A method for preparing rigid thermal insulation tile

Abstract

The present invention provides a method for preparing a rigid thermal insulation tile, which belongs to the field of rigid thermal insulation tiles. The method for preparing the rigid thermal insulation tile consists of the following steps: preparing a modified composite slurry, preparing a modified composite fiber material, preparing a molded body, and post-processing. The method for preparing the rigid thermal insulation tile of the present invention can effectively improve the toughness of the rigid thermal insulation tile while improving the compatibility and bonding performance of the ceramic fiber and the phenolic resin material, effectively improve the reinforcing effect of the phenolic resin material on the rigid thermal insulation tile, improve the overall stability of the rigid thermal insulation tile, effectively avoid the thermal stress problem of the rigid thermal insulation tile in a continuous high temperature or rapid temperature rise and fall environment, and improve the effective service life of the rigid thermal insulation tile; and further improve the bonding performance of the sintering enhancement additive and the phenolic resin material.

Description

Technical Field

[0001] The invention relates to the field of rigid thermal insulation tiles, and in particular to a method for preparing the rigid thermal insulation tiles. Background Art

[0002] When a high-Mach number spacecraft enters the atmosphere, there is a severe aerodynamic heating effect due to high-speed friction. Therefore, lightweight thermal insulation and protective materials must be laid on the outer surface of the spacecraft to block heat from transferring to the interior of the spacecraft, thereby ensuring the safety of equipment and personnel in the spacecraft.

[0003] Compared with metal thermal protection systems, ceramic fiber rigid thermal insulation tiles have the advantages of high temperature resistance, high strength, erosion resistance and good stability, which can effectively make up for the shortcomings of metal thermal protection systems in terms of structural quality, thermal expansion and connection sealing. In the prior art, rigid thermal insulation tiles have been successfully applied in the 900-1500K sub-high temperature area on the surface of aerospace vehicles, and have the characteristics of heat insulation, light weight and low thermal conductivity. Since the 1960s, the prior art has disclosed the successful development of ceramic fiber rigid thermal insulation tiles with various material systems, such as fiber refractory composite insulation FRCI, aluminum modified enhanced insulation AETB, high thermal performance insulation HTP, etc., which are the thermal protection materials of choice for space shuttles, manned return capsules and hypersonic vehicles.

[0004] The conventional preparation method of ceramic fiber rigid insulation tile usually uses quartz fiber, alumina fiber and the like as main raw materials, and is obtained through processes such as short cutting, slurry preparation, vacuum filtration molding, low temperature drying, and high temperature sintering.

[0005] However, the toughness of the ceramic fiber rigid thermal insulation tile is poor, and it is not resistant to high-speed airflow erosion. In actual use, due to external factors such as aerodynamic force and vibration-coupled load, it cannot effectively disperse and absorb impact force, and is prone to brittle fracture, and the overall stability is not ideal. In order to overcome the above defects, the prior art discloses a related technology for preparing rigid thermal insulation tiles by combining ceramic fiber with phenolic resin materials. The technology improves the toughness and overall stability of the ceramic fiber rigid thermal insulation tile by combining the thermal insulation protection and toughening properties of the ceramic fiber with the phenolic resin material.

[0006] However, the defect of the above technical means is that the ceramic fiber and the phenolic resin material are not compatible and have poor mutual bonding performance, which not only makes the ceramic fiber and the phenolic resin material unable to cooperate effectively, reduces the reinforcing effect of the phenolic resin material on the rigid insulation tile, but also leads to poor structural stability of the rigid insulation tile. Therefore, in a continuous high temperature or rapid temperature rise and fall environment, the rigid insulation tile will be affected by thermal stress, causing cracks or fractures inside the rigid insulation tile, which in turn causes damage to its overall structure, and ultimately leads to a significant reduction in the thermal insulation performance and mechanical properties of the rigid insulation tile, a short effective service life, and the need for frequent maintenance and replacement, and low reliability.

[0007] Furthermore, in the process of preparing rigid insulation tiles by combining ceramic fibers and phenolic resin materials, the bonding performance between the sintering reinforcement agent and the phenolic resin material is poor, resulting in an imbalance in the insulation and mechanical properties of different parts of the rigid insulation tiles, further leading to the deterioration of their overall stability. Summary of the invention

[0008] In order to solve the technical problems existing in the prior art, the present invention provides a method for preparing a rigid thermal insulation tile, which can effectively improve the toughness of the rigid thermal insulation tile while improving the compatibility and bonding performance of ceramic fibers and phenolic resin materials, effectively improve the reinforcement effect of phenolic resin materials on rigid thermal insulation tiles, improve the overall stability of rigid thermal insulation tiles, effectively avoid the thermal stress problem of rigid thermal insulation tiles in a continuous high temperature or rapid temperature rise and fall environment, and improve the effective service life of rigid thermal insulation tiles; and further improve the bonding performance of sintering enhancement additives and phenolic resin materials.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing a rigid heat-insulating tile comprises the following steps: preparing a modified composite slurry, preparing a modified composite fiber material, preparing a molded body, and post-processing.

