A layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel and a preparation method thereof

Abstract

The application relates to the technical field of sandwich panels, in particular to a layered polyurethane rock wool heat-preservation fireproof integrated sandwich panel and a preparation method thereof. The layered polyurethane rock wool heat-preservation fireproof integrated sandwich panel is characterized by comprising a fireproof water-repellent layer and a heat-preservation layer, and the preparation method comprises the following steps: step one, submerging a rock wool board in water-repellent sol and drying to obtain a rock wool core material; step two, taking a metal plate, coating an adhesive on one side of the metal plate, and bonding the rock wool core material to the metal plate to obtain a to-be-foamed board; step three, fixing another metal plate above one side of the rock wool core material of the to-be-foamed board to reserve a foaming space, and then sealing the edges in the length direction to obtain a sandwich panel semi-finished product; step four, preparing a polyurethane pre-foaming solution; step five, spraying the polyurethane pre-foaming solution from the edges in the width direction of the sandwich panel semi-finished product to the foaming space, and foaming and curing to obtain polyurethane foam; and step six, trimming to obtain the layered polyurethane rock wool heat-preservation fireproof integrated sandwich panel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sandwich panels, in particular to a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel and a preparation method thereof. BACKGROUND

[0002] For large refrigeration warehouses and high-thermal-insulation requirement workshop construction, both thermal insulation and fireproof requirements need to be considered, but a single product cannot meet the requirements, and both polyurethane sandwich panels and rock wool sandwich panels need to be used, which undoubtedly increases the construction difficulty and cost, and also makes it difficult to meet the fireproof requirements.

[0003] Therefore, it is necessary to prepare a sandwich panel that combines thermal insulation and fireproof performance, and the present application provides a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel and a preparation method thereof. SUMMARY

[0004] The present application aims to provide a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel and a preparation method thereof to solve the problems in the background art.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] A layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel, comprising a fireproof and water-repellent layer and a thermal insulation layer, wherein the fireproof and water-repellent layer is a rock wool core material, the thermal insulation layer is a polyurethane foam, and the thickness ratio of the fireproof and water-repellent layer to the thermal insulation layer is 1:(1-3).

[0007] Further, the preparation method of the layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel comprises the following steps:

[0008] Step 1: immerse the rock wool board in a water-repellent sol, and after 5-10 min of pressure maintaining under a pressure of 100-150 MPa, take it out and dry it at a temperature of 70-100℃ for 2-24 h to obtain a rock wool core material;

[0009] Step 2: take a metal plate, coat an adhesive on one side of the metal plate, cover the rock wool core material on the side, and press it under a pressure of 1-3 MPa for 30-60 min to obtain a to-be-foamed plate;

[0010] Step 3: fix another metal plate above one side of the rock wool core material of the to-be-foamed plate, leaving a foaming space between the rock wool core material and the metal plate, and then seal the edges in the length direction to obtain a sandwich panel semi-finished product;

[0011] Step four: (1) mixing polyether polyol A, polyether polyol B, modified polyether polyol C, modified silica, flame retardant, catalyst, foaming agent, foam stabilizer according to the proportion of the formula to obtain mixed solution A; (2) mixing mixed solution A and isocyanate according to the proportion of the formula to obtain polyurethane pre-foaming solution;

[0012] Step five: spraying polyurethane pre-foaming solution from the two width direction sides of the sandwich panel semi-finished product to the foaming space, foaming and curing at 50-70℃ for 2-24h to obtain polyurethane foam; trimming to obtain layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel.

[0013] Further, the preparation method of the hydrophobic sol is: (1) adding 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator into 50V / V% ethanol solution, ultrasonic dispersion for 5-15min, then using 365nm ultraviolet light irradiation for 15-60min to end the reaction, and then rotary evaporation to obtain modified silane coupling agent; (2) under stirring, adding tetraethyl orthosilicate into 50V / V% ethanol solution, after completion of the addition, continuing to stir for 1-2h, then slowly adding hydrochloric acid into the reaction system to adjust the pH value to 1.0-2.2, and continuing to stir for 6-12h to obtain reaction liquid B; (3) under stirring, heating reaction liquid B to 65-85℃, and adding modified silane coupling agent into it, after stirring for 4-8h, ending the reaction, and then naturally cooling the reaction system to room temperature to obtain the hydrophobic sol.

