Industrial thermal insulation fireproof coating and preparation method thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to an industrial thermal insulation fireproof coating and a preparation method thereof. The industrial thermal-insulation fireproof coating is prepared from the following raw materials: a film-forming base material, silicon dioxide aerogel, hollow glass beads, manganese dioxide, a wetting agent, a suspension stabilizer and the like. According to the invention, the silicon dioxide aerogel is used as a barrier heat-insulating filler, the hollow glass beads are used as a reflective heat-insulating filler, the manganese dioxide is used as a radiation heat-insulating filler, and three heat-insulating mechanisms of barrier, reflection and radiation are combined to prepare the composite heat-insulating coating, so that the heat-insulating coating has an excellent heat-insulating effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to an industrial heat-insulating and fireproof coating and a preparation method thereof. Background Art

[0002] With the development of society and technology, energy and environmental problems need to be solved urgently. How to achieve energy conservation and consumption reduction and how to effectively improve energy utilization efficiency have become increasingly hot research topics. Traditional thermal insulation materials for industrial high-temperature pipelines and equipment include aluminosilicate wool, rock wool, glass plates, calcium silicate plates, perlite pipe shells, etc. However, such thermal insulation measures are prone to detachment from industrial pipelines, equipment, etc. during long-term service, resulting in voids, seriously reducing the effect of the thermal insulation measures; in addition, in wet weather such as rain, such thermal insulation measures are prone to absorb moisture, increasing their bulk density and reducing their strength, seriously affecting their service life and thermal insulation effect.

[0003] As a paste-like and amorphous material, the heat-insulating and heat-reflecting coating can form a seamless and integrally formed thermal insulation structure when used for industrial high-temperature heat pipes, which can greatly reduce the heat loss of industrial pipelines, equipment, etc., and effectively improve the energy-saving effect. Traditional heat-insulating and heat-reflecting coatings have been widely used in industry. However, due to their large thermal conductivity, low surface strength of the coating, and low high-temperature resistance, they cannot meet the increasing industrial requirements. In order to meet the industrial energy-saving requirements, reducing the thermal conductivity of the coating, enhancing the adhesion of the coating, and improving the high-temperature resistance are still the research directions of the heat-insulating and heat-reflecting coating. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an industrial heat-insulating and fireproof coating, and at the same time provide a preparation method of the coating.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An industrial heat-insulating and fireproof coating, in parts by weight, the raw materials include: 30-50 parts of film-forming base material, 1-5 parts of silica aerogel, 5-10 parts of hollow glass microspheres, 1-5 parts of manganese dioxide, 1-5 parts of Al-Fe-LDH, 1-5 parts of Al-Fe-LDH-TiO2, 0.1-0.5 part of dispersant, 0.1-0.5 part of wetting agent, 0.1-0.5 of suspension stabilizer, 0.5-1 part of film-forming aid, 0.5-2 parts of thickener, and 20-50 parts of deionized water.

[0007] The film-forming base material is one or more of pure acrylic emulsion, silicone resin, and silica sol.

[0008] The porosity of the silica aerogel is 80-98%, the average pore diameter is 20-50 nm, and the dry density is 30-100 kg / m 3, the thermal conductivity at room temperature is 0.015 - 0.02 W / m·k.

[0009] The main components of the hollow glass microspheres are SiO2, CaO, and Na2O, the median particle size is 30 - 60 μm, and the apparent density is 200 - 600 kg / m 3 , the thermal conductivity at room temperature is 0.025 - 0.035 W / m·k.

[0010] The dispersant is one or more of ammonium polyacrylate and sodium polycarboxylate; the wetting agent is one or more of alkylphenol polyoxyethylene ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty alcohol ether, and alkyl sulfate.

[0011] The suspension stabilizer is one or more of sodium polyacrylate, polyvinyl alcohol, sodium dodecylbenzenesulfonate, and carboxymethyl cellulose.

[0012] The film-forming aid is one or more of dodecyl alcohol ester, propylene glycol methyl ether, and propylene glycol butyl ether; the thickener is one or more of polyurethane thickeners, polyacrylate, and hydroxyethyl cellulose.

