Thermal insulation filling material and steel shell anti-corrosion thermal insulation pipe

Abstract

The present invention discloses a thermal insulation filling material and a steel-shell anti-corrosion insulation pipe, belonging to the technical field of thermal insulation materials. The material comprises a main ingredient, auxiliary ingredients, and additives. The main ingredients include expanded perlite, mica powder, multi-coated vitrified microspheres, expanded vermiculite silica fume, and high-temperature resistant chopped glass fiber; auxiliary ingredients include phenolic resin, aluminum silicate fiber, glass fiber, sulfoaluminate cement, and slag powder; and additives include redispersible latex powder, hydroxypropyl methylcellulose ether, polypropylene fiber, a water reducer, aluminum hydroxide, melamine cyanurate, and expanded graphite. This material addresses the problems of existing thermal insulation filling materials, such as high thermal conductivity, insufficient compressive strength, and poor flame retardancy. It offers comprehensive performance, safety, and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of heat insulation materials, and in particular to a heat insulation filling material and a steel shell anti-corrosion heat insulation pipe. Background Art

[0002] With the acceleration of industrialization and urbanization, pipeline transportation systems have been widely used in energy, chemical, and municipal engineering sectors. Steel pipelines, due to their high strength and durability, have become a primary material for transporting liquids and gases. However, over time, steel pipelines face serious corrosion and heat loss issues. These problems not only shorten the pipeline's service life but also lead to energy waste and environmental pollution.

[0003] Although traditional anti-corrosion coatings can protect pipelines from corrosion to a certain extent, they are prone to falling off or becoming ineffective in highly corrosive environments, such as marine environments and chemical plants, leading to increased corrosion of pipelines. Although cathodic protection technology is effective, it has high maintenance costs and is difficult to implement in certain complex environments. Traditional insulation materials such as rock wool and polyurethane foam are prone to aging and deformation during long-term use, resulting in a decrease in insulation effect and increased energy loss. At the same time, many traditional insulation materials are unstable in harsh environments such as high temperature, low temperature, and humidity, and are prone to losing their original insulation properties. In addition, traditional anti-corrosion and insulation materials require complex processes and technologies during construction, with long construction cycles and high costs. Once the pipeline is corroded or the insulation fails, repair and replacement work is cumbersome and the maintenance cost is high.

[0004] Therefore, there is an urgent need for an insulating filling material and a steel shell anti-corrosion insulating pipe to solve the defects in the existing technology, significantly improve the insulation effect and anti-corrosion performance of steel pipelines, extend the service life of the pipeline, and reduce energy waste. Summary of the Invention

[0005] To this end, the present invention provides an insulating filling material and a steel shell anti-corrosion insulating pipe, which solves the problems of high thermal conductivity, insufficient compressive strength and poor flame retardant performance of existing insulating filling materials, and provides an insulating filling material and a steel shell anti-corrosion insulating pipe with comprehensive performance, safety and reliability.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] According to a first aspect of the present invention, a thermal insulation filling material is provided, comprising a main ingredient, auxiliary ingredients, and additives, wherein the main ingredient comprises the following raw materials in parts by weight: 45-75 parts of expanded perlite, 5-10 parts of mica powder, 8-12 parts of multi-coated vitrified microspheres, 2.8-5.3 parts of expanded vermiculite silica fume, and 1-3 parts of high-temperature resistant chopped glass fiber;

[0008] The auxiliary materials include the following raw materials in parts by weight: 8-14 parts of phenolic resin, 3-6 parts of aluminum silicate fiber, 4.5-7.5 parts of glass fiber, 30-50 parts of sulphoaluminate cement, and 9-16 parts of slag powder;

[0009] The additive comprises the following raw materials in parts by weight: 4.5-6.5 parts of redispersible latex powder, 0.5-0.8 parts of hydroxypropyl methylcellulose ether, 0.07-0.12 parts of polypropylene fiber, 0.03-0.1 parts of water reducer, 20-30 parts of aluminum hydroxide, 3-8 parts of melamine cyanurate, and 5-10 parts of expanded graphite.

[0010] Furthermore, the method for preparing the multi-coated glass microspheres comprises the following steps:

[0011] S1. The vitrified microspheres were first coated with silica with methyl orthosilicate, and then coated with alumina with aluminum nitrate. After washing, filtering, drying and calcining, silica / alumina double-coated vitrified microspheres were obtained.

[0012] S2. n-butyl titanate was dissolved in an ethanol solution, tartaric acid was added, and the reaction mixture was stirred to form a mixed solution. Then, double-coated vitrified microspheres were added. After solvent thermal treatment, double-coated vitrified microspheres preliminarily coated with titanium dioxide were obtained.

[0013] S3. The double-coated vitrified microspheres coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500-600 ° C for 3-5 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain a preliminary sintered titanium dioxide / vitrified microspheres.

[0014] The preliminarily sintered titanium dioxide / vitrified microspheres are placed in a tube furnace, the sintering temperature is set to 800-900°C, the sintering time is 4-6 hours, and after sintering, they are naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres;

[0015] S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 1.5-3 parts of polydimethylsiloxane, 1.5-3 parts of thioglycolic acid, and 0.03-0.15 parts of a photoinitiator are added to the mixture to react. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

[0016] Furthermore, the specific steps of S1 are as follows:

[0017] (1) Weigh 0.8-1.5 parts of vitrified microspheres, add 7-12 parts of distilled water, mix well to form a slurry, place the slurry in a constant temperature water bath at 55°C, add 0.2-0.3 parts of 2% surfactant, and stir thoroughly for 10-15 minutes to prepare a vitrified microsphere suspension; adjust the pH value of the system to 9-10 with 10% sodium hydroxide solution, slowly add 22-30 parts of 10% methyl orthosilicate solution, and continue the reaction for 4-8 hours. After the reaction is completed, wash with water, filter, and dry, calcine at 400-600°C for 2-3 hours, then mix the vitrified microspheres with the sodium hydroxide solution, stir well, heat to 50-60°C, stir for 2-4 hours, then add methyl orthosilicate, continue stirring for 5-8 hours, filter out the treated vitrified microspheres, wash with pure water 3-5 times, place in an oven, and dry under air conditions to obtain silica-coated vitrified microspheres;

[0018] (2) Add 9-11 parts of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.2-0.3 parts of a 2% surfactant, and stir thoroughly for 10-15 minutes to prepare a glass microsphere suspension. Use 10% hydrochloric acid solution to adjust the pH of the system to 2-4; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 3-7 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 450-750°C to obtain silica / alumina double-coated glass microspheres.

[0019] Furthermore, the specific steps of S2 are as follows:

[0020] Dissolve 0.1-0.2 parts of n-butyl titanate in 5-10 parts of anhydrous ethanol, stir evenly, add 0.01-0.02 parts of tartaric acid, continue stirring for 20-40 minutes to form a mixed reaction liquid, add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 20-40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 180-220°C for solvent thermal treatment, maintaining the reaction temperature at 180-220°C for 16-22 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 70-90°C for 10-14 hours to obtain double-coated glass microspheres preliminarily coated with titanium dioxide.