[0011] The method for preparing the modified composite slurry comprises: putting zirconium oxide, boron carbide, hafnium carbide, tantalum boride, and ethanol solution (volume concentration of 40-45%) into a ball mill, controlling the ball-to-material mass ratio to be 5-6:1, the ball milling speed to be 200-230 rpm, and ball milling for 20-30 minutes to obtain a primary ball milled product; adjusting the pH value of the primary ball milled product to 5-5.5 with hydrochloric acid, spraying a composite modifier, controlling the ball milling temperature to be 60-65° C., and continuing ball milling for 1-2 hours to obtain a modified composite slurry.

[0012] In the preparation of the modified composite slurry, the composite modifier is a silane coupling agent KH-792 and a titanate coupling agent GR-110; the weight ratio of the silane coupling agent KH-792 to the titanate coupling agent GR-110 is 3-3.2:1;

[0013] The weight ratio of zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution is 10-12:10-12:4-5:1.5-1.7:12-13;

[0014] The weight ratio of the primary ball-milled product to the composite modifier is 1:0.12-0.15.

[0015] The method for preparing the modified composite fiber material comprises: chopping alumina fiber, fused quartz glass fiber and aluminum borosilicate fiber to a length of 0.7-0.9 cm respectively to obtain chopped alumina fiber, chopped fused quartz glass fiber and chopped aluminum borosilicate fiber; then putting the chopped alumina fiber, chopped fused quartz glass fiber and chopped aluminum borosilicate fiber into a multi-component modified phenolic treatment liquid, controlling the vacuum degree to be 0.085-0.095 MPa, performing vacuum impregnation for 10-12 hours, filtering out solid matter; transferring the solid matter into a constant temperature box, standing and aging for 48-50 hours at a temperature of 70-75°C, and then drying to obtain the modified composite fiber material.

[0016] In the preparation of the modified composite fiber material, the diameter of the alumina fiber is 10-12 μm, and the alumina content is 85-87 wt%;

[0017] The diameter of fused silica glass fiber is 9-10 μm and the silica content is 97-99 wt%;

[0018] The diameter of aluminum borosilicate fibers is 2-3 μm;

[0019] The weight ratio of the chopped alumina fiber, the chopped fused quartz glass fiber, the chopped aluminum borosilicate fiber, and the multi-modified phenolic treatment liquid is 13-15:18-20:34-35:400-420.

[0020] The preparation method of the multi-modified phenolic treatment liquid is as follows: phenol, formaldehyde and a sodium hydroxide solution with a concentration of 32-35wt% are introduced into a reaction kettle, stirred evenly, heated to 70-75°C at a heating rate of 0.2-0.3°C / min, kept warm and refluxed and stirred for 60-90min, and then the first modified liquid and the second modified liquid are dripped at the same time, and the dripping time of the first modified liquid and the second modified liquid is controlled to be 70-80min; after the first modified liquid and the second modified liquid are dripped, the heat preservation and reflux stirring are continued for 20-30min, and then the third modified liquid is dripped, and the dripping time of the third modified liquid is controlled to be 40-50min; after the third modified liquid is dripped, the heat preservation and reflux stirring are continued for 2-3h to obtain a reaction liquid; the reaction liquid is placed in a vacuum thermostat, and in a vacuum environment of 0.07-0.08MPa, the reaction liquid is kept warm and concentrated at 60-65°C for 1-1.5h to obtain the multi-modified phenolic treatment liquid.

[0021] In the multi-component modified phenolic treatment liquid, the weight ratio of phenol, formaldehyde, sodium hydroxide solution, the first modified liquid, the second modified liquid, and the third modified liquid is 25-27:12-12.5:2-3:8-8.5:5.5-6:8-8.5.

[0022] The preparation method of the first modified liquid is to mix zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol uniformly to obtain the first modified liquid; the weight ratio of zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol in the first modified liquid is 6-6.2:5-5.5:5-5.5:16-17.

[0023] The preparation method of the second modified liquid is to mix tetraisopropyl titanate and anhydrous ethanol evenly to obtain the second modified liquid; the weight ratio of tetraisopropyl titanate to anhydrous ethanol in the second modified liquid is 1:5-5.5.

[0024] The preparation method of the third modified liquid is as follows: dicarbonyl bis(cyclopentadienyl) titanium, phenol, and a sodium hydroxide solution with a concentration of 32-35wt% are put into a reactor, stirred evenly, heated to 70-75°C, and stirred for 1-1.5 hours to obtain a third modifier; the weight ratio of dicarbonyl bis(cyclopentadienyl) titanium, phenol, and sodium hydroxide solution is 60-62:21-23:3-3.5.

[0025] The method for preparing the molded body comprises: uniformly mixing the modified composite slurry, the modified composite fiber material and deionized water to obtain the molded body slurry; introducing the molded body slurry into a mold with a drainage hole, standing for 10-15 minutes, vacuum filtering to remove excess liquid, and then controlling the pressing pressure to 5-6MPa to perform a pressing process to obtain the molded body.

[0026] In the preparation of the molded body, the weight ratio of the modified composite slurry, the modified composite fiber material and the deionized water is 7-7.5:20-22:18-20.

