A high-strength thermal insulation board and a preparation method thereof

Abstract

The present application relates to the technical field of thermal insulation boards, and specifically discloses a high-strength thermal insulation board and a preparation method thereof. A high-strength thermal insulation board comprises the following substances in parts by weight: 75-90 parts of polystyrene; 5-10 parts of reinforcing material; 0.5-3 parts of nucleating agent; 1-5 parts of flame retardant; 5-10 parts of foaming agent; the reinforcing material comprises any one or more of polyamide 6, ABS, and PC, the reinforcing material also comprises PPO, and the polystyrene comprises general-purpose polystyrene and polystyrene grafted with polybutadiene. The preparation method thereof is as follows: S1, raw material preparation; S2, thermal insulation board preparation. The thermal insulation board of the present application can be used in the fields of elevated cold storage floor insulation, civil engineering, etc., and has the advantages of high strength and high thermal insulation.

Description

Technical Field

[0001] The present application relates to the technical field of thermal insulation boards, and more specifically, to a high-strength thermal insulation board and a preparation method thereof. Background Art

[0002] Extruded polystyrene (XPS) foam refers to a foam material made from general-grade polystyrene using a continuous extrusion foaming method. Due to its excellent thermal insulation performance, moisture resistance, high compressive strength, chemical corrosion resistance, and easy processing, it is widely used in transportation, refrigeration, construction, interior decoration and other fields.

[0003] However, most of them have a compressive strength between 150KPa and 350KPa, and are widely used in the fields of external wall insulation and roof insulation of civil buildings. In terms of compressive strength, they can only meet the use of external wall insulation and roof insulation of civil buildings, but cannot meet the performance requirements of compressive strength higher than 400KPa in elevated cold storage floor insulation and civil engineering. Summary of the invention

[0004] In order to improve the high temperature stability of the insulation board, the present application provides a high-strength insulation board and a preparation method thereof, adopting the following technical solutions:

[0005] In a first aspect, the present application provides a high-strength thermal insulation board, comprising the following materials in parts by weight:

[0006] Polystyrene 75-90 parts;

[0007] 5-10 parts of reinforcing material;

[0008] Nucleating agent 0.5-3 parts;

[0009] Flame retardant 1-5 parts;

[0010] 5-10 parts of foaming agent;

[0011] The reinforcing material includes any one or more of polyamide 6, ABS, and PC, and the reinforcing material also includes PPO. The polystyrene includes general-grade polystyrene and polystyrene grafted with polybutadiene.

[0012] By adopting the above technical solution and adding reinforcing materials, the melt strength of the PS matrix can be made higher, which is more conducive to forming a stable pore structure during the pore growth process in the composite insulation board, and enables the composite insulation board to obtain excellent compressive strength and heat deformation temperature.

[0013] Polyamide 6 can significantly enhance the compressive strength of XPS while maintaining the thermal conductivity coefficient unchanged, while improving the side compressive strength. And as the amount of PA6 increases, the compressive strength of the front and side also increases. The introduction of reinforcing materials can also increase the thermal deformation temperature of XPS and increase its use temperature range. Therefore, the introduction of reinforcing materials such as PA6 can significantly increase the mechanical properties of XPS.

[0014] PPO is preferably used as the reinforcing material. PPO has relatively good compatibility with polystyrene. PPO can act as a rigid particle, play the role of a pore opener and a nucleator in the insulation board, increase the bubble nucleation sites in the insulation board, and form a closed-cell structure in the insulation board. PPO can also cooperate with polystyrene to form a sea-island structure, effectively improving the mechanical strength of the insulation board.

[0015] In the present application, general-purpose polystyrene and polystyrene grafted with polybutadiene are preferably used as the base material of the insulation board. Polybutadiene grafted with polystyrene can improve the brittleness and heat resistance of polystyrene, move the dispersed phase into the polystyrene and form a sea-island structure, further improving the mechanical strength of the insulation board.