[0021] According to a second aspect of the present invention, there is provided a method for preparing the above-mentioned thermal insulation filling material, comprising the following steps:

[0022] S1. Weigh 45-75 parts of expanded perlite, 5-10 parts of mica powder, 8-12 parts of multi-coated vitrified microspheres, 2.8-5.3 parts of expanded vermiculite silica fume, mix well, put into an ultrasonic disperser, and ultrasonically disperse at 55-65 ° C at 200-300W power for 30-60min to obtain a main ingredient mixture;

[0023] S2. Weigh 8-14 parts of phenolic resin, 3-6 parts of aluminum silicate fiber, 4.5-7.5 parts of glass fiber, 30-50 parts of sulfoaluminate cement, 9-16 parts of slag powder, 0.03-0.1 parts of water reducer, sieved and mixed in a low-speed mixer, followed by addition of 0.03-0.1 parts of water reducer, 20-30 parts of aluminum hydroxide, 3-8 parts of melamine cyanurate, 5-10 parts of expanded graphite, and stir to form a mixed slurry of auxiliary materials;

[0024] S3. The main ingredient mixture obtained in S1 and the auxiliary material mixture slurry obtained in S2 were injected together into a double-roll mixer and mixed to obtain a uniform mixture;

[0025] S4. The mixture obtained in S3 is injected into a twin-screw extruder at a screw temperature of 230-240°C and a screw speed of 500-540 rpm / min to obtain a thermal insulation filling material.

[0026] According to a third aspect of the present invention, there is provided a steel shell anti-corrosion insulation pipe, comprising a connection assembly, an insulation layer, a fixing rope, a protective shell and a fixing shell, wherein the insulation layer is made of any one of the above-mentioned insulation filling materials, wherein:

[0027] Connecting components, outer surfaces of which are wrapped with thermal insulation;

[0028] A fixing rope, wound around the outside of the insulation layer;

[0029] A protective shell is installed outside the fixing rope;

[0030] The fixed shell is sleeved on the outside of the protective shell, and the fixed shell is arranged on the outsides of the two protective shells.

[0031] Furthermore, the connection component includes:

[0032] The pipe body has an outer surface covered with an anti-corrosion coating;

[0033] The limiting collars are arranged in pairs and sleeved on the outside of the tube body. The limiting collars are respectively arranged at both ends of the tube body. The thermal insulation layer is arranged between the two limiting collars. The inner surface of the protective shell is in contact with the outer surface of the limiting collars.

[0034] The protrusion is installed at the end of the pipe body, and the two protrusion ends are opposite to each other to form a butt joint pipe body, and the outer side of the butt joint pipe body is covered with the insulation layer.

[0035] Furthermore, the fixed shell is wrapped around the outside of the two ends of the protective shell, the surface of the fixed shell is covered with anti-corrosion paint, and the fixed shell is made of galvanized steel pipe.

[0036] Furthermore, the insulation layer of the insulation pipe includes an insulation coating in addition to the insulation filling material.

[0037] Furthermore, the anti-corrosion coating is a water-based two-component polyurethane-based anti-corrosion coating.

[0038] The present invention has the following advantages:

[0039] 1. The thermal insulation filling material of this application uses low thermal conductivity materials such as multiple coated glass microspheres, expanded perlite and expanded vermiculite silica fume, which significantly reduces the thermal conductivity coefficient, effectively reduces heat transfer, and improves the thermal insulation effect; the reasonable formula ratio makes the dry density of the material moderate, which not only ensures the lightweight characteristics but also meets the structural strength requirements, and is suitable for a variety of construction and industrial applications.

[0040] 2. The thermal insulation filling material of the present application has good compressive strength by adding reinforcing materials such as phenolic resin, aluminum silicate fiber, glass fiber and sulfoaluminate cement, ensuring the structural stability of the material when it is subjected to a large load; and by optimizing the formula and adding polypropylene fiber, the fracture energy of the material is significantly improved, thereby enhancing the material's crack resistance and ductility, and improving the overall durability.

[0041] 3. The thermal insulation filling material of the present application is also added with flame retardants such as aluminum hydroxide, melamine cyanurate and expanded graphite, which has excellent flame retardant properties, can effectively prevent the spread of fire, and improve the safety of the material.

[0042] 4. The anti-corrosion and thermal insulation pipe of this application integrates a high-performance anti-corrosion coating and thermal insulation filling materials, providing not only excellent corrosion resistance but also excellent thermal insulation. This makes the anti-corrosion and thermal insulation pipe suitable for various harsh environments such as marine engineering, petrochemicals, and construction, effectively extending the service life of the pipe and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0044] The structures, proportions, sizes, etc. illustrated in this specification are intended only to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall still fall within the scope of the technical contents disclosed herein.

[0045] Figure 1 A three-dimensional diagram of the steel shell anti-corrosion and thermal insulation pipe provided by the present invention;

[0046] Figure 2 A cross-sectional view of the thermal insulation layer provided by the present invention;

[0047] Figure 3 A three-dimensional diagram of the connection assembly provided by the present invention;

[0048] In the figure: 1. Fixed shell; 2. Protective shell; 3. Connecting assembly; 31. Protrusion; 32. Anti-corrosion coating; 33. Pipe body; 34. Limiting ring; 4. Insulation layer; 5. Fixing rope. DETAILED DESCRIPTION

[0049] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0050] Unless otherwise indicated herein, all percentages, ratios, or parts are by weight. "Parts by weight" refers to the basic unit of measurement for the weight ratio of multiple components. One part can represent any unit weight, for example, 1 part can represent 1 g, 1.5 g, or 5 g.

[0051] The present invention provides a thermal insulation filling material, comprising a main material, auxiliary materials and additives, wherein the main material comprises the following raw materials in parts by weight: 45-75 parts of expanded perlite, 5-10 parts of mica powder, 8-12 parts of multi-coated vitrified microspheres, 2.8-5.3 parts of expanded vermiculite silica fume, and 1-3 parts of high-temperature resistant chopped glass fiber;

[0052] The auxiliary materials include the following raw materials in parts by weight: 8-14 parts of phenolic resin, 3-6 parts of aluminum silicate fiber, 4.5-7.5 parts of glass fiber, 30-50 parts of sulphoaluminate cement, and 9-16 parts of slag powder;

[0053] The additives include the following raw materials in parts by weight: 4.5-6.5 parts of redispersible latex powder, 0.5-0.8 parts of hydroxypropyl methylcellulose ether, 0.07-0.12 parts of polypropylene fiber, 0.03-0.1 parts of water reducer, 20-30 parts of aluminum hydroxide, 3-8 parts of melamine cyanurate and 5-10 parts of expanded graphite.

