Process for preparing a fireproof composite board containing metal core material

Abstract

The application discloses a kind of preparation process of fireproof composite board with metal core material, belong to composite board technical field, the present application includes the following steps: metal substrate is obtained by coating modified polyurethane adhesive, paving organic-inorganic composite flame-retardant material, to obtain composite board material, composite board material is formed by hydraulic pressure, to obtain fireproof composite board with metal core material;The present application is to sodium dodecyl benzene sulfonate modified corn starch, improve the dispersibility of adhesive, and design the modified adhesive of multiple epoxy groups to improve the bonding strength of preparation adhesive, vinyltriethoxysilane is modified with methacrylic acid dodecafluoroheptyl ester, improve the fireproof performance of coupling agent in flame-retardant material, so that the prepared composite board material has the characteristics of adhesive viscosity uniform, large bonding strength, and the excellent fire resistance of composite board material.

Description

Technical Field

[0001] This invention relates to the field of composite panel technology, and specifically to a preparation process of a fireproof composite panel containing a metal core material. Background Technology

[0002] One of the major problems facing the construction industry is the energy problem. Building energy consumption accounts for a large proportion of the total energy consumption in society. Most buildings have extremely low energy utilization rates and are classified as high-energy-consuming buildings. Therefore, building energy conservation is one of the most effective ways to save energy and is conducive to alleviating the current situation of insufficient energy supply.

[0003] Petroleum-based adhesives commonly used in composite panels can cause pollution to human health and the environment. Bio-based adhesives are gradually gaining attention due to their safety and environmental friendliness. Starch has advantages in the development of bio-based adhesives because it is renewable, non-toxic, and biodegradable. However, the stress distribution caused by the aggregation of starch molecules and the uneven fusion of molecules inside the adhesive film lead to problems such as uneven viscosity distribution and low bonding strength in starch-based adhesives. In addition, how to improve the fire resistance of composite panels is also a technical problem that urgently needs to be solved.

[0004] Furthermore, patent application CN112477320A discloses a high-temperature resistant composite board, comprising a refractory layer, a reinforcing layer, and a metal plate layer. The refractory layer includes silicone rubber, methyl silicone oil, silicon carbide, aluminum oxide, silicon micropowder, phenyltributylone oxime silane, and a tin catalyst. It combines inorganic and organic refractory materials to create a composite board with advantages such as fire resistance and high-temperature resistance. However, the aforementioned high-temperature resistant composite board does not modify traditional adhesives to address the technical problems of uneven viscosity distribution and poor bonding strength of bio-based adhesives.

[0005] To address the aforementioned technical shortcomings, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a preparation process for a fire-resistant composite board containing a metal core, which solves the technical problems of uneven viscosity distribution, low bonding strength, and poor fire resistance of metal composite boards caused by the bio-based adhesives used in the prior art.

[0007] The objective of this invention can be achieved through the following technical solution: a preparation process for a fireproof composite board containing a metal core material, comprising the following steps:

[0008] S1. A modified polyurethane adhesive is coated on one side of a metal substrate to obtain a first adhesive layer; an organic-inorganic composite flame retardant material is laid on the first adhesive layer to obtain a fireproof layer; a metal core board is placed on the fireproof layer, and then a modified polyurethane adhesive is coated on the metal core board to obtain a second adhesive layer; another metal substrate is placed on the second adhesive layer to obtain a composite board.

[0009] S2. Add the composite board to the hydraulic forming mold and press it at room temperature. The compressive stress is 300-500MPa and the hydraulic time is 3-5s to obtain a fireproof composite board with a metal core.

[0010] Further, in step S1, the preparation method of the modified polyurethane adhesive includes the following steps:

[0011] A1. Mix corn starch and hydrochloric acid, and acid-hydrolyze at 50-60℃ for 100-120 min to obtain acid hydrolysate. Add NaOH solution dropwise to adjust the pH of the acid hydrolysate to neutral to obtain a mixed solution.

[0012] A2. Add an initiator to the mixture, add 0.1 mol / L hydrochloric acid dropwise to adjust the pH of the mixture to 4-5, add sodium dodecylbenzenesulfonate to the mixture, react at 70-80℃ for 30-60 min, and obtain grafted corn starch through post-processing.

[0013] In an acidic environment, the polyhydroxyl groups in corn starch and the sulfonic acid groups of sodium dodecylbenzenesulfonate undergo an esterification reaction to obtain grafted corn starch.