[0027] The post-treatment method is as follows: placing the molded body in a constant temperature box, standing it for 10-12 hours at a temperature of 85-90°C, drying it at a temperature of 115-125°C for 22-24 hours, demolding it, and obtaining a dried molded body; then placing the dried molded body in a roasting furnace, controlling the heating rate to be 2-2.5°C / min, heating it to 1200-1250°C, roasting it at this temperature for 2-3 hours, and cooling it to room temperature with the furnace to obtain a rigid insulation tile.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The method for preparing the rigid thermal insulation tile of the present invention comprises the following steps: in the step of preparing the modified composite slurry, zirconium oxide, boron carbide, hafnium carbide and tantalum boride are selected as the main raw materials of the main sintering enhancement additives, and after ball milling to obtain the primary ball milled product, the composite modifier (silane coupling agent KH-792 and titanate coupling agent GR-110) is used to perform ball milling modification treatment on the product. On the one hand, the dual reactivity of the diamino functional group and the three hydrolyzed methoxy functional groups in the silane coupling agent KH-792 is utilized to improve the compatibility of zirconium oxide, boron carbide, hafnium carbide and tantalum boride in the modified composite slurry with the subsequent phenolic resin material, thereby improving the bonding performance of the two; on the other hand, the titanate coupling agent GR-110 is used to improve the bonding performance of the two. The long-chain alkane group and titanium hydroxyl activity of R-110 further improve the bonding performance of each component in the aforementioned modified composite slurry with the phenolic resin material; in the step of preparing the modified composite fiber material, alumina fiber, fused quartz glass fiber, and aluminum borosilicate fiber are selected as ceramic fiber raw materials, and after being chopped, they are put into a multi-component modified phenolic treatment liquid for vacuum impregnation to obtain a modified composite fiber material; wherein, in the preparation of the multi-component modified phenolic treatment liquid, the phenolic reaction liquid is first modified with a zirconium modification liquid (a first modification liquid) and an organic titanium modification liquid (a second modification liquid), and then a coordination modification liquid is used in which dicarbonyl bis(cyclopentadienyl) titanium and phenol undergo a coordination reaction under base catalysis. (The third modified liquid) modifies the phenolic reaction liquid; in the process of phenolic synthesis, zirconium raw materials, organic titanium, and coordinated titanium are introduced as cross-linking points to enhance the interaction between phenolic resin materials, promote the cross-linking reaction of phenolic resin materials, and improve their thermal insulation performance. At the same time, the cross-linking effect between phenolic resin materials and ceramic fiber raw materials is improved, the interaction force and composite strength between the two are enhanced, and the coating performance of ceramic fiber raw materials is improved, thereby achieving the toughening effect of rigid thermal insulation tiles, improving the strengthening effect of phenolic resin materials on rigid thermal insulation tiles, and improving the overall stability of rigid thermal insulation tiles; and further improving the bonding performance of phenolic resin materials and sintering enhancement additives, and achieving The strengthening and modification effect on rigid insulation tiles can improve the stability of rigid insulation tiles in continuous high temperature or rapid temperature rise and fall environments, and further improve the mechanical properties of rigid insulation tiles; the aforementioned technical means cooperate and work synergistically with each other, which can effectively improve the toughness of rigid insulation tiles while improving the compatibility and bonding performance of ceramic fibers and phenolic resin materials, effectively improve the strengthening effect of phenolic resin materials on rigid insulation tiles, improve the overall stability of rigid insulation tiles, effectively avoid thermal stress problems of rigid insulation tiles in continuous high temperature or rapid temperature rise and fall environments, and increase the effective service life of rigid insulation tiles; and further improve the bonding performance of sintering enhancement additives and phenolic resin materials.

[0030] (2) The method for preparing the rigid thermal insulation tile of the present invention has a thermal conductivity of 0.029-0.031 W / (m·k), a compressive strength of 6.30-6.33 MPa, a tensile strength of 2.70-2.72 MPa, a flexural strength of 2.21-2.25 MPa, and a fracture toughness of 1.50-1.51 MPa·m 1 / 2 .

[0031] (3) The method for preparing the rigid thermal insulation tile of the present invention, after the rigid thermal insulation tile is placed in a temperature environment of 1200°C for 300 hours, no cracks or deformation occur, and the compression strength can still reach 5.87-5.92MPa, the tensile strength can still reach 2.57-2.60MPa, the bending strength can still reach 2.07-2.11MPa, and the fracture toughness can still reach 1.42-1.45MPa·m 1 / 2 .

[0032] (4) The method for preparing the rigid thermal insulation tile of the present invention can produce a rigid thermal insulation tile without cracks or deformation after 20 rapid temperature changes (from room temperature to 1200°C), and the compression strength can still reach 5.77-5.83MPa, and the bending strength can still reach 2.00-2.05MPa. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described.

[0034] Example 1

[0035] This embodiment provides a method for preparing a rigid thermal insulation tile, specifically:

[0036] 1. Preparation of modified composite slurry

[0037] Zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution (volume concentration of 40%) are put into a ball mill, the ball-to-material mass ratio is controlled to 5:1, the ball milling speed is 200 rpm, and the ball milling treatment is carried out for 20 minutes to obtain a primary ball milled product; after adjusting the pH of the primary ball milled product to 5 with hydrochloric acid, a composite modifier is sprayed in, the ball milling temperature is controlled to 60°C, and the ball milling is continued for 1 hour to obtain a modified composite slurry.

