Lightweight high-strength and high-temperature-resistant composite ceramsite and preparation method thereof
By using a high-temperature composite curing agent formulation and a rolling molding process, lightweight, high-strength, and high-temperature resistant composite ceramic particles were prepared, solving the problems of high energy consumption and poor temperature resistance of sound-absorbing materials for rail transit. This enabled the materials to be used stably and have excellent acoustic performance in high-temperature environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 天津中材工程研究中心有限公司
- Filing Date
- 2026-01-21
- Publication Date
- 2026-06-05
AI Technical Summary
Existing sound-absorbing materials in the rail transit field suffer from high energy consumption and pollution during production, as well as poor temperature resistance, resulting in reduced acoustic performance and failure to meet the requirements for use in high-temperature environments.
A high-temperature composite curing agent formulation system was adopted, combined with a rolling molding process, to prepare lightweight, high-strength, and high-temperature resistant composite ceramic particles. By layer-by-layer coating of epoxy resin and filler, the thickness of the resin layer and the amount of filler were controlled to improve the glass transition temperature and the overall performance of the material.
The glass transition temperature of the composite ceramic particles was increased, enhancing the high-temperature mechanical properties of the material and reducing the water absorption rate, thus enabling the material to be used stably in high-temperature environments and making it suitable for sound-absorbing materials in rail transit.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of rail transit technology, and in particular relates to a lightweight, high-strength, high-temperature resistant composite ceramsite and its preparation method. Background Technology
[0002] Currently, traditional sound-absorbing materials in the rail transit sector are fibrous materials such as rock wool and glass wool. The main problems with fibrous sound-absorbing materials are: firstly, their production process is energy-intensive and highly polluting, and detrimental to the health of production workers; secondly, the sound barrier unit panels are subjected to vehicle-induced wind pressure and natural wind pressure over a long period, leading to quality problems such as tearing, powdering, and collapse due to rainwater immersion within five years. After the sound-absorbing material is damaged, the acoustic performance of the unit panels decreases, increasing the noise impact of passing trains and increasing the risk of complaints; thirdly, noise control is costly and technically challenging. Unlike railways, urban rail transit is often located in economically developed areas with higher population density, stricter environmental regulations, and investment and construction units are more sensitive to operating costs. In April 2019, the "Technical Standard for Sound Barrier Structures" (GB / T51335-2018) came into effect, explicitly prohibiting the use of rock wool and glass wool products as sound-absorbing materials for sound barriers. Therefore, research and application of high-performance ceramsite as an alternative to traditional sound-absorbing materials have emerged in the rail transit sector.
[0003] The basic principle of traditional lightweight ceramsite production is as follows: specific raw materials are softened and melted at high temperatures, while an internal chemical reaction generates gas, causing the material to expand. After cooling, it forms a type of spherical or ellipsoidal lightweight aggregate with uniform, closed pores and a hardened surface. However, the traditional lightweight ceramsite preparation process is outdated, resulting in excessively high bulk density and low compressive strength, which cannot meet the stringent requirements for sound-absorbing materials in the current rail transportation sector.
[0004] Meanwhile, in the field of sound-absorbing materials for rail transit, there are high requirements for the temperature resistance of the materials, with a glass transition temperature needing to be higher than 100℃, and in some applications even requiring 300℃. If the glass transition temperature of the composite ceramic particles used as the main filler is low, it will inevitably affect the overall high-temperature mechanical properties of the material. Due to the poor temperature resistance of existing materials, they cannot be used in some high-temperature synthesis processes, nor can they be used in some rail transit applications. Therefore, it is necessary to develop high-temperature resistant, lightweight, and high-strength composite ceramic particle fillers. Summary of the Invention
[0005] The purpose of this application is to provide a lightweight, high-strength, high-temperature resistant composite ceramsite and its preparation method to solve the technical problems in the prior art.
