Water-based temperature-control heating coating capable of being used for wall surfaces and floors

Abstract

The invention relates to the technical field of heating coatings, and discloses a water-based temperature-control heating coating capable of being used for walls and floors, the water-based temperature-control heating coating comprises 8-25 parts of a conductive heating material, 30-50 parts of a water-based resin matrix, 5-15 parts of a temperature-control functional material, 15-30 parts of a filler and 0.9-4.5 parts of an auxiliary agent, the water-based resin matrix is an acrylic emulsion; the temperature control functional material is poly (N-isopropylacrylamide) microgel, the filler is composed of mica powder and titanium dioxide, and the auxiliaries comprise a dispersing agent, a defoaming agent, a thickening agent and a flatting agent. The water-based temperature-control heating coating obtained by the invention has relatively high heating efficiency; meanwhile, an automatic temperature control function is achieved, and when the room temperature is too high or too low, the indoor temperature can be kept stable by improving the heating efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat generating paint, in particular to a water-based temperature control heat generating paint for wall and floor. BACKGROUND

[0002] With the continuous improvement of people's quality of life, higher requirements are put forward for the comfort of indoor environment. In winter, heating becomes a key requirement to ensure indoor comfort. Traditional heating methods such as central heating, air conditioning heating, etc. have problems such as high energy consumption, uneven temperature distribution, complex installation and maintenance, etc. At the same time, in some areas without central heating facilities, the heating problem is more prominent.

[0003] As a new type of heating material, electric heating paint has many advantages. It can convert electrical energy into heat energy and directly heat the wall, floor, etc., reducing the loss in the heat transfer process and having high thermal efficiency. Moreover, electric heating paint can be flexibly constructed according to needs and is suitable for various building structures and decoration styles. However, existing electric heating paint still has some shortcomings.

[0004] On the one hand, the heating performance of some electric heating paint is not ideal, which cannot reach the ideal heating temperature in a short time, or uneven heating occurs during long-term use, resulting in uneven indoor temperature distribution and affecting the heating effect. On the other hand, the stability of some electric heating paint is poor, which is prone to aging, cracking, etc. during repeated heating and cooling, reducing the service life of the paint and increasing the maintenance cost. In addition, most of the existing electric heating paint is solvent-based paint, which contains a large amount of volatile organic compounds (VOC), which will pollute the indoor environment during use and is not conducive to human health.

[0005] In recent years, with the enhancement of environmental awareness, water-based paint has received widespread attention due to its low VOC emission, environmental safety and other advantages. It has important practical significance to combine the advantages of water-based paint and electric heating paint to develop a water-based temperature control heat generating paint for wall and floor. This paint not only meets people's demand for heating, but also meets the requirements of environmental protection and safety, and has broad market prospects. SUMMARY

[0006] In view of this, the present application provides a water-based temperature control heat generating paint for wall and floor, which aims to solve at least one of the above background technical problems.

[0007] The present application provides a water-based temperature control heat generating paint for wall and floor, which comprises the following components by mass fraction:

[0008] Conductive heating material 8-25 parts, water-based resin matrix 30-50 parts, temperature control functional material 5-15 parts, filler 15-30 parts and auxiliary agent 0.9-4.5 parts;

[0009] The conductive heating material comprises graphene and carbon nanotubes, and the mass fractions of the graphene and the carbon nanotubes are 5-15 parts and 3-10 parts respectively.

[0010] The water-based resin matrix is an acrylic emulsion.

[0011] The temperature control functional material is poly-N-isopropyl acrylamide microgel.

[0012] The filler is composed of mica powder and titanium dioxide, and the mass fractions of the mica powder and the titanium dioxide are 10-20 parts and 5-10 parts respectively.

[0013] The auxiliary agent comprises a dispersing agent, a defoaming agent, a thickening agent and a leveling agent, and the mass fractions of the dispersing agent, the defoaming agent, the thickening agent and the leveling agent are 0.5-2 parts, 0.1-1 part, 0.2-1 part and 0.1-0.5 part respectively.

[0014] Preferably, the graphene is a product obtained by reduction treatment of graphene oxide, has a flake diameter of 5-50 μm and a thickness of 0.5-2 nm; and the carbon nanotube is a multi-walled carbon nanotube, has a diameter of 10-50 nm and a length of 5-30 μm.

[0015] Preferably, the acrylic emulsion has a solid content of 40-60%, a glass transition temperature (Tg) of 20-40°C and a particle size of 50-200 nm.