[0014] A3. Grafted corn starch, isophorone diisocyanate, dibutyltin dilaurate, modified crosslinking agent and DMF are mixed and heated to 70-75℃ for 60-100 min. Then, DMF is removed by vacuum distillation, triethylamine is added for neutralization, and deionized water is added for emulsification to obtain modified polyurethane adhesive.

[0015] A modified polyurethane adhesive was prepared by using grafted corn starch as a polyol, isophorone diisocyanate as a diisocyanate monomer, and a modified crosslinking agent as a chain extender.

[0016] Further, in step A1, the concentration of hydrochloric acid is 0.1 mol / L, and the ratio of corn starch to hydrochloric acid is 20-35 g: 50 mL; the concentration of NaOH solution is 1 mol / L; in step A2, the initiator is ammonium persulfate, and the amount of initiator is 0.15-0.3 g; the amount of sodium dodecylbenzenesulfonate is 10-20 g; the post-treatment process includes: adjusting the pH of the mixture to neutral with 10% wt sodium bicarbonate solution; precipitating the neutral mixture with ethanol to obtain a solid; washing the solid with distilled water, centrifuging and drying to obtain grafted corn starch.

[0017] Furthermore, in step A3, the preparation method of the modified crosslinking agent includes the following steps:

[0018] 17g of gallic acid, 100-200mL of epichlorohydrin and 0.05g of tetrabutylammonium iodide were mixed evenly to obtain a mixed solid-liquid mixture. The mixed solid-liquid mixture was heated to 100-110℃ and reacted for 5h to obtain the product. The product was distilled under reduced pressure and washed three times with deionized water to obtain the modified crosslinking agent.

[0019] Using tetrabutylammonium iodide as a catalyst, gallic acid, which contains one carboxyl group and three hydroxyl groups, was prepared by nucleophilic substitution reaction with epichlorohydrin to obtain a polyepoxylated modified crosslinking agent.

[0020] The reaction formula for preparing a modified crosslinking agent by reacting gallic acid and epichlorohydrin is as follows:

[0021]

[0022] Furthermore, the ratio of grafted corn starch, isophorone diisocyanate, dibutyltin dilaurate, modified crosslinking agent, DMF, triethylamine, and deionized water is 30g:20-30g:2-3g:10-20g:100g:10g:200mL; the neutralization reaction time is 30min; the emulsification speed is 1500-2000r / min; and the emulsification time is 100-120min.

[0023] Furthermore, in step S1, the preparation method of the organic-inorganic composite flame retardant material includes the following steps:

[0024] B1. Silicon carbide, boron carbide and titanium carbide are mixed and ball-milled to obtain a mixed carbide with a particle size of 10-20 μm; aluminum hydroxide and magnesium hydroxide are mixed and ball-milled to obtain a mixed metal hydroxide with a particle size of 20-30 μm; the mixed carbide and the mixed metal hydroxide are mixed evenly to obtain a composite refractory powder.

[0025] B2, dodecafluoroheptyl methacrylate, benzoyl peroxide and ethyl acetate are mixed, and then vinyltriethoxysilane is added dropwise. The mixture is reacted at 70-75℃ for 2-3 hours, and then the temperature is raised to 80℃ until all the ethyl acetate solvent has evaporated completely, to obtain the modified fluorosilicone coupling agent.

[0026] Modified fluorosilicone coupling agents were prepared by using ethyl acetate as solvent and benzoyl peroxide as initiator to undergo addition polymerization of dodecafluoroheptyl methacrylate and vinyltriethoxysilane.

[0027] The reaction formula for dodecafluoroheptyl methacrylate and vinyltriethoxysilane is as follows:

[0028]

[0029] B3. Mix the modified fluorosilicone coupling agent and the composite refractory material powder evenly to obtain an organic-inorganic composite flame retardant material.

[0030] Furthermore, the ratio of silicon carbide, boron carbide, and titanium carbide is 100g:100g:100g, the ratio of aluminum hydroxide to magnesium hydroxide is 100g:100g, and the ratio of mixed carbides to mixed metal hydroxides is 100g:300g.