[0013] The preparation method of the industrial heat-insulating and fireproof coating includes the following steps:

[0014] 1) Take each raw material in proportion;

[0015] 2) Add silica aerogel, hollow glass microspheres, manganese dioxide, dispersant, wetting agent, and suspension stabilizer to deionized water and stir; stir at a speed of 600 - 800 r / min for 20 - 40 min;

[0016] 3) Adjust the rotation speed to 1000 - 1200 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 40 - 80 min;

[0017] 4) Adjust the rotation speed to 600 - 800 r / min, continue to add the film-forming base material and stir for 20 - 40 min, and finally add the film-forming aid and thickener and stir for 5 - 10 min to obtain the industrial heat-insulating and fireproof coating.

[0018] The Al-Fe-LDH is prepared by the laboratory precipitation method, and the raw materials used are iron nitrate Fe(NO3)3·9H2O (0.1 mol / L), aluminum nitrate Al(NO3)2·6H2O, and sodium hydroxide NaOH (1 mol / L).

[0019] Specific steps:

[0020] (1) Add the configured iron nitrate solution Fe(NO3)3·9H2O (0.1 mol / L), aluminum nitrate solution Al(NO3)2·6H2O, and sodium hydroxide solution NaOH (1 mol / L) dropwise into a four-necked flask containing 200 ml of deionized water simultaneously under a nitrogen environment;

[0021] (2) Stir the solution with a magnetic stirrer at a speed of 800 - 1000 r / min for 3 - 5 h, and then age and crystallize the solution in a vacuum drying oven at 60 - 80 °C for 12 - 24 h;

[0022] (3) Filter and wash the above solution 3 - 5 times with hot distilled water at 70 - 90 °C, and then transfer it to a vacuum drying oven and dry it at 60 - 80 °C for 12 - 24 h to obtain the Al-Fe-LDH product.

[0023] The Al-Fe-LDH-TiO2 is prepared by the laboratory precipitation method, and the raw materials used are iron nitrate Fe(NO3)3·9H2O (0.1 mol / L), aluminum nitrate Al(NO3)2·6H2O, sodium hydroxide NaOH (1 mol / L), and titanium dioxide.

[0024] The Al-Fe-LDH-TiO2 is prepared by the following method:

[0025] Add titanium dioxide into deionized water and stir; dilute the titanate coupling agent with absolute ethanol and add it, then stir; continue to add Al-Fe-LDH and stir; filter and wash the obtained solution with hot distilled water, and then dry the solid to obtain the Al-Fe-LDH-TiO2 product.

[0026] The Al-Fe-LDH-TiO2 is prepared by the following specific method:

[0027] 1) Add 1 - 5 parts of titanium dioxide into deionized water and stir with a magnetic stirrer at a speed of 800 - 1000 r / min for 30 - 50 min; dilute 0.1 - 0.5 parts of the titanate coupling agent with absolute ethanol and add it, then stir at a speed of 600 - 800 r / min for 30 - 50 min;

[0028] 2) Continue to add Al-Fe-LDH and stir with a magnetic stirrer at a speed of 800 - 1000 r / min for 3 - 5 h;

[0029] 3) Filter and wash the obtained solution 3 - 5 times with hot distilled water at 70 - 90 °C, and then dry the solid in a vacuum drying oven at 100 - 110 °C for 12 - 24 h to obtain the Al-Fe-LDH-TiO2 product.

[0030] The manganese dioxide is commercially available, with a black powder appearance and analytical purity; the titanium dioxide is commercially available, with a white powder appearance and analytical purity.

[0031] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0032] 1. In the present invention, silica aerogel is used as a barrier heat insulation filler, hollow glass microspheres are used as a reflective heat insulation filler, and manganese dioxide is used as a radiative heat insulation filler. A composite heat insulation coating is prepared by combining the three heat insulation mechanisms of barrier, reflection, and radiation, so that the heat insulation coating has excellent heat insulation effect.

[0033] 2. On the basis of the three heat insulation mechanisms, Al-Fe-LDH is added in the present invention. When encountering a high-temperature combustion environment, the gas between layers blocks combustion, making LDH produce flame retardancy. The functional groups and middle ions in the LDH structure can fall off from the stacked layers at different temperature environments, so that flame-retardant substances are produced at 200-800 °C. However, due to the relatively high thermal conductivity of Al-Fe-LDH itself and its lack of photocatalytic degradation function, it cannot cope with the complexity of the coating's use environment. Therefore, there are problems of insufficient excellent heat insulation performance and poor weather resistance when using Al-Fe-LDH alone.