[0006] The technical solution adopted in this application embodiment to solve the technical problems existing in the prior art is as follows:
[0007] A method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite, comprising the following steps: Step 2-1: Place the single-layer composite ceramsite into a ball rolling machine. The ball rolling machine rotates at 5-10 revolutions per minute and the temperature is 90-120℃ to preheat the single-layer composite ceramsite. Step 2-2: Pour the epoxy resin adhesive into the ball rolling machine and mix it evenly with the single-layer composite ceramic particles at 60-90 rpm. Steps 2-3: Blow compressed air into the filler and roll it for 30-90 minutes at 90-120℃ and 5-90 rpm. Step 2-4: Repeat steps 2-2 and 2-3 until the composite ceramsite reaches the specified density; Steps 2-5: The composite ceramsite is kept in an oven at 150-200℃ for 3-6 hours to complete the curing process.
[0008] The embodiments of this application may also employ the following technical solutions: In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the epoxy resin adhesive further comprises: 100 parts by weight of E51 type epoxy resin, 70-100 parts by weight of anhydride type curing agent, 0.5-4 parts by weight of phenolic curing accelerator, and 0-2 parts by weight of silane coupling agent.
[0009] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the anhydride-type curing agent is methyltetrahydrophthalic anhydride, the phenolic curing accelerator is DMP-30 type accelerator, and the silane coupling agent is KH560.
[0010] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the filler is further described as hollow glass microspheres or high aspect ratio filler. When the actual density of the composite ceramsite is ≤0.15 g / cm³, the filler is hollow glass microspheres; When the actual density of the composite ceramsite is greater than 0.15 g / cm³, the filler is a high aspect ratio filler, which is one or more of chopped glass fiber, chopped carbon fiber, potassium titanate whiskers, and gypsum whiskers.
[0011] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite, the method for preparing single-layer composite ceramsite in step 2-1 further includes the following steps: Step 1-1: Place the lightweight foamed balls in a kneader, pour in the epoxy resin adhesive, and stir at a constant speed at 30-60℃ until the epoxy resin adhesive is evenly coated on the surface of the lightweight foamed balls. Steps 1-2: Pour the lightweight foamed balls coated with epoxy resin adhesive into the ball rolling machine and mix them with hollow glass microspheres; Steps 1-3: Roll molding for 30-90 minutes at 90-120℃ and 5-90 rpm to obtain single-layer composite ceramsite.
[0012] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the epoxy resin adhesive in step 1-1 further comprises: 100 parts by weight of E51 type epoxy resin, 70-100 parts by weight of anhydride type curing agent, 0.5-4 parts by weight of phenolic curing accelerator, and 0-2 parts by weight of silane coupling agent.
[0013] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the lightweight foamed balls in step 1-1 are made of polyurethane or polystyrene, with a bulk density of 10-100 kg / m³ and a diameter of 2-50 mm.
[0014] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the actual density of the hollow glass microspheres in steps 1-2 is 0.15-0.60 g / cm³.
[0015] In the above-mentioned method for preparing lightweight, high-strength, and high-temperature resistant composite ceramic particles, the mass ratio of the lightweight foamed balls, epoxy resin adhesive, and hollow glass microspheres is further 100 parts: 20-45 parts: 7-60 parts.
[0016] A lightweight, high-strength, and high-temperature resistant composite ceramsite, characterized in that: the lightweight, high-strength, and high-temperature resistant composite ceramsite is prepared by any one of the above-mentioned methods for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite.
[0017] One or more technical solutions provided in the embodiments of this application have at least the following beneficial effects: 1. This invention selects a high-temperature composite curing agent formulation system and designs a matching rolling molding process to increase the glass transition temperature of the filler from the previous 50-60℃ to 110-160℃, thereby greatly improving the temperature resistance of the filler and giving it a higher glass transition temperature.
[0018] 2. Existing composite ceramic particles have relatively low glass transition temperatures, which can lead to failure and breakage during high-temperature molding, resulting in a deterioration of the overall mechanical properties of the material. This invention uses an adhesive system with a high glass transition temperature, and its curing process requires a high-temperature environment above 100°C. Therefore, the composite ceramic particles of this patent are more suitable for preparing sound-absorbing materials for rail transit.
[0019] 3. In existing technologies, the filler / resin ratio in the raw materials used to prepare spherical shells is a fixed constant. Because the viscosity of the resin varies significantly at different temperatures, the thickness and quality of the resin layer obtained by the impregnation method fluctuate greatly due to environmental influences. This invention sprays the resin into a roll forming device, where the resin layer thickness is entirely determined by the amount of resin sprayed, facilitating precise control. Furthermore, by using a fixed mass of resin sprayed in, the amount of microspheres or fibers added can be kept relatively stable, making it easier to control the quality of the spherical shells.