[0016] Preferably, the poly-N-isopropyl acrylamide microgel is prepared by the following steps, specifically:

[0017] Dissolve N-isopropyl acrylamide monomer, N,N-methylene bisacrylamide crosslinking agent and potassium persulfate initiator in deionized water according to a mass ratio of 100:2-5:1-3 to form an aqueous phase;

[0018] Add sodium dodecyl sulfate emulsifier to the oil phase according to 1-3% of the mass of the aqueous phase, and stir until dissolved;

[0019] Slowly drop the aqueous phase into the oil phase, react at 60-70°C for 4-6 hours under nitrogen protection, and then obtain poly-N-isopropyl acrylamide microgel after centrifugation, washing and drying, which has a particle size of 100-500 nm.

[0020] Preferably, the mica powder is wet-ground white mica powder, has a particle size of 5-30 μm and a whiteness of ≥90%; and the titanium dioxide is rutile type, has a particle size of 0.2-0.5 μm.

[0021] Preferably, the dispersant is polyvinyl alcohol, the defoaming agent is a silicone-based defoaming agent, the thickening agent is hydroxyethyl cellulose, and the leveling agent is an acrylate-based leveling agent.

[0022] The application also provides a preparation method of the water-based temperature control heating paint for walls and floors.

[0023] Preprocessing of the conductive heating material: graphene and carbon nanotubes are respectively added to deionized water, and ultrasonic dispersion is performed for 30-60 minutes to obtain graphene dispersion liquid with a concentration of 5-15 wt% and carbon nanotube dispersion liquid with a concentration of 3-10 wt%; the graphene dispersion liquid and the carbon nanotube dispersion liquid are mixed, and ultrasonic dispersion is continued for 15-30 minutes to obtain a composite conductive dispersion liquid;

[0024] Paint mixing: the acrylic emulsion is stirred, the composite conductive dispersion liquid, poly-N-isopropyl acrylamide microgel, mica powder and titanium dioxide are sequentially added, first stirring is performed; and the dispersant, the defoaming agent, the thickening agent and the leveling agent are added, second stirring is performed, and mixed materials are obtained;

[0025] Grinding and refining: the mixed materials are sent into a sand mill, zirconium beads are used as grinding medium, and grinding is performed until the particle size is less than or equal to 50 μm, and the water-based temperature control heating paint is obtained after filtration.

[0026] Preferably, the rotating speed of the first stirring is 300-500 r / min, and the stirring time is 10-20 minutes; and the rotating speed of the second stirring is 800-1000 r / min, and the stirring time is 30-60 minutes.

[0027] The application also provides an application of the water-based temperature control heating paint for walls and floors in wall heating systems and floor heating systems.

[0028] Preferably, the application method in the wall heating system is specifically as follows:

[0029] Base layer treatment: the wall surface is polished and dusted to ensure that the surface flatness error is less than or equal to 2 mm and the water content is less than or equal to 8%;

[0030] Coating of the paint: the paint is coated by spraying or rolling, the wet film thickness is controlled to be 0.5-2 mm, and the coating is performed in 1-3 passes, and the interval time between each pass is greater than or equal to 4 hours;

[0031] Curing treatment: natural drying is performed for 24-48 hours or 60-80 °C drying is performed for 4-6 hours to form a conductive coating layer.

[0032] System assembly: Lay a glass fiber cloth insulation layer on the coating surface, set copper electrodes at intervals of 50-100cm, connect the electrodes to a thermostat and a 220V AC power supply through wires, and set the temperature range of the thermostat to 16-30℃;

[0033] The application method in the floor heating system is specifically as follows:

[0034] Base treatment: After the ground is leveled, apply the interface agent, and after it dries, lay a 1-2cm thick insulation layer, and lay an aluminum foil reflective layer on the surface of the insulation layer;

[0035] Coating: Apply the coating by scraping, with the wet film thickness controlled at 1-3mm. Dry at room temperature for 24 hours before scraping and leveling for the second time;

[0036] Construction of protective layer: After the coating is cured, lay a 0.5-1mm thick epoxy resin wear-resistant layer, and then lay the ceramic tile or wooden floor decorative layer;

[0037] System assembly: Pre-embed nickel-chromium alloy electrodes between the insulation layer and the coating layer, with an electrode spacing of 80-150cm. Connect the power supply through the temperature control module, which has built-in overheat protection (automatic power off at ≥60℃);

[0038] The temperature controller or temperature control module includes a temperature sensor, a relay and a single-chip microcomputer. The sensor sampling frequency is 1-5Hz, the temperature control accuracy is ±1°C, and the response time is ≤10 seconds.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) Highly efficient heating performance: The conductive network formed by the graphene and carbon nanotube composite can quickly convert electrical energy into thermal energy, giving the coating a high heating efficiency. At the same power, the water-based temperature-controlled heating coating of the present invention can increase the indoor temperature in a shorter time, improving the heating effect.

