阅读说明：本技术 一种防开裂保温涂料 (Anti-cracking heat-insulating coating ) 是由 何冬梅 于 2019-10-22 设计创作，主要内容包括：本粉末公开了一种防开裂保温涂料,属于建筑材料技术领域。按重量份数计,依次称取：60～80份聚合物乳液,2～5份分散剂,2～4份流平剂,15～25份改性隔热骨料和2～4防沉剂；将聚合物乳液与分散剂混合于搅拌机中,并向搅拌机中加入流平剂,改性隔热骨料和防沉剂,于温度为30～50℃,转速为300～380r/min的条件下,搅拌混合30～40min后,得防开裂保温涂料。本发明技术方案制备的保温隔热涂料具有优异的隔热性能的特点,在高分子保温材料技术行业的发展中具有广阔的前景。(The powder discloses an anti-cracking heat-insulating coating, and belongs to the technical field of building materials. Weighing the following components in parts by weight: 60-80 parts of polymer emulsion, 2-5 parts of dispersing agent, 2-4 parts of flatting agent, 15-25 parts of modified heat insulation aggregate and 2-4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 30-40 min at the temperature of 30-50 ℃ and the rotating speed of 300-380 r/min to obtain the anti-cracking heat insulation coating. The heat-insulating coating prepared by the technical scheme of the invention has the characteristic of excellent heat-insulating property and has wide prospect in the development of the polymer heat-insulating material technical industry.)

1. The anti-cracking heat-insulating coating is characterized by comprising the following raw materials in parts by weight: 60-80 parts of polymer emulsion, 2-5 parts of dispersing agent, 2-4 parts of flatting agent, 15-25 parts of modified heat insulation aggregate and 2-4 parts of anti-settling agent;

the preparation method of the modified heat insulation aggregate comprises the following steps:

mixing an initiator and an ethanol solution according to a mass ratio of 1: 200-1: 300, adding a styrene monomer with the mass 100-120 times that of the initiator, stirring and reacting to obtain a prepolymer dispersion, and mixing the prepolymer dispersion with a methacryloyl ethylene oxide ammonium chloride solution according to a mass ratio of 80: 1-9: 1, mixing, stirring and reacting under the nitrogen atmosphere, and then centrifugally separating, filtering and drying to obtain pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, wherein the mass ratio of the polystyrene microspheres to the modified powder is 1: 1-2: 1, adding ethanol with the mass of 8-18 times that of the polystyrene microsphere, stirring and mixing, performing ultrasonic dispersion, filtering, and drying to obtain the modified polystyrene microsphere, namely the modified heat insulation aggregate.

2. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the polymer emulsion is styrene-acrylic emulsion with solid content of 45-55% or silicone-acrylic emulsion with solid content of 50-55%.

3. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the dispersant is any one of dispersant NNO, dispersant MF or dispersant 5040.

4. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the leveling agent is any one of silicone oil or polydimethylsiloxane.

5. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the anti-settling agent is any one of organic bentonite, polyamide wax or fumed silica.

6. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the initiator is any one of azodiisobutyronitrile, benzoyl peroxide or diisophenylpropyl peroxide.

7. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 18-1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution.

8. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the foaming condition is that foaming is carried out for 2-5 min under the conditions that the steam pressure is 0.4-0.6 MPa and the temperature is 85-98 ℃.

9. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: the modified powder is prepared by mixing titanium dioxide and potassium carbonate according to a molar ratio of 4.0: 1.3, mixing, grinding, calcining, washing and drying to obtain pretreatment powder, wherein the pretreatment powder and ethanol are mixed according to a mass ratio of 1: 15-1: 20, adding dodecylamine with the mass 2-3 times that of the pretreated powder, performing ultrasonic dispersion, filtering, and drying to obtain modified powder.

10. The anti-cracking heat-insulating coating as claimed in claim 1, wherein: modified sodium lignosulfonate which is 0.1-0.2 times of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with the mass 1-4 times that of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 90: 1-100: 1, adding 1, 6-dibromohexane which is 0.2-0.3 times of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and performing rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Technical Field

The powder discloses an anti-cracking heat-insulating coating, and belongs to the technical field of building materials.