[0014] Further, the mass ratio of 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator is 1:1:(0.01-0.02).

[0015] Further, the volume ratio of tetraethyl orthosilicate and ethanol solution is 2:1.

[0016] Further, the adding amount of modified silane coupling agent is 5-10% of the adding volume of tetraethyl orthosilicate.

[0017] Further, the volume of the foaming space is 1-3 times of the volume of the fireproof hydrophobic layer in the sandwich panel.

[0018] Further, the polyurethane pre-foaming solution comprises the following components, and the weight fraction is: polyether polyol A 10-20 parts, polyether polyol B 5-15 parts, modified polyether polyol C 5-10 parts, isocyanate 45-60 parts, modified silica 10-22.5 parts, flame retardant 10-20 parts, catalyst 0.5-2 parts, foaming agent 10-30 parts, and foam stabilizer 1.5-3 parts; wherein the adding amount of modified silica is half of the total adding amount of polyether polyol A, polyether polyol B and modified polyether polyol C.

[0019] Further, the polyether polyol A is of model HF-4110Y, with a hydroxyl value of 445-465 mgKOH / g and a viscosity of 4000-5800 mPa.s at 25℃; the polyether polyol B is of model H4110S, with a hydroxyl value of 400-420 mgKOH / g and a viscosity of 1900-3500 mPa.s at 25℃.

[0020] Further, the preparation method of the modified polyether polyol C is as follows: tolylene diisocyanate and allyl hydroxyethyl ether are added into a reaction container, and stirred to be heated to 60-80℃, reacted for 30-60 min, then heated to 75-95℃, reacted for 2-4 h; cooled to 40-55℃, and then polyoxyethyl glyceryl ether is added into the reaction container, stirred to be heated to 65-85℃, reacted for 30-60 min, then heated to 75-95℃, reacted for 2-4 h; cooled to 40-55℃, and then azobisisobutyronitrile, styrene and acrylamide are added into the reaction container, stirred to be heated to 70-85℃, reacted for 3-6 h, and then the reaction is ended, and the mixture is naturally cooled to room temperature to obtain the modified polyether polyol C.

[0021] Further, the mass ratio of tolylene diisocyanate, allyl hydroxyethyl ether, polyoxyethyl glyceryl ether, styrene and acrylamide is 1:(0.5-1):(1-2):1:1.

[0022] Further, the addition amount of azobisisobutyronitrile is 5% of the mass sum of styrene and acrylamide.

[0023] Further, the preparation method of the modified silica is as follows: nano-silica is added into anhydrous ethanol, and ultrasonically dispersed for 5-15 min, then a modified silane coupling agent is added, stirred at 40-70℃ for 6-12 h, and then centrifuged, filtered, washed and dried to obtain the modified silica; the preparation method of the modified silane coupling agent is the same as that of the hydrophobic sol described above.

[0024] Further, the addition amount of the modified silane coupling agent is 5-10% of the addition amount of nano-silica.

[0025] Further, the particle size of the nano-silica is 10-20 μm.

[0026] Further, the isocyanate includes but is not limited to one or more of a combination of polyphenyl polymethylene polyisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate and tolylene diisocyanate.

[0027] Further, the isocyanate is polyphenyl polymethylene isocyanate.

[0028] Further, the flame retardant is obtained by mixing the three of antimony trioxide, urea and dimethyl methylphosphonate in a mass ratio of (3-5):3:1.

[0029] Further, the catalyst is an amine catalyst.

[0030] Further, the foaming agent includes but is not limited to any one of cyclopentane and monofluorodichloroethane.