[0031] Further, in step S1, both the metal substrate and the metal core are galvanized steel sheets, the thickness of the metal substrate is 0.3 mm, the thickness of the metal core is 0.1 mm, the thickness of the fireproof layer is 0.1-0.3 mm, the thickness of the first adhesive layer is 0.1-0.3 mm, and the thickness of the second adhesive layer is 0.1-0.3 mm.

[0032] The present invention has the following beneficial effects:

[0033] 1. The specific structure of the composite board designed in this invention, from bottom to top, is as follows: metal substrate - first adhesive layer - fireproof layer - metal core board - second adhesive layer - metal substrate; the first adhesive layer and the second adhesive layer in this invention are both coated with modified polyurethane adhesive; the modified polyurethane adhesive is obtained by reacting grafted corn starch, modified crosslinking agent, isophorone diisocyanate, etc.; the corn starch is first acidified with hydrochloric acid to reduce its molecular weight, thereby improving its reactivity and exposing more hydroxyl functional groups; in the grafted corn starch, sodium dodecylbenzenesulfonate and corn starch form an inclusion structure, thereby improving the dispersibility of corn starch and improving the problem of uneven viscosity distribution of starch-based adhesives; in this invention, gallic acid and epichlorohydrin undergo nucleophilic substitution to obtain a modified crosslinking agent; the polyepoxy modified crosslinking agent can react with the hydroxyl groups in corn starch and the isocyanate groups of isophorone diisocyanate, thereby improving the mechanical properties and adhesive strength of the prepared modified adhesive through multi-site crosslinking.

[0034] 2. The fireproof layer in the composite board of this invention is specifically an organic-inorganic composite flame-retardant material; silicon carbide belongs to the hexagonal crystal system and has the characteristics of high temperature resistance, wear resistance, and corrosion resistance; boron carbide has strong covalent bond bonds between B and C, and has the characteristics of acid immersion corrosion resistance and good chemical stability; titanium carbide is a transition metal carbide, which is a mixture of ionic bonds, covalent bonds, and metallic bonds in the same crystal structure, and has the advantages of high strength and high hardness; the above three carbides are mixed and ball-milled to obtain a mixed carbide; aluminum hydroxide and magnesium hydroxide improve their own flame-retardant effect by absorbing heat and isolating air; the mixed carbide and the mixed metal hydroxide are mixed evenly to obtain a composite refractory material powder, which is an inorganic flame-retardant material. Dodecafluoroheptyl methacrylate and vinyltriethoxysilane undergo an addition polymerization reaction to obtain a polyfluorinated modified fluorosilicone coupling agent. The siloxane groups contained in the modified fluorosilicone coupling agent can undergo a dehydration reaction with the -OH groups of aluminum hydroxide and magnesium hydroxide in the composite refractory powder, hydrolyzing to obtain -Si(OH)3. This allows the modified fluorosilicone coupling agent to be grafted onto the surface of the composite refractory material, introducing a large amount of fluorine into the composite refractory powder, thereby improving its flame retardant effect and forming an organic-inorganic composite flame retardant material.

[0035] 3. The modified polyurethane adhesive prepared in this invention is coated on the surface of a metal substrate and can be bonded and formed by natural curing at room temperature; however, by using a pressure curing process, air between the modified polyurethane adhesive and the metal substrate, and between the modified polyurethane adhesive and the organic-inorganic composite flame retardant material, can be eliminated, thereby improving the bonding density and strength between the layers. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] This embodiment provides a method for preparing an organic-inorganic composite flame-retardant material for fire-resistant composite panels containing a metal core, comprising the following steps:

[0039] B1. Mix 100g of silicon carbide, 100g of boron carbide and 100g of titanium carbide, and ball mill them to obtain a mixed carbide with a particle size of 10μm; mix 100g of aluminum hydroxide and 100g of magnesium hydroxide, and ball mill them to obtain a metal hydroxide with a particle size of 20μm; mix 100g of the mixed carbide and 300g of the metal hydroxide evenly to obtain a composite refractory powder.

[0040] B2. Select a 250mL three-necked flask and add 20mL of dodecafluoroheptyl methacrylate, 3g of benzoyl peroxide, and 100mL of ethyl acetate into the flask. The three-necked flask is equipped with a magnetic stir bar inside and a thermometer, reflux condenser, and separatory funnel on the outside. Transfer the three-necked flask to a water bath and add 20g of vinyltriethoxysilane dropwise to the flask through the separatory funnel. React at 70℃ for 2 hours at a constant temperature of 100r / min. Then raise the temperature to 80℃ until all the ethyl acetate solvent has evaporated completely to obtain an organic liquid modified fluorosilicone coupling agent.