[0020] 4. Except for the first layer, the remaining shell layers of this invention are all prepared in the medium-high temperature environment of the ball rolling machine. Therefore, the curing speed is faster and less affected by the ambient temperature, and the process is more stable.
[0021] 5. This invention uses epoxy resin with a high-temperature resistant formulation as an adhesive and glass fiber, hollow microspheres, and gypsum whiskers as fillers. It employs a layer-by-layer coating and rolling molding process to prepare lightweight, high-strength, high-temperature resistant, low-water-absorption, and uniformly sized millimeter-scale composite ceramsite. This ceramsite exhibits uniform size, and its bulk density can be precisely controlled within the range of 50-700 kg / m³. Its specific strength and water absorption are far superior to existing traditional ceramsite, showing promising application prospects in the field of sound-absorbing materials for rail transit. Detailed Implementation
[0022] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.
[0023] Example 1 The fabrication process of the first-layer composite spherical shell: Step 1: Prepare epoxy resin adhesive; The epoxy resin adhesive formulation in step 1 is as follows: 100 parts of E51 type epoxy resin, 70-100 parts of anhydride type curing agent (such as methyltetrahydrophthalic anhydride), 0.5-4 parts of phenolic curing accelerator (such as DMP-30 type accelerator), and 0-2 parts of silane coupling agent (such as KH560). Step 2: Place an appropriate amount of lightweight foamed balls in a kneader, pour in an appropriate amount of epoxy resin adhesive, and stir at a uniform speed at 30-60℃ until the epoxy resin adhesive is evenly coated on the surface of the foamed balls. The foamed balls in step 2 are made of polyurethane or polystyrene, with a bulk density of 10-100 kg / m³ and a diameter of 1-50 mm. Step 3: Pour the foamed balls coated with epoxy resin adhesive into the ball rolling machine and mix them with an appropriate amount of hollow glass microspheres; The actual density of the hollow glass microspheres in step 3 is 0.15-0.60 g / cm³.
[0024] Step 4: Roll molding at 90-120℃ and 5-90 rpm for 30-90 minutes to obtain single-layer composite ceramsite.
[0025] Preparation process of other layered composite ceramic granule shells: Step 1: Place the above-mentioned single-layer composite ceramsite into a ball rolling machine. The ball rolling machine rotates at 5-10 revolutions per minute and the temperature is 90-120℃ to preheat the single-layer composite ceramsite. Step 2: Prepare the epoxy resin adhesive; The epoxy resin adhesive formulation in step 2 is the same as that used in the first layer of composite spherical shell, which is: 100 parts of E51 type epoxy resin, 70-100 parts of acid anhydride type curing agent (such as methyltetrahydrophthalic anhydride), 0.5-4 parts of phenolic curing accelerator (such as DMP-30 type accelerator), and 0-2 parts of silane coupling agent (such as KH560). Step 3: Spray the epoxy resin adhesive into the ball rolling machine and mix it evenly with the composite ceramsite at 60-90 rpm. Step 4: Blow in an appropriate amount of filler (hollow glass microspheres or high aspect ratio filler) with compressed air, and roll it for 30-90 minutes at 90-120℃ and 5-90 rpm. In step 4, when the actual density of the composite ceramsite is ≤0.15 g / cm³, the filler is hollow glass microspheres (the same as those used in the first layer of composite spherical shell); when the actual density of the composite ceramsite is >0.15 g / cm³, the filler is chopped glass fiber, chopped carbon fiber, potassium titanate whiskers, or gypsum whiskers.
[0026] Composite ceramic granules made from hollow microspheres have low shell density and low shrinkage, but are slightly more expensive; composite ceramic granules made from chopped glass fibers, chopped carbon fibers, potassium titanate whiskers, etc., have high shell density, high shrinkage, and are less expensive.
[0027] Step 5: Repeat steps 1-4 until the composite ceramsite reaches the specified density (depending on the application, the density of the composite ceramsite can be 0.10-1.5 g / cm³). 3 The density of the expanded clay aggregate can be freely controlled within a certain range. However, high-density composite expanded clay aggregate currently has no practical applications. Step 6: In an oven at 150-200℃, the composite ceramsite is kept at a temperature of 3-6 hours to complete the curing process.