[0016] Optionally, SEBS-g-MAH is also included.

[0017] By adopting the above technical solution and adding SEBS-g-MAH, the compatibility between polystyrene and PPO can be effectively improved, forming a stable sea island structure in the insulation board, and the compatibility between PPO and PA6 can be improved, so that the reinforcing material can be fully combined with polystyrene, which is beneficial to improving the strength of the insulation board.

[0018] Optionally, the reinforcing material further comprises silica microspheres having a hollow structure.

[0019] By adopting the above technical scheme, it is preferred to use silica microspheres with a hollow structure as reinforcing materials. The addition of silica microspheres can increase nucleation sites in the insulation board, improve the foaming effect in the insulation board, and introduce a regular hollow structure in the insulation board, so that the insulation board obtains more uniform mechanical strength.

[0020] Optionally, the silica microspheres are submicron hollow silica microspheres.

[0021] By adopting the above technical solution, the particle size of silica microspheres is optimized. Preferably, submicron-sized silica microspheres are used to form a grading effect with the pore structure in the insulation board, so that a dense pore structure is formed in the insulation board, further improving the mechanical strength of the insulation board.

[0022] Optionally, the hollow silica microspheres are prepared as follows: styrene, water and polyvinyl pyrrolidone are mixed, heated, ammonium persulfate is added, reacted to obtain a PS solution, hexadecyltrimethylammonium bromide is added to anhydrous ethanol, ultrasonically dispersed, the PS solution and ammonia water are added, ultrasonically dispersed, tetraethyl orthosilicate is added, centrifuged, dried, and sintered to obtain hollow silica microspheres.

[0023] Optionally, the silica microspheres are loaded with a foaming agent.

[0024] By adopting the above technical scheme, silica microspheres are used to load the foaming agent, which can effectively reduce the occurrence of foaming agent agglomeration, caking and the like, so that the foaming agent can be evenly dispersed in the insulation board driven by the silica microspheres, and the composite foaming agent is used as the nucleation point of the bubble to achieve the refinement of the pores, so that the insulation board obtains a uniform pore structure, and the pore structure can be generated around the silica microspheres. In other words, the silica microspheres can serve as a supporting structure for the surrounding pore structure, reduce the possibility of collapse of the pore structure, and further improve the mechanical strength of the insulation board.

[0025] Optionally, the silica microspheres are silica microspheres modified with a silane coupling agent.

[0026] By adopting the above technical solution, preferably using a silane coupling agent to modify the silica microspheres, the compatibility between the silica microspheres and the insulation board substrate can be enhanced, so that the silica microspheres can be evenly dispersed in the insulation board, and the insulation board can obtain uniform mechanical strength.

[0027] Optionally, the reinforcing material also includes glass fiber.

[0028] By adopting the above technical scheme, the addition of glass fibers can form an interlaced fiber network structure in the insulation board, and because the silica microspheres are modified by a silane coupling agent, the silica microspheres can be partially loaded on the fiber network structure, which can further improve the uniformity of silica dispersion in the insulation board, and the pore structure in the insulation board can be generated around the glass fibers and the silica microspheres, effectively reducing the possibility of collapse of the pore structure of the insulation board, thereby improving the mechanical strength of the insulation board.

[0029] Optionally, the foaming agent includes any one or more of alcohol, CO2, R-152a, HFO-1233zd and HFO-1234ze.

[0030] By adopting the above technical solution, R-152a, HFO-1233zd and HFO-1234ze are all foaming agents with low thermal conductivity, which can reduce foam density, increase foam compression strength, and make pore size distribution uniform, thereby improving the thermal insulation effect and mechanical strength of the insulation board.