[0041] (2) Good temperature uniformity: By optimizing the coating formula and preparation process, the conductive heating material and temperature control functional material are uniformly dispersed in the water-based resin matrix, so that the coating can achieve uniform temperature distribution during the heating process, avoiding local overheating or overcooling, and improving the comfort of the indoor environment.

[0042] (3) Automatic temperature control function: The introduced poly (N-isopropylacrylamide) microgel has temperature-sensitive properties and can automatically adjust the heating power of the coating according to changes in ambient temperature, thus achieving automatic temperature control. When the indoor temperature is too high, the heating power of the coating is reduced to avoid energy waste; when the indoor temperature is too low, the heating power of the coating is increased to maintain a stable indoor temperature.

[0043] (4) Good stability: the acrylic emulsion as the water-based resin matrix has good film-forming property, adhesion and weather resistance, and can provide stable structural support for the paint. Meanwhile, the addition of fillers such as mica powder and titanium dioxide further enhances the stability and durability of the paint, so that the paint is not prone to aging, cracking and other problems during repeated heating and cooling, and the service life of the paint is prolonged.

[0044] (5) Environmental protection and safety: the water-based temperature control heating paint of the application uses water as the dispersion medium and does not contain organic solvents, has low VOC emission, does not pollute the indoor environment, and is beneficial to human health. At the same time, the paint has good insulation performance and will not cause safety hazards such as electric leakage during use. DETAILED DESCRIPTION

[0045] The detailed description of the various exemplary embodiments of the application is not to be considered as limiting the application, but rather merely as an illustration of certain aspects, features and embodiments of the application. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0046] In addition, for the numerical ranges in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range within any stated range or within any stated intermediate value is also included in the present application. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, preferred methods and materials are described. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict between the content of the specification and that of any document incorporated herein by reference, the content of the specification prevails.

[0048] Various modifications and changes can be made to the specific embodiments of the application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application.

[0049] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", and the like are open-ended terms that are intended to mean including, but not limited to.

[0050] The application provides a water-based temperature control heating coating for walls and floors, which comprises the following components in mass fractions:

[0051] 5-15 parts of a temperature control functional material, 15-30 parts of a filler, and 0.9-4.5 parts of an additive;

[0052] The conductive heating material comprises graphene and carbon nanotubes, and the mass fractions of the graphene and the carbon nanotubes are 5-15 parts and 3-10 parts respectively.

[0053] The water-based resin matrix is an acrylic emulsion.

[0054] The temperature control functional material is poly-N-isopropyl acrylamide microgel.

[0055] The filler is composed of mica powder and titanium dioxide, and the mass fractions of the mica powder and the titanium dioxide are 10-20 parts and 5-10 parts respectively.

[0056] The additive comprises a dispersant, a defoaming agent, a thickening agent and a leveling agent, and the mass fractions of the dispersant, the defoaming agent, the thickening agent and the leveling agent are 0.5-2 parts, 0.1-1 part, 0.2-1 part and 0.1-0.5 part respectively.

[0057] The application adopts a composite system of graphene and carbon nanotubes as the conductive heating material. The graphene has excellent electrical properties and ultrahigh thermal conductivity, and can quickly convert electrical energy into heat energy and conduct heat efficiently. The carbon nanotubes have good electrical conductivity and mechanical properties, and can form a more stable conductive network after being combined with the graphene, thereby improving the overall conductive heating performance of the coating.

[0058] The application selects an acrylic emulsion as the water-based resin matrix. The acrylic emulsion has good film-forming property, adhesion and weather resistance, and can provide stable structural support for the coating.

[0059] The application introduces poly-N-isopropyl acrylamide (PNIPAM) microgel with temperature-sensitive properties as the temperature control functional material. When the temperature is lower than the lower critical solution temperature (LCST, about 32 DEG C), the PNIPAM microgel is in a swollen state, the electrical conductivity of the coating is good, and the heating power is high. When the temperature is higher than the LCST, the PNIPAM microgel shrinks, hinders the electron conduction, and reduces the heating power of the coating, thereby realizing the automatic temperature control function.

[0060] The application adopts mica powder and titanium dioxide as the filler. The mica powder has good heat insulation performance and chemical stability, and can improve the heat insulation effect of the coating and reduce heat loss. The titanium dioxide has high whiteness and hiding power, and can improve the appearance of the coating, and also can enhance the weather resistance of the coating.