[0034] 3. The Al-Fe-LDH-TiO2 obtained by the inventor's modification of Al-Fe-LDH with TiO2 shows more excellent heat insulation and fire prevention performance, making up for certain heat insulation performance. At the same time, Al-Fe-LDH-TiO2 also has photocatalytic and ultraviolet shielding effects, endowing the coating with the functions of degrading complex environmental pollutants and resisting sunlight, making the coating have better weather resistance and anti-aging performance, expanding the use range of the coating and prolonging the service time of the coating. However, not all of the advantages are brought by Al-Fe-LDH-TiO2. The addition of Al-Fe-LDH-TiO2 will affect the dispersion stability of the coating. Therefore, the addition amount needs to be strictly controlled.

[0035] 4. Film-forming binders are added in the present invention, such as silicone resin, silica sol, and pure acrylic emulsion. These film-forming binders have excellent characteristics such as high temperature resistance, high weather resistance, and high adhesion. In industrial high-temperature pipelines and equipment, they can endow the coating with good temperature resistance and heat insulation performance, adhesion performance, and weather resistance.

[0036] 5. The preparation process of the industrial heat preservation, heat insulation and fire prevention coating of the present invention is simple and efficient, and has broad prospects for popularization. Specific embodiments

[0037] The following examples are used to illustrate the specific embodiments of the present invention, but the following examples are only used to illustrate the present invention in detail and do not limit the scope of the present invention in any way.

[0038] In the following examples,

[0039] The silica aerogel filler is commercially available, with a porosity of 80 - 98%, an average pore diameter of 20 - 50 nm, and a dry density of 30 - 100 kg / m 3 , and the thermal conductivity at room temperature is 0.015 - 0.02 W / m·k.

[0040] The main components of the hollow glass microspheres are SiO2, CaO, and Na2O, the median particle size is 30 μm, and the apparent density is 200 - kg / m 3 , and the thermal conductivity at room temperature is 0.025 W / m·k.

[0041] The manganese dioxide is commercially available, with a black powder appearance and analytical purity. The titanium dioxide is commercially available, with a white powder appearance and analytical purity.

[0042] Example 1:

[0043] A method for preparing an industrial heat-insulating and fireproof coating is prepared by the following method:

[0044] 1) Preparation of Al-Fe-LDH

[0045] 80 g of the prepared iron nitrate solution Fe(NO3)3·9H2O (0.1 mol / L), 30 g of the aluminum nitrate solution Al(NO3)2·6H2O (0.5 mol / L), and 40 g of the sodium hydroxide solution NaOH (1 mol / L) are simultaneously added dropwise into a four-necked flask containing 2000 ml of deionized water under a nitrogen atmosphere; the solution is stirred with a magnetic stirrer at a speed of 800 r / min for 3 h, and then the solution is aged and crystallized in a vacuum drying oven at 60 °C for 24 h; the above solution is filtered and washed 3 times with hot distilled water at 70 °C, and then transferred to a vacuum drying oven and dried at 60 °C for 24 h to obtain 60 g of the Al-Fe-LDH product.

[0046] 2) Preparation of Al-Fe-LDH-TiO2

[0047] Add 40 g of titanium dioxide to a three-necked flask containing 2000 ml of deionized water, and stir the solution at a speed of 800 r / min for 50 min with a magnetic stirrer; dilute 2 g of titanate coupling agent with absolute ethanol and add it to the three-necked flask, and stir at a speed of 600 r / min for 50 min; add 30 g of Al-Fe-LDH to the three-necked flask, and stir the solution at a speed of 800 r / min for 5 h with a magnetic stirrer; filter and wash the above solution 5 times with hot distilled water at 70 °C, and then transfer it to a vacuum drying oven and dry it in an environment of 100 °C for 24 h to obtain 30 g of Al-Fe-LDH-TiO2 product;

[0048] 3) Take raw materials: 400 g of pure acrylic emulsion, 30 g of silica aerogel, 80 g of hollow glass microspheres, 30 g of manganese dioxide, 30 g of Al-Fe-LDH, 30 g of Al-Fe-LDH-TiO2, 3 g of ammonium polyacrylate, 3 g of alkylphenol polyoxyethylene ether, 3 g of sodium polyacrylate, 8 g of dodecyl alcohol ester, 10 g of polyurethane thickener, 400 g of deionized water.

[0049] 4) Add silica aerogel, hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and sodium polyacrylate to deionized water and stir, and stir at a speed of 700 r / min for 30 min;

[0050] 5) Adjust the rotation speed to 1000 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 80 min;

[0051] 6) Adjust the rotation speed to 600 r / min, continue to add pure acrylic emulsion and stir, and finally add dodecyl alcohol ester and polyurethane thickener and stir to obtain an industrial heat-insulating and fireproof coating.