[0054] Specifically, the preparation method of multi-coated glass microspheres includes the following steps:

[0055] S1. The vitrified microspheres were first coated with silica with methyl orthosilicate, and then coated with alumina with aluminum nitrate. After washing, filtering, drying and calcining, silica / alumina double-coated vitrified microspheres were obtained.

[0056] S2. n-butyl titanate was dissolved in an ethanol solution, tartaric acid was added, and the reaction mixture was stirred to form a mixed solution. Then, double-coated vitrified microspheres were added. After solvent thermal treatment, double-coated vitrified microspheres preliminarily coated with titanium dioxide were obtained.

[0057] S3. The double-coated vitrified microspheres coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500-600 ° C for 3-5 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain a preliminary sintered titanium dioxide / vitrified microspheres.

[0058] The preliminarily sintered titanium dioxide / vitrified microspheres are placed in a tube furnace, the sintering temperature is set to 800-900°C, the sintering time is 4-6 hours, and after sintering, they are naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres;

[0059] S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 1.5-3 parts of polydimethylsiloxane, 1.5-3 parts of thioglycolic acid, and 0.03-0.15 parts of a photoinitiator are added to the mixture to react. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

[0060] The specific steps of S1 are as follows:

[0061] (1) Weigh 0.8-1.5 parts of vitrified microspheres, add 7-12 parts of distilled water, mix well to form a slurry, place the slurry in a constant temperature water bath at 55°C, add 0.2-0.3 parts of 2% surfactant, stir thoroughly for 10-15 minutes to prepare a vitrified microsphere suspension; adjust the pH value of the system to 9-10 with 10% sodium hydroxide solution, slowly add 22-30 parts of 10% methyl orthosilicate solution, continue the reaction for 4-8 hours, and after the reaction is completed , washed with water, filtered, dried, calcined at 400-600 ° C for 2-3 hours to obtain silica-coated vitrified microspheres; the vitrified microspheres are mixed with alkali solution, stirred evenly, heated to 50-60 ° C, stirred for 2-4 hours, then added with methyl orthosilicate, and continued to stir for 5-8 hours, filtered out the treated vitrified microspheres, washed with pure water 3-5 times, placed in an oven, and dried under air conditions to obtain silica-coated vitrified microspheres;

[0062] (2) Add 9-11 parts of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.2-0.3 parts of a 2% surfactant, and stir thoroughly for 10-15 minutes to prepare a glass microsphere suspension. Use 10% hydrochloric acid solution to adjust the pH of the system to 2-4; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 3-7 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 450-750°C to obtain silica / alumina double-coated glass microspheres.

[0063] The specific steps of S2 are as follows:

[0064] Dissolve 0.1-0.2 parts of n-butyl titanate in 5-10 parts of anhydrous ethanol, stir evenly, add 0.01-0.02 parts of tartaric acid, continue stirring for 20-40 minutes to form a mixed reaction liquid, add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 20-40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 180-220°C for solvent thermal treatment, maintaining the reaction temperature at 180-220°C for 16-22 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 70-90°C for 10-14 hours to obtain double-coated glass microspheres preliminarily coated with titanium dioxide.

[0065] The present invention provides a method for preparing the above-mentioned thermal insulation filling material, comprising the following steps:

[0066] S1. Weigh 45-75 parts of expanded perlite, 5-10 parts of mica powder, 8-12 parts of multi-coated vitrified microspheres, 2.8-5.3 parts of expanded vermiculite silica fume, mix well, put into an ultrasonic disperser, and ultrasonically disperse at 55-65 ° C at 200-300W power for 30-60min to obtain a main ingredient mixture;

[0067] S2. Weigh 8-14 parts of phenolic resin, 3-6 parts of aluminum silicate fiber, 4.5-7.5 parts of glass fiber, 30-50 parts of sulfoaluminate cement, 9-16 parts of slag powder, 0.03-0.1 parts of water reducer, sieved and mixed in a low-speed mixer, followed by addition of 0.03-0.1 parts of water reducer, 20-30 parts of aluminum hydroxide, 3-8 parts of melamine cyanurate, 5-10 parts of expanded graphite, and stir to form a mixed slurry of auxiliary materials;

[0068] S3. The main ingredient mixture obtained in S1 and the auxiliary material mixture slurry obtained in S2 were injected together into a double-roll mixer and mixed to obtain a uniform mixture;

[0069] S4. The mixture obtained in S3 is injected into a twin-screw extruder at a screw temperature of 230-240°C and a screw speed of 500-540 rpm / min to obtain a thermal insulation filling material.

[0070] The present invention provides a steel shell anti-corrosion insulation pipe, such as Figure 1-3 As shown, it includes a connecting component 3, a thermal insulation layer 4, a fixing rope 5, a protective shell 2 and a fixing shell 1, and the thermal insulation layer 4 is made of the above-mentioned thermal insulation filling material, wherein:

[0071] The connecting component 3 has an outer surface covered with a thermal insulation layer 4;

[0072] A fixing rope 5 is wound around the outside of the insulation layer 4;

[0073] The protective shell 2 is installed outside the fixing rope 5;

[0074] The fixed shell 1 is sleeved on the outside of the protective shell 2 , and the fixed shell 1 is arranged on the outsides of the two protective shells 2 .

[0075] Wherein, the connection component 3 includes:

[0076] The outer surface of the pipe body 33 is covered with an anti-corrosion coating 32;

[0077] The limiting collars 34 are arranged in pairs and sleeved on the outside of the tube body 33. The limiting collars 34 are respectively arranged at both ends of the tube body 3. The insulation layer 4 is arranged between the two limiting collars 34 to protect the inner surface of the outer shell 2 from being attached to the outer surface of the limiting collars 34.

[0078] The protrusion 31 is mounted on the end of the tube body 33. The two ends of the protrusion 31 are opposite to each other to form a butt joint tube body. The outer side of the butt joint tube body is covered with a heat-insulating layer 4.

[0079] The fixed shell 1 is wrapped around the outer sides of the ends of the two protective shells 2 , the surface of the fixed shell 1 is covered with anti-corrosion paint, and the fixed shell 1 is made of galvanized steel pipe.

[0080] Among them, the insulation layer of the insulation pipe includes insulation coating in addition to insulation filling material.

[0081] Among them, the anti-corrosion coating is a water-based two-component polyurethane-based anti-corrosion coating.

[0082] Specifically, the waterborne two-component polyurethane-based anti-corrosion coating includes the following components in parts by weight:

[0083] 80-100 parts of water-based two-component polyurethane, 25-35 parts of fluorocarbon resin, 6-9 parts of nano-cerium dioxide, 3-6 parts of nano-silicon dioxide, 3-8 parts of nano-titanium dioxide, 3-5 parts of dispersant, 1.2-2 parts of defoaming agent, and 0.5-1.5 parts of leveling agent;

[0084] The waterborne two-component polyurethane comprises 30-40 parts of waterborne epoxy resin, 20-30 parts of polycarbonate waterborne polyurethane, 25-35 parts of hyperbranched waterborne polyurethane and 10-20 parts of bio-based waterborne polyurethane.