Background

The heat-insulating coating is a novel heat-insulating material, and realizes heat insulation through low heat conductivity and high heat resistance. The product is made by adding chemical additive and high temperature adhesive into high quality natural mineral substance, and through the processes of pulping, molding, shaping, drying, finished product and packaging. The coating is a novel heat-insulating material, and the product is a high-quality high-efficiency heat-insulating material integrating a closed microporous structure and a reticular fiber structure. Within the temperature range of use. The heat insulation material can be used for a long time, is not easy to age, does not deteriorate, is nontoxic and tasteless, has the characteristics of light weight, small heat conductivity coefficient, cold insulation, heat insulation, shock resistance, sound absorption and the like, can be widely applied to industries such as metallurgy, chemical industry, petroleum, ships, textiles, medicine, traffic, thermoelectricity, buildings and the like, is convenient to construct, does not pollute the environment, does not stimulate the skin, has no loss in construction and the like. The heat-insulating coating adopts special solution, nano ceramic hollow particles, silicon-aluminum fibers and various reflecting materials as main raw materials, the heat conductivity coefficient is only 0.03W/m.K, the temperature resistance range is-80-1800 ℃, the heat conduction and the radiation heat of infrared rays can be effectively inhibited and shielded, the heat insulation inhibition efficiency can reach about 90 percent, the heat radiation and the heat loss of high-temperature objects can be inhibited, 70 percent of indoor heat can be kept not to be dissipated, the cold insulation can be effectively kept for low-temperature objects, the cold loss caused by the radiation heat of the environment can be inhibited, and the occurrence of condensation can be prevented. The temperature of the object coated with the 8mm high-temperature heat-insulating coating at 1100 ℃ can be reduced to be within 100 ℃. The external surface spraying at high temperature pipeline, equipment, container can effectively restrain the loss of heat radiation and heat, through the test: the heat loss can be reduced by more than 30% by only coating the high-temperature heat-insulating coating with the thickness of 6mm on the outer surface of the industrial kiln, the coating on the inner wall of the kiln can be smoother and smoother than the surface of any material and has the flame infrared reflection function, the heat absorption of the kiln wall is reduced, and the flame temperature of a hearth is increased. Coating a high-temperature heat-insulating coating with the thickness of 10mm on a box body at the temperature of minus 30 ℃, wherein the temperature in the box body is not lower than 0 ℃ within 24 hours. In addition, the high-temperature heat-insulating coating has zero chloride ion content, and can prevent air or wet chloride in the process from entering and contacting the metal surface, so that weld embrittlement in metal welding cannot be caused. The insulating coefficient of the coating is very high, and the coating has a good insulating effect at high temperature. Building energy conservation is one of the key points of energy-saving work, and external wall external heat preservation becomes a main product of building energy conservation. For areas mainly used for heat preservation in thermal engineering design, such as severe cold areas and cold areas, external wall external heat preservation is reasonable, applicable and fast in development. For the hot and warm areas in summer, which are generally only considered for heat insulation during thermal design, or the hot and cold areas in summer, which are mainly used for heat insulation during thermal design, a further perfect space exists for the external heat insulation of some external walls at present. According to the solar radiation heat balance equation of the building envelope structure, various heat insulation coatings are reasonably selected and used according to the climatic characteristics of different regions to form a composite system, so that the heat is insulated, and the purposes of comfortable indoor thermal environment, energy conservation and consumption reduction are achieved. The main raw materials of the coating comprise nano hollow microspheres, high-grade emulsion, titanium dioxide and the like, wherein the content of the nano hollow microspheres in the coating is at least more than 80 percent, after the coating is brushed, a three-dimensional network hollow structure connected by closed microbeads can be formed on the surface of an object, the nanometer hollow ceramic micro-beads and the micro-beads form a static air group which is overlapped and clamped one by one, namely a heat insulation unit, the heat conductivity coefficient of the coating can reach 0.04W/(m.K), can effectively prevent heat conduction, has excellent heat insulation and heat preservation, the heat insulation grade of the coating reaches R-30.1, the heat reflectivity is more than 90 percent, the infrared ray can be reflected in a large quantity, the infrared ray is prevented from heating an object, the radiation heat and heat conduction of the sun and the infrared ray can be effectively inhibited, and the heat insulation and preservation inhibiting efficiency can reach about 90%.