[0061] The present application additionally adds a series of auxiliary agents, including dispersants, defoamers, thickeners, leveling agents, etc. The dispersant is used to ensure that the conductive heating material, filler, etc. is uniformly dispersed in the water-based resin matrix, improving the stability of the paint; the defoamer is used to eliminate the bubbles generated during the preparation and construction of the paint, ensuring the quality of the paint; the thickener is used to adjust the viscosity of the paint, making it have good construction performance; the leveling agent is used to enable the paint to form a smooth coating after construction.

[0062] In the present application, the graphene is preferably the product after reduction treatment of graphene oxide, with a flake diameter of 5-50 μm and a thickness of 0.5-2 nm; the carbon nanotube is a multi-walled carbon nanotube, with a diameter of 10-50 nm and a length of 5-30 μm.

[0063] In the present application, the solid content of the acrylic emulsion is preferably 40-60%, the glass transition temperature (Tg) is preferably 20-40℃, and the particle size is preferably 50-200 nm.

[0064] In the present application, the poly-N-isopropyl acrylamide microgel is prepared by the following steps, specifically preferably by:

[0065] Dissolve N-isopropyl acrylamide monomer, N,N-methylene bisacrylamide crosslinking agent, and potassium persulfate initiator in deionized water according to a mass ratio of 100:2-5:1-3 to form an aqueous phase;

[0066] Add 1-3% of sodium dodecyl sulfate emulsifier based on the mass of the aqueous phase to the oil phase and stir until dissolved;

[0067] Slowly drop the aqueous phase into the oil phase under nitrogen protection, and react at 60-70℃ for 4-6 hours. After centrifugation, washing, and drying, poly-N-isopropyl acrylamide microgel with a particle size of 100-500 nm is obtained.

[0068] In the present application, the mica powder is a wet-ground white mica powder with a particle size of 5-30 μm and a whiteness of ≥90%; the titanium dioxide is rutile type with a particle size of 0.2-0.5 μm.

[0069] In the present application, the dispersant is preferably polyvinyl alcohol, the defoamer is preferably an organic silicon-based defoamer, the thickener is preferably hydroxyethyl cellulose, and the leveling agent is preferably an acrylic ester-based leveling agent.

[0070] Further, the present application only limits the large category of defoaming agent and leveling agent, and does not limit the specific type, and the defoaming agent and leveling agent in the category known to those skilled in the art can be used, and no special limitation is made, and the defoaming agent in the embodiment of the present application is BYK-024 (Bik Chemical), and the main component is polyether modified polysiloxane emulsion, and the leveling agent is BYK-358N (Bik Chemical), and the main component is acrylic copolymer solution.

[0071] The present application also provides a preparation method of the water-based temperature control heating coating for walls and floors, which comprises the following steps:

[0072] Preprocessing of the conductive heating material: graphene and carbon nanotubes are respectively added into deionized water, and ultrasonic dispersion is carried out for 30-60 minutes to obtain graphene dispersion liquid with a concentration of 5-15wt% and carbon nanotube dispersion liquid with a concentration of 3-10wt%; the two kinds of dispersion liquids are mixed, and ultrasonic dispersion is continuously carried out for 15-30 minutes to obtain a composite conductive dispersion liquid;

[0073] Coating mixing: the acrylic emulsion is stirred, the composite conductive dispersion liquid, poly-N-isopropyl acrylamide microgel, mica powder and titanium dioxide are sequentially added, first stirring is carried out; and then the dispersing agent, defoaming agent, thickening agent and leveling agent are added, second stirring is carried out, and the mixed material is obtained;

[0074] Grinding and refining: the mixed material is sent into a sand mill, zirconium beads are used as grinding medium, and grinding is carried out until the particle size is less than or equal to 50μm, and the water-based temperature control heating coating is obtained after filtration.

[0075] In the preparation of the water-based temperature control heating coating, the conductive heating material is first pretreated to construct a three-dimensional conductive network foundation, the ultrasonic frequency in the ultrasonic dispersion adopted in the present application is 20-40kHz, the ultrasonic wave produces "cavitation effect" in the liquid, the micro-bubbles formed by violent vibration are instantaneously broken, impact waves are released, the agglomerates of graphene and carbon nanotubes are broken, the graphene (two-dimensional sheet) and the carbon nanotubes (one-dimensional fiber) form a three-dimensional network through π-π stacking, the carbon nanotubes are inserted into the interlayer gap of the graphene sheet, the conductive percolation threshold is reduced, and uniform conduction of the coating is ensured at a low addition amount.

