boards include polyurethane-edge-sealed rock wool composite boards and steel-belt-edge-sealed rock wool composite boards. The polyurethane-edge-sealed rock wool composite board has poor fire resistance because it uses flammable polyurethane materials; while the steel-belt-edge-sealed rock wool composite board has large gaps between the boards after installation and poor heat insulation effect. Currently, most of the market uses bare rock wool boards as the heat insulation material for building facades. Rock wool is made of fiber materials. Due to the characteristics of fibers being afraid of water and moisture, ordinary rock wool boards do not have the function of moisture-proof and mildew-proof during use; in addition, the tensile strength of ordinary low-density rock wool on the market is very low and cannot meet the strength requirements of the project. The high-density rock wool has high strength and can meet the strength requirements of the project, but the manufacturing cost is high, and the sound absorption effect is significantly weakened. Therefore, there is an urgent need for a flame-retardant composite board with high tensile strength and good sound absorption effect.

[0004] In summary, after a large number of searches by the applicant, there are at least problems in the field such as low tensile strength, poor sound absorption effect, and poor flame retardancy of the flame-retardant composite board. Therefore, it is necessary to develop or improve a flame-retardant composite board and a preparation method thereof. Summary of the Invention

[0005] Based on this, in order to solve the problems of low tensile strength, poor sound absorption effect, and poor flame retardancy of the composite board, the present invention provides a flame-retardant composite board and a preparation method thereof. The specific technical solutions are as follows:

[0006] A flame-retardant composite board, which includes a glass fiber layer, a flame-retardant layer, and a rock wool layer;

[0007] The flame-retardant layer is arranged between the glass fiber layer and the rock wool layer;

[0008] By mass, the flame-retardant layer includes 25-35 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 22-28 parts of polybenzimidazole-modified biphenyl-type polyimide, 8-12 parts of polybutylene terephthalate, 28-32 parts of kaolin, and 3-8 parts of polydimethylsiloxane.

[0009] Further, the thickness of the glass fiber layer is 3-7 mm.

[0010] Further, the thickness of the rock wool layer is 30-50 mm.

[0011] Furthermore, the thickness of the flame retardant layer is 2 - 5 mm.

[0012] Furthermore, the average particle size of the kaolin is 0.5 - 1.1 μm.

[0013] This technical solution also provides a preparation method for a composite board, which includes the following steps:

[0014] By mass, premix 25 - 35 parts of semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin, 22 - 28 parts of polybenzimidazole - modified biphenyl - type polyimide, and 8 - 12 parts of polybutylene terephthalate to obtain a premix.

[0015] Mix the premix, 28 - 32 parts of kaolin, and 3 - 8 parts of polydimethylsiloxane to obtain a flame retardant layer mixture.

[0016] Lay the flame retardant layer mixture on the rock wool layer and perform pre - pressing to form a board blank with a flame retardant layer.

[0017] Place the glass fiber layer on one side of the board blank with the flame retardant layer, and then perform hot pressing to obtain the composite board.

[0018] Furthermore, the temperature of the premixing is 38 - 42 °C, the stirring speed of the premixing is 300 - 360 r / min, and the time of the premixing is 25 - 28 min.

[0019] Furthermore, the conditions for the mixing are:

[0020] At 46 - 52 °C, stir at a speed of 180 - 220 r / min for 19 - 23 min, and then continue to stir at a speed of 180 - 220 r / min until room temperature.

[0021] Furthermore, the pressure of the pre - pressing is 0.3 - 0.5 MPa, and the time of the pre - pressing is 5 - 8 s.

[0022] Furthermore, the pressure of the hot pressing is 2.2 - 2.8 MPa, and the temperature of the hot pressing is 118 - 122 °C.