The heat-insulating coating with barrier property is a coating which realizes heat insulation through low heat conductivity coefficient and high heat resistance. The most widely used heat-insulating coating with barrier property is a composite silicate heat-insulating coating. The coating is developed in the late 20 th century and 80 years and has different product names, such as composite magnesium aluminum silicate heat insulation coating, rare earth heat insulation coating, coating type composite silicate heat insulation coating and the like. It is a heat-insulating coating made up by using inorganic and/or organic adhesive, heat-insulating aggregate (for example sepiolite, vermiculite and pearlite powder) and air-entraining agent.

The problem that the heat insulation performance and the crack resistance of the traditional anti-cracking heat insulation coating can not be further improved at present is solved, and the problem to be solved is to explore and develop the anti-cracking heat insulation coating with good comprehensive performance.

Disclosure of Invention

The invention mainly solves the technical problems that: aiming at the problem that the heat insulation performance and the crack resistance of the traditional anti-cracking heat insulation coating cannot be further improved, the anti-cracking heat insulation coating is provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the anti-cracking heat-insulating coating is prepared from the following raw materials in parts by weight: 60-80 parts of polymer emulsion, 2-5 parts of dispersing agent, 2-4 parts of flatting agent, 15-25 parts of modified heat insulation aggregate and 2-4 parts of anti-settling agent;

the preparation method of the modified heat insulation aggregate comprises the following steps:

mixing an initiator and an ethanol solution according to a mass ratio of 1: 200-1: 300, adding a styrene monomer with the mass 100-120 times that of the initiator, stirring and reacting to obtain a prepolymer dispersion, and mixing the prepolymer dispersion with a methacryloyl ethylene oxide ammonium chloride solution according to a mass ratio of 80: 1-9: 1, mixing, stirring and reacting under the nitrogen atmosphere, and then centrifugally separating, filtering and drying to obtain pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, wherein the mass ratio of the polystyrene microspheres to the modified powder is 1: 1-2: 1, adding ethanol with the mass of 8-18 times that of the polystyrene microsphere, stirring and mixing, performing ultrasonic dispersion, filtering, and drying to obtain the modified polystyrene microsphere, namely the modified heat insulation aggregate.

The polymer emulsion is styrene-acrylic emulsion with solid content of 45-55% or silicone-acrylic emulsion with solid content of 50-55%.

The dispersant is any one of dispersant NNO, dispersant MF or dispersant 5040.

The leveling agent is any one of silicone oil or polydimethylsiloxane.

The anti-settling agent is any one of organic bentonite, polyamide wax or fumed silica.

The initiator is any one of azodiisobutyronitrile, benzoyl peroxide or diisophenylpropyl peroxide.

The methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 18-1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution.

The foaming condition is that foaming is carried out for 2-5 min under the conditions that the steam pressure is 0.4-0.6 MPa and the temperature is 85-98 ℃.

The modified powder is prepared by mixing titanium dioxide and potassium carbonate according to a molar ratio of 4.0: 1.3, mixing, grinding, calcining, washing and drying to obtain pretreatment powder, wherein the pretreatment powder and ethanol are mixed according to a mass ratio of 1: 15-1: 20, adding dodecylamine with the mass 2-3 times that of the pretreated powder, performing ultrasonic dispersion, filtering, and drying to obtain modified powder.

Modified sodium lignosulfonate which is 0.1-0.2 times of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with the mass 1-4 times that of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 90: 1-100: 1, adding 1, 6-dibromohexane which is 0.2-0.3 times of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and performing rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

The invention has the beneficial effects that:

(1) the invention uses modified heat insulation aggregate when preparing anti-cracking heat insulation coating, firstly, adding methacryloyl ethylene ammonium chloride solution when preparing polystyrene microsphere, the methacryloyl ethylene ammonium chloride can make the surface of polystyrene microsphere have positive charge, thus making polystyrene microsphere not easy to agglomerate after adding into product, improving heat insulation performance of product, secondly, adding modified powder into modified heat insulation aggregate, adding potassium tetratitanate with lamellar structure into modified powder, on one hand, the lamellar structure of potassium tetratitanate contains negative charge to absorb positive charge, and after dodecylamine and ultrasonic treatment, the spacing of potassium tetratitanate is enlarged, and peeled into monolithic layer structure, after mixing with polystyrene microsphere, it can be absorbed on the surface of polystyrene microsphere, reducing contact between polystyrene microsphere and air, the fire resistance of polystyrene is improved, and on the other hand, because the dodecylamine grafted on the surface of the potassium tetratitanate powder can improve the hydrophobicity of modified powder, the water resistance of the surface of a product is improved, the probability of cracking of the product due to water immersion is reduced, and because of the existence of long carbon chain organic matters, the bonding force between the modified heat insulation aggregate and polymer molecular chains in the product is improved while the connection strength between polystyrene microspheres and microspheres is improved, so that the cracking resistance of the product is improved;

(2) according to the invention, modified sodium lignosulfonate can be added during preparation of the anti-cracking heat-insulating coating, the sodium lignosulfonate not only has a three-dimensional network structure after being modified, but also contains sulfonic acid groups in the three-dimensional structure, and can be adsorbed on the surface of polystyrene after being added into a product, so that the bonding force in the product is improved, and the anti-cracking performance of the product is improved.