[0076] In the present application, the rotation speed of the first stirring is preferably 300-500r / min, and the time is preferably 10-20 minutes; the rotation speed of the second stirring is preferably 800-1000r / min, and the stirring time is preferably 30-60 minutes.

[0077] The present application also provides an application of the water-based temperature control heating coating for walls and floors in wall heating systems and floor heating systems, and the water-based temperature control heating coating for walls and floors is the water-based temperature control heating coating according to the above technical solution.

[0078] Specifically, for wall construction: before wall construction, first, the wall surface is treated to ensure that the wall surface is flat, dry and clean. Then, the water-based temperature control heating paint is evenly applied on the wall surface by brushing, spraying or rolling, and the wet film thickness is controlled to be 0.5-2mm. After the application is completed, it is naturally dried or dried at low temperature, so that the paint forms a firm coating. Then, an insulating layer such as glass fiber cloth is laid on the surface of the coating, and a conductive electrode is installed, and the power supply and temperature control device are connected, so that the wall surface can realize the temperature control heating function.

[0079] For ground construction: for ground construction, the ground is also first treated. Then, the water-based temperature control heating paint is evenly applied on the ground, and the application thickness is 1-3mm. After the paint is dried, a ground material with good heat conductivity, such as ceramic tile or wood floor, is laid on its surface. During the laying of the ground material, attention should be paid to avoid damaging the paint coating. Finally, the conductive electrode and the temperature control device are installed, and the power supply is connected, so that the ground can realize temperature control heating.

[0080] In the present application, the application method in the wall heating system is specifically:

[0081] Base treatment: the wall surface is polished and dusted to ensure that the surface flatness error is ≤2mm and the moisture content is ≤8%;

[0082] Coating paint: the paint is coated by spraying or rolling, the wet film thickness is controlled to be 0.5-2mm, and it is constructed in 1-3 times, and the interval time is ≥4 hours;

[0083] Curing treatment: naturally dried for 24-48 hours or dried at 60-80℃ for 4-6 hours to form a conductive coating;

[0084] System assembly: glass fiber cloth insulation layer is laid on the surface of the coating, copper electrode is arranged at intervals of 50-100cm, the electrode is connected to the temperature controller and 220V alternating current power supply through the wire, and the temperature controller is set to a temperature range of 16-30℃;

[0085] The application method in the ground heating system is specifically:

[0086] Base treatment: after the ground is leveled, the interface agent is brushed, and after drying, a 1-2cm thick insulation layer is laid, and an aluminum foil reflecting layer is laid on the surface of the insulation layer;

[0087] Coating paint: the paint is coated by scraping, the wet film thickness is controlled to be 1-3mm, and after 24 hours of normal temperature drying, secondary scraping and leveling are performed;

[0088] Protection layer construction: after the paint is cured, a 0.5-1mm thick epoxy resin wear-resistant layer is laid, and a ceramic tile or wood floor decorative layer is laid.

[0089] System assembly: embed nickel-chromium alloy electrodes between the insulation layer and the paint layer, electrode spacing 80-150 cm, connect power supply through temperature control module, overheat protection (≥60℃ automatic power off) built-in temperature control module;

[0090] The temperature controller or temperature control module comprises a temperature sensor, a relay and a single-chip microcomputer, the sampling frequency of the sensor is 1-5 Hz, the temperature control accuracy is ±1℃, and the response time is ≤10 seconds.

[0091] Example 1

[0092] (1) Pretreatment of conductive heating material: take 5g graphene and 3g carbon nanotube, respectively, and add them to 100mL deionized water, and ultrasonic dispersion for 60 minutes. Then mix the two dispersions and continue ultrasonic dispersion for 30 minutes to obtain a composite conductive heating material dispersion;

[0093] (2) Preparation of PNIPAM microgel: dissolve 5g N-isopropyl acrylamide monomer, 0.1g N,N-methylene bisacrylamide crosslinking agent and 0.05g potassium persulfate initiator in 50mL deionized water, and stir uniformly. Add the mixed solution to 100mL oil phase containing 0.5g sodium dodecyl sulfate emulsifier, and stir at 60℃ under nitrogen protection for 6 hours. After the reaction is completed, the PNIPAM microgel is obtained by centrifugal separation, washing and drying;

[0094] (3) Preparation of paint: add 30g acrylic emulsion to a stirred tank, and stir at a speed of 300r / min. Add the composite conductive heating material dispersion, 5g PNIPAM microgel, 10g mica powder and 5g titanium dioxide in sequence, and stir for 10 minutes. Then add 0.5g dispersant, 0.1g defoamer, 0.2g thickener and 0.1g leveling agent, increase the stirring speed to 800r / min, and continue stirring for 60 minutes to make the components fully mixed and uniform. The dispersant is polyvinyl alcohol, the thickener is hydroxyethyl cellulose, the defoamer is silicone-based defoamer of type BYK-024 (Bik Chemical), and the leveling agent is leveling agent of type BYK-358N (Bik Chemical).