[0038] The composite modifier is a silane coupling agent KH-792 and a titanate coupling agent GR-110; the weight ratio of the silane coupling agent KH-792 and the titanate coupling agent GR-110 is 3:1.

[0039] The weight ratio of zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution is 10:10:4:1.5:12.

[0040] The weight ratio of the primary ball-milled product to the composite modifier is 1:0.12.

[0041] 2. Preparation of modified composite fiber materials

[0042] Alumina fiber, fused quartz glass fiber, and aluminum borosilicate fiber are chopped to a length of 0.7 cm respectively to obtain chopped alumina fiber, chopped fused quartz glass fiber, and chopped aluminum borosilicate fiber; then the chopped alumina fiber, chopped fused quartz glass fiber, and chopped aluminum borosilicate fiber are put into a multi-modified phenolic treatment liquid, the vacuum degree is controlled to be 0.085 MPa, and after vacuum impregnation for 10 hours, the solid matter is filtered out; the solid matter is transferred to a constant temperature box, aged at 70°C for 48 hours, and then dried to obtain a modified composite fiber material.

[0043] The diameter of the alumina fiber is 11 μm and the alumina content is 86 wt%.

[0044] The diameter of the fused silica glass fiber is 9 μm and the silica content is 98 wt%.

[0045] The diameter of the aluminum borosilicate fibers is 2 μm.

[0046] The weight ratio of the chopped alumina fiber, the chopped fused silica glass fiber, the chopped aluminum borosilicate fiber, and the multi-modified phenolic treatment liquid is 13:18:34:400.

[0047] The preparation method of the multi-modified phenolic treatment liquid is as follows: phenol, formaldehyde and sodium hydroxide solution (with a concentration of 32wt%) are introduced into a reaction kettle, stirred for 5 minutes, and then heated to 70°C at a heating rate of 0.2°C / min with stirring, and then the first modified liquid and the second modified liquid are simultaneously dripped, and the dripping time of the first modified liquid and the second modified liquid is controlled to be 70 minutes; after the first modified liquid and the second modified liquid are dripped, the stirring is continued for 20 minutes under the heat preservation and reflux, and then the third modified liquid is dripped, and the dripping time of the third modified liquid is controlled to be 40 minutes; after the dripping of the third modified liquid is completed, the stirring is continued for 2 hours under the heat preservation and reflux, and a reaction liquid is obtained; the reaction liquid is placed in a vacuum thermostat, and in a vacuum environment of 0.07MPa, the reaction liquid is concentrated at 60°C for 1 hour to obtain the multi-modified phenolic treatment liquid.

[0048] Among them, the weight ratio of phenol, formaldehyde, sodium hydroxide solution, the first modifying liquid, the second modifying liquid and the third modifying liquid is 25:12:2:8:5.5:8.

[0049] The preparation method of the first modified liquid is to mix zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol uniformly to obtain the first modified liquid; the weight ratio of zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol in the first modified liquid is 6:5:5:16.

[0050] The preparation method of the second modified liquid is to mix tetraisopropyl titanate and anhydrous ethanol evenly to obtain the second modified liquid; the weight ratio of tetraisopropyl titanate to anhydrous ethanol in the second modified liquid is 1:5.

[0051] The preparation method of the third modified liquid is as follows: dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution (concentration of 32wt%) are added into a reaction kettle, stirred for 5 minutes, heated to 70°C with stirring, and stirred for 1 hour to obtain a third modifier. The weight ratio of dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution is 60:21:3.

[0052] 3. Preparation of molded body

[0053] The modified composite slurry, the modified composite fiber material and the deionized water are mixed evenly to obtain a molded body slurry; the molded body slurry is introduced into a mold with a drainage hole, and after standing for 10 minutes, the excess liquid is removed by vacuum filtration, and then the pressing pressure is controlled to 5 MPa, and a pressing process is performed to obtain a molded body.

[0054] Among them, the weight ratio of modified composite slurry, modified composite fiber material and deionized water is 7:20:18.

[0055] 4. Post-processing

[0056] The molded body is placed in a constant temperature box, allowed to stand at 85°C for 10 hours, dried at 115°C for 22 hours, and demolded to obtain a dry molded body; the dry molded body is then placed in a roasting furnace, the heating rate is controlled to be 2°C / min, the temperature is raised to 1200°C, and the heat is kept and roasted for 2 hours, and the furnace is cooled to room temperature to obtain a rigid insulating tile.

[0057] Example 2

[0058] This embodiment provides a method for preparing a rigid thermal insulation tile, specifically:

[0059] 1. Preparation of modified composite slurry

[0060] Zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution (volume concentration of 42%) are put into a ball mill, the ball-to-material mass ratio is controlled to 5.5:1, the ball milling speed is 220 rpm, and the ball milling treatment is carried out for 25 minutes to obtain a primary ball milled product; after adjusting the pH of the primary ball milled product to 5.2 with hydrochloric acid, a composite modifier is sprayed in, the ball milling temperature is controlled to 62°C, and the ball milling is continued for 1.5 hours to obtain a modified composite slurry.

[0061] The composite modifier is a silane coupling agent KH-792 and a titanate coupling agent GR-110; the weight ratio of the silane coupling agent KH-792 to the titanate coupling agent GR-110 is 3.1:1.