[0085] The dispersant is Disperbyk-161; the defoamer is BYK-088; and the leveling agent is BYK-306.

[0086] Specifically, the coating process of the waterborne two-component polyurethane-based anti-corrosion coating includes the following steps:

[0087] (1) Quantitatively weigh the raw materials of the anti-corrosion coating and set aside;

[0088] (2) adding water-based two-component polyurethane and fluorocarbon resin into a stirring container, stirring at low speed for 5-10 minutes to ensure that the two resins are initially mixed evenly, adding nano-cerium dioxide, nano-silicon dioxide and nano-graphene in sequence, stirring at low speed for 5-10 minutes after addition, and then adding dispersant, defoamer and leveling agent in sequence, stirring at low speed again for 5-10 minutes after addition, and finally transferring the above mixture to a high-speed disperser, setting the speed to 1500-2000 rpm, and dispersing for 30-60 minutes to ensure that all raw materials are fully mixed;

[0089] (3) Ensure that the surface of the substrate is clean, free of oil and dust, check the spraying equipment, and then pour the mixed paint into the spraying equipment to ensure uniform spraying. The spraying thickness is 50-150μm, and 1-5 layers are sprayed. After each layer is sprayed, wait for the previous layer to dry before spraying the next layer;

[0090] (4) After spraying, the sprayed substrate is cured at 60-80°C for more than 6 hours, and then cured at room temperature for more than 12 hours to obtain a water-based two-component polyurethane-based anti-corrosion coating.

[0091] Example 1

[0092] This embodiment provides a thermal insulation filling material, including a main material, auxiliary materials and additives. The main material includes the following raw materials: 65g of expanded perlite, 9g of mica powder, 12g of multi-coated vitrified microspheres, 4.5g of expanded vermiculite silica fume, and 3g of high-temperature resistant chopped glass fiber;

[0093] The auxiliary materials include the following raw materials: phenolic resin 12g, aluminum silicate fiber 5g, glass fiber 6g, sulphoaluminate cement 40g, slag powder 14g;

[0094] The additives include the following raw materials: 6 g of redispersible latex powder, 0.6 g of hydroxypropyl methylcellulose ether, 0.1 g of polypropylene fiber, 0.06 g of water reducer, 25 g of aluminum hydroxide, 6 g of melamine cyanurate, and 8 g of expanded graphite.

[0095] Specifically, the preparation method of multi-coated glass microspheres includes the following steps:

[0096] The specific steps of S1 are as follows: (1) weighing 1.2 g of vitrified microspheres, adding 10 g of distilled water, and mixing them evenly to form a slurry, placing the slurry in a constant temperature water bath at 55°C, adding 0.3 g of a 2% surfactant, and stirring thoroughly for 15 min to obtain a vitrified microsphere suspension; adjusting the pH value of the system to 9-10 with a 10% sodium hydroxide solution, slowly adding 27 g of a 10% methyl orthosilicate solution dropwise, and continuing the reaction for 6 h. After the reaction is completed, washing with water, filtering, drying, and calcining at 600°C for 3 h to obtain silica-coated vitrified microspheres;

[0097] The vitrified microspheres were mixed with sodium hydroxide solution, stirred evenly, heated to 57°C, and stirred for 3 hours. Methyl orthosilicate was then added and stirred for 6 hours. The treated vitrified microspheres were filtered out, washed with pure water for 3-5 times, and then placed in an oven for drying under air conditions to obtain silica-coated vitrified microspheres.

[0098] (2) Add 10 g of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.3 g of a 2% surfactant, and stir thoroughly for 15 minutes to prepare a glass microsphere suspension. Use 10% hydrochloric acid solution to adjust the pH of the system to 2-4; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 6 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 750°C to obtain silica / alumina double-coated glass microspheres.

[0099] The specific steps of S2 are as follows:

[0100] Dissolve 0.15 g of n-butyl titanate in 7.5 g of anhydrous ethanol, stir evenly, add 0.015 g of tartaric acid, and continue stirring for 30 minutes to form a mixed reaction liquid. Add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 200°C for solvent thermal treatment, maintaining the reaction temperature at 220°C for 19 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 80°C for 12 hours to obtain double-coated glass microspheres initially coated with titanium dioxide.

[0101] S3. The double-coated vitrified microspheres initially coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500°C for 4 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain the initially sintered titanium dioxide / vitrified microspheres.

[0102] The preliminarily sintered titanium dioxide / vitrified microspheres were placed in a tube furnace, the sintering temperature was set to 800°C, the sintering time was set to 5 hours, and after sintering, they were naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres;

[0103] S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 2 g of polydimethylsiloxane, 2 g of thioglycolic acid, and 0.15 g of a photoinitiator are added to the mixture for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

[0104] This embodiment provides a method for preparing the above-mentioned thermal insulation filling material, comprising the following steps:

[0105] S1. Weigh expanded perlite, mica powder, multi-coated vitrified microspheres and expanded vermiculite silica fume, mix well, put into an ultrasonic disperser, and ultrasonically disperse at 300W power at 60 ° C for 45min to obtain a main ingredient mixture;

[0106] S2 weighed phenolic resin, aluminum silicate fiber, glass fiber, sulfoaluminate cement, slag powder and water reducer sieved, put into a low-speed mixer mixed, followed by the addition of MasterGlenium SKY, aluminum hydroxide, melamine cyanurate, expanded graphite, stirred to form a mixed slurry of auxiliary materials;

[0107] S3. The main ingredient mixture obtained in S1 and the auxiliary material mixture slurry obtained in S2 were injected together into a double-roll mixer and mixed to obtain a uniform mixture;

[0108] S4. The mixture obtained in S3 was injected into a twin-screw extruder at a screw temperature of 240°C and a screw speed of 500 rpm / min to obtain a thermal insulation filling material.

[0109] Specifically, the water-based two-component polyurethane-based anti-corrosion coating covering the outer surface of the pipe body 33 includes the following components:

[0110] 100g water-based two-component polyurethane, 30g fluorocarbon resin, 8g nano-cerium dioxide, 6g nano-silicon dioxide, 6g nano-titanium dioxide, 5g dispersant, 2g defoamer, 1.5g leveling agent;

[0111] The waterborne two-component polyurethane includes 40 g of waterborne epoxy resin, 30 g of polycarbonate waterborne polyurethane, 30 g of hyperbranched waterborne polyurethane and 20 g of bio-based waterborne polyurethane.

[0112] The dispersant is Disperbyk-161; the defoamer is BYK-088; and the leveling agent is BYK-306.