[0095] Finally, the mixed material is sent to a sand mill, and zirconium beads are used as grinding medium to grind to a particle size of ≤50μm. After filtration, the water-based temperature control heating paint is obtained.

[0096] Example 2

[0097] (1) Pretreatment of conductive heating material: 10 g of graphene and 6 g of carbon nanotubes were weighed and added to 150 mL of deionized water, respectively, and ultrasonically dispersed for 45 minutes. Then the two dispersions were mixed and ultrasonically dispersed for another 20 minutes to obtain a composite conductive heating material dispersion;

[0098] (2) Preparation of PNIPAM microgel: 10 g of N-isopropyl acrylamide monomer, 0.2 g of N,N-methylene bisacrylamide crosslinking agent, and 0.1 g of potassium persulfate initiator were dissolved in 80 mL of deionized water and stirred uniformly. The mixed solution was added to 150 mL of oil phase containing 0.8 g of sodium dodecyl sulfate emulsifier, and stirred at 65°C for 5 hours under nitrogen protection. After the reaction was completed, the PNIPAM microgel was obtained through centrifugal separation, washing, drying and other steps.

[0099] (3) Preparation of paint: 40 g of acrylic emulsion was added to a stirred tank and stirred at a speed of 400 r / min. The composite conductive heating material dispersion, 10 g of PNIPAM microgel, 15 g of mica powder, and 8 g of titanium dioxide were added in sequence, and stirred for 10 minutes. Then 1 g of dispersant, 0.5 g of defoaming agent, 0.5 g of thickening agent, and 0.3 g of leveling agent were added, and the stirring speed was increased to 900 r / min. The mixture was stirred for another 45 minutes to ensure uniform mixing of all components. The dispersant was polyvinyl alcohol, the thickening agent was hydroxyethyl cellulose, the defoaming agent was silicone-based defoaming agent of type BYK-024 (Bik Chemical), and the leveling agent was leveling agent of type BYK-358N (Bik Chemical).

[0100] Finally, the mixed material was sent to a sand mill for grinding with zirconium beads as the grinding medium to a particle size of ≤50 μm. The water-based temperature-controlled heating paint was obtained after filtration.

[0101] Example 3

[0102] (1) Pretreatment of conductive heating material: 15 g of graphene and 10 g of carbon nanotubes were weighed and added to 200 mL of deionized water, respectively, and ultrasonically dispersed for 30 minutes. Then the two dispersions were mixed and ultrasonically dispersed for another 15 minutes to obtain a composite conductive heating material dispersion.

[0103] (2) Preparation of PNIPAM microgel: 15 g of N-isopropyl acrylamide monomer, 0.3 g of N,N-methylene bisacrylamide crosslinking agent, and 0.15 g of potassium persulfate initiator were dissolved in 100 mL of deionized water and stirred uniformly. The mixed solution was added to 200 mL of oil phase containing 1 g of sodium dodecyl sulfate emulsifier, and stirred at 70°C for 4 hours under nitrogen protection. After the reaction was completed, the PNIPAM microgel was obtained through centrifugal separation, washing, drying and other steps.

[0104] (3) Preparation of the paint: 50 g of acrylic emulsion was added to a stirred tank, and stirred at a speed of 300 r / min. The above-mentioned composite conductive heating material dispersion liquid, 15 g of PNIPAM microgel, 20 g of mica powder, and 10 g of titanium dioxide were added in sequence, and stirred for 10 minutes. Then, 2 g of dispersant, 1 g of defoaming agent, 1 g of thickening agent, and 0.5 g of leveling agent were added, and the stirring speed was increased to 1000 r / min. The stirring was continued for 30 minutes to fully mix and uniformly disperse the components. The dispersant was polyvinyl alcohol, the thickening agent was hydroxyethyl cellulose, the defoaming agent was silicone-based defoaming agent of type BYK-024 (Bik Chemical), and the leveling agent was leveling agent of type BYK-358N (Bik Chemical).

[0105] Finally, the mixed material was sent to a sand mill, and ground with zirconium beads as the grinding medium to a particle size of ≤50 μm. After filtration, the water-based temperature control heating paint was obtained.

[0106] Example 4

[0107] The water-based temperature control heating paint obtained in Example 1 was used for wall construction and floor construction, respectively.