[0028] Examples 2-6 Based on Example 1, Examples 2-6 were carried out. Examples 2-6 included the following steps, and the specific process parameters are shown in Table 1.
[0029] The fabrication process of the first spherical shell: Step 1: Prepare epoxy resin adhesive, the specific components of which are shown in Table 1; Step 2: Place 100 parts of lightweight foamed balls in a kneader, pour in 20-45 parts of epoxy resin adhesive, and stir at a uniform speed until the epoxy resin adhesive is evenly coated on the surface of the foamed balls. The stirring temperature is shown in Table 1. The foamed balls are made of polyurethane or polystyrene, with a bulk density of 10-100 kg / m³, and the diameter of the foamed balls is shown in Table 1. Step 3: Pour the foamed balls coated with epoxy resin adhesive into the ball rolling machine and mix with 7-60 parts of hollow glass microspheres; Step 4: Roll molding at 90-120℃ and 5-90 r / m for 30-90 minutes to obtain composite ceramsite. The specific temperature, speed and rolling molding time are shown in Table 1.
[0030] Preparation process of other layered spherical shells: Step 5: Place the above single-layer composite ceramsite into a ball rolling machine. The rotation speed of the ball rolling machine is 5 r / m, and the temperature is shown in Table 1. Step 6: Prepare epoxy resin adhesive (the formula is the same as in Step 1, and the specific components are shown in Table 1). Step 7: Spray the epoxy resin adhesive into the ball rolling machine and mix it evenly with the composite ceramic particles at a speed of 60-90 r / m. Step 8: Blow in the packing material using compressed air. The packing material is shown in Table 1. Roll the material for 30-90 minutes at 90-120℃ and 5-90 r / m. The specific temperature, speed, and rolling time are shown in Table 1.
[0031] Step 9: Repeat steps 6-8 until the composite ceramsite reaches the density shown in Table 1; Step 10: In an oven at 150-200℃, the composite ceramsite is kept at a temperature of 3-6 hours to complete the curing process.
[0032] Table 1 Specific process parameters for Examples 2-6
[0033] In conventional epoxy resin products, if polyamide or polyamine curing agents are used, the glass transition temperature of the product is generally around 50-60℃, and the strength decay rate is as high as 60% after 24 hours at 450℃. In this solution, by using methyltetrahydrophthalic anhydride and DMP-30 (a room temperature curing agent that promotes curing) as composite curing agents, the glass transition temperature of the product is significantly increased to over 110℃, and the strength decay at 450℃ for 24 hours is no more than 5%, resulting in a significant improvement in temperature resistance.
[0034] In existing technologies, foaming balls or ceramsite are completely immersed in resin and then removed and allowed to drain naturally. As a result, the thickness of the resin layer is greatly affected by the ambient temperature, which is not conducive to the stability of production. In this solution, except for the first layer, the resin is mixed with ceramsite by spraying. The thickness of the resin layer is uniform and precisely controllable. Therefore, the overall density range of the ceramsite is more concentrated, and the strength is more uniform and controllable.
[0035] In existing technologies, foamed balls or ceramsite first need to be immersed in resin for slurry coating, then removed from the resin and allowed to drain naturally. Next, the particles are separated in a ball rolling machine by the action of fillers, and then the temperature is increased for rolling and molding, which is a time-consuming process. In this solution, after the upper shell layer is initially cured in a high-temperature environment, no preheating is required. Resin and fillers can be added immediately, and slurry coating and separation are carried out in the ball rolling machine. Then, the curing of this shell layer continues in the high-temperature environment of the ball rolling machine. There is no need to remove the material from the equipment, and the heating process is eliminated. This not only shortens the production cycle to 30% of the original, but also makes the resin layer thickness no longer affected by the ambient temperature, resulting in a more stable process.