[0041] B3. Add 20g of modified fluorosilicone coupling agent and 50g of composite refractory material powder to a beaker, mix evenly, and obtain organic-inorganic composite flame retardant material.

[0042] Example 2

[0043] This embodiment provides a method for preparing an organic-inorganic composite flame-retardant material for fire-resistant composite panels containing a metal core, comprising the following steps:

[0044] B1. Mix 100g of silicon carbide, 100g of boron carbide and 100g of titanium carbide, and ball mill them to obtain a mixed carbide with a particle size of 15μm; mix 100g of aluminum hydroxide and 100g of magnesium hydroxide, and ball mill them to obtain a metal hydroxide with a particle size of 25μm; mix 100g of the mixed carbide and 300g of the metal hydroxide evenly to obtain a composite refractory powder.

[0045] B2. Select a 250mL three-necked flask and add 30mL of dodecafluoroheptyl methacrylate, 3g of benzoyl peroxide, and 100mL of ethyl acetate into the flask. The three-necked flask is equipped with a stir bar inside and a thermometer, reflux condenser, and separatory funnel on the outside. Transfer the three-necked flask to a water bath and add 20g of vinyltriethoxysilane dropwise to the flask through the separatory funnel. React at 72℃ and 100r / min for 2.5h. Then raise the temperature to 80℃ until all the ethyl acetate solvent has evaporated completely to obtain an organic liquid modified fluorosilicone coupling agent.

[0046] B3. Mix 30g of modified fluorosilicone coupling agent and 50g of composite refractory powder evenly to obtain organic-inorganic composite flame retardant material.

[0047] Example 3

[0048] This embodiment provides a method for preparing an organic-inorganic composite flame-retardant material for fire-resistant composite panels containing a metal core, comprising the following steps:

[0049] B1. Mix 100g of silicon carbide, 100g of boron carbide and 100g of titanium carbide, and ball mill them to obtain a mixed carbide with a particle size of 20μm; mix 100g of aluminum hydroxide and 100g of magnesium hydroxide, and ball mill them to obtain a metal hydroxide with a particle size of 30μm; mix 100g of the mixed carbide and 300g of the metal hydroxide evenly to obtain a composite refractory powder.

[0050] B2. Select a 250mL three-necked flask and add 40mL of dodecafluoroheptyl methacrylate, 3g of benzoyl peroxide, and 100mL of ethyl acetate into the flask. The three-necked flask is equipped with a stir bar inside and a thermometer, reflux condenser, and separatory funnel on the outside. Transfer the three-necked flask to a water bath and add 20g of vinyltriethoxysilane dropwise to the flask through the separatory funnel. React at 75℃ for 3 hours at a constant temperature of 100r / min. Then raise the temperature to 80℃ until all the ethyl acetate solvent has evaporated completely to obtain an organic liquid modified fluorosilicone coupling agent.

[0051] B3. Add 40g of modified fluorosilicone coupling agent and 50g of composite refractory material powder to a beaker, mix evenly, and obtain organic-inorganic composite flame retardant material.

[0052] Example 4

[0053] This embodiment provides a method for preparing a modified polyurethane adhesive for fire-resistant composite panels containing a metal core, comprising the following steps:

[0054] A1. Mix 20g of corn starch and 50mL of 0.1mol / L hydrochloric acid and add them to a four-necked round-bottom flask. Transfer the four-necked round-bottom flask to a water bath and set the temperature of the water bath to 50℃. Acidify at this temperature for 100min to obtain the acid hydrolysate. Then adjust the pH of the acid hydrolysate to neutral with 1mol / L NaOH solution to obtain the mixed solution.

[0055] A2. Add 0.15g of ammonium persulfate as an initiator to the mixture, add 0.1mol / L hydrochloric acid dropwise to adjust the pH of the mixture to 4, add 10g of sodium dodecylbenzenesulfonate, adjust the temperature of the water bath to 70℃, continue the reaction for 30min, and then adjust the pH of the mixture to neutral with 10%wt sodium bicarbonate solution; precipitate the neutral mixture with ethanol to obtain a solid; wash the solid with distilled water, centrifuge and dry to obtain grafted corn starch.