Detailed Description

Titanium dioxide and potassium carbonate are mixed according to a molar ratio of 4.0: 1.3, mixing and grinding the mixture in a grinding machine for 20-30 hours to obtain mixed powder, calcining the mixed powder at the constant temperature of 700-850 ℃ for 15-20 hours to obtain a pretreated powder blank, washing the pretreated powder blank with hydrochloric acid with the mass fraction of 15-25% for 8-10 times, drying the washed blank at the temperature of 80-90 ℃ for 1-2 hours to obtain pretreated powder, and mixing the pretreated powder and ethanol according to the mass ratio of 1: 15-1: 20, mixing the mixture in a beaker, adding dodecylamine which is 2-3 times of the mass of the pretreated powder into the beaker, performing ultrasonic dispersion for 2-5 hours under the condition of frequency of 45-55 kHz, filtering to obtain a modified powder blank, and drying the modified powder blank for 1-3 hours under the condition of temperature of 60-80 ℃ to obtain modified powder; mixing an initiator and an ethanol solution according to a mass ratio of 1: 200-1: 300, mixing the prepolymer dispersion solution and a methacryloxyethylene ammonium chloride solution in a mass ratio of 80: 1-9: 1, mixing the materials in a three-neck flask, introducing nitrogen into the three-neck flask at the speed of 30-35 mL/min, stirring and reacting for 20-22 h under the conditions that the temperature is 50-80 ℃ and the rotating speed is 300-350 r/min, centrifuging and separating the three-neck flask physically at the rotating speed of 2000-3000 r/min for 10-20 min, filtering to obtain a filter cake, and drying the filter cake at the temperature of 60-80 ℃ for 1-2 h to obtain pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, wherein the mass ratio of the polystyrene microspheres to the modified powder is 1: 1-2: 1, adding ethanol with the mass of 8-18 times that of polystyrene microsphere microspheres into a mixture of the polystyrene microsphere and modified powder, stirring and mixing for 20-30 min at the temperature of 30-50 ℃ and the rotating speed of 200-380 r/min, ultrasonically dispersing for 20-60 min at the frequency of 45-55 kHz, filtering to obtain a modified polystyrene microsphere blank, and drying the modified polystyrene microsphere blank at the temperature of 50-80 ℃ for 1-2 h to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 60-80 parts of polymer emulsion, 2-5 parts of dispersing agent, 2-4 parts of flatting agent, 15-25 parts of modified heat insulation aggregate and 2-4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 30-40 min at the temperature of 30-50 ℃ and the rotating speed of 300-380 r/min to obtain the anti-cracking heat insulation coating. The polymer emulsion is styrene-acrylic emulsion with solid content of 45-55% or silicone-acrylic emulsion with solid content of 50-55%. The dispersant is any one of dispersant NNO, dispersant MF or dispersant 5040. The leveling agent is any one of silicone oil or polydimethylsiloxane. The anti-settling agent is any one of organic bentonite, polyamide wax or fumed silica. The initiator is any one of azodiisobutyronitrile, benzoyl peroxide or diisophenylpropyl peroxide. The methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 18-1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution. The foaming condition is that foaming is carried out for 2-5 min under the conditions that the steam pressure is 0.4-0.6 MPa and the temperature is 85-98 ℃. Modified sodium lignosulfonate which is 0.1-0.2 times of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with the mass 1-4 times that of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 90: 1-100: 1, adding 1, 6-dibromohexane which is 0.2-0.3 times of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and performing rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Titanium dioxide and potassium carbonate are mixed according to a molar ratio of 4.0: 1.3 mixing the raw materials in a grinder, grinding for 30h to obtain mixed powder, calcining the mixed powder at a constant temperature of 850 ℃ for 20h to obtain pretreated powder blank, washing the pretreated powder blank with 25 mass percent hydrochloric acid for 10 times, drying at a temperature of 90 ℃ for 2h to obtain pretreated powder, and mixing the pretreated powder and ethanol according to a mass ratio of 1: 20, mixing the mixture in a beaker, adding dodecylamine with the mass being 3 times that of the pretreated powder into the beaker, performing ultrasonic dispersion for 5 hours under the condition of the frequency of 55kHz, filtering to obtain a modified powder blank, and drying the modified powder blank for 3 hours under the condition of the temperature of 80 ℃ to obtain modified powder; mixing an initiator and an ethanol solution according to a mass ratio of 1: 300, adding a styrene monomer 120 times the mass of an initiator into a flask, introducing nitrogen into the flask at a rate of 30mL/min, bubbling for 40min, stirring and reacting for 3h under the conditions that the temperature is 75 ℃ and the rotating speed is 350r/min to obtain a prepolymer dispersion, and mixing the prepolymer dispersion with a methacryloxyethylene ammonium chloride solution according to a mass ratio of 9: 1, mixing the mixture in a three-mouth flask, introducing nitrogen into the three-mouth flask at the speed of 35mL/min, stirring and reacting for 22 hours at the temperature of 80 ℃ and the rotating speed of 350r/min, centrifuging and separating the three-mouth flask for 20 minutes at the physical rotating speed of 3000r/min, filtering to obtain a filter cake, and drying the filter cake for 2 hours at the temperature of 80 ℃ to obtain the pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, wherein the mass ratio of the