[0031] Further, the foam stabilizer is silicon oil AK8805.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] (1) Rock wool is a material with excellent heat preservation, fireproofing and water absorption performance. When it is processed into a sandwich panel, the water absorption performance becomes a burden. Too high water absorption performance will cause more water to penetrate into the sandwich panel, resulting in a decrease in the heat preservation performance of the sandwich panel. Over time, the water in the rock wool will also accelerate the corrosion of the metal plate outside the sandwich panel and increase the weight bearing capacity of the sandwich panel, leading to damage to the sandwich panel. Therefore, in the scheme, sol-gel technology is used to make tetraethyl orthosilicate hydrolyze and polymerize under the catalysis of hydrochloric acid to generate silica sol (the sol not only has low thermal conductivity but also has super hydrophobicity). By loading it onto the rock wool and coating the rock wool, the rock wool is given good hydrophobicity without significantly affecting its heat preservation performance. In order to further enhance the hydrophobicity and heat resistance of the rock wool, 3-mercaptopropyltrimethoxysilane and allyl pentafluorobenzene are further subjected to a click reaction to generate a silane coupling agent with a halogen group. Finally, the silane coupling agent is hydrolyzed and condensed with the silica sol to prepare a hydrophobic sol. Under the action of the silica sol and the halogen group, the hydrophobic sol can greatly improve the hydrophobicity of the rock wool, effectively inhibit the infiltration of water into the rock wool, and further enhance the heat resistance of the rock wool. When used as a core material of a sandwich panel, it can greatly guarantee the quality and performance of the sandwich panel.

[0034] (2) Since the viscosity of polyether polyol is closely related to the formation of bubbles, too high viscosity will make it difficult to form bubbles, and too low viscosity will cause the bubbles to break easily. After curing, the structure of the polyurethane foam is not uniform, which will affect the heat preservation of the sandwich panel. Therefore, two kinds of polyether polyols are combined to obtain a stable and uniform polyurethane foam structure.

[0035] (3) In order to further enhance the performance of polyurethane foam, the hydroxyl groups of toluene diisocyanate are reacted with allyl hydroxyethyl ether and polyoxyethyl glycerol ether respectively to obtain polyether polyols with unsaturated double bonds, which are then grafted with styrene and acrylamide to obtain modified polyether polyols C; styrene contains a benzene ring and has a certain rigidity, which can improve the strength of the foam after subsequent polyurethane foaming; meanwhile, amide groups are also introduced, which can easily form hydrogen bonds between molecules to make the foam more closely arranged, which helps to improve the foaming and stabilizing performance; after comprehensive action, a uniform and dense polyurethane foam with certain strength is obtained;

[0036] (4) The nano-silica with a particle size of 10-20 μm is selected, which is a small substance added to the polyurethane pre-foaming liquid and can act as a nucleating agent to promote foaming due to its large surface area; however, nano-silica with too small or too large particle size should not be selected, as too small particle size will cause the nucleation effect to overflow in the initial foaming stage, the filler cannot be effectively utilized, and stable bubble structure cannot be formed; too large particle size will cause the initial formed foam to be unable to resist the weight due to gravity, making foaming difficult. Further modification of the nano-silica with a modified silane coupling agent can enhance the hydrophobicity of the silica due to the presence of halogen groups, and the hydrophobic particles have a positive effect on polyurethane foaming; finally, by controlling the amount of modified nano-silica (too much or too little will also inhibit foaming), the polyurethane foam can be stabilized, and the foam can also be given certain flame retardancy;

[0037] (5) The flame retardant is formulated to improve the flame retardancy of the polyurethane foam by the synergistic modification of nano-silica with antimony trioxide, urea, and methyl phosphoric acid dimethyl ester. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application and explain the present application together with the embodiments, but do not constitute a limitation on the present application. In the drawings:

[0039] Figure 1 is a specific schematic diagram of a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] In this embodiment, it should be noted that there is no special restriction on the purchase manufacturer of all raw materials involved in the present application, which exemplarily includes: 3-mercaptopropyl trimethoxysilane, urea with a purity of 99%, purchased from Hebei Zhen Tian Food Additives Co., Ltd.; allyl pentafluorobenzene, tetraethyl silicate, toluene diisocyanate, allyl hydroxyethyl ether, styrene, monofluorodichloroethane, N,N-dimethylcyclohexylamine with a purity of 99%, purchased from Shanghai Jinjile Industrial Co., Ltd.; polyether polyol HF-4110Y and H4110S, purchased from Ruby Group Co., Ltd.; polyoxyethyl glycerol ether and polyphenyl polymethylene isocyanate with a purity of 99%, purchased from Hubei Yongkong Technology Co., Ltd.; acrylamide with a purity of 99.9%, purchased from Jiangsu Chuangteng New Material Technology Co., Ltd.; nano-silicon dioxide with a purity of 99% and a particle size of 10-20 μm, purchased from Shanghai Domann Pharmaceutical Chemical Co., Ltd.; antimony trioxide with a purity of 99%, purchased from Hubei Qifei Pharmaceutical Chemical Co., Ltd.; dimethyl methylphosphonate with a purity of 99%, purchased from Shenzhen Nangang Hengshun Trade Co., Ltd.; silicone oil AK8805, purchased from Jinan Tangyi Chemical Co., Ltd.; and the metal plate is 1080 type aluminum plate, purchased from Guangzhou Kaimai Metal Building Material Co., Ltd.