[0056] A3. Add 17g of gallic acid and 100mL of epichlorohydrin to a 250mL four-necked flask, then add 0.05g of tetrabutylammonium iodide, mix and stir until homogeneous to obtain a mixed solid-liquid mixture; transfer the mixed solid-liquid mixture to a water bath, heat to 100℃ and react for 5h to obtain the product; distill the product under reduced pressure and wash it three times with deionized water to obtain the modified crosslinking agent.

[0057] A4. Connect a 250mL three-necked flask to a reflux condenser. Add 30g of grafted corn starch to the three-necked flask, then transfer the flask to a water bath and set the water bath temperature to 50℃. Add 20g of isophorone diisocyanate, 2g of dibutyltin dilaurate catalyst, 10g of modified crosslinking agent, and 100mL of DMF to the three-necked flask. Raise the temperature to 70℃ and continue the reaction for 60min. Then remove the DMF by vacuum distillation, add 10g of triethylamine for neutralization reaction for 30min, and finally add 200mL of deionized water to the three-necked flask. Emulsify at 1500r / min for 100min to obtain the modified polyurethane adhesive.

[0058] Example 5

[0059] This embodiment provides a method for preparing a modified polyurethane adhesive for fire-resistant composite panels containing a metal core, comprising the following steps:

[0060] A1. Mix 25g of corn starch and 50mL of 0.1mol / L hydrochloric acid and add them to a four-necked round-bottom flask. Transfer the four-necked round-bottom flask to a water bath and set the temperature of the water bath to 55℃. Acidify at this temperature for 110min to obtain the acid hydrolysate. Then adjust the pH of the acid hydrolysate to neutral with 1mol / L NaOH solution to obtain the mixed solution.

[0061] A2. Add 0.2g of ammonium persulfate as an initiator to the mixture, and add 0.1mol / L hydrochloric acid dropwise to adjust the pH of the mixture to 4.5. Then adjust the temperature of the water bath to 75℃ and continue the reaction for 40min. Then adjust the pH of the mixture to neutral with 10%wt sodium bicarbonate solution. The neutral mixture is precipitated with ethanol to obtain a solid. The solid is washed with distilled water, centrifuged and dried to obtain grafted corn starch.

[0062] A3. Add 17g of gallic acid and 150mL of epichlorohydrin to a 250mL four-necked flask, then add 0.05g of tetrabutylammonium iodide, mix and stir until homogeneous to obtain a mixed solid-liquid mixture; transfer the mixed solid-liquid mixture to a water bath, heat to 105℃ and react for 5h to obtain the product; distill the product under reduced pressure and wash with deionized water to obtain the modified crosslinking agent.

[0063] A4. Connect a 250mL three-necked flask to a reflux condenser. Add 30g of modified corn starch to the flask, then transfer the flask to a water bath and set the water bath temperature to 55℃. Add 25g of isophorone diisocyanate, 2.3g of dibutyltin dilaurate catalyst, 13g of modified crosslinking agent, and 100mL of DMF to the flask. Heat to 72℃ and continue the reaction for 80min. Then remove the DMF by vacuum distillation, add 10g of triethylamine for neutralization reaction for 30min, and finally add 200mL of deionized water to the flask. Emulsify at 1600r / min for 110min to obtain the modified polyurethane adhesive.

[0064] Example 6

[0065] This embodiment provides a method for preparing a modified polyurethane adhesive for fire-resistant composite panels containing a metal core, comprising the following steps:

[0066] A1. Mix 35g of corn starch and 50mL of 0.1mol / L hydrochloric acid and add them to a four-necked round-bottom flask. Transfer the four-necked round-bottom flask to a water bath and set the temperature of the water bath to 60℃. Acidify at this temperature for 120min to obtain the acid hydrolysate. Then adjust the pH of the acid hydrolysate to neutral with 1mol / L NaOH solution to obtain the mixed solution.

[0067] A2. Add 0.3g of ammonium persulfate as an initiator to the mixture, and add 0.1mol / L hydrochloric acid dropwise to adjust the pH of the mixture to 5. Then adjust the temperature of the water bath to 80℃ and continue the reaction for 60min. Then adjust the pH of the mixture to neutral with 10%wt sodium bicarbonate solution. The neutral mixture is precipitated with ethanol to obtain a solid. The solid is washed with distilled water, centrifuged and dried to obtain grafted corn starch.