[0036] Compared to traditional lightweight ceramsite, the ceramsite particle size of this solution is more uniform (the foamed core directly determines the particle size of the product); the shell is dense, resulting in extremely low water absorption; the product has a foamed core wrapped with a high-strength resin / filler composite shell layer, thus possessing the advantages of being lightweight and high-strength, and therefore its overall performance far surpasses that of traditional lightweight ceramsite. As in Examples 2-4, it can be used as a high-performance lightweight aggregate in fields such as rail transportation; in Example 5, whiskers, which have slightly lower performance but are cheaper, are used instead of chopped glass fibers, making it a more cost-effective lightweight aggregate for applications such as construction engineering; in Example 6, chopped carbon fibers with better performance are used instead of chopped glass fibers, further reducing the product density while ensuring mechanical properties, making it suitable as an ultra-high-performance lightweight filler for applications in fields such as marine engineering and aerospace.
[0037] In summary, this invention provides a lightweight, high-strength, and high-temperature resistant composite ceramsite and its preparation method.
[0038] The above embodiments have provided a detailed description of the present invention, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.
Claims
1. A method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite, characterized in that: The preparation method of the lightweight, high-strength, and high-temperature resistant composite ceramsite includes the following steps: Step 2-1: Place the single-layer composite ceramsite into a ball rolling machine. The ball rolling machine rotates at 5-10 revolutions per minute and the temperature is 90-120℃ to preheat the single-layer composite ceramsite. Step 2-2: Pour the epoxy resin adhesive into the ball rolling machine and mix it evenly with the single-layer composite ceramsite at 60-90 rpm. Steps 2-3: Blow compressed air into the filler and roll it for 30-90 minutes at 90-120℃ and 5-90 rpm. Step 2-4: Repeat steps 2-2 and 2-3 until the composite ceramsite reaches the specified density; Steps 2-5: The composite ceramsite is kept in an oven at 150-200℃ for 3-6 hours to complete the curing process.
2. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 1, characterized in that: The epoxy resin adhesive comprises: 100 parts by weight of E51 type epoxy resin, 70-100 parts by weight of anhydride type curing agent, 0.5-4 parts by weight of phenolic curing accelerator, and 0-2 parts by weight of silane coupling agent.
3. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 2, characterized in that: The anhydride-type curing agent is methyltetrahydrophthalic anhydride, the phenolic curing accelerator is DMP-30 type accelerator, and the silane coupling agent is KH560.
4. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 1, characterized in that: The filler is hollow glass microspheres or a high aspect ratio filler. When the actual density of the composite ceramsite is ≤0.15 g / cm³, the filler is hollow glass microspheres; When the actual density of the composite ceramsite is greater than 0.15 g / cm³, the filler is a high aspect ratio filler, which is one or more of chopped glass fiber, chopped carbon fiber, potassium titanate whiskers, and gypsum whiskers.
5. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 1, characterized in that: The preparation method of single-layer composite ceramsite in step 2-1 includes the following steps: Step 1-1: Place the lightweight foamed balls in a kneader, pour in the epoxy resin adhesive, and stir at a constant speed at 30-60℃ until the epoxy resin adhesive is evenly coated on the surface of the lightweight foamed balls. Steps 1-2: Pour the lightweight foamed balls coated with epoxy resin adhesive into the ball rolling machine and mix them with hollow glass microspheres; Steps 1-3: Roll molding for 30-90 minutes at 90-120℃ and 5-90 rpm to obtain single-layer composite ceramsite.
6. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 5, characterized in that: The epoxy resin adhesive in step 1-1 includes: 100 parts by weight of E51 type epoxy resin, 70-100 parts by weight of anhydride type curing agent, 0.5-4 parts by weight of phenolic curing accelerator, and 0-2 parts by weight of silane coupling agent.
7. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 5, characterized in that: The lightweight foamed balls in step 1-1 are made of polyurethane or polystyrene, with a bulk density of 10-100 kg / m³ and a diameter of 2-50 mm.
8. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 5, characterized in that: The actual density of the hollow glass microspheres in steps 1-2 is 0.15-0.60 g / cm³.
9. The method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to claim 1, characterized in that: The mass ratio of the lightweight foamed balls, epoxy resin adhesive, and hollow glass microspheres is 100 parts: 20-45 parts: 7-60 parts.
10. A lightweight, high-strength, high-temperature resistant composite ceramsite, characterized in that: The lightweight, high-strength, and high-temperature resistant composite ceramsite is prepared by the method for preparing lightweight, high-strength, and high-temperature resistant composite ceramsite according to any one of claims 1-9.