[0113] Specifically, the coating process of the waterborne two-component polyurethane-based anti-corrosion coating includes the following steps:

[0114] (1) Quantitatively weigh the raw materials of the anti-corrosion coating and set aside;

[0115] (2) Adding water-based two-component polyurethane and fluorocarbon resin into a stirring container, stirring at low speed for 10 minutes to make the two resins preliminarily mixed, then adding nano-cerium dioxide, nano-silicon dioxide and nano-graphene in sequence, stirring at low speed for 10 minutes after each addition, then adding dispersant, defoamer and leveling agent in sequence, stirring at low speed again for 10 minutes after addition, finally transferring the above mixture to a high-speed disperser, setting the speed to 1800 rpm, and dispersing for 45 minutes to make all the raw materials fully mixed;

[0116] (3) Ensure that the surface of the substrate is clean, free of oil and dust, check the spraying equipment, and then pour the mixed paint into the spraying equipment to ensure uniform spraying. The spraying thickness is 75-100μm, and 2-3 layers are sprayed. After each layer is sprayed, wait for the previous layer to dry before spraying the next layer;

[0117] (4) After spraying, the sprayed substrate is cured at 80°C for more than 6 hours, and then cured at room temperature for more than 12 hours to obtain a water-based two-component polyurethane-based anti-corrosion coating.

[0118] Example 2

[0119] This embodiment provides a thermal insulation filling material, including a main material, auxiliary materials and additives. The main material includes the following raw materials: 65g of expanded perlite, 9g of mica powder, 10g of multi-coated vitrified microspheres, 4.5g of expanded vermiculite silica fume, and 3g of high-temperature resistant chopped glass fiber;

[0120] The auxiliary materials include the following raw materials: phenolic resin 12g, aluminum silicate fiber 5g, glass fiber 6g, sulphoaluminate cement 40g, slag powder 14g;

[0121] The additives include the following raw materials: 6 g of redispersible latex powder, 0.6 g of hydroxypropyl methylcellulose ether, 0.1 g of polypropylene fiber, 0.06 g of water reducer, 25 g of aluminum hydroxide, 6 g of melamine cyanurate, and 8 g of expanded graphite.

[0122] Specifically, the preparation method of multi-coated glass microspheres includes the following steps:

[0123] The specific steps of S1 are as follows: (1) weighing 1.2 g of vitrified microspheres, adding 10 g of distilled water, and mixing them evenly to form a slurry, placing the slurry in a constant temperature water bath at 55°C, adding 0.3 g of a 2% surfactant, and stirring thoroughly for 15 min to obtain a vitrified microsphere suspension; adjusting the pH value of the system to 9-10 with a 10% sodium hydroxide solution, slowly adding 27 g of a 10% methyl orthosilicate solution dropwise, and continuing the reaction for 6 h. After the reaction is completed, washing with water, filtering, drying, and calcining at 600°C for 3 h to obtain silica-coated vitrified microspheres;

[0124] The vitrified microspheres were mixed with sodium hydroxide solution, stirred evenly, heated to 57°C, and stirred for 3 hours. Methyl orthosilicate was then added and stirred for 6 hours. The treated vitrified microspheres were filtered out, washed with pure water for 3-5 times, and then placed in an oven for drying under air conditions to obtain silica-coated vitrified microspheres.

[0125] (2) Add 10 g of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.3 g of a 2% surfactant, and stir thoroughly for 15 minutes to prepare a glass microsphere suspension. Use 10% hydrochloric acid solution to adjust the pH of the system to 2-4; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 6 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 750°C to obtain silica / alumina double-coated glass microspheres.

[0126] The specific steps of S2 are as follows:

[0127] Dissolve 0.15 g of n-butyl titanate in 7.5 g of anhydrous ethanol, stir evenly, add 0.015 g of tartaric acid, and continue stirring for 30 minutes to form a mixed reaction liquid. Add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 200°C for solvent thermal treatment, maintaining the reaction temperature at 220°C for 19 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 80°C for 12 hours to obtain double-coated glass microspheres initially coated with titanium dioxide.

[0128] S3. The double-coated vitrified microspheres initially coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500°C for 4 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain the initially sintered titanium dioxide / vitrified microspheres.

[0129] The preliminarily sintered titanium dioxide / vitrified microspheres were placed in a tube furnace, the sintering temperature was set to 800°C, the sintering time was set to 5 hours, and after sintering, they were naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres;

[0130] S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 2 g of polydimethylsiloxane, 2 g of thioglycolic acid, and 0.15 g of a photoinitiator are added to the mixture for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

[0131] This embodiment provides a method for preparing the above-mentioned thermal insulation filling material, comprising the following steps:

[0132] S1. Weigh expanded perlite, mica powder, multi-coated vitrified microspheres and expanded vermiculite silica fume, mix well, put into an ultrasonic disperser, and ultrasonically disperse at 300W power at 60 ° C for 45min to obtain a main ingredient mixture;

[0133] S2 weighed phenolic resin, aluminum silicate fiber, glass fiber, sulfoaluminate cement, slag powder and water reducer sieved, put into a low-speed mixer mixed, followed by the addition of MasterGlenium SKY, aluminum hydroxide, melamine cyanurate, expanded graphite, stirred to form a mixed slurry of auxiliary materials;

[0134] S3. The main ingredient mixture obtained in S1 and the auxiliary material mixture slurry obtained in S2 were injected together into a double-roll mixer and mixed to obtain a uniform mixture;

[0135] S4. The mixture obtained in S3 was injected into a twin-screw extruder at a screw temperature of 240°C and a screw speed of 500 rpm / min to obtain a thermal insulation filling material.

[0136] Specifically, the water-based two-component polyurethane-based anti-corrosion coating covering the outer surface of the pipe body 33 includes the following components:

[0137] 90g water-based two-component polyurethane, 30g fluorocarbon resin, 8g nano-cerium dioxide, 6g nano-silicon dioxide, 6g nano-titanium dioxide, 5g dispersant, 2g defoamer, 1.5g leveling agent;

[0138] The waterborne two-component polyurethane includes 40 g of waterborne epoxy resin, 30 g of polycarbonate waterborne polyurethane, 30 g of hyperbranched waterborne polyurethane and 20 g of bio-based waterborne polyurethane.

[0139] The dispersant is Disperbyk-161; the defoamer is BYK-088; and the leveling agent is BYK-306.

[0140] Specifically, the coating process of the waterborne two-component polyurethane-based anti-corrosion coating includes the following steps:

[0141] (1) Quantitatively weigh the raw materials of the anti-corrosion coating and set aside;

[0142] (2) Adding water-based two-component polyurethane and fluorocarbon resin into a stirring container, stirring at low speed for 10 minutes to make the two resins preliminarily mixed, then adding nano-cerium dioxide, nano-silicon dioxide and nano-graphene in sequence, stirring at low speed for 10 minutes after each addition, then adding dispersant, defoamer and leveling agent in sequence, stirring at low speed again for 10 minutes after addition, finally transferring the above mixture to a high-speed disperser, setting the speed to 1800 rpm, and dispersing for 45 minutes to make all the raw materials fully mixed;

[0143] (3) Ensure that the surface of the substrate is clean, free of oil and dust, check the spraying equipment, and then pour the mixed paint into the spraying equipment to ensure uniform spraying. The spraying thickness is 75-100μm, and 2-3 layers are sprayed. After each layer is sprayed, wait for the previous layer to dry before spraying the next layer;

[0144] (4) After spraying, the sprayed substrate is cured at 80°C for more than 6 hours, and then cured at room temperature for more than 12 hours to obtain a water-based two-component polyurethane-based anti-corrosion coating.