[0052] Example 2

[0053] A preparation method of an industrial heat-insulating and fireproof coating is prepared by the following method:

[0054] 1) Prepare Al-Fe-LDH

[0055] 80 g of the configured iron nitrate solution Fe(NO3)3·9H2O (0.1 mol / L), 30 g of aluminum nitrate solution Al(NO3)2·6H2O (0.5 mol / L), and 40 g of sodium hydroxide solution NaOH (1 mol / L) were simultaneously added dropwise into a four-necked flask containing 2000 ml of deionized water under a nitrogen environment; the solution was stirred with a magnetic stirrer at a speed of 900 r / min for 5 h, and then the solution was aged and crystallized in a vacuum drying oven at 70 °C for 18 h; the above solution was filtered and washed 5 times with hot distilled water at 80 °C, and then transferred to a vacuum drying oven and dried at 70 °C for 18 h to obtain 60 g of Al-Fe-LDH product.

[0056] 2) Preparation of Al-Fe-LDH-TiO2

[0057] 30 g of titanium dioxide was added to a three-necked flask containing 2000 ml of deionized water, and the solution was stirred with a magnetic stirrer at a speed of 900 r / min for 40 min; 3 g of titanate coupling agent was diluted with anhydrous ethanol and added to the three-necked flask, and stirred at a speed of 700 r / min for 40 min; 10 g of Al-Fe-LDH was added to the three-necked flask, and the solution was stirred with a magnetic stirrer at a speed of 900 r / min for 4 h; the above solution was filtered and washed 4 times with hot distilled water at 80 °C, and then transferred to a vacuum drying oven and dried at 100 °C for 18 h to obtain 10 g of Al-Fe-LDH-TiO2 product;

[0058] 3) Take raw materials: 500 g of silicone resin, 10 g of silica aerogel, 100 g of hollow glass microspheres, 10 g of manganese dioxide, 50 g of Al-Fe-LDH, 10 g of Al-Fe-LDH-TiO2, 5 g of polycarboxylate sodium salt, 1 g of polyoxyethylene alkylphenol ether, 5 g of polyvinyl alcohol, 5 g of dodecyl alcohol ester, 20 g of polyacrylate, 500 g of deionized water;

[0059] 4) Add silica aerogel, hollow glass microspheres, manganese dioxide, polycarboxylate sodium salt, polyoxyethylene alkylphenol ether, and polyvinyl alcohol to deionized water and stir, and stir at a speed of 600 r / min for 40 min;

[0060] 5) Adjust the rotation speed to 1100 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 60 min;

[0061] 6) Adjust the rotation speed to 700 r / min, continue to add silicone resin and stir, and finally add dodecyl alcohol ester and polyacrylate and stir to obtain an industrial heat-insulating and fireproof coating.

[0062] Example 3

[0063] Preparation method of industrial heat-insulating and fireproof coating, which is prepared by the following method:

[0064] 1) Preparation of Al-Fe-LDH

[0065] 80 g of prepared iron nitrate solution Fe(NO3)3·9H2O (0.1 mol / L), 30 g of aluminum nitrate solution Al(NO3)2·6H2O (0.5 mol / L), and 40 g of sodium hydroxide solution NaOH (1 mol / L) were simultaneously added dropwise into a four-necked flask containing 2000 ml of deionized water under a nitrogen atmosphere; the solution was stirred with a magnetic stirrer at a speed of 1000 r / min for 4 h, and then the solution was aged and crystallized in a vacuum drying oven at 80 °C for 12 h; the above solution was filtered and washed 4 times with hot distilled water at 90 °C, and then transferred into a vacuum drying oven and dried at 80 °C for 12 h to obtain 60 g of Al-Fe-LDH product.

[0066] 2) Preparation of Al-Fe-LDH-TiO2

[0067] 30 g of titanium dioxide was added into a three-necked flask containing 200 ml of deionized water, and the solution was stirred with a magnetic stirrer at a speed of 1000 r / min for 30 min; 4 g of titanate coupling agent was diluted with absolute ethanol and added into the three-necked flask, and stirred at a speed of 800 r / min for 30 min; 50 g of Al-Fe-LDH was added into the three-necked flask in step (4), and the solution was stirred with a magnetic stirrer at a speed of 1000 r / min for 3 h; the above solution was filtered and washed 3 times with hot distilled water at 90 °C, and then transferred into a vacuum drying oven and dried at 110 °C for 12 h to obtain 50 g of Al-Fe-LDH-TiO2 product;