[0031] In a second aspect, the present application provides a method for preparing a high-strength thermal insulation board, which adopts the following technical solution:

[0032] A method for preparing a high-strength thermal insulation board comprises the following steps:

[0033] S1. Raw material preparation: Weigh polystyrene, reinforcing material, nucleating agent, flame retardant and foaming agent respectively by weight;

[0034] S2. Preparation of thermal insulation board: polystyrene, reinforcing material, nucleating agent and flame retardant are added to the first-stage extruder, mixed, foaming agent is injected from the foaming agent injection port, mixed, extruded, conveyed to the second-stage extruder through the screen changer, stirred, mixed, molded, cut to obtain a composite thermal insulation board.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. In this application, PPO is preferably used as a reinforcing material. PPO has relatively good compatibility with polystyrene. PPO can act as a rigid particle and play the role of a cell opener and nucleator in the insulation board, increase the bubble nucleation sites in the insulation board, and form a closed-cell structure in the insulation board. In addition, PPO can form a sea-island structure with polystyrene, effectively improving the mechanical strength of the insulation board. General-grade polystyrene and polystyrene grafted with polybutadiene are used as the base material of the insulation board. Polybutadiene grafted with polystyrene can improve the brittleness and heat resistance of polystyrene, move the dispersed phase into polystyrene and form a sea-island structure, further improving the mechanical strength of the insulation board.

[0037] 2. The present application utilizes silica microspheres to load the foaming agent, which effectively reduces the occurrence of foaming agent agglomeration, caking and the like, so that the foaming agent can be evenly dispersed in the insulation board driven by the silica microspheres, and the composite foaming agent is used as the nucleation point of the bubbles to achieve the refinement of the pores, so that the insulation board obtains a uniform pore structure, and the pore structure can be generated around the silica microspheres. In other words, the silica microspheres can serve as a supporting structure for the surrounding pore structure, reduce the possibility of collapse of the pore structure, and further improve the mechanical strength of the insulation board.

[0038] 3. The addition of glass fibers in the present application can form an interlaced fiber network structure in the insulation board, and because the silica microspheres are modified by a silane coupling agent, the silica microspheres can be partially loaded on the fiber network structure, which can further improve the uniformity of silica dispersion in the insulation board, and the pore structure in the insulation board can be generated around the glass fibers and silica microspheres, effectively reducing the possibility of collapse of the pore structure of the insulation board, thereby improving the mechanical strength of the insulation board. DETAILED DESCRIPTION

[0039] The present application is further described in detail below with reference to the embodiments.

[0040] Preparation Example

[0041] Preparation Example of Polystyrene Grafted with Polybutadiene

[0042] Preparation Example 1

[0043] High impact polystyrene is selected as the polystyrene grafted with polybutadiene.

[0044] Preparation Example of Hollow Silica Microspheres

[0045] Preparation Example 2

[0046] Take 10mL of styrene, 90mL of water and 1mL of polyvinyl pyrrolidone, mix them, heat them to 85°C, add ammonium persulfate, react to obtain a polystyrene latex microsphere solution (PS solution), take hexadecyltrimethylammonium bromide, add anhydrous ethanol, ultrasonically disperse, add 10mL of PS solution and ammonia water (10mol / L) to adjust the pH to 11, ultrasonically disperse, add 3mL of tetraethyl orthosilicate, centrifuge at 8000rpm, dry at 80°C, and sinter at 800°C to obtain hollow silica microspheres.

[0047] Preparation Example 3

[0048] The hollow silica microspheres in Preparation Example 2 were mixed with a silane coupling agent solution (solid-to-liquid ratio of 1:5), filtered, and dried to obtain hollow silica microspheres modified with a silane coupling agent.

[0049] Preparation Example 4

[0050] 0.5 kg of the hollow silica microspheres prepared in Preparation Example 2 were immersed in the blowing agent HFO-1233zd, stirred for 30 min, ultrasonicated for 10 min, allowed to stand for 24 h, filtered, washed, and dried to obtain hollow silica microspheres loaded with the blowing agent.