[0108] Wall construction: After the wall base was treated, the water-based temperature control heating paint was uniformly sprayed on the wall surface by spraying, and the coating thickness was 1 mm. After the spraying was completed, the coating was dried at 50°C for 12 hours. Then, an insulating layer was laid on the surface of the coating, and a conductive electrode was installed, and a power supply and a temperature control device were connected.

[0109] Floor construction: After the floor base was treated, the water-based temperature control heating paint was uniformly applied to the floor surface by brushing, and the coating thickness was 2 mm. After the paint was dried, wooden floor was laid on the surface. A conductive electrode and a temperature control device were installed, and a power supply was connected.

[0110] Examples 5-6

[0111] The other steps were the same as those in Example 4, except that the water-based temperature control heating paint obtained in Examples 2-3 was used, respectively.

[0112] Comparative Example 1

[0113] The other steps were the same as those in Example 1, except that no carbon nanotubes were added.

[0114] Comparative Example 2

[0115] The other steps were the same as those in Example 1, except that no PNIPAM microgel was added, and the temperature control functional material was replaced by an equal amount of silicon dioxide.

[0116] Performance and Test

[0117] (1) Heat performance test

[0118] The heat performance of the water-based temperature-controlled heat paint prepared in Examples 1-3 and Comparative Examples 1-2 was tested under the same experimental environment.

[0119] The paint was coated on test panels of the same size, and the power supply was connected with a voltage of 220V. The change of the surface temperature of the test panel with time was recorded. The test results showed that the temperature of the paint of Examples 1-3 rapidly rose after being powered on, and the stable temperature was reached within 30 minutes, and the stable temperature was all above 40℃. Among them, the heat performance of the paint of Example 2 was the best, and the temperature reached 45℃ within 20 minutes. Since only graphene was used as the conductive heat material in Comparative Example 1, the conductive network was not stable enough, and the heating speed was slow, and the temperature reached only 35℃ at 30 minutes. Since no PNIPAM microgel with temperature-sensitive properties was added in Comparative Example 2, the automatic temperature control function could not be realized, and the temperature continued to rise during heating, exceeding the safe temperature range.

[0120] (2) Temperature uniformity test

[0121] The infrared thermal imager was used to test the temperature uniformity of the test panel after heating. The results showed that the surface temperature of the paint coating of Examples 1-3 was uniformly distributed, and the temperature difference was within ±2℃. There was a significant temperature difference on the surface of the paint coating of Comparative Example 1, and the temperature of some areas was too high and the temperature of some areas was too low, and the temperature difference was more than ±5℃. This shows that the composite system of graphene and carbon nanotubes and the optimized preparation process in the present application can effectively improve the temperature uniformity of the paint.

[0122] (3) Stability test: The test panel was repeatedly heated and cooled to simulate the actual use environment. After 500 cycles, the appearance change of the paint coating was observed. The paint coating of Examples 1-3 did not show obvious aging, cracking and other phenomena, and the coating was still firm. The paint coating of Comparative Examples 1 and 2 showed different degrees of aging and cracking after 200 cycles, and Comparative Example 2 was more serious. This shows that the water-based temperature-controlled heat paint of the present application has good stability and durability.

[0123] (4) Environmental performance test: The VOC content of the paint of Examples 1-3 and Comparative Examples 1-2 was tested by gas chromatography-mass spectrometry. The test results showed that the VOC content of the paint of Examples 1-3 was less than 10g / L, which met the national environmental protection standard. The VOC content of the paint of Comparative Examples 1 and 2 was 30g / L and 40g / L respectively, which exceeded the environmental protection standard. This fully proves that the water-based temperature-controlled heat paint of the present application has the advantages of environmental protection and safety.

[0124] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A water-based temperature-controlled heating paint that can be used on walls and floors, characterized in that: The composition includes the following parts by weight: 8-25 parts of conductive heating material, 30-50 parts of water-based resin matrix, 5-15 parts of temperature control functional material, 15-30 parts of filler and 0.9-4.5 parts of additives; The conductive heating material comprises graphene and carbon nanotubes, with the weight proportions being 5 to 15 parts of graphene and 3 to 10 parts of carbon nanotubes respectively. The water-based resin matrix is ​​acrylic emulsion; The temperature control functional material is poly (N-isopropylacrylamide) microgel; The filler is composed of mica powder and titanium dioxide, and the weight proportions thereof are: 10-20 parts of mica powder and 5-10 parts of titanium dioxide; The auxiliary agents include a dispersant, a defoamer, a thickener and a leveling agent, and the weight proportions thereof are respectively: 0.5-2 parts of the dispersant, 0.1-1 parts of the defoamer, 0.2-1 parts of the thickener and 0.1-0.5 parts of the leveling agent.