[0068] 3) Take raw materials: 300 g of silica sol, 50 g of silica aerogel, 50 g of hollow glass microspheres, 50 g of manganese dioxide, 10 g of Al-Fe-LDH, 50 g of Al-Fe-LDH-TiO2, 1 g of ammonium polyacrylate, 5 g of alkyl sulfate, 1 g of sodium dodecylbenzenesulfonate, 10 g of propylene glycol butyl ether, 5 g of hydroxyethyl cellulose, 300 g of deionized water;

[0069] 4) Add silica aerogel, hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkyl sulfate, and sodium dodecylbenzenesulfonate into deionized water and stir, and stir at a speed of 800 r / min for 20 min;

[0070] 5) Adjust the rotation speed to 1200 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 40 min;

[0071] 6) Adjust the rotational speed to 800 r / min, continue to add silica sol and stir, and finally add propylene glycol monobutyl ether and hydroxyethyl cellulose and stir to obtain the industrial heat-insulating, fireproof coating.

[0072] Example 4

[0073] The preparation method of the industrial heat-insulating, fireproof coating is prepared by the following method:

[0074] 1) Prepare Al-Fe-LDH

[0075] Drop 80 g of the prepared iron nitrate solution Fe(NO3)3·9H2O (0.1 mol / L), 30 g of aluminum nitrate solution Al(NO3)2·6H2O (0.5 mol / L), and 40 g of sodium hydroxide solution NaOH (1 mol / L) into a four-necked flask containing 2000 ml of deionized water drop by drop simultaneously under a nitrogen environment; use a magnetic stirrer to stir the solution at a speed of 800 r / min for 3 h, and then age and crystallize the solution in a vacuum drying oven at 60 °C for 12 h; filter and wash the above solution 3 times with hot distilled water at 70 °C, and then transfer it to a vacuum drying oven and dry it at 60 °C for 12 h to obtain 60 g of Al-Fe-LDH product.

[0076] 2) Take raw materials: 400 g of pure acrylic emulsion, 30 g of silica aerogel, 80 g of hollow glass microspheres, 30 g of manganese dioxide, 60 g of Al-Fe-LDH, 3 g of ammonium polyacrylate, 3 g of alkylphenol polyoxyethylene ether, 3 g of sodium polyacrylate, 8 g of dodecyl acetate, 10 g of polyurethane thickener, and 400 g of deionized water.

[0077] 3) Add silica aerogel, hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and sodium polyacrylate to deionized water and stir, and stir at a speed of 700 r / min for 30 min;

[0078] 4) Adjust the rotational speed to 1000 r / min, and continue to add Al-Fe-LDH and stir for 80 min;

[0079] 5) Adjust the rotational speed to 600 r / min, continue to add pure acrylic emulsion and stir, and finally add dodecyl acetate and polyurethane thickener and stir to obtain the industrial heat-insulating, fireproof coating.

[0080] Example 5

[0081] The preparation method of the industrial heat-insulating, fireproof coating is prepared by the following method:

[0082] 1) Prepare Al-Fe-LDH-TiO2

[0083] Add 30 g of titanium dioxide into a three-necked flask containing 2000 ml of deionized water, and stir the solution at a speed of 800 - 1000 r / min for 30 - 50 min with a magnetic stirrer; dilute 4 g of titanate coupling agent with absolute ethanol and then add it into the three-necked flask, and stir at a speed of 600 - 800 r / min for 30 - 50 min; add 60 g of Al-Fe-LDH into the three-necked flask, and stir the solution at a speed of 800 - 1000 r / min for 3 - 5 h with a magnetic stirrer; filter and wash the above solution with hot distilled water at 70 - 90 °C for 3 - 5 times, and then transfer it into a vacuum drying oven and dry it at 100 - 110 °C for 12 - 24 h to obtain 60 g of Al-Fe-LDH-TiO2 product;

[0084] 2) Take raw materials: 400 g of pure acrylic emulsion, 30 g of silica aerogel, 80 g of hollow glass microspheres, 30 g of manganese dioxide, 60 g of Al-Fe-LDH-TiO2, 3 g of ammonium polyacrylate, 3 g of alkylphenol polyoxyethylene ether, 3 g of sodium polyacrylate, 8 g of dodecyl alcohol ester, 10 g of polyurethane thickener, 400 g of deionized water;

[0085] 3) Add silica aerogel, hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and sodium polyacrylate into deionized water and stir, and stir at a speed of 700 r / min for 30 min;

[0086] 4) Adjust the rotation speed to 1000 r / min, and continue to add Al-Fe-LDH-TiO2 and stir for 80 min;

[0087] 5) Adjust the rotation speed to 600 r / min, continue to add pure acrylic emulsion and stir, and finally add dodecyl alcohol ester and polyurethane thickener and stir to obtain an industrial heat-insulating, fireproof coating.