[0051] Preparation Example 5

[0052] 0.5 kg of the hollow silica microspheres modified by the silane coupling agent prepared in Preparation Example 3 were immersed in the blowing agent HFO-1233zd, stirred for 30 min, ultrasonicated for 10 min, allowed to stand for 24 h, filtered, washed, and dried to obtain hollow silica microspheres loaded with the blowing agent. Example

[0053] Examples 1-4

[0054] On the one hand, the present application provides a polystyrene composite insulation board, including polystyrene, a reinforcing material, a nucleating agent, a flame retardant and a foaming agent, and the specific qualities are shown in the table below.

[0055] Specifically, the polystyrene is general-grade polystyrene and the polystyrene prepared in Preparation Example 1, the reinforcing material is PA6 and PPO, the nucleating agent is talcum powder, the flame retardant is methyl octabromoether and ammonium polyphosphate, and the foaming agent is carbon dioxide, HFO-1233zd and R-152a.

[0056]

[0057] On the other hand, the present application provides a method for preparing a polystyrene composite insulation board, comprising the following steps:

[0058] S1. Raw material preparation: Weigh polystyrene, reinforcing material, nucleating agent, flame retardant and foaming agent respectively by weight;

[0059] S2. Preparation of thermal insulation board: polystyrene, reinforcing material, nucleating agent and flame retardant are added to the first-stage extruder, mixed, foaming agent is injected from the foaming agent injection port, mixed, extruded, conveyed to the second-stage extruder through the screen changer, stirred, mixed, molded, cut to obtain a composite thermal insulation board.

[0060] Specifically, step S2, preparing the insulation board includes:

[0061] S21, adding polystyrene, reinforcing material, nucleating agent and flame retardant into a first-stage extruder (twin-screw extruder), and setting the temperature of each zone of the twin-screw extruder to 200-230°C;

[0062] Among them: the section from the feeding port to the foaming agent injection port is mainly a strong shearing section, which is used to fully mix the materials.

[0063] S22, the foaming agent is continuously and stably injected into the twin-screw extruder from the foaming agent injection port through the foaming agent metering pump, and mixed to obtain a mixed melt;

[0064] Among them: the foaming agent should be injected in liquid state and should be pressurized before injection to prevent gas backflow. The injection position is where the polystyrene, reinforcement material, nucleating agent and flame retardant components are evenly mixed. The screw is designed with multiple protrusions at the injection point to prevent the formation of liquid pools and promote rapid and uniform dispersion of gas in the melt. The plasticization of the melt by the foaming agent leads to a decrease in melt strength. The barrel temperature here is set to 200-210℃.

[0065] S23, the mixed melt is filtered out of large impurities through a screen changer and transported to the second-stage extruder (single screw extruder) through a melt conveying pipeline.

[0066] Among them: the single screw extruder can cool down the homogeneous melt whose melt strength has been greatly reduced after being plasticized by the foaming agent, so as to improve the melt strength and reach the viscosity range required for the molded product;

[0067] The screen changer uses a replaceable screen changing system. After a period of operation, large impurities on the wire mesh are replaced and cleaned to reduce the impact on production efficiency.

[0068] The melt delivery pipeline does not contain a screw, and its barrel temperature is set at 180-200°C;

[0069] The single screw extruder adopts a step-down mode from the front to the head to fully cool the melt. The temperature of each zone is set at 90-140℃. The speed of the single screw should not be too fast to prevent the screw shear heat from heating the melt. The melt cooling rate should be efficient and rapid. Static mixing or melt pump equipment should be set in front of the single screw head to control and maintain the pressure of the melt to prevent the melt from premature pressure release and pre-foaming. The static mixing temperature should be appropriately increased, generally set to 110-130℃, to prevent the melt from flowing in a dead zone where it stagnates.

[0070] S24, after cooling, the homogeneous melt passes through the die head and die lip, where the thermodynamic steady state is broken due to rapid pressure relief, and the foaming agent gas quickly escapes from the polymer, causing the melt volume to expand and form a closed cell structure. The XPS is then sized by the shaping template, the whole platform, the traction roller, etc.