[0068] A3. Add 17g of gallic acid and 200mL of epichlorohydrin to a 250mL four-necked flask, then add 0.05g of tetrabutylammonium iodide, mix and stir until homogeneous to obtain a mixed solid-liquid mixture; transfer the mixed solid-liquid mixture to a water bath, heat to 10℃ and react for 5h to obtain the product; distill the product under reduced pressure and wash with deionized water to obtain the modified crosslinking agent.

[0069] A4. Connect a 250mL three-necked flask to a reflux condenser. Add 30g of modified corn starch to the flask, then transfer the flask to a water bath and set the water bath temperature to 60℃. Add 30g of isophorone diisocyanate, 3g of dibutyltin dilaurate catalyst, 20g of modified crosslinking agent, and 100mL of DMF to the flask. Raise the temperature to 75℃ and continue the reaction for 100min. Then remove the DMF by vacuum distillation, add 10g of triethylamine for neutralization reaction for 30min, and finally add 200mL of deionized water to the flask. Emulsify at 2000r / min for 120min to obtain the modified polyurethane adhesive.

[0070] Example 7

[0071] This embodiment provides a preparation process for a fireproof composite board containing a metal core material, including the following steps:

[0072] S1. A galvanized steel sheet with a thickness of 0.3 mm is selected as the metal substrate. The modified polyurethane adhesive prepared in Example 4 is coated on one side of the metal substrate to obtain a first adhesive layer. The organic-inorganic composite flame retardant material prepared in Example 1 is laid flat on the first adhesive layer to obtain a fireproof layer with a thickness of 0.1 mm. A metal core board is placed on the fireproof layer, and then the modified polyurethane adhesive prepared in Example 4 is coated on the metal core board to obtain a second adhesive layer. Another metal substrate is placed on the second adhesive layer to obtain a composite board. The metal core board and the metal substrate are made of the same material, which is galvanized steel sheet, and the thickness of the metal core board is 0.1 mm. The thickness of the first adhesive layer is 0.1 mm and the thickness of the second adhesive layer is 0.1 mm.

[0073] S2. Add the composite board to the hydraulic forming mold and press it at room temperature. The compressive stress is 300 Pa and the hydraulic time is 5 s to obtain a fireproof composite board with a metal core.

[0074] Example 8

[0075] S1. A galvanized steel sheet with a thickness of 0.3 mm is selected as the metal substrate. The modified polyurethane adhesive prepared in Example 5 is coated on one side of the metal substrate to obtain a first adhesive layer. The organic-inorganic composite flame retardant material prepared in Example 2 is laid flat on the first adhesive layer to obtain a fireproof layer with a thickness of 0.2 mm. A metal core board is placed on the fireproof layer, and then the modified polyurethane adhesive prepared in Example 5 is coated on the metal core board to obtain a second adhesive layer. Another metal substrate is placed on the second adhesive layer to obtain a composite board. The metal core board and the metal substrate are made of the same material, which is galvanized steel sheet, and the thickness of the metal core board is 0.1 mm. The thickness of the first adhesive layer is 0.2 mm and the thickness of the second adhesive layer is 0.2 mm.

[0076] S2. Add the composite board to the hydraulic forming mold and press it at room temperature. The compressive stress is 400 Pa and the hydraulic time is 4 s to obtain a fireproof composite board with a metal core.

[0077] Example 9

[0078] This embodiment provides a preparation process for a fireproof composite board containing a metal core material, including the following steps:

[0079] S1. A galvanized steel sheet with a thickness of 0.3 mm is selected as the metal substrate. The modified polyurethane adhesive prepared in Example 6 is coated on one side of the metal substrate to obtain a first adhesive layer. The organic-inorganic composite flame retardant material prepared in Example 3 is laid flat on the first adhesive layer to obtain a fireproof layer with a thickness of 0.3 mm. A metal core board is placed on the fireproof layer, and then the modified polyurethane adhesive prepared in Example 6 is coated on the metal core board to obtain a second adhesive layer. Another metal substrate is placed on the second adhesive layer to obtain a composite board. The metal core board and the metal substrate are made of the same material, which is galvanized steel sheet, and the thickness of the metal core board is 0.1 mm. The thickness of the first adhesive layer is 0.3 mm and the thickness of the second adhesive layer is 0.3 mm.