[0042] Example 1: A preparation method of a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel

[0043] Step one: 1. Preparation of hydrophobic sol: (1) 3-mercaptopropyl trimethoxysilane, allyl pentafluorobenzene and photoinitiator were added to 50V / V% ethanol solution at a mass ratio of 1:1:0.01, ultrasonic dispersion for 10 min, then 365 nm ultraviolet light was used for irradiation reaction for 30 min, and the reaction was stopped. After rotary evaporation, a modified silane coupling agent was obtained; (2) 20L of tetraethyl silicate and 10L of 50V / V% ethanol solution were mixed and stirred for 2h, then hydrochloric acid was slowly added to the mixed solution to adjust the pH value to 1.2, and the stirring reaction was continued for 8h to obtain reaction liquid B; (3) under stirring, reaction liquid B was heated to 70℃, and 1.4L of modified silane coupling agent was added thereto, and after stirring reaction for 6h, the reaction was stopped. After the reaction system was naturally cooled to room temperature, a hydrophobic sol was obtained;

[0044] 2. The rock wool board was immersed in the hydrophobic sol, taken out after pressure maintaining for 5 min under 120 MPa, and placed at 80℃ for heat preservation and drying for 12h to obtain a 30mm thick rock wool core material;

[0045] Step two: setting a fireproof and hydrophobic layer: a 2mm thick 1080 type aluminum plate was cut into the size of the rock wool core material, and an epoxy resin adhesive was coated on one side of the aluminum plate to make the rock wool core material contact and bond with the aluminum plate, and a pressure of 2MPa was applied for 60 min to obtain a to-be-foamed plate;

[0046] Step three: fix another 1080 type aluminum plate above the rock wool core material of the to-be-foamed plate, and keep a 60mm-thick foaming space between the rock wool core material and the aluminum plate, and seal the edges of the two length directions with 1080 type aluminum material to obtain a sandwich panel semi-finished product;

[0047] Step four: 1. Preparation of modified polyether polyol C: 5 parts of toluene diisocyanate, 4 parts of allyl hydroxyethyl ether were added to the reaction container, and stirred to warm up to 70℃, reacted for 45min, then warmed up to 85℃, reacted for 3h; cooled to 50℃, 10 parts of polyoxyethyl glycerol ether was added to the reaction container, stirred to warm up to 70℃, reacted for 45min, then warmed up to 85℃, reacted for 3h; cooled to 50℃, 0.5 parts of azobisisobutyronitrile, 5 parts of styrene, 5 parts of acrylamide were added to the reaction container, stirred to warm up to 80℃, reacted for 5h, and the reaction was ended, and it was naturally cooled to room temperature to obtain the modified polyether polyol C;

[0048] 2. Preparation of modified silica: 25 parts of nano-silica were added to anhydrous ethanol, ultrasonically dispersed for 10min, then 2 parts of modified silane coupling agent was added, stirred at 60℃ for 8h, centrifuged, filtered, washed, and dried to obtain the modified silica;

[0049] 3. The flame retardant was obtained by mixing antimony trioxide, urea, and methyl phosphonate dimethyl in a mass ratio of 4:3:1;

[0050] 4. (1) 15 parts of polyether polyol A, 10 parts of polyether polyol B, 10 parts of modified polyether polyol C, 17.5 parts of modified silica, 15 parts of flame retardant, 1 part of N,N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane, and 2 parts of silicon oil AK8805 were added to the container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added to the mixed solution A to obtain a polyurethane pre-foaming solution;

[0051] Step five: set the thermal insulation layer: spray the polyurethane pre-foaming solution from the two width direction sides of the sandwich panel semi-finished product to the foaming space, after spraying, foam and mature at 55℃ for 18h to obtain a polyurethane foam; trim to obtain a 94mm-thick layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel.