[0088] Example 6

[0089] A preparation method of an industrial heat-insulating, fireproof coating is prepared by the following method:

[0090] Differing from Example 1,

[0091] The preparation process is as follows:

[0092] 1) Take raw materials: 400 g of pure acrylic emulsion, 80 g of hollow glass microspheres, 30 g of manganese dioxide, 30 g of Al-Fe-LDH, 30 g of Al-Fe-LDH-TiO2, 3 g of ammonium polyacrylate, 3 g of alkylphenol polyoxyethylene ether, 3 g of sodium polyacrylate, 8 g of dodecyl alcohol ester, 10 g of polyurethane thickener, 400 g of deionized water;

[0093] 2) Add hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and sodium polyacrylate to deionized water and stir at a speed of 700 r / min for 30 min;

[0094] 3) Adjust the rotation speed to 1000 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 80 min;

[0095] 4) Adjust the rotation speed to 600 r / min, continue to add pure acrylic emulsion and stir, and finally add dodecyl alcohol ester and polyurethane thickener and stir to obtain the industrial heat-insulating, fireproof coating.

[0096] Example 7

[0097] A preparation method of an industrial heat-insulating, fireproof coating is prepared by the following method:

[0098] Different from Example 1,

[0099] The preparation process is as follows:

[0100] 1) Take raw materials: 30 g of silica aerogel, 80 g of hollow glass microspheres, 30 g of manganese dioxide, 30 g of Al-Fe-LDH, 30 g of Al-Fe-LDH-TiO2, 3 g of ammonium polyacrylate, 3 g of alkylphenol polyoxyethylene ether, 3 g of sodium polyacrylate, 8 g of dodecyl alcohol ester, 10 g of polyurethane thickener, and 400 g of deionized water.

[0101] 2) Add silica aerogel, hollow glass microspheres, manganese dioxide, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and sodium polyacrylate to deionized water and stir at a speed of 700 r / min for 30 min;

[0102] 3) Adjust the rotation speed to 1000 r / min, and continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir for 80 min;

[0103] 4) Adjust the rotation speed to 600 r / min, add dodecyl alcohol ester and polyurethane thickener and stir to obtain the industrial heat-insulating, fireproof coating.

[0104] Effect experiment:

[0105] The above Examples 1-7 were tested for their main properties such as the appearance of the coating, thermal conductivity, heat insulation temperature difference, in accordance with the standard HG / T 5182-2017 "Thermal Insulation Coatings for Petroleum and Chemical Equipment". The method for determining the limit fire resistance time is as follows: Small plate combustion method (alcohol blowtorch method): A 70mm×40mm×0.7mm iron sheet with one side coated with fireproof coating and completely dried, with the coating (2mm thick) side facing down, is placed 100mm above an alcohol blowtorch (with anhydrous ethanol as the combustion medium). Thermocouples are placed at the center of the alcohol blowtorch and 10mm directly opposite the back of the coating. The back of the coating and the vacant area are tightly wrapped with heat-insulating asbestos. The temperature of the coating back plate is measured after the alcohol blowtorch burns for 30 minutes, and the average value is taken after 3 tests.

[0106] The test results are shown in the following table:

[0107] Appearance of the coating Thermal conductivity (W / m·k) Insulating temperature difference (℃) Ultimate fire resistance time (s) Example 1 Uniform without lumps after stirring 0.043 17 1590 Example 2 Uniform without lumps after stirring 0.047 13 1521 Example 3 Uniform without lumps after stirring 0.041 20 1685 Example 4 Uniform without lumps after stirring 0.057 9 1392 Example 5 Uniform without lumps after stirring 0.039 23 1733 Example 6 Uniform without lumps after stirring 0.069 5 1457 Example 7 There are lumps after stirring 0.061 8 1492

[0108] From the results in the above table, it can be seen that when the coating does not contain silica aerogel (Example 6), its thermal conductivity is the highest and the heat insulation temperature difference is the smallest, indicating that silica aerogel can significantly affect the heat insulation performance of the coating. When the coating does not contain Al-Fe-LDH-TiO2 (Example 4), the fire resistance limit is the lowest, indicating that Al-Fe-LDH can only affect the fireproof performance of the coating to a certain extent. When the coating does not contain Al-Fe-LDH (Example 5), the fire resistance limit is the highest, indicating that coating modification of Al-Fe-LDH can improve the fireproof performance of the coating.