[0071] Among them: the design of the die runner must ensure that the melt flow rate at each part of the die lip is equivalent, and the pressure drop distribution in each area of ​​the mold should be calculated under the premise of controlling the total pressure drop of the melt; the pulling roller speed should be matched with the melt extrusion amount at the die mouth to ensure that the tensile force on the sheet in the lateral direction is consistent.

[0072] S25. After the XPS board is shaped and flattened, a small amount of edge material on both sides is cut off by a cutter, and after side coding and embossing on the front and back sides, it is sliced ​​by a transverse cutting machine and packaged for storage to obtain a composite insulation board.

[0073] Table 1

[0074]

[0075] Example 5

[0076] The difference from Example 4 is that the insulation board also includes 1 kg of SEBS-g-MAH (general grade produced by Dongguan Shengli New Materials Co., Ltd.).

[0077] Example 6

[0078] The difference from Example 4 is that the reinforcing material includes PA6, PPO and the silica microspheres in Preparation Example 2 in a mass ratio of 5:3:2.

[0079] Example 7

[0080] The difference from Example 4 is that the reinforcing material includes PA6, PPO and the silica microspheres in Preparation Example 3 in a mass ratio of 5:3:2.

[0081] Example 8

[0082] The difference from Example 4 is that the reinforcing material includes PA6, PPO and the silica microspheres in Preparation Example 4 in a mass ratio of 5:3:2.

[0083] Example 9

[0084] The difference from Example 4 is that the reinforcing material includes PA6, PPO and the silica microspheres in Preparation Example 5 in a mass ratio of 5:3:2.

[0085] Example 10

[0086] The difference from Example 4 is that the reinforcing material includes PA6, PPO, the silica microspheres in Preparation Example 5 and glass fiber in a mass ratio of 5:2:2:1. Comparative Example

[0087] Comparative Example 1

[0088] The difference between this comparative example and Example 4 is that no reinforcing material is added in this comparative example.

[0089] Performance testing

[0090] (1) Apparent density test: The test shall be conducted in accordance with the test method of GB / T6343-1996 "Determination of apparent (bulk) density of cellular plastics and rubber".

[0091] (2) Thickness detection: Use a ruler to measure the thickness of the insulation board.

[0092] (3) Compression strength test: Test the 10% compression strength and side compression strength of the insulation board according to GB / T8813-1998 "Compression test method for rigid foam plastics".

[0093] (4) Thermal deformation test: Use a thermal deformation Vicat softening point tester to test the thermal deformation temperature of the insulation board.

[0094] (5) Thermal conductivity test: The thermal conductivity test equipment uses FOX200 produced by TA Instruments of the United States.

[0095] (6) Combustion performance test: The combustion performance level of the insulation board is tested according to GB / T 10801.2-2018 Extruded polystyrene foam for thermal insulation.

[0096] Table 2 Performance test

[0097]

[0098] Combining the performance test comparison in Table 2, we can find that:

[0099] 1. By comparing Examples 1-4 with Comparative Example 1, it can be found that the mechanical strength of the insulation board prepared in Examples 1-4 is improved, which means that in the present application, PPO can be used as rigid particles, and play the role of a pore opener and a nucleating agent in the insulation board to form a sea-island structure; general-grade polystyrene and polystyrene grafted with polybutadiene are used as the base material of the insulation board. Polybutadiene grafted polystyrene can improve the brittleness and heat resistance of polystyrene, move a dispersed phase into the polystyrene and form a sea-island structure, thereby further improving the mechanical strength of the insulation board.

[0100] 2. By comparing Example 5 with Example 4, it can be found that the mechanical strength of the insulation board prepared in Example 5 is improved, which means that in the present application, the addition of SEBS-g-MAH can effectively improve the compatibility between polystyrene and PPO, form a stable sea island structure in the insulation board, and also improve the compatibility between PPO and PA6, so that the reinforcing material is fully combined with polystyrene, which is beneficial to improve the strength of the insulation board.