[0080] S2. Add the composite board to the hydraulic forming mold and press it at room temperature. The compressive stress is 500 Pa and the hydraulic time is 3 s to obtain a fireproof composite board with a metal core.

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 6 is that no crosslinking agent was added when preparing the modified polyurethane adhesive.

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 6 is that the corn starch was not modified with sodium dodecylbenzenesulfonate when preparing the modified polyurethane adhesive.

[0085] Comparative Example 3

[0086] The difference between this comparative example and Example 9 is that, in the preparation of the composite board, the first adhesive layer did not have an organic-inorganic composite flame-retardant material laid flat, and no fireproof layer was provided.

[0087] Performance testing:

[0088] 1. In accordance with the GB / T2791-1995 standard "Adhesives T Peel Strength Test Method: Flexible Material to Flexible Material", the bond strength of the modified polyurethane adhesives prepared in Examples 4-6 was tested; test conditions: tensile rate of 100 mm / min and spacing of 100 mm.

[0089] 2. According to GB / T12008.7-2010 "Plastic Polyether Polyols: Determination of Viscosity", the modified polyurethane adhesives prepared in Examples 4-6 were weighed and placed in the sample cell of a rotational viscometer. Rotor No. 1 was selected, and the viscosity of the modified polyurethane adhesives prepared in Examples 4-6 was measured at room temperature at a rotation speed of 60 r / min.

[0090] The test results are shown in Table 1:

[0091] Table 1 - Performance Test Data of Samples

[0092]

[0093] Data Analysis:

[0094] The modified polyurethane adhesives prepared in Examples 4-6 of this invention all have excellent mechanical properties and bonding strength. Specifically, the modified polyurethane adhesives have high peel strength and viscosity values. However, in Comparative Example 1, no crosslinking agent was added when preparing the modified polyurethane adhesive, which reduced the active sites of the reaction between the modified polyurethane adhesive and isophorone diisocyanate and lowered its viscosity.

[0095] In Comparative Example 2, the corn starch was not modified with sodium dodecylbenzene sulfonate, which failed to improve the dispersibility of the corn starch, resulting in uneven viscosity distribution of the prepared modified polyurethane adhesive, which in turn led to a decrease in the peel strength of the tested modified polyurethane adhesive.

[0096] 3. Based on GB / T5464-2010 "Test Methods for Non-combustibility of Building Materials", determine the combustion performance of the fireproof composite boards containing metal core materials prepared in Examples 7-9 and calculate the continuous combustion time.

[0097] Table 2 - Performance Test Data of Samples

[0098]

[0099] Data Analysis:

[0100] The fire-resistant composite panels with metal cores prepared in Examples 7-9 of this invention all have excellent fire resistance, which is manifested in that the fire-resistant composite panels with metal cores prepared in Examples 7-9 have a long continuous burning time and excellent fire resistance.

[0101] However, in Comparative Example 3, the fireproof composite board containing metal core material was not provided with a fireproof layer, which reduced its fireproof performance, as evidenced by a decrease in the continuous burning time.

[0102] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0103] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0104] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A process for producing a fireproof composite board material containing a metal core material, characterized by, The method comprises the following steps: S1, coating a modified polyurethane adhesive on one side of a metal substrate to obtain a first adhesive layer; laying an organic-inorganic composite flame-retardant material on the first adhesive layer to obtain a fireproof layer; arranging a metal core plate on the fireproof layer, and then coating a modified polyurethane adhesive on the metal core plate to obtain a second adhesive layer; placing another metal substrate on the second adhesive layer to obtain a composite board; S2, putting the composite board into a hydraulic forming mold, and performing compression molding at room temperature, wherein the compression stress is 300-500 MPa, and the hydraulic time is 3-5 s, to obtain a fireproof composite board containing a metal core material; In step S1, the preparation method of the modified polyurethane adhesive comprises the following steps: A1, mixing corn starch and hydrochloric acid, and acidizing at 50-60 DEG C for 100-120 min to obtain an acidized solution; adding NaOH solution to adjust the pH value of the acidized solution to neutral to obtain a mixed solution; A2, adding an initiator to the mixed solution, adjusting the pH value of the mixed solution to 4-5 by dropwise adding 0.1 mol / L hydrochloric acid, and then adding sodium dodecyl benzene sulfonate to the mixed solution, and reacting at 70-80 DEG C for 30-60 min to obtain grafted corn starch through a post-treatment process; A3, mixing the grafted corn starch, isophorone diisocyanate, dibutyltin dilaurate, a modified crosslinking agent and DMF, heating to 70-75 DEG C for 60-100 min, removing DMF through post-reduced pressure distillation, adding triethylamine for neutralization, and adding deionized water for emulsification to obtain the modified polyurethane adhesive; The preparation method of the modified crosslinking agent comprises the following steps: uniformly mixing 17 g of gallic acid, 100-200 mL of epichlorohydrin and 0.05 g of tetrabutylammonium iodide to obtain a mixed solid-liquid; heating the mixed solid-liquid to 100-110 DEG C for 5 h to obtain a product; and removing the product through reduced pressure distillation, and washing with deionized water for three times to obtain the modified crosslinking agent.