[0145] Example 3

[0146] This embodiment provides a thermal insulation filling material, including a main material, auxiliary materials and additives. The main material includes the following raw materials: 65g of expanded perlite, 9g of mica powder, 8g of multi-coated vitrified microspheres, 4.5g of expanded vermiculite silica fume, and 3g of high-temperature resistant chopped glass fiber;

[0147] The auxiliary materials include the following raw materials: phenolic resin 12g, aluminum silicate fiber 5g, glass fiber 6g, sulphoaluminate cement 40g, slag powder 14g;

[0148] The additives include the following raw materials: 6 g of redispersible latex powder, 0.6 g of hydroxypropyl methylcellulose ether, 0.1 g of polypropylene fiber, 0.06 g of water reducer, 25 g of aluminum hydroxide, 6 g of melamine cyanurate, and 8 g of expanded graphite.

[0149] Specifically, the preparation method of multi-coated glass microspheres includes the following steps:

[0150] The specific steps of S1 are as follows: (1) weighing 1.2 g of vitrified microspheres, adding 10 g of distilled water, and mixing them evenly to form a slurry, placing the slurry in a constant temperature water bath at 55°C, adding 0.3 g of a 2% surfactant, and stirring thoroughly for 15 min to obtain a vitrified microsphere suspension; adjusting the pH value of the system to 9-10 with a 10% sodium hydroxide solution, slowly adding 27 g of a 10% methyl orthosilicate solution dropwise, and continuing the reaction for 6 h. After the reaction is completed, washing with water, filtering, drying, and calcining at 600°C for 3 h to obtain silica-coated vitrified microspheres;

[0151] The vitrified microspheres were mixed with sodium hydroxide solution, stirred evenly, heated to 57°C, and stirred for 3 hours. Methyl orthosilicate was then added and stirred for 6 hours. The treated vitrified microspheres were filtered out, washed with pure water for 3-5 times, and then placed in an oven for drying under air conditions to obtain silica-coated vitrified microspheres.

[0152] (2) Add 10 g of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.3 g of a 2% surfactant, and stir thoroughly for 15 minutes to prepare a glass microsphere suspension. Use 10% hydrochloric acid solution to adjust the pH of the system to 2-4; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 6 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 750°C to obtain silica / alumina double-coated glass microspheres.

[0153] The specific steps of S2 are as follows:

[0154] Dissolve 0.15 g of n-butyl titanate in 7.5 g of anhydrous ethanol, stir evenly, add 0.015 g of tartaric acid, and continue stirring for 30 minutes to form a mixed reaction liquid. Add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 200°C for solvent thermal treatment, maintaining the reaction temperature at 220°C for 19 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 80°C for 12 hours to obtain double-coated glass microspheres initially coated with titanium dioxide.

[0155] S3. The double-coated vitrified microspheres initially coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500°C for 4 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain the initially sintered titanium dioxide / vitrified microspheres.

[0156] The preliminarily sintered titanium dioxide / vitrified microspheres were placed in a tube furnace, the sintering temperature was set to 800°C, the sintering time was set to 5 hours, and after sintering, they were naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres;

[0157] S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 2 g of polydimethylsiloxane, 2 g of thioglycolic acid, and 0.15 g of a photoinitiator are added to the mixture for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

[0158] This embodiment provides a method for preparing the above-mentioned thermal insulation filling material, comprising the following steps:

[0159] S1. Weigh expanded perlite, mica powder, multi-coated vitrified microspheres and expanded vermiculite silica fume, mix well, put into an ultrasonic disperser, and ultrasonically disperse at 300W power at 60 ° C for 45min to obtain a main ingredient mixture;

[0160] S2 weighed phenolic resin, aluminum silicate fiber, glass fiber, sulfoaluminate cement, slag powder and water reducer sieved, put into a low-speed mixer mixed, followed by the addition of MasterGlenium SKY, aluminum hydroxide, melamine cyanurate, expanded graphite, stirred to form a mixed slurry of auxiliary materials;

[0161] S3. The main ingredient mixture obtained in S1 and the auxiliary material mixture slurry obtained in S2 were injected together into a double-roll mixer and mixed to obtain a uniform mixture;

[0162] S4. The mixture obtained in S3 was injected into a twin-screw extruder at a screw temperature of 240°C and a screw speed of 500 rpm / min to obtain a thermal insulation filling material.

[0163] Specifically, the water-based two-component polyurethane-based anti-corrosion coating covering the outer surface of the pipe body 33 includes the following components:

[0164] 80g water-based two-component polyurethane, 30g fluorocarbon resin, 8g nano-cerium dioxide, 6g nano-silicon dioxide, 6g nano-titanium dioxide, 5g dispersant, 2g defoamer, 1.5g leveling agent;

[0165] The waterborne two-component polyurethane includes 40 g of waterborne epoxy resin, 30 g of polycarbonate waterborne polyurethane, 30 g of hyperbranched waterborne polyurethane and 20 g of bio-based waterborne polyurethane.

[0166] The dispersant is Disperbyk-161; the defoamer is BYK-088; and the leveling agent is BYK-306.

[0167] Specifically, the coating process of the waterborne two-component polyurethane-based anti-corrosion coating includes the following steps:

[0168] (1) Quantitatively weigh the raw materials of the anti-corrosion coating and set aside;

[0169] (2) Adding water-based two-component polyurethane and fluorocarbon resin into a stirring container, stirring at low speed for 10 minutes to make the two resins preliminarily mixed, then adding nano-cerium dioxide, nano-silicon dioxide and nano-graphene in sequence, stirring at low speed for 10 minutes after each addition, then adding dispersant, defoamer and leveling agent in sequence, stirring at low speed again for 10 minutes after addition, finally transferring the above mixture to a high-speed disperser, setting the speed to 1800 rpm, and dispersing for 45 minutes to make all the raw materials fully mixed;

[0170] (3) Ensure that the surface of the substrate is clean, free of oil and dust, check the spraying equipment, and then pour the mixed paint into the spraying equipment to ensure uniform spraying. The spraying thickness is 75-100μm, and 2-3 layers are sprayed. After each layer is sprayed, wait for the previous layer to dry before spraying the next layer;

[0171] (4) After spraying, the sprayed substrate is cured at 80°C for more than 6 hours, and then cured at room temperature for more than 12 hours to obtain a water-based two-component polyurethane-based anti-corrosion coating.