[0052] Example 2: compared with example 1, example 2 is adjusted as follows:

[0053] Step one: 1. Preparation of hydrophobic sol: (1) 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene, photoinitiator were added into 50V / V% ethanol solution with mass ratio of 1:1:0.01, after ultrasonic dispersion for 10 min, 365 nm ultraviolet light was used to irradiate the reaction for 15 min, the reaction was ended, and modified silane coupling agent was obtained by rotary evaporation; (2) 20L of tetraethyl silicate and 10L of 50V / V% ethanol solution were mixed and stirred for 2h, then hydrochloric acid was slowly added to the mixed solution to adjust the pH value to 1.2, and the stirring reaction was continued for 8h to obtain reaction liquid B; (3) under stirring, reaction liquid B was heated to 70℃, and 1L of modified silane coupling agent was added, and after stirring for 4h, the reaction was ended, and the reaction system was naturally cooled to room temperature to obtain the hydrophobic sol; other processes remain unchanged.

[0054] Example 3: Compared with example 1, example 3 is adjusted as follows:

[0055] Step four: 1. Preparation of modified polyether polyol C: 5 parts of toluene diisocyanate and 2.5 parts of allyl hydroxyethyl ether were added to a reaction vessel, which was stirred and heated to 70℃, reacted for 45 min, then heated to 85℃, reacted for 3h; cooled to 50℃, 5 parts of polyoxyethyl glycerol ether were added to the reaction vessel, stirred and heated to 70℃, reacted for 45 min, then heated to 85℃, reacted for 3h; cooled to 50℃, 0.5 parts of azobisisobutyronitrile, 5 parts of styrene and 5 parts of acrylamide were added to the reaction vessel, stirred and heated to 80℃, reacted for 5h, the reaction was ended, and the reaction was naturally cooled to room temperature to obtain the modified polyether polyol C; other processes remain unchanged.

[0056] Example 4: Compared with example 1, example 4 is adjusted as follows:

[0057] Step four: 4. (1) 20 parts of polyether polyol A, 5 parts of polyether polyol B, 10 parts of modified polyether polyol C, 17.5 parts of modified silica, 15 parts of flame retardant, 1 part of N,N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane and 2 parts of silicon oil AK8805 were added to a container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added to the mixed solution A to obtain a polyurethane pre-foaming liquid; other processes remain unchanged.

[0058] Example 5: Compared with example 1, example 5 is adjusted as follows:

[0059] Step four: (1) 15 parts of polyether polyol A, 10 parts of polyether polyol B, 5 parts of modified polyether polyol C, 15 parts of modified silica, 15 parts of flame retardant, 1 part of N, N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane, 2 parts of silicone oil AK8805 were added into the container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added into the mixed solution A to obtain a polyurethane pre-foaming solution; other processes remained unchanged.

[0060] Comparative Example 1: Comparative Example 1 was adjusted based on Example 1, specifically, the rock wool was not subjected to hydrophobic treatment, and the specific adjustment was as follows:

[0061] Step one: the rock wool was processed into a 30mm-thick rock wool core material; other processes remained unchanged.

[0062] Comparative Example 2: Comparative Example 2 was adjusted based on Example 1, specifically, the modified polyether polyol C was not added, and the specific adjustment was as follows:

[0063] Step four: (1) 15 parts of polyether polyol A, 10 parts of polyether polyol B, 5 parts of modified polyether polyol C, 15 parts of flame retardant, 1 part of N, N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane, 2 parts of silicone oil AK8805 were added into the container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added into the mixed solution A to obtain a polyurethane pre-foaming solution; other processes remained unchanged.

[0064] Comparative Example 3: Comparative Example 3 was adjusted based on Example 1, specifically, the modified silica was not added, and the specific adjustment was as follows:

[0065] Step four: (1) 15 parts of polyether polyol A, 10 parts of polyether polyol B, 5 parts of modified polyether polyol C, 15 parts of flame retardant, 1 part of N, N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane, 2 parts of silicone oil AK8805 were added into the container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added into the mixed solution A to obtain a polyurethane pre-foaming solution; other processes remained unchanged.