[0023] The composite board of the above invention creatively uses a combination of a semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin in a specific proportion, a polybenzimidazole - modified biphenyl - type polyimide in a specific proportion, and kaolin with a specific average particle size and a specific proportion in the middle flame - retardant layer, so that the finally obtained composite board has high tensile strength, good sound - absorption effect and excellent flame - retardancy. The semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin has a unique flexible structure, and the polybenzimidazole - modified biphenyl - type polyimide can interact with the semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin through polar bonds. Further, under the framework of the semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin and the polybenzimidazole - modified biphenyl - type polyimide, kaolin with a specific average particle size corresponding to the intermolecular voids is evenly distributed, which can enhance the interaction force of the middle flame - retardant layer on the glass fiber layer and the rock wool layer, thereby improving the tensile strength of the composite board; it can also effectively improve the sound - absorption performance and flame - retardant performance of the middle flame - retardant layer, thus enhancing the sound - absorption effect and flame - retardancy of the composite board. Detailed implementation manners

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in combination with its embodiments. It should be understood that the specific implementation manners described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this specification are only for the purpose of describing specific implementation manners and are not intended to limit the present invention. The term “and / or” used herein includes any and all combinations of one or more of the related listed items.

[0026] A flame - retardant composite board in an embodiment of the present invention includes a glass fiber layer, a flame - retardant layer and a rock wool layer;

[0027] The flame - retardant layer is disposed between the glass fiber layer and the rock wool layer;

[0028] By mass, the flame - retardant layer includes 25 - 35 parts of a semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin, 22 - 28 parts of a polybenzimidazole - modified biphenyl - type polyimide, 8 - 12 parts of polybutylene terephthalate, 28 - 32 parts of kaolin and 3 - 8 parts of polydimethylsiloxane.

[0029] In one of the embodiments, the thickness of the glass fiber layer is 3 - 7 mm. Preferably, the thickness of the glass fiber layer is 3 - 6 mm. Further preferably, the thickness of the glass fiber layer is 5 - 6 mm.

[0030] In one embodiment, the thickness of the rock wool layer is 30 to 50 mm. Preferably, the thickness of the rock wool layer is 35 to 45 mm. More preferably, the thickness of the rock wool layer is 38 to 42 mm.

[0031] In one embodiment, the thickness of the flame retardant layer is 2 to 5 mm. Preferably, the thickness of the flame retardant layer is 3 to 5 mm. More preferably, the thickness of the flame retardant layer is 3 to 4 mm.

[0032] In one embodiment, the average particle size of the kaolin is 0.5 to 1.1 μm. Preferably, the average particle size of the kaolin is 0.6 to 1.0 μm. More preferably, the average particle size of the kaolin is 0.7 to 0.9 μm.

[0033] In one embodiment, the present invention provides a method for preparing a composite board, which comprises the following steps:

[0034] By mass, 25 to 35 parts of semi-capped isocyanate modified epoxy itaconic acid ester aqueous resin, 22 to 28 parts of polybenzimidazole modified biphenyl type polyimide and 8 to 12 parts of polybutylene terephthalate are premixed to obtain a premixed material;

[0035] The premixed material, 28 to 32 parts of kaolin and 3 to 8 parts of polydimethylsiloxane are mixed to obtain a flame retardant layer mixture;

[0036] The flame retardant layer mixture is laid on the rock wool layer and pre-pressed to form a board blank with a flame retardant layer;

[0037] A glass fiber layer is placed on one side of the board blank with the flame retardant layer, and then hot-pressed to obtain the composite board.

[0038] In one embodiment, the temperature of the premixing is 38 to 42 °C, the stirring speed of the premixing is 300 to 360 r / min, and the time of the premixing is 25 to 28 min. Preferably, the temperature of the premixing is 39 to 41 °C, the stirring speed of the premixing is 310 to 350 r / min, and the time of the premixing is 26 to 28 min. More preferably, the temperature of the premixing is 39 to 41 °C, the stirring speed of the premixing is 320 to 330 r / min, and the time of the premixing is 26 to 27 min.

[0039] In one embodiment, the conditions for the mixing are:

[0040] At 46 to 52 °C, stirring is carried out at a speed of 180 to 220 r / min for 19 to 23 min, and then stirring is continued at a speed of 180 to 220 r / min until room temperature. Preferably, the conditions for the mixing are:

[0041] Stir at a speed of 190 - 220 r / min for 20 - 23 min at 47 - 51 °C, and then continue to stir at a speed of 180 - 210 r / min until room temperature. Further preferably, the conditions for mixing are:

[0042] Stir at a speed of 190 - 210 r / min for 20 - 22 min at 48 - 50 °C, and then continue to stir at a speed of 190 - 210 r / min until room temperature.