[0062] The weight ratio of zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution is 11:11:4.5:1.6:12.5.

[0063] The weight ratio of the primary ball-milled product to the composite modifier is 1:0.13.

[0064] 2. Preparation of modified composite fiber materials

[0065] Alumina fibers, fused quartz glass fibers, and aluminum borosilicate fibers were chopped to a length of 0.8 cm respectively to obtain chopped alumina fibers, chopped fused quartz glass fibers, and chopped aluminum borosilicate fibers; the chopped alumina fibers, chopped fused quartz glass fibers, and chopped aluminum borosilicate fibers were then put into a multinarily modified phenolic treatment solution, the vacuum degree was controlled to be 0.09 MPa, and after vacuum impregnation for 11 hours, the solid matter was filtered out; the solid matter was transferred to a constant temperature box, aged at 72°C for 49 hours, and then dried to obtain a modified composite fiber material.

[0066] The diameter of the alumina fiber is 11 μm and the alumina content is 86 wt%.

[0067] The diameter of the fused silica glass fiber is 9 μm and the silica content is 98 wt%.

[0068] The diameter of the aluminum borosilicate fibers is 2 μm.

[0069] The weight ratio of the chopped alumina fiber, the chopped fused quartz glass fiber, the chopped aluminum borosilicate fiber, and the multi-modified phenolic treatment liquid is 14:19:34.5:410.

[0070] The preparation method of the multi-modified phenolic treatment liquid is as follows: phenol, formaldehyde and sodium hydroxide solution (with a concentration of 33wt%) are introduced into a reaction kettle, stirred for 8 minutes, and then heated to 72°C at a heating rate of 0.25°C / min, kept warm and refluxed for 80 minutes, and then the first modified liquid and the second modified liquid are dripped at the same time, and the dripping time of the first modified liquid and the second modified liquid is controlled to be 75 minutes; after the first modified liquid and the second modified liquid are dripped, the stirring is continued for 25 minutes, and then the third modified liquid is dripped, and the dripping time of the third modified liquid is controlled to be 45 minutes; after the dripping of the third modified liquid is completed, the stirring is continued for 2.5 hours to obtain a reaction liquid; the reaction liquid is placed in a vacuum thermostat, and in a vacuum environment of 0.075MPa, the reaction liquid is concentrated at 62°C for 1.2 hours to obtain the multi-modified phenolic treatment liquid.

[0071] Among them, the weight ratio of phenol, formaldehyde, sodium hydroxide solution, the first modifying liquid, the second modifying liquid and the third modifying liquid is 26:12.2:2.5:8.3:5.8:8.2.

[0072] The preparation method of the first modified liquid is to mix zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol uniformly to obtain the first modified liquid; the weight ratio of zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol in the first modified liquid is 6.1:5.2:5.2:16.5.

[0073] The preparation method of the second modified liquid is to mix tetraisopropyl titanate and anhydrous ethanol evenly to obtain the second modified liquid; the weight ratio of tetraisopropyl titanate to anhydrous ethanol in the second modified liquid is 1:5.3.

[0074] The preparation method of the third modified liquid is as follows: dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution (concentration of 34wt%) are added into a reactor, stirred for 8 minutes, heated to 72°C with stirring, and stirred for 1.3 hours to obtain a third modifier. The weight ratio of dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution is 61:22:3.3.

[0075] 3. Preparation of molded body

[0076] The modified composite slurry, the modified composite fiber material and the deionized water are mixed evenly to obtain a molded body slurry; the molded body slurry is introduced into a mold with a drainage hole, and after standing for 12 minutes, the excess liquid is removed by vacuum filtration, and then the pressing pressure is controlled to 5.5 MPa, and a pressing process is performed to obtain a molded body.

[0077] Among them, the weight ratio of the modified composite slurry, the modified composite fiber material and the deionized water is 7.3:21:19.

[0078] 4. Post-processing

[0079] The molded body is placed in a constant temperature box, allowed to stand at 88°C for 11 hours, dried at 120°C for 23 hours, and demolded to obtain a dry molded body; the dry molded body is then placed in a roasting furnace, the heating rate is controlled to be 2.2°C / min, the temperature is raised to 1230°C, and the heat is kept and roasted for 2.5 hours, and the furnace is cooled to room temperature to obtain a rigid insulating tile.

[0080] Example 3

[0081] This embodiment provides a method for preparing a rigid thermal insulation tile, specifically:

[0082] 1. Preparation of modified composite slurry

[0083] Zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution (volume concentration of 45%) are put into a ball mill, the ball-to-material mass ratio is controlled to 6:1, the ball milling speed is 230 rpm, and the ball milling treatment is carried out for 30 minutes to obtain a primary ball milled product; after adjusting the pH of the primary ball milled product to 5.5 with hydrochloric acid, a composite modifier is sprayed in, the ball milling temperature is controlled to 65°C, and the ball milling is continued for 2 hours to obtain a modified composite slurry.

[0084] The composite modifier is a silane coupling agent KH-792 and a titanate coupling agent GR-110; the weight ratio of the silane coupling agent KH-792 to the titanate coupling agent GR-110 is 3.2:1.

[0085] The weight ratio of zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution is 12:12:5:1.7:13.