[0066] Comparative Example 4: Comparative Example 4 was adjusted based on Example 1, specifically, the flame retardant was not added, and the specific adjustment was as follows:

[0067] Step four: (1) 15 parts of polyether polyol A, 10 parts of polyether polyol B, 10 parts of modified polyether polyol C, 17.5 parts of modified silica, 1 part of N,N-dimethylcyclohexylamine, 20 parts of monofluorodichloroethane, 2 parts of silicone oil AK8805 were added into a container and mixed uniformly to obtain a mixed solution A; (2) 50 parts of polyphenyl polymethylene isocyanate were added into the mixed solution A to obtain a polyurethane pre-foaming solution; and other processes remained unchanged.

[0068] Performance test: the layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panels prepared in Examples 1-5 and Comparative Examples 1-4 were tested for performance, and the specific performance test results are shown as follows:

[0069] (1) Thermal conductivity: the thermal conductivity of each sandwich panel was tested according to the test method in GB / T 3399-1982;

[0070] (2) Flame retardant property: the limiting oxygen index of each sandwich panel was determined according to the test method in GB / T 2046.2-2009;

[0071] (3) Water absorption property: the water absorption property of each sandwich panel was tested according to the method in GB / T 25975-2018;

[0072] (4) Deformation rate: the deformation rates of each sandwich panel under low temperature (-80℃, 72h) and high temperature (80℃, 72h) were tested according to the standard in GB / T 8811-2008;

[0073] The specific data are shown in Table 1 below:

[0074] Table 1

[0075]

[0076] Result analysis: from the above data, it can be seen that, by using different types of polyether polyols (polyether polyol A, polyether polyol B, modified polyether polyol C), and introducing and modifying silica, the sandwich panel has a lower thermal conductivity, i.e. the thermal insulation performance is enhanced; by treating the hydrophobic sol of rock wool, the water absorption property of the sandwich panel is obviously improved; finally, the sandwich panel prepared by the present application has a high limiting oxygen index, indicating that it has excellent fireproof performance; the deformation rates under low temperature and high temperature are both low, indicating that the sandwich panel has good dimensional stability.