polystyrene microspheres to the modified powder is 2: 1, adding ethanol with the mass being 18 times that of the polystyrene microsphere microspheres into a mixture of the polystyrene microsphere microspheres and the modified powder, stirring and mixing for 30min at the temperature of 50 ℃ and the rotating speed of 380r/min, performing ultrasonic dispersion for 60min at the frequency of 55kHz, filtering to obtain modified polystyrene microsphere blanks, and drying the modified polystyrene microsphere blanks at the temperature of 80 ℃ for 2h to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 80 parts of polymer emulsion, 5 parts of dispersing agent, 4 parts of flatting agent, 25 parts of modified heat-insulating aggregate and 4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 40min at the temperature of 50 ℃ and the rotating speed of 380r/min to obtain the anti-cracking heat-insulating coating. The polymer emulsion is styrene-acrylic emulsion with the solid content of 55% or silicone-acrylic emulsion with the solid content of 55%. The dispersant is dispersant NNO. The leveling agent is silicone oil. The anti-settling agent is organic bentonite. The initiator is azobisisobutyronitrile. The methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution. The foaming condition is that foaming is carried out for 5min under the conditions that the steam pressure is 0.6MPa and the temperature is 98 ℃. Modified sodium lignosulfonate which is 0.2 time of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with 4 times of the mass of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 100: 1, adding 1, 6-dibromohexane which is 0.3 time of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and carrying out rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Titanium dioxide and potassium carbonate are mixed according to a molar ratio of 4.0: 1.3 mixing the raw materials in a grinder, grinding for 30h to obtain mixed powder, calcining the mixed powder at a constant temperature of 850 ℃ for 20h to obtain pretreated powder blank, washing the pretreated powder blank with 25 mass percent hydrochloric acid for 10 times, drying at a temperature of 90 ℃ for 2h to obtain pretreated powder, and mixing the pretreated powder and ethanol according to a mass ratio of 1: 20, mixing the mixture in a beaker, adding dodecylamine with the mass being 3 times that of the pretreated powder into the beaker, performing ultrasonic dispersion for 5 hours under the condition of the frequency of 55kHz, filtering to obtain a modified powder blank, and drying the modified powder blank for 3 hours under the condition of the temperature of 80 ℃ to obtain modified powder; mixing an initiator and an ethanol solution according to a mass ratio of 1: 300, mixing the mixture in a flask, adding a styrene monomer with the mass 120 times of that of an initiator into the flask, introducing nitrogen into the flask at the speed of 30mL/min, bubbling for 40min, stirring and reacting for 3h under the conditions of the temperature of 75 ℃ and the rotating speed of 350r/min to obtain a prepolymer dispersion, introducing the prepolymer dispersion into a three-neck flask, introducing nitrogen into the three-neck flask at the speed of 35mL/min, stirring and reacting for 22h under the conditions of the temperature of 80 ℃ and the rotating speed of 350r/min, centrifuging and separating the physical inside of the three-neck flask for 20min under the condition of the rotating speed of 3000r/min, filtering to obtain a filter cake, drying the filter cake for 2h under the temperature of 80 ℃ to obtain pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, wherein the mass ratio of the polystyrene microspheres to the modified powder is 2: 1, adding ethanol with the mass being 18 times that of the polystyrene microsphere microspheres into a mixture of the polystyrene microsphere microspheres and the modified powder, stirring and mixing for 30min at the temperature of 50 ℃ and the rotating speed of 380r/min, performing ultrasonic dispersion for 60min at the frequency of 55kHz, filtering to obtain modified polystyrene microsphere blanks, and drying the modified polystyrene microsphere blanks at the temperature of 80 ℃ for 2h to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 80 parts of polymer emulsion, 5 parts of dispersing agent, 4 parts of flatting agent, 25 parts of modified heat-insulating aggregate and 4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 40min at the temperature of 50 ℃ and the rotating speed of 380r/min to obtain the anti-cracking heat-insulating coating. The polymer emulsion is styrene-acrylic emulsion with the solid content of 55% or silicone-acrylic emulsion with the solid content of 55%. The dispersant is dispersant NNO. The leveling agent is silicone oil. The anti-settling agent is organic bentonite. The initiator is azobisisobutyronitrile. The foaming condition is that foaming is carried out for 5min under the conditions that the steam pressure is 0.6MPa and the temperature is 98 ℃. Modified sodium lignosulfonate which is 0.2 time of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with 4 times of the mass of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 100: 1, adding 1, 6-dibromohexane which is 0.3 time of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and carrying out rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Mixing an initiator and an ethanol solution according to a mass ratio of 1: 300, adding a styrene monomer 120 times the mass of an initiator into a flask, introducing nitrogen into the flask at a rate of 30mL/min, bubbling for 40min, stirring and reacting for 3h under the conditions that the temperature is 75 ℃ and the rotating speed is 350r/min to obtain a prepolymer dispersion, and mixing