[0086] The weight ratio of the primary ball-milled product to the composite modifier is 1:0.15.

[0087] 2. Preparation of modified composite fiber materials

[0088] Alumina fibers, fused quartz glass fibers, and aluminum borosilicate fibers were chopped to a length of 0.9 cm respectively to obtain chopped alumina fibers, chopped fused quartz glass fibers, and chopped aluminum borosilicate fibers; the chopped alumina fibers, chopped fused quartz glass fibers, and chopped aluminum borosilicate fibers were then put into a multinarily modified phenolic treatment solution, the vacuum degree was controlled to be 0.095 MPa, and after vacuum impregnation for 12 hours, the solid matter was filtered out; the solid matter was transferred into a constant temperature box, aged for 50 hours at 75°C, and then dried to obtain a modified composite fiber material.

[0089] The diameter of the alumina fiber is 11 μm and the alumina content is 86 wt%.

[0090] The diameter of the fused silica glass fiber is 9 μm and the silica content is 98 wt%.

[0091] The diameter of the aluminum borosilicate fibers is 2 μm.

[0092] The weight ratio of the chopped alumina fiber, the chopped fused silica glass fiber, the chopped aluminum borosilicate fiber, and the multi-modified phenolic treatment liquid is 15:20:35:420.

[0093] The preparation method of the multi-component modified phenolic treatment liquid is as follows: phenol, formaldehyde and sodium hydroxide solution (with a concentration of 35wt%) are introduced into a reaction kettle, stirred for 10 minutes, and then heated to 75°C at a heating rate of 0.3°C / min, and kept warm and refluxed for 90 minutes, and then the first modified liquid and the second modified liquid are dripped at the same time, and the dripping time of the first modified liquid and the second modified liquid is controlled to be 80 minutes; after the first modified liquid and the second modified liquid are dripped, the stirring is continued for 30 minutes, and then the third modified liquid is dripped, and the dripping time of the third modified liquid is controlled to be 50 minutes; after the dripping of the third modified liquid is completed, the stirring is continued for 3 hours to obtain a reaction liquid; the reaction liquid is placed in a vacuum thermostat, and in a vacuum environment of 0.08MPa, it is kept warm and concentrated at 65°C for 1.5 hours to obtain the multi-component modified phenolic treatment liquid.

[0094] Among them, the weight ratio of phenol, formaldehyde, sodium hydroxide solution, the first modifying liquid, the second modifying liquid and the third modifying liquid is 27:12.5:3:8.5:6:8.5.

[0095] The preparation method of the first modified liquid is to mix zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol evenly to obtain the first modified liquid; the weight ratio of zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol in the first modified liquid is 6.2:5.5:5.5:17.

[0096] The preparation method of the second modified liquid is to mix tetraisopropyl titanate and anhydrous ethanol evenly to obtain the second modified liquid; the weight ratio of tetraisopropyl titanate to anhydrous ethanol in the second modified liquid is 1:5.5.

[0097] The preparation method of the third modified liquid is as follows: dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution (concentration of 35wt%) are added into a reactor, stirred for 10 minutes, heated to 75°C with stirring, and stirred for 1.5 hours to obtain a third modifier. The weight ratio of dicarbonyl bis(cyclopentadienyl)titanium, phenol, and sodium hydroxide solution is 62:23:3.5.

[0098] 3. Preparation of molded body

[0099] The modified composite slurry, the modified composite fiber material and the deionized water are mixed evenly to obtain a molded body slurry; the molded body slurry is introduced into a mold with a drainage hole, and after standing for 15 minutes, the excess liquid is removed by vacuum filtration, and then the pressing pressure is controlled to 6 MPa, and a pressing process is performed to obtain a molded body.

[0100] Among them, the weight ratio of the modified composite slurry, the modified composite fiber material and the deionized water is 7.5:22:20.

[0101] 4. Post-processing

[0102] The molded body is placed in a constant temperature box, allowed to stand at 90°C for 12 hours, dried at 125°C for 24 hours, and demolded to obtain a dry molded body; the dry molded body is then placed in a roasting furnace, the heating rate is controlled to be 2.5°C / min, the temperature is raised to 1250°C, and the heat is kept and roasted for 3 hours, and the furnace is cooled to room temperature to obtain a rigid insulating tile.

[0103] Comparative Example 1

[0104] The technical solution of Example 2 is adopted, but the differences are: 1) in the step of preparing the modified composite slurry, the addition of the silane coupling agent KH-792 and the titanate coupling agent GR-110 is omitted; 2) in the step of preparing the modified composite fiber material, the addition of the third modifying liquid is omitted.

[0105] Comparative Example 2

[0106] The technical solution of Example 2 is adopted, but the differences are: 1) in the step of preparing the modified composite slurry, the addition of hafnium carbide and tantalum boride is omitted; 2) in the step of preparing the modified composite fiber material, the addition of the first modifying liquid and the second modifying liquid is omitted.