2. The water-based temperature-controlled heating paint that can be used for walls and floors according to claim 1, characterized in that: The graphene is a product of graphene oxide after reduction treatment, with a sheet diameter of 5-50 μm and a thickness of 0.5-2 nm; the carbon nanotube is a multi-walled carbon nanotube with a diameter of 10-50 nm and a length of 5-30 μm.

3. The water-based temperature-controlled heating paint that can be used for walls and floors according to claim 1, characterized in that: The acrylic emulsion has a solid content of 40-60%, a glass transition temperature of 20-40° C., and a particle size of 50-200 nm.

4. The water-based temperature-controlled heating paint that can be used for walls and floors according to claim 1, characterized in that: The poly (N-isopropylacrylamide) microgel is prepared by the following steps, specifically: Dissolve N-isopropylacrylamide monomer, N,N-methylenebisacrylamide crosslinker, and potassium persulfate initiator in deionized water at a mass ratio of 100:2-5:1-3 to form an aqueous phase; Add 1-3% of sodium lauryl sulfate emulsifier to the oil phase and stir until dissolved; The aqueous phase is slowly dripped into the oil phase, and the reaction is carried out at 60-70°C for 4-6 hours under nitrogen protection. After centrifugation, washing and drying, poly (N-isopropylacrylamide) microgel with a particle size of 100-500 nm is obtained.

5. The water-based temperature-controlled heating paint that can be used for walls and floors according to claim 1, characterized in that: The mica powder is wet-ground muscovite powder with a particle size of 5-30 μm and a whiteness of ≥90%. The titanium dioxide is rutile with a particle size of 0.2-0.5 μm.

6. The water-based temperature-controlled heating paint that can be used for walls and floors according to claim 1, characterized in that: The dispersant is polyvinyl alcohol, the defoaming agent is a silicone defoaming agent, the thickener is hydroxyethyl cellulose, and the leveling agent is an acrylic ester leveling agent.

7. The method for preparing the water-based temperature-controlled heating paint for walls and floors according to any one of claims 1 to 6, characterized in that: The following steps are involved: Conductive heating material pretreatment: adding graphene and carbon nanotubes to deionized water respectively, and ultrasonically dispersing them for 30-60 minutes to obtain a graphene dispersion with a concentration of 5-15wt% and a carbon nanotube dispersion with a concentration of 3-10wt%; mixing the graphene dispersion and the carbon nanotube dispersion, and continuing ultrasonically dispersing them for 15-30 minutes to obtain a composite conductive dispersion; Coating mixing; stirring the acrylic emulsion, and sequentially adding the composite conductive dispersion, poly (N-isopropylacrylamide) microgel, mica powder, and titanium dioxide, performing a first stirring; then adding the dispersant, defoamer, thickener, and leveling agent, performing a second stirring to obtain a mixed material; Grinding and refining: the mixed material is fed into a sand mill, and is ground using zirconium beads as a grinding medium to a particle size of ≤50 μm, and filtered to obtain the water-based temperature-controlled heating paint.

8. The method for preparing the water-based temperature-controlled heating paint that can be used for walls and floors according to claim 7, characterized in that: The first stirring speed is 300-500 r / min, and the stirring time is 10-20 minutes; the second stirring speed is 800-1000 r / min, and the stirring time is 30-60 minutes.

9. An application of a water-based temperature-controlled heating paint for walls and floors in wall heating systems and floor heating systems, characterized in that: The water-based temperature-controlled heating paint that can be used for walls and floors is the water-based temperature-controlled heating paint according to any one of claims 1 to 6.

10. The use according to claim 9, characterized in that The application method in the wall heating system is specifically as follows: Base treatment: polish and remove dust from the wall surface to ensure that the surface flatness error is ≤2mm and the moisture content is ≤8%; Coating: Apply the coating by spraying or roller coating, with the wet film thickness controlled at 0.5-2mm, in 1-3 passes, with an interval of ≥4 hours between each pass; Curing treatment: natural drying for 24-48 hours or drying at 60-80℃ for 4-6 hours to form a conductive coating; System assembly: Lay a glass fiber cloth insulation layer on the coating surface, set copper electrodes at intervals of 50-100cm, connect the electrodes to a thermostat and a 220V AC power supply through wires, and set the temperature range of the thermostat to 16-30℃; The application method in the floor heating system is specifically as follows: Base treatment: After the ground is leveled, apply the interface agent, and