[0172] Comparative Example 1 This example serves as a comparative example of Example 1, except that the multi-coated vitrified microspheres are replaced with ordinary vitrified microspheres, and the other steps and parameters are the same as those of Example 1.

[0173] Comparative Example 2 This example serves as a comparative example of Example 1, except that the multi-coated glass microspheres are removed. Other steps and parameters are the same as those of Example 1.

[0174] Comparative Example 3 This example serves as a comparative example of Example 1, except that the water-based two-component polyurethane is replaced with ordinary solvent-based polyurethane, and the other steps and parameters are the same as those of Example 1.

[0175] Comparative Example 4 This example serves as a comparative example of Example 1, except that the fluorocarbon resin is replaced by acrylic resin, and the other steps and parameters are the same as those of Example 1.

[0176] Test Example 1:

[0177] In order to more clearly illustrate the present invention, the thermal insulation filling materials in Examples 1-3 of the present invention and Comparative Examples 1-2 were tested according to the method specified in GB / T 20473-2021 "Building Thermal Insulation Mortar" standard, and the dry density, compressive strength, and thermal conductivity of the thermal insulation filling materials were tested; the combustion performance and fracture energy were tested; the test results are as follows:

[0178] Table 1 Various performance tests of the thermal insulation filling materials prepared in Examples 1-3 and Comparative Examples 1-2

[0179]

[0180] Through comprehensive analysis of the performance test results of the thermal insulation filling materials prepared in Examples 1-3 and Comparative Examples 1-2, the following conclusions can be drawn:

[0181] 1. The thermal conductivity of Examples 1-3 is from 0.055W·(m·K) -1 Gradually increase to 0.058W·(m·K) -1 This shows that as the content of multi-coated glass microspheres decreases, the thermal conductivity increases, but still remains at a low level. This shows that multi-coated glass microspheres have a significant positive effect on reducing thermal conductivity and improving the thermal insulation performance of the material. The thermal conductivity of Comparative Example 1 increased significantly to 0.075W·(m·K) -1 The thermal insulation performance of ordinary glass microspheres is poor, resulting in a significant increase in thermal conductivity. The thermal conductivity of Comparative Example 2 increased significantly to 0.082W·(m·K) -1 After removing the multi-coated glass beads, the thermal conductivity coefficient increased significantly.

[0182] 2. The combustion performance of Examples 1-3 was all A1. The multi-coated vitrified microspheres significantly improved the material's combustion performance, giving it a higher fire rating. The combustion performance of Comparative Example 1 dropped to A2. Ordinary vitrified microspheres have poor fire resistance, resulting in decreased combustion performance. The combustion performance of Comparative Example 2 dropped significantly to A12. Without the multi-coated vitrified microspheres, combustion performance was significantly reduced.

[0183] 3. The change in the amount of multi-coated glass microspheres has little effect on the compressive strength, dry density and fracture energy of Examples 1-3. The compressive strength gradually decreases from 1.08 MPa to 1.06 MPa, and the dry density decreases from 298 kg·m -3 Gradually reduced to 297 kg·m -3 , the fracture energy is from 366N·m -1 Gradually reduced to 364N·m -1 , all maintained within a relatively high range. The compressive strength, dry density, and fracture energy of Comparative Examples 1-2 were lower than those of Examples 1-3. This demonstrates that the multi-coated vitrified microspheres play a positive role in improving the mechanical strength, dry density, and toughness of the material, while the synergistic effects of other ingredients and the preparation process further optimize the material's overall performance.

[0184] In summary, by comparing the data of Examples 1-3 and Comparative Examples 1-2, it can be seen that the multi-coated glass microspheres significantly improve the performance of thermal insulation filling materials, which is specifically manifested in the following aspects: (1) Thermal insulation performance: Multi-coated glass microspheres significantly reduce the thermal conductivity and improve the thermal insulation performance of the material. The thermal conductivity of Comparative Examples 1 and 2 increased significantly, indicating that the thermal insulation performance of ordinary glass microspheres and glass microspheres without multi-coating is poor. (2) Flame retardant performance: Multi-coated glass microspheres significantly improve the combustion performance of the material, reaching the A1 fire protection standard, and enhancing the safety and reliability of the material. The combustion performance of Comparative Examples 1 and 2 decreased significantly, indicating that the fire protection performance of ordinary glass microspheres and glass microspheres without multi-coating is poor. (3) The compressive strength and dry density of Examples 1-3 are maintained at a high level. At the same time, the multi-coated glass microspheres significantly improve the fracture energy of the material, enhance the toughness and crack resistance of the material. This shows that the synergistic effect of multi-coated glass microspheres with other ingredients and preparation processes effectively optimizes the comprehensive performance of the material and improves the overall quality and reliability of the material.

[0185] Test Example 2:

[0186] The steel-shelled, insulated pipes from Examples 1-3 and Comparative Examples 3-4 were immersed in a corrosive solution for 30 days. The solution consisted of 20% sodium hydroxide, 15% diesel fuel, 10% crude oil, and the balance highly mineralized formation water (with a total salinity of 65,000). The temperature of the solution was 70°C. The coatings were observed after the test, and the results are shown in Table 2.

[0187] Table 2 Performance test of the anticorrosion coating of the steel shell anticorrosion insulation pipe of Examples 1-3 and Comparative Examples 3-4

[0188] Test items Coating status Example 1 The coating is intact and the surface is smooth Example 2 The coating is intact and the surface is smooth Example 3 The coating is intact and the surface is smooth Comparative Example 3 The coating surface is rough and has pits, and the surface loses its gloss Comparative Example 4 The coating surface is rough and has pits, and the surface loses its gloss

[0189] in conclusion:

[0190] Through comprehensive analysis of the test results of the anti-corrosion coating performance of the steel shell anti-corrosion insulation pipes prepared in Examples 1-3 and Comparative Examples 3-4, the following conclusions can be drawn:

[0191] After 30 days of immersion in a highly corrosive environment, the coatings of Examples 1-3 remained intact and had a smooth surface, indicating that the combination of multiple coated glass microspheres and a water-based two-component polyurethane-based anti-corrosion coating had excellent corrosion resistance and stability. The coatings of Comparative Examples 3 and 4 showed roughness, pitting, and loss of gloss, indicating that ordinary solvent-based polyurethane and acrylic resin had poor anti-corrosion performance in a highly corrosive environment. This shows that the multiple coated glass microspheres and the water-based two-component polyurethane-based anti-corrosion coating in the present technical solution play a key role in the steel shell anti-corrosion insulation pipe, significantly improving the material's anti-corrosion performance. Specifically, the combination of water-based two-component polyurethane and fluorocarbon resin exhibits excellent corrosion resistance and weather resistance in a highly corrosive environment, and the coating remains intact and has a smooth surface. The combination of multiple coated glass microspheres and a water-based two-component polyurethane-based anti-corrosion coating ensures the integrity and stability of the coating in a highly corrosive environment.