[0107] Rigid thermal insulation tiles were prepared using the technical solutions of Examples 1-3 and Comparative Examples 1-2, and the thermal conductivity, compressive strength, tensile strength, flexural strength, and fracture toughness of the rigid thermal insulation tiles prepared in Examples 1-3 and Comparative Examples 1-2 were tested respectively. At the same time, the rigid thermal insulation tiles prepared in Examples 1-3 and Comparative Examples 1-2 were placed in a high-temperature box furnace, heated to 1200°C, and subjected to heat treatment for 300 hours. After cooling to room temperature with the furnace, the compressive strength, tensile strength, flexural strength, and fracture toughness of the rigid thermal insulation tiles after heat treatment were tested respectively, and the rigid thermal insulation tiles were observed to see whether cracks or deformation occurred.

[0108] Among them, the fracture toughness was tested by the single-edge notched beam method (SENB method).

[0109] The specific test results are shown in the following table:

[0110]

[0111] Furthermore, the rigid thermal insulation tiles prepared in Examples 1-3 and Comparative Examples 1-2 were placed in a high-temperature box furnace, and the heating rate was controlled to be 30°C / min, and the temperature was raised from room temperature to 1200°C. After keeping the temperature for 30 minutes, the cooling rate was controlled to be 20°C / min, and the temperature was lowered from 1200°C to room temperature, and the temperature was left at room temperature for 30 minutes. The aforementioned rapid heating and cooling process from room temperature to 1200°C was regarded as one temperature change cycle. After 20 consecutive temperature change cycles, each rigid thermal insulation tile was observed to see if cracks or deformation occurred, and the compressive strength and bending strength of each rigid thermal insulation tile were tested. The specific test results are shown in the following table:

[0112]

[0113] It can be seen that in the preparation method of the rigid thermal insulation tile of Examples 1-3, in the step of preparing the modified composite slurry, zirconium oxide, boron carbide, hafnium carbide, and tantalum boride are selected as the main raw materials of the main sintering enhancement additives, and after ball milling to obtain the primary ball-milled product, a composite modifier (silane coupling agent KH-792 and titanate coupling agent GR-110) is used to perform ball milling modification treatment on it. On the one hand, the dual reactivity of the diamino functional group and the three hydrolyzed methoxy functional groups in the silane coupling agent KH-792 is utilized to improve the compatibility of zirconium oxide, boron carbide, hafnium carbide, and tantalum boride in the modified composite slurry with the subsequent phenolic resin material, thereby improving the bonding performance of the two; on the other hand, the titanate coupling agent is used to The long-chain alkane group and titanium hydroxyl activity of the cross-linking agent GR-110 are used to further improve the bonding performance of each component in the modified composite slurry with the phenolic resin material; in the step of preparing the modified composite fiber material, alumina fiber, fused quartz glass fiber, and aluminum borosilicate fiber are selected as ceramic fiber raw materials, and after being chopped, they are put into the multi-component modified phenolic treatment liquid for vacuum impregnation to obtain the modified composite fiber material; wherein, in the preparation of the multi-component modified phenolic treatment liquid, the phenolic reaction liquid is first modified by a zirconium modification liquid (a first modification liquid) and an organic titanium modification liquid (a second modification liquid), and then a coordination modification method in which dicarbonyl bis (cyclopentadienyl) titanium and phenol undergo a coordination reaction under base catalysis is used. The phenolic reaction liquid is modified by a modified liquid (the third modified liquid); in the process of phenolic synthesis, zirconium raw materials, organic titanium, and coordinated titanium are introduced as cross-linking points to enhance the interaction between phenolic resin materials, promote the cross-linking reaction of phenolic resin materials, and improve their thermal insulation performance. At the same time, the cross-linking effect between phenolic resin materials and ceramic fiber raw materials is improved, the interaction force and composite strength between the two are enhanced, and the coating performance of ceramic fiber raw materials is improved, thereby achieving the toughening effect of rigid thermal insulation tiles, improving the strengthening effect of phenolic resin materials on rigid thermal insulation tiles, and improving the overall stability of rigid thermal insulation tiles; and further improving the bonding performance of phenolic resin materials and sintering enhancement additives, with the actual The present invention has an enhancing and modifying effect on rigid insulation tiles, improves the stability of rigid insulation tiles in continuous high temperature or rapid temperature rise and fall environments, and further improves the mechanical properties of rigid insulation tiles; the aforementioned technical means cooperate and work synergistically with each other, which can effectively improve the toughness of rigid insulation tiles while improving the compatibility and bonding performance of ceramic fibers and phenolic resin materials, effectively improve the reinforcing effect of phenolic resin materials on rigid insulation tiles, improve the overall stability of rigid insulation tiles, effectively avoid thermal stress problems of rigid insulation tiles in continuous high temperature or rapid temperature rise and fall environments, and increase the effective service life of rigid insulation tiles; and further improve the bonding performance of sintering enhancement additives and phenolic resin materials.

[0114] Unless otherwise specified, all percentages used in the present invention are by mass.