2. The process for preparing a fireproof composite board material containing a metal core material according to claim 1, characterized by, In step A1, the concentration of hydrochloric acid is 0.1 mol / L, and the amount ratio of corn starch to hydrochloric acid is 20-35 g:50 mL; the concentration of NaOH solution is 1 mol / L; in step A2, the initiator is ammonium persulfate, and the amount of the initiator is 0.15-0.3 g; The amount of sodium dodecyl benzene sulfonate is 10-20 g; The post-treatment process comprises: adjusting the pH value of the mixed solution to neutral by using 10%wt sodium bicarbonate solution; precipitating the neutral mixed solution by using ethanol to obtain a solid; and washing the solid with distilled water, centrifuging and drying to obtain the grafted corn starch.

3. The process for preparing a fireproof composite board material containing a metal core material according to claim 1, characterized by, The amount ratio of the grafted corn starch, isophorone diisocyanate, dibutyltin dilaurate, modified crosslinking agent, DMF, triethylamine and deionized water is 30 g:20-30 g:2-3 g:10-20 g:100 g:10 g:200 mL; the neutralization reaction time is 30 min; the emulsification rotation speed is 1500-2000 r / min, and the emulsification time is 100-120 min.

4. The process for preparing a fireproof composite board containing a metal core material according to claim 1, characterized in that, In step S1, the preparation method of the organic-inorganic composite flame-retardant material comprises the following steps: B1, silicon carbide, boron carbide and titanium carbide are mixed and ball milled to obtain mixed carbide with particle size of 10-20 μm; aluminum hydroxide and magnesium hydroxide are mixed and ball milled to obtain mixed metal hydroxide with particle size of 20-30 μm; the mixed carbide and the mixed metal hydroxide are mixed uniformly to obtain composite refractory material powder; B2, dodecafluoroheptyl methacrylate, benzoyl peroxide and ethyl acetate are mixed, and then vinyltriethoxysilane is added dropwise, and the reaction is carried out at 70-75℃ for 2-3h, and then the temperature is increased to 80℃ until all the ethyl acetate solvent is completely volatilized to obtain modified fluorosilicon coupling agent; B3, the modified fluorosilicon coupling agent and the composite refractory material powder are mixed uniformly to obtain organic-inorganic composite flame-retardant material.

5. The process for producing a fireproof composite panel material containing a metal core material according to claim 4, characterized by, The amount ratio of silicon carbide, boron carbide and titanium carbide is 100g:100g:100g, the amount ratio of aluminum hydroxide and magnesium hydroxide is 100g:100g, and the amount ratio of mixed carbide and mixed metal hydroxide is 100g:300g.

6. The process for preparing a fireproof composite board material containing a metal core material according to claim 4, characterized by, In step B2, the amount ratio of dodecafluoroheptyl methacrylate, benzoyl peroxide, ethyl acetate and vinyltriethoxysilane is 20-40mL:3g:100mL:20g; in step B3, the amount ratio of modified fluorosilicon coupling agent and composite refractory material powder is 20-40g:50g.

7. The process for preparing a fireproof composite board material containing a metal core material according to claim 1, characterized by, In step S1, the metal substrate and the metal core material are both galvanized steel plates, the thickness of the metal substrate is 0.3mm, the thickness of the metal core plate is 0.1mm, the thickness of the fireproof layer is 0.1-0.3mm, the thickness of the first adhesive layer is 0.1-0.3mm, and the thickness of the second adhesive layer is 0.1-0.3mm.

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