[0077] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0078] Finally, it should be noted that the above-mentioned only constitutes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will still be able to modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a layered polyurethane rock wool insulation and fireproof integrated sandwich panel, characterized in that: Includes the following steps: Step 1: Immerse the rock wool board in the hydrophobic sol, hold it under pressure of 100-150MPa for 5-10 minutes, then remove it and place it at 70-100℃ for 2-24 hours to dry, thus obtaining the rock wool core material; Step 2: Take a metal plate, apply adhesive to one side of it, cover the surface with rock wool core material, and apply pressure of 1-3 MPa for 30-60 minutes to obtain the foaming board; Step 3: Fix another metal plate on top of one side of the rock wool core material to be foamed, leaving a foaming space between the rock wool core material and the metal plate, and then seal the two sides along the length to obtain a sandwich panel semi-finished product. Step 4: (1) Mix polyether polyol A, polyether polyol B, modified polyether polyol C, modified silica, flame retardant, catalyst, foaming agent and foam stabilizer evenly according to the formula ratio to obtain mixture A; (2) Mix mixture A and isocyanate evenly according to the formula ratio to obtain polyurethane pre-foaming liquid. Step 5: Spray polyurethane pre-foaming liquid into the foaming space from the two width directions of the sandwich panel semi-finished product, and foam and mature it at a temperature of 50-70℃ for 2-24 hours to obtain polyurethane foam; trim it to obtain a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel. The preparation method of the hydrophobic sol is as follows: (1) 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator are added to a 50V / V% ethanol solution, ultrasonically dispersed for 5-15 min, and then irradiated with 365nm ultraviolet light for 15-60 min. The reaction is then stopped, and the modified silane coupling agent is obtained by rotary evaporation; (2) under stirring, tetraethyl silicate is added to a 50V / V% ethanol solution. After the addition is complete, stirring is continued for 1-2 h. Then, hydrochloric acid is slowly added to the reaction system to adjust the pH value to 1.0-2.2, and stirring is continued. (3) Stir the reaction for 6-12 hours to obtain reaction solution B; (4) Under stirring, heat reaction solution B to 65-85℃ and add modified silane coupling agent to it. After stirring for 4-8 hours, stop the reaction and let the reaction system cool naturally to room temperature to obtain hydrophobic sol; wherein, the mass ratio of 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator is 1:1:(0.01-0.02), the volume ratio of tetraethyl silicate and ethanol solution is 2:1, and the amount of modified silane coupling agent added is 5-10% of the volume of tetraethyl silicate added; The polyurethane pre-foaming liquid comprises the following components, by weight: 10-20 parts of polyether polyol A, 5-15 parts of polyether polyol B, 5-10 parts of modified polyether polyol C, 45-60 parts of isocyanate, 10-22.5 parts of modified silica, 10-20 parts of flame retardant, 0.5-2 parts of catalyst, 10-30 parts of foaming agent, and 1.5-3 parts of foam stabilizer; wherein the amount of modified silica added is half of the total amount of polyether polyol A, polyether polyol B, and modified polyether polyol C added. The modified silica is prepared as follows: (1) 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator are added to a 50V / V% ethanol solution, ultrasonically dispersed for 5-15 min, and then irradiated with 365nm ultraviolet light for 15-60 min. The reaction is then stopped, and the modified silane coupling agent is obtained by rotary evaporation; (2) Nano silica is added to anhydrous ethanol, ultrasonically dispersed for 5-15 min, and then the modified silane coupling agent is added. The mixture is stirred at 40-70℃ for 6-12 h, and then centrifuged, filtered, washed and dried to obtain modified silica; wherein, the mass ratio of 3-mercaptopropyltrimethoxysilane, allyl pentafluorobenzene and photoinitiator is 1:1:(0.01-0.02); the nano silica particle size is 10-20μm, and the amount of modified silane coupling agent added is 5-10% of the amount of nano silica added; The modified polyether polyol C is prepared as follows: Toluene diisocyanate and allyl hydroxyethyl ether are added to a reaction vessel, stirred and heated to 60–80°C for 30–60 min, then heated to 75–95°C for 2–4 h; the temperature is then lowered to 40–55°C, polyoxyethyl glycerol ether is added to the reaction vessel, stirred and heated to 65–85°C for 30–60 min, then heated to 75–95°C for 2–4 h; the temperature is then lowered to 40–55°C. At 55℃, azobisisobutyronitrile, styrene, and acrylamide are added to the reaction vessel. The mixture is stirred and heated to 70-85℃, and the reaction is carried out for 3-6 hours. The reaction is then stopped, and the mixture is allowed to cool naturally to room temperature to obtain modified polyether polyol C. The mass ratio of toluene diisocyanate, allyl hydroxyethyl ether, polyoxyethyl glycerol ether, styrene, and acrylamide is 1:(0.5-1):(1-2):1:1, and the amount of azobisisobutyronitrile added is 5% of the total mass of styrene and acrylamide.

2. The method for preparing a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel according to claim 1, characterized in that: The volume of the foamed space is 1 to 3 times the volume of the sandwich panel occupied by the rock wool core material.

3. The method for preparing a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel according to claim 1, characterized in that: The flame retardant is obtained by mixing antimony trioxide, urea, and dimethyl methyl phosphate in a mass ratio of (3-5):3:

1.

4. The method for preparing a layered polyurethane rock wool thermal insulation and fireproof integrated sandwich panel according to claim 1, characterized in that: The polyether polyol A is designated as HF-4110Y, with a hydroxyl value of 445–465 mg KOH / g and a viscosity of 4000–5800 mPa·s at 25°C; the polyether polyol B is designated as H4110S, with a hydroxyl value of 400–420 mg KOH / g and a viscosity of 1900–3500 mPa·s at 25°C.

5. The layered polyurethane rock wool insulation and fireproof integrated sandwich panel prepared by the method according to any one of claims 1 to 4; characterized in that: It includes a fireproof and water-repellent layer and a thermal insulation layer; the fireproof and water-repellent layer is a rock wool core material, and the thermal insulation layer is a polyurethane foam, wherein the thickness ratio of the fireproof and water-repellent layer to the thermal insulation layer is 1:(1-3).

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