[0115] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a rigid thermal insulation tile, characterized in that: The method comprises the following steps: preparing a modified composite slurry, preparing a modified composite fiber material, preparing a molded body, and post-processing; The method for preparing the modified composite slurry is to put zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution into a ball mill and grind them evenly to obtain a primary ball milled product; after adjusting the pH of the primary ball milled product to 5-5.5, spray a composite modifier, continue ball milling, and obtain a modified composite slurry; The composite modifier is a silane coupling agent KH-792 and a titanate coupling agent GR-110; The method for preparing the modified composite fiber material comprises: putting short-cut alumina fibers, short-cut fused quartz glass fibers, and short-cut aluminum borosilicate fibers into a multi-component modified phenolic treatment solution, performing vacuum impregnation, and filtering out solids; the solids are allowed to stand for aging at a temperature of 70-75° C., and then dried to obtain the modified composite fiber material; The preparation method of the multi-component modified phenolic treatment liquid comprises the following steps: introducing phenol, formaldehyde and sodium hydroxide solution into a reaction kettle, mixing them uniformly, heating to 70-75° C., preserving the temperature, refluxing and stirring, and then simultaneously dripping a first modified liquid and a second modified liquid, and after the dripping is completed, continuing the preserving temperature, refluxing and stirring, and then dripping a third modified liquid, and after the dripping is completed, continuing the preserving temperature, refluxing and stirring to obtain a reaction liquid; the reaction liquid is vacuum concentrated to obtain a multi-component modified phenolic treatment liquid; The first modified liquid is prepared by uniformly mixing zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol; The second modified liquid is prepared by uniformly mixing tetraisopropyl titanate and anhydrous ethanol; The preparation method of the third modified liquid is to mix dicarbonyl bis(cyclopentadienyl)titanium, phenol and sodium hydroxide solution, heat it to 70-75° C., and stir it while keeping warm. The method for preparing the molded body comprises: uniformly mixing the modified composite slurry, the modified composite fiber material and deionized water to obtain a molded body slurry; statically forming the molded body slurry, vacuum filtering and pressing to obtain a molded body; The weight ratio of the modified composite slurry, the modified composite fiber material, and the deionized water is 7-7.5:20-22:18-20; The post-treatment method is that the molded body is dried and calcined to obtain a rigid thermal insulation tile.

2. The method for preparing the rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the modified composite slurry, after the composite modifier is sprayed, the ball milling temperature is controlled to be 60-65° C. and the ball milling time is 1-2 h; The weight ratio of the silane coupling agent KH-792 to the titanate coupling agent GR-110 in the composite modifier is 3-3.2:

1.

3. The method for preparing the rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the modified composite slurry, the weight ratio of zirconium oxide, boron carbide, hafnium carbide, tantalum boride and ethanol solution is 10-12:10-12:4-5:1.5-1.7:12-13; The weight ratio of the primary ball-milled product to the composite modifier is 1:0.12-0.

15.

4. The method for preparing the rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the modified composite fiber material, the length of the chopped alumina fiber is 0.7-0.9 cm, the diameter is 10-12 μm, and the alumina content is 85-87 wt %; The chopped fused silica glass fibers have a length of 0.7-0.9 cm, a diameter of 9-10 μm, and a silica content of 97-99 wt%; The length of the chopped aluminum borosilicate fibers is 0.7-0.9 cm and the diameter is 2-3 μm.

5. The method for preparing the rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the modified composite fiber material, the vacuum degree of vacuum impregnation is 0.085-0.095 MPa, and the vacuum impregnation time is 10-12 hours; The static aging time at 70-75℃ is 48-50h; The weight ratio of the chopped alumina fiber, the chopped fused quartz glass fiber, the chopped aluminum borosilicate fiber, and the multi-modified phenolic treatment liquid is 13-15:18-20:34-35:400-420.

6. The method for preparing the rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the poly-modified phenolic treatment solution, the concentration of the sodium hydroxide solution is 32-35wt%; The heating rate to 70-75°C is 0.2-0.3°C / min; The dripping time of the first modifying liquid and the second modifying liquid is 70-80 minutes.

7. The method for preparing a rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the multi-component modified phenolic treatment solution, the third modified solution is added dropwise for 40-50 minutes; After the third modified liquid is added, continue to keep warm and reflux with stirring for 2-3 hours; The vacuum degree of vacuum concentration is 0.07-0.08MPa, the temperature is 60-65°C, and the insulation treatment time is 1-1.5h.

8. The method for preparing a rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the multi-modified phenolic treatment liquid, the weight ratio of phenol, formaldehyde, sodium hydroxide solution, first modified liquid, second modified liquid, and third modified liquid is 25-27:12-12.5:2-3:8-8.5:5.5-6:8-8.5; The weight ratio of zirconium oxychloride, acetylacetone, hydrogen peroxide and anhydrous ethanol in the first modified liquid is 6-6.2:5-5.5:5-5.5:16-17; The weight ratio of tetraisopropyl titanate to anhydrous ethanol in the second modified solution is 1:5-5.5; In the preparation of the third modified solution, the weight ratio of dicarbonylbis(cyclopentadienyl)titanium, phenol and sodium hydroxide solution is 60-62:21-23:3-3.

5.

9. The method for preparing a rigid thermal insulation tile according to claim 1, characterized in that: In the preparation of the molded body, the static molding time is 10-15 minutes; The pressing pressure is 5-6MPa.

10. The method for preparing a rigid thermal insulation tile according to claim 1, characterized in that: The post-treatment method is as follows: the molded body is allowed to stand at a temperature of 85-90° C. for 10-12 hours, then dried at a temperature of 115-125° C. for 22-24 hours, and demoulded to obtain a dried molded body; the dried molded body is calcined at 1200-1250° C. to obtain a rigid thermal insulation tile.

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