[0109] According to Examples 1 and 4, the photocatalytic performance, weather resistance, anti-aging performance, and dispersion stability were tested. The test methods are as follows: Aging test: Two iron sheets of 70mm×40mm×0.7mm with both sides coated with the coating and completely dried are placed in the outdoor environment, and their appearance changes are recorded after 30 days of exposure. Before and after the aging experiment, the photocatalytic performance of the two coatings is tested respectively, and the change in the degradation rate is compared. Photocatalytic performance test: Two iron sheets of 70mm×40mm×0.7mm with both sides coated with the coating and completely dried are respectively placed in beakers containing 100ml of methylene blue solution (10mg / l). The two beakers are placed in the dark and stirred at 600r / min for 30 minutes to achieve adsorption equilibrium. After the end of the dark adsorption stage, the initial absorbance A0 of the solution is measured. The two beakers are placed under an ultraviolet lamp, with the distance between the light source and the liquid surface maintained at 10cm, and the light source is turned on to start the light reaction. Samples are taken every thirty minutes, 2ml each time, and the absorbance is measured at 664nm using a UV-visible spectrophotometer.

[0110] The test results are shown in the following table:

[0111] Photocatalytic data before aging:

[0112] Time (min) Example 1 (Absorbance) Degradation rate (%) Example 4 (Absorbance) Degradation rate (%) 0 0.650 0 0.650 0 30 0.450 30.8 0.550 15.4 60 0.370 43.1 0.500 23.1 90 0.310 52.3 0.450 30.8 120 0.260 60.0 0.400 38.5

[0113] Photocatalytic data after aging:

[0114] Time (min) Example 1 (Absorbance) Degradation rate (%) Example 4 (Absorbance) Degradation rate (%) 0 0.650 0 0.650 0 30 0.530 18.5 0.610 4.6 60 0.460 29.2 0.590 9.2 90 0.390 40.0 0.550 15.4 120 0.320 50.8 0.520 20.0

[0115] As can be seen from the results in the above table, when the coating contains Al-Fe-LDH-TiO2 (Example 1), the degradation rate of methylene blue under light illumination conditions is significantly higher than that without Al-Fe-LDH-TiO2 (Example 4). This indicates that the introduction of TiO2 significantly improves the photocatalytic performance. After the aging experiment, the decline in the photocatalytic performance of the coating containing Al-Fe-LDH-TiO2 (Example 1) is relatively small (9.2%), while the decline in the photocatalytic performance of the coating containing Al-Fe-LDH (Example 4) is relatively large (18.5%). This shows that the coating containing Al-Fe-LDH-TiO2 has better weather resistance and anti-aging performance.

[0116] According to Examples 1-5, the effect of Al-Fe-LDH-TiO2 on the dispersion stability of the coating was measured. The test method was as follows: The prepared coating was filled into a 25 ml graduated cylinder, and the initial volume (V0) was recorded. After standing for 7 days, the sedimentation volume (V s ) was read, and the sedimentation volume fraction was calculated.

[0117] The test results are shown in the following table:

[0118] <![CDATA[Initial volume V0 (ml)]]> <![CDATA[Settling volume V s (ml)]]> <![CDATA[Settling volume fraction (V s / V0)]]> Example 1 25 9.0 0.36 Example 2 25 11.0 0.44 Example 3 25 13.0 0.52 Example 4 25 6.0 0.24 Example 5 25 15.0 0.60

[0119] As can be seen from the results in the above table, when the coating does not contain Al-Fe-LDH (Example 5), the sedimentation volume fraction is the highest (0.60), and when the coating does not contain Al-Fe-LDH-TiO2 (Example 4), the sedimentation volume fraction is the lowest (0.24). This shows that the addition of Al-Fe-LDH-TiO2 will affect the dispersion stability of the coating.