[0101] 3. By comparing Examples 6-7 with Example 4, it can be found that the mechanical strength of the insulation board prepared in Examples 6-7 is improved, which means that the submicron-sized silica microspheres used in the present application can form a grading effect with the pore structure in the insulation board, so that a dense pore structure is formed in the insulation board, further improving the mechanical strength of the insulation board.

[0102] 4. By comparing Examples 8-9 with Example 4, it can be found that the mechanical strength of the insulation board prepared in Examples 8-9 is improved, which means that the use of silica microspheres to load the foaming agent in the present application can effectively reduce the occurrence of foaming agent agglomeration, agglomeration and the like, so that the foaming agent can be evenly dispersed in the insulation board driven by the silica microspheres, and the composite foaming agent is used as the nucleation point of the bubbles to achieve the refinement of the pores, so that the insulation board obtains a uniform pore structure, and the pore structure can be generated around the silica microspheres. That is to say, the silica microspheres can serve as a supporting structure for the surrounding pore structure, reduce the possibility of collapse of the pore structure, and further improve the mechanical strength of the insulation board.

[0103] 5. By comparing Example 10 with Example 4, it can be found that the mechanical strength of the insulation board prepared in Example 10 is improved, which means that in the present application, since the silica microspheres are modified by a silane coupling agent, the silica microspheres can be partially loaded on the fiber network structure, which can further improve the uniformity of silica dispersion in the insulation board, and the pore structure in the insulation board can be generated around the glass fibers and the silica microspheres, effectively reducing the possibility of collapse of the pore structure of the insulation board, thereby improving the mechanical strength of the insulation board.

[0104] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high-strength insulation board, characterized in that: The following materials are included in parts by weight: Polystyrene 75-90 parts; 5-10 parts of reinforcing material; Nucleating agent 0.5-3 parts; Flame retardant 1-5 parts; 5-10 parts of foaming agent; The reinforcing material includes any one or more of polyamide 6, ABS, and PC, the reinforcing material also includes PPO, and the polystyrene includes general-grade polystyrene and polystyrene grafted with polybutadiene; The reinforcing material also includes silicon dioxide microspheres with a hollow structure; The silica microspheres are submicron hollow silica microspheres; The hollow silica microspheres are prepared as follows: styrene, water and polyvinyl pyrrolidone are mixed, heated, ammonium persulfate is added, reacted to obtain a PS solution, hexadecyltrimethylammonium bromide is added to anhydrous ethanol, ultrasonically dispersed, the PS solution and ammonia water are added, ultrasonically dispersed, tetraethyl orthosilicate is added, centrifuged, dried, and sintered to obtain hollow silica microspheres.

2. A high-strength thermal insulation board according to claim 1, characterized in that: Also included is SEBS-g-MAH.

3. The high-strength thermal insulation board according to claim 1, characterized in that: The silica microspheres are loaded with a foaming agent.

4. The high-strength thermal insulation board according to claim 1, characterized in that: The silica microspheres are silica microspheres modified by a silane coupling agent.

5. The high-strength thermal insulation board according to claim 4, characterized in that: The reinforcement material also includes glass fibers.

6. The high-strength thermal insulation board according to claim 1, characterized in that: The foaming agent includes any one or more of alcohol, CO2, R-152a, HFO-1233zd and HFO-1234ze.

7. A method for preparing a high-strength thermal insulation board according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Raw material preparation: Weigh polystyrene, reinforcing material, nucleating agent, flame retardant and foaming agent respectively by weight; S2. Preparation of thermal insulation board: polystyrene, reinforcing material, nucleating agent and flame retardant are added to the first-stage extruder, mixed, foaming agent is injected from the foaming agent injection port, mixed, extruded, conveyed to the second-stage extruder through the screen changer, stirred, mixed, molded, cut to obtain a composite thermal insulation board.

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