[0192] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A thermal insulation filling material, characterized in that: The invention comprises a main material, auxiliary materials and additives, wherein the main material comprises the following raw materials in parts by weight: 45-75 parts of expanded perlite, 5-10 parts of mica powder, 8-12 parts of multi-coated vitrified microspheres, 2.8-5.3 parts of expanded vermiculite silica fume, and 1-3 parts of high-temperature resistant chopped glass fiber; The auxiliary materials include the following raw materials in parts by weight: 8-14 parts of phenolic resin, 3-6 parts of aluminum silicate fiber, 4.5-7.5 parts of glass fiber, 30-50 parts of sulphoaluminate cement, and 9-16 parts of slag powder; The additive comprises the following raw materials in parts by weight: 4.5-6.5 parts of redispersible latex powder, 0.5-0.8 parts of hydroxypropyl methylcellulose ether, 0.07-0.12 parts of polypropylene fiber, 0.03-0.1 parts of water reducer, 20-30 parts of aluminum hydroxide, 3-8 parts of melamine cyanurate, and 5-10 parts of expanded graphite; The method for preparing the multi-coated glass microspheres comprises the following steps: The specific steps of S1 are as follows: (1) Weigh 0.8-1.5 parts of glass microspheres, add 7-12 parts of distilled water, mix well to form a slurry, place the slurry in a constant temperature water bath at 55°C, add 0.2-0.3 parts of 2% surfactant, stir thoroughly for 10-15 minutes, and prepare a glass microsphere suspension; adjust the pH value of the system to 9-10 with 10% sodium hydroxide solution, slowly add 22-30 parts of 10% methyl orthosilicate solution, and continue the reaction for 4-8 hours. After the reaction is completed, wash with water, filter, and dry, calcine at 400-600°C for 2-3 hours, then mix the glass microspheres with the sodium hydroxide solution, stir well, heat to 50-60°C, stir for 2-4 hours, then add methyl orthosilicate, continue stirring for 5-8 hours, filter out the treated glass microspheres, wash with pure water 3-5 times, place in an oven, and dry under air conditions to obtain silica-coated glass microspheres; (2) Add 9-11 parts of distilled water to the silica-coated glass microspheres obtained in step (1) to prepare a slurry, place the slurry in a constant temperature water bath at 75°C, add 0.2-0.3 parts of a 2% surfactant, stir thoroughly for 10-15 minutes to prepare a glass microsphere suspension, adjust the pH of the system to 2-4 with a 10% hydrochloric acid solution; slowly add 10% aluminum nitrate solution dropwise, and continue the reaction for 3-7 hours. After the reaction is completed, wash with water, filter, dry, and finally calcine at 450-750°C to obtain silica / alumina double-coated glass microspheres; S2. n-butyl titanate was dissolved in an ethanol solution, tartaric acid was added, and the reaction mixture was stirred to form a mixed solution. Then, double-coated vitrified microspheres were added. After solvent thermal treatment, double-coated vitrified microspheres preliminarily coated with titanium dioxide were obtained. S3. The double-coated vitrified microspheres coated with titanium dioxide were placed in a muffle furnace at a sintering temperature of 500-600 ° C for 3-5 hours. After sintering, the microspheres were cooled to room temperature, washed, filtered, and dried. The sample was removed, washed, and filtered to obtain a preliminary sintered titanium dioxide / vitrified microspheres. The preliminarily sintered titanium dioxide / vitrified microspheres are placed in a tube furnace, the sintering temperature is set to 800-900°C, the sintering time is 4-6 hours, and after sintering, they are naturally cooled to room temperature, washed with water, filtered and dried to obtain the final titanium dioxide / vitrified microspheres; S4. Titanium dioxide / glass microspheres are uniformly dispersed in N,N-dimethylformamide, and then 1.5-3 parts of polydimethylsiloxane, 1.5-3 parts of thioglycolic acid, and 0.03-0.15 parts of a photoinitiator are added to the mixture to react. After the reaction is completed, the mixture is naturally cooled to room temperature, washed with water, filtered, and dried to obtain multi-coated glass microspheres.

2. The thermal insulation filling material according to claim 1, characterized in that: The specific steps of S2 are as follows: Dissolve 0.1-0.2 parts of n-butyl titanate in 5-10 parts of anhydrous ethanol, stir evenly, add 0.01-0.02 parts of tartaric acid, continue stirring for 20-40 minutes to form a mixed reaction liquid, add the double-coated glass microspheres obtained in S1 to the mixed reaction liquid, continue stirring for 20-40 minutes, transfer the resulting mixture to a polytetrafluoroethylene-lined reactor, seal the reactor, and place it in an oven preheated to 180-220°C for solvent thermal treatment, maintaining the reaction temperature at 180-220°C for 16-22 hours. After the reaction is completed, cool the reactor to room temperature, take out the product from the reactor, wash it with distilled water 3-5 times, filter the washed product, and then dry it at 70-90°C for 10-14 hours to obtain double-coated glass microspheres preliminarily coated with titanium dioxide.

3. A steel shell anti-corrosion insulation pipe, characterized in that: The invention comprises a connecting assembly (3), a heat-insulating layer (4), a fixing rope (5), a protective shell (2) and a fixing shell (1), wherein the heat-insulating layer (4) is made of the heat-insulating filling material according to any one of claims 1 to 2, wherein: A connecting component (3) having an outer surface covered with a thermal insulation layer (4); A fixing rope (5) is wound around the outside of the thermal insulation layer (4); A protective shell (2) is mounted on the outside of the fixing rope (5); The fixed shell (1) is sleeved on the outside of the protective shells (2), and the fixed shell (1) is arranged on the outside of the two protective shells (2).

4. The steel shell anticorrosion insulation pipe according to claim 3, characterized in that: The connecting component (3) comprises: A pipe body (33) having an outer surface covered with an anti-corrosion coating (32); The limiting collars (34) are arranged in pairs and sleeved on the outside of the tube body (33). The limiting collars (34) are respectively arranged at both ends of the tube body (33). The thermal insulation layer (4) is arranged between the two limiting collars (34). The inner surface of the protective shell (2) is in contact with the outer surface of the limiting collars (34). The protrusion (31) is mounted on the end of the tube body (33), and the two ends of the protrusion (31) are opposed to each other to form a butt joint tube body, and the outer side of the butt joint tube body is covered with the thermal insulation layer (4).

5. The steel shell anticorrosion insulation pipe according to claim 4, characterized in that: The fixed shell (1) is wrapped around the outside of the ends of the two protective shells (2); the surface of the fixed shell (1) is covered with anti-corrosion paint; and the fixed shell (1) is made of a galvanized steel pipe.

6. The steel shell anticorrosive thermal insulation pipe according to claim 5, characterized in that: The anti-corrosion coating is a water-based two-component polyurethane-based anti-corrosion coating.

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