[0120] According to Examples 1 and 7, the effects of the film-forming base material on the temperature resistance, weather resistance, and adhesion of the coating were detected. The test method was as follows: A 70 mm × 40 mm × 0.7 mm iron sheet coated with the coating and completely dried was placed in a high-temperature oven, heated to 200 °C, and maintained for 2 h. After cooling, the cracking and peeling of the coating were observed. The weather resistance was measured using a QUV accelerated aging tester, with the light illumination period set at 8 h / day, the temperature at 60 °C, and the humidity at 50%. The test period was 100 h, and the change in the light retention rate and color difference of the coating was observed. The adhesion was tested using a cross-cut tester. 100 grids (2 mm spacing) were drawn on the coating, and after sticking with tape and then tearing it off, the peeling of the coating was observed. The adhesion grade was evaluated according to CB / T9286-2001 "Cross-Cut Test for Paints and Varnishes".

[0121] The test results are shown in the following table:

[0122] Coating state (200℃, 2h) Gloss retention rate (%) Color difference change (ΔE) Adhesion rating Example 1 No cracking, no peeling, slight discoloration 90 1.2 Grade 1 Example 7 Cracking, peeling, severe discoloration 60 3.5 Grade 4

[0123] As can be seen from the results in the above table, when the coating contains a film-forming binder (Example 1), the coating shows better heat resistance and higher coating integrity. When the coating does not contain a film-forming binder (Example 7), the weather resistance, gloss retention rate and color difference change of the coating are all lower than those of the coating containing a film-forming binder (Example 1). When the coating contains a film-forming binder (Example 1), its adhesion is significantly higher than that of the coating without a film-forming binder (Example 7). It shows that the film-forming binder can improve the heat resistance, weather resistance and adhesion of the coating.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Any other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. An industrial heat-insulating and fireproof coating, characterized in that, By weight, the raw materials include: 30-50 parts of film-forming base material, 1-5 parts of silica aerogel, 5-10 parts of hollow glass microspheres, 1-5 parts of manganese dioxide, 1-5 parts of Al-Fe-LDH, 1-5 parts of Al-Fe-LDH-TiO2, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of wetting agent, 0.1-0.5 parts of suspension stabilizer, 0.5-1 part of film-forming aid, 0.5-2 parts of thickener, and 20-50 parts of deionized water.

2. The industrial heat-insulating and fireproof coating according to claim 1, characterized in that, The film-forming base material is one or more of pure acrylic emulsion, silicone resin, and silica sol.

3. The industrial heat-insulating and fireproof coating according to claim 1, characterized in that The porosity of the silica aerogel is 80-98%, the average pore size is 20-50 nm, and the dry density is 30-100 kg / m 3 , and the thermal conductivity at room temperature is 0.015-0.02 W / m·k.

4. The industrial heat-insulating and fireproof coating according to claim 1, wherein The main components of the hollow glass microspheres are SiO2, CaO, and Na2O, with a median particle size of 30-60 μm and an apparent density of 200-600 kg / m 3 , and the thermal conductivity at room temperature is 0.025-0.035 W / m·k.

5. The industrial heat-insulating and fireproof paint according to claim 1, wherein The dispersant is one or more of ammonium polyacrylate salt and sodium polycarboxylate salt; the wetting agent is one or more of alkylphenol polyoxyethylene ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty alcohol ether, and alkyl sulfate.

6. The industrial heat-insulating and fireproof coating according to claim 1, wherein, The suspension stabilizer is one or more of sodium polyacrylate, polyvinyl alcohol, sodium dodecylbenzenesulfonate, and carboxymethyl cellulose.

7. The industrial heat-insulating and fireproof coating according to claim 1, characterized in that, The film-forming aid is one or more of dodecyl alcohol ester, propylene glycol methyl ether, and propylene glycol butyl ether; the thickener is one or more of polyurethane thickeners, polyacrylate, and hydroxyethyl cellulose.

8. The preparation method of the industrial heat-insulating and fireproof coating according to claim 1, characterized in that, It includes the following steps: 1) Take each raw material in proportion. 2) Add silica aerogel, hollow glass microspheres, manganese dioxide, dispersant, wetting agent, and suspension stabilizer into deionized water and stir. 3) Continue to add Al-Fe-LDH and Al-Fe-LDH-TiO2 and stir. 4) Continue to add the film-forming base material and stir, and finally add the film-forming aid and thickener and stir to obtain an industrial heat-insulating and fireproof coating.

9. The preparation method according to claim 8, characterized in that, Al-Fe-LDH-TiO2 is prepared by the following method: Add titanium dioxide into deionized water and stir; dilute the titanate coupling agent with absolute ethanol and add it, then stir; continue to add Al-Fe-LDH and stir; filter and wash the obtained solution with hot distilled water, and then dry the solid to obtain the Al-Fe-LDH-TiO2 product.