the prepolymer dispersion with a methacryloxyethylene ammonium chloride solution according to a mass ratio of 9: 1, mixing the mixture in a three-mouth flask, introducing nitrogen into the three-mouth flask at the speed of 35mL/min, stirring and reacting for 22 hours at the temperature of 80 ℃ and the rotating speed of 350r/min, centrifuging and separating the three-mouth flask for 20 minutes at the physical rotating speed of 3000r/min, filtering to obtain a filter cake, and drying the filter cake for 2 hours at the temperature of 80 ℃ to obtain the pretreated polystyrene microspheres; foaming pretreated polystyrene to obtain polystyrene microspheres, adding ethanol with the mass being 18 times that of the polystyrene microspheres into the polystyrene microspheres, stirring and mixing for 30min at the temperature of 50 ℃ and the rotating speed of 380r/min, performing ultrasonic dispersion for 60min at the frequency of 55kHz, filtering to obtain modified polystyrene microsphere blanks, and drying the modified polystyrene microsphere blanks for 2h at the temperature of 80 ℃ to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 80 parts of polymer emulsion, 5 parts of dispersing agent, 4 parts of flatting agent, 25 parts of modified heat-insulating aggregate and 4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 40min at the temperature of 50 ℃ and the rotating speed of 380r/min to obtain the anti-cracking heat-insulating coating. The polymer emulsion is styrene-acrylic emulsion with the solid content of 55% or silicone-acrylic emulsion with the solid content of 55%. The dispersant is dispersant NNO. The leveling agent is silicone oil. The anti-settling agent is organic bentonite. The initiator is azobisisobutyronitrile. The methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution. The foaming condition is that foaming is carried out for 5min under the conditions that the steam pressure is 0.6MPa and the temperature is 98 ℃. Modified sodium lignosulfonate which is 0.2 time of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with 4 times of the mass of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 100: 1, adding 1, 6-dibromohexane which is 0.3 time of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and carrying out rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Titanium dioxide and potassium carbonate are mixed according to a molar ratio of 4.0: 1.3 mixing the raw materials in a grinder, grinding for 30h to obtain mixed powder, calcining the mixed powder at a constant temperature of 850 ℃ for 20h to obtain pretreated powder blank, washing the pretreated powder blank with 25 mass percent hydrochloric acid for 10 times, drying at a temperature of 90 ℃ for 2h to obtain pretreated powder, and mixing an initiator and an ethanol solution according to a mass ratio of 1: 300, adding a styrene monomer 120 times the mass of an initiator into a flask, introducing nitrogen into the flask at a rate of 30mL/min, bubbling for 40min, stirring and reacting for 3h under the conditions that the temperature is 75 ℃ and the rotating speed is 350r/min to obtain a prepolymer dispersion, and mixing the prepolymer dispersion with a methacryloxyethylene ammonium chloride solution according to a mass ratio of 9: 1, mixing the mixture in a three-mouth flask, introducing nitrogen into the three-mouth flask at the speed of 35mL/min, stirring and reacting for 22 hours at the temperature of 80 ℃ and the rotating speed of 350r/min, centrifuging and separating the three-mouth flask for 20 minutes at the physical rotating speed of 3000r/min, filtering to obtain a filter cake, and drying the filter cake for 2 hours at the temperature of 80 ℃ to obtain the pretreated polystyrene microspheres; foaming the pretreated polystyrene to obtain polystyrene microspheres, and mixing the polystyrene microsphere pretreated powder according to a mass ratio of 2: 1, adding ethanol with the mass being 18 times that of the polystyrene microsphere microspheres into a mixture of the polystyrene microsphere microspheres and the pretreatment powder, stirring and mixing for 30min at the temperature of 50 ℃ and the rotating speed of 380r/min, performing ultrasonic dispersion for 60min at the frequency of 55kHz, filtering to obtain modified polystyrene microsphere blanks, and drying the modified polystyrene microsphere blanks at the temperature of 80 ℃ for 2h to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 80 parts of polymer emulsion, 5 parts of dispersing agent, 4 parts of flatting agent, 25 parts of modified heat-insulating aggregate and 4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 40min at the temperature of 50 ℃ and the rotating speed of 380r/min to obtain the anti-cracking heat-insulating coating. The polymer emulsion is styrene-acrylic emulsion with the solid content of 55% or silicone-acrylic emulsion with the solid content of 55%. The dispersant is dispersant NNO. The leveling agent is silicone oil. The anti-settling agent is organic bentonite. The initiator is azobisisobutyronitrile. The methacryloxyethylene ammonium chloride solution is prepared by mixing methacryloxyethylene ammonium chloride and water according to the mass ratio of 1: 22 to obtain a methacryloyloxyvinyl ammonium chloride solution. The foaming condition is that foaming is carried out for 5min under the conditions that the steam pressure is 0.6MPa and the temperature is 98 ℃. Modified sodium lignosulfonate which is 0.2 time of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with 4 times of the mass of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 100: 1, adding 1, 6-dibromohexane which is 0.3 time of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and carrying out rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