[0043] In one embodiment, the pressure of pre - pressing is 0.3 - 0.5 MPa, and the time of pre - pressing is 5 - 8 s. Preferably, the pressure of pre - pressing is 0.3 - 0.5 MPa, and the time of pre - pressing is 6 - 8 s. Further preferably, the pressure of pre - pressing is 0.3 - 0.5 MPa, and the time of pre - pressing is 6 - 7 s.

[0044] In one embodiment, the pressure of hot - pressing is 2.2 - 2.8 MPa, and the temperature of hot - pressing is 118 - 122 °C. Preferably, the pressure of hot - pressing is 2.3 - 2.7 MPa, and the temperature of hot - pressing is 119 - 122 °C. Further preferably, the pressure of hot - pressing is 2.5 - 2.6 MPa, and the temperature of hot - pressing is 119 - 121 °C.

[0045] The embodiments of the present invention will be described in detail below in conjunction with specific examples.

[0046] Example 1:

[0047] By mass, premix 30 parts of semi - blocked isocyanate - modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole - modified biphenyl - type polyimide, and 10 parts of polybutylene terephthalate. The temperature of premixing is 40 °C, the stirring speed of premixing is 330 r / min, and the time of premixing is 26 min to obtain a premix; Mix the obtained premix, 30 parts of 0.8 - μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame - retardant layer mixture; Lay the obtained flame - retardant layer mixture on a 40 - mm rock wool layer, pre - press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame - retardant layer; Place a 5 - mm glass fiber layer on one side of the board blank with the flame - retardant layer, and then hot - press it at 120 °C at a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame - retardant layer of the composite board is 3 mm.

[0048] Example 2:

[0049] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 28 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40 °C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; Mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120 °C and a pressure of 2.5 MPa to obtain a composite board. The thickness of the flame-retardant layer of the composite board is 3 mm.

[0050] Example 3:

[0051] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 22 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40 °C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; Mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120 °C and a pressure of 2.5 MPa to obtain a composite board. The thickness of the flame-retardant layer of the composite board is 3 mm.

[0052] Example 4:

[0053] By mass, premix 35 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40°C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49°C at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the board blank with the flame-retardant layer, and then hot-press it at 120°C at a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0054] Example 5:

[0055] By mass, premix 25 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40°C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49°C at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the board blank with the flame-retardant layer, and then hot-press it at 120°C at a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0056] Example 6:

[0057] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40°C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 1.1 μm kaolin, and 5 parts of polydimethylsiloxane at 49°C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120°C and a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0058] Example 7:

[0059] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40°C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 0.5 μm kaolin, and 5 parts of polydimethylsiloxane at 49°C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120°C and a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0060] Example 8:

[0061] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40 °C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; Mix the obtained premixed material, 32 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the board blank with a flame-retardant layer, and then hot-press it at 120 °C under a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0062] Example 9:

[0063] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The temperature of the premixing is 40 °C, the stirring speed of the premixing is 330 r / min, and the time of the premixing is 26 min to obtain a premixed material; Mix the obtained premixed material, 28 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the board blank with a flame-retardant layer, and then hot-press it at 120 °C under a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0064] Comparative Example 1:

[0065] By mass, premix 30 parts of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, 25 parts of biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The premixing temperature is 40 °C, the stirring speed of premixing is 330 r / min, and the premixing time is 26 min to obtain a premixed material; Mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120 °C under a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0066] Comparative Example 2:

[0067] By mass, premix 30 parts of semi-blocked isocyanate, 25 parts of polybenzimidazole-modified biphenyl-type polyimide, and 10 parts of polybutylene terephthalate. The premixing temperature is 40 °C, the stirring speed of premixing is 330 r / min, and the premixing time is 26 min to obtain a premixed material; Mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C and stir at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; Lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer and pre-press it at a pressure of 0.4 MPa for 6 s to form a blank board with a flame-retardant layer; Place a 5 mm glass fiber layer on one side of the blank board with a flame-retardant layer, and then hot-press it at 120 °C under a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0068] Comparative Example 3:

[0069] By mass, premix 30 parts of epoxy itaconic acid ester, 25 parts of polybenzimidazole modified biphenyl type polyimide, and 10 parts of polybutylene terephthalate. The temperature of premixing is 40 °C, the stirring speed of premixing is 330 r / min, and the time of premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 0.8 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer, pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the board blank with a flame-retardant layer, and then hot-press it at 120 °C at a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0070] Comparative Example 4:

[0071] By mass, premix 30 parts of semi-blocked isocyanate modified epoxy itaconic acid ester aqueous resin, 25 parts of polybenzimidazole modified biphenyl type polyimide, and 10 parts of polybutylene terephthalate. The temperature of premixing is 40 °C, the stirring speed of premixing is 330 r / min, and the time of premixing is 26 min to obtain a premixed material; mix the obtained premixed material, 30 parts of 10 μm kaolin, and 5 parts of polydimethylsiloxane at 49 °C at a speed of 200 r / min for 21 min, and then continue to stir at a speed of 200 r / min until room temperature to obtain a flame-retardant layer mixture; lay the obtained flame-retardant layer mixture on a 40 mm rock wool layer, pre-press it at a pressure of 0.4 MPa for 6 s to form a board blank with a flame-retardant layer; place a 5 mm glass fiber layer on one side of the board blank with a flame-retardant layer, and then hot-press it at 120 °C at a pressure of 2.5 MPa to obtain a composite board, and the thickness of the flame-retardant layer of the composite board is 3 mm.

[0072] Test the flame retardancy rating, sound insulation amount, and tensile strength of the composite boards obtained in Examples 1-9 and Comparative Examples 1-4, and the results are shown in Table 1.

[0073] Table 1:

[0074]

[0075]

[0076] As can be seen from the above table, due to the composite board of the present invention, a specific proportion of semi-blocked isocyanate-modified epoxy itaconic acid ester aqueous resin, a specific proportion of polybenzimidazole-modified biphenyl-type polyimide, and kaolin with a specific proportion and a specific average particle size are creatively used in the middle flame-retardant layer, so that the finally obtained composite board has high tensile strength, good sound absorption effect and excellent flame retardancy. Among them, the flame retardancy grades of the composite boards in the embodiments provided by the present invention all reach Class A, the sound insulation amount is above 55 dB, and the tensile strength is above 25 kPa.

[0077] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0078] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A flame-retardant composite board, characterized in that, It includes a glass fiber layer, a flame retardant layer and a rock wool layer; The flame retardant layer is arranged between the glass fiber layer and the rock wool layer; By mass, the flame retardant layer includes 25-35 parts of semi-blocked isocyanate modified epoxy itaconic acid ester aqueous resin, 22-28 parts of polybenzimidazole modified biphenyl type polyimide, 8-12 parts of polybutylene terephthalate, 28-32 parts of kaolin and 3-8 parts of polydimethylsiloxane.

2. The composite board according to claim 1, wherein The thickness of the glass fiber layer is 3-7 mm.

3. The composite board according to claim 1, characterized in that, The thickness of the rock wool layer is 30-50 mm.

4. The composite board according to claim 1, wherein The thickness of the flame retardant layer is 2-5 mm.

5. The composite board according to claim 1, characterized in that, The average particle size of the kaolin is 0.5-1.1 μm.

6. A method for preparing a composite board according to any one of claims 1 to 5, characterized in that, It includes the following steps: By mass, premix 25-35 parts of semi-blocked isocyanate modified epoxy itaconic acid ester aqueous resin, 22-28 parts of polybenzimidazole modified biphenyl type polyimide and 8-12 parts of polybutylene terephthalate to obtain a premix; Mix the premix, 28-32 parts of kaolin and 3-8 parts of polydimethylsiloxane to obtain a flame retardant layer mixture; Lay the flame retardant layer mixture on the rock wool layer and perform pre-pressing to form a slab with a flame retardant layer; Place the glass fiber layer on one side of the slab with the flame retardant layer, and then perform hot pressing to obtain the composite board.

7. The preparation method according to claim 6, characterized in that, The temperature of the premixing is 38-42 °C, the stirring speed of the premixing is 300-360 r / min, and the time of the premixing is 25-28 min.

8. The preparation method according to claim 6, characterized in that, The conditions for the mixing are: At 46-52 °C, stir at a speed of 180-220 r / min for 19-23 min, and then continue to stir at a speed of 180-220 r / min until room temperature.

9. The preparation method according to claim 6, characterized in that, The pressure of the pre-pressing is 0.3-0.5 MPa, and the time of the pre-pressing is 5-8 s.

10. The preparation method according to claim 6, characterized in that, The pressure of the hot pressing is 2.2-2.8 MPa, and the temperature of the hot pressing is 118-122 °C.

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