Comparative example: mixing an initiator and an ethanol solution according to a mass ratio of 1: 300, mixing the mixture in a flask, adding a styrene monomer with the mass 120 times of that of an initiator into the flask, introducing nitrogen into the flask at the speed of 30mL/min, bubbling for 40min, stirring and reacting for 3h under the conditions of the temperature of 75 ℃ and the rotating speed of 350r/min to obtain a prepolymer dispersion, introducing the prepolymer dispersion into a three-neck flask, introducing nitrogen into the three-neck flask at the speed of 35mL/min, stirring and reacting for 22h under the conditions of the temperature of 80 ℃ and the rotating speed of 350r/min, centrifuging and separating the physical inside of the three-neck flask for 20min under the condition of the rotating speed of 3000r/min, filtering to obtain a filter cake, drying the filter cake for 2h under the temperature of 80 ℃ to obtain pretreated polystyrene microspheres; foaming pretreated polystyrene to obtain polystyrene microspheres, adding ethanol with the mass being 18 times that of the polystyrene microspheres into the polystyrene microspheres, stirring and mixing for 30min at the temperature of 50 ℃ and the rotating speed of 380r/min, performing ultrasonic dispersion for 60min at the frequency of 55kHz, filtering to obtain modified polystyrene microsphere blanks, and drying the modified polystyrene microsphere blanks for 2h at the temperature of 80 ℃ to obtain modified polystyrene microspheres, thus obtaining modified heat insulation aggregate; weighing the following components in parts by weight: 80 parts of polymer emulsion, 5 parts of dispersing agent, 4 parts of flatting agent, 25 parts of modified heat-insulating aggregate and 4 parts of anti-settling agent; and mixing the polymer emulsion and a dispersing agent in a stirrer, adding a leveling agent, a modified heat insulation aggregate and an anti-settling agent into the stirrer, and stirring and mixing for 40min at the temperature of 50 ℃ and the rotating speed of 380r/min to obtain the anti-cracking heat-insulating coating. The polymer emulsion is styrene-acrylic emulsion with the solid content of 55% or silicone-acrylic emulsion with the solid content of 55%. The dispersant is dispersant NNO. The leveling agent is silicone oil. The anti-settling agent is organic bentonite. The initiator is azobisisobutyronitrile. The foaming condition is that foaming is carried out for 5min under the conditions that the steam pressure is 0.6MPa and the temperature is 98 ℃. Modified sodium lignosulfonate which is 0.2 time of the mass of the polymer emulsion can be added into the polymer emulsion, wherein the modified sodium lignosulfonate is prepared by mixing a sodium lignosulfonate solution and formaldehyde according to a mass ratio of 14: 1, mixing, adding sodium sulfite with 4 times of the mass of formaldehyde, stirring and reacting under an alkaline condition to obtain a pretreated sodium lignosulfonate solution, and mixing the pretreated sodium lignosulfonate solution with potassium iodide according to a mass ratio of 100: 1, adding 1, 6-dibromohexane which is 0.3 time of the mass of the pretreated sodium lignosulfonate solution, stirring and reacting under an alkaline condition to obtain a treating agent mixture, extracting the treating agent mixture, filtering to obtain a filtrate, and carrying out rotary evaporation and concentration on the filtrate to obtain the modified sodium lignosulfonate.

The anti-cracking heat-insulating coating obtained in the examples 1 to 4 and the comparative product are subjected to performance detection, and the specific detection method is as follows:

coefficient of thermal conductivity: testing according to GB/T10294; and smearing the test piece on a steel plate of 30cm multiplied by 30cm for curing, soaking the cured steel plate in water for 3 days, drying at constant temperature of 40 ℃ for 24 hours, and observing the surface of the steel plate.

Specific detection results are shown in table 1:

TABLE 1 anti-cracking thermal insulation coating Performance test results

Detecting items	Example 1	Example 2	Example 3	Examples of the invention4	Comparative example
						Thermal conductivity/(W/(m.K)	0.031	0.062	0.051	0.073	0.097
Crack resistance	Without cracks	Has cracks	Has cracks	Has cracks	Has cracks

As can be seen from the detection results in Table 1, the anti-cracking heat-insulating coating prepared by the technical scheme of the invention has the characteristics of excellent heat-insulating property and crack resistance, and has a wide prospect in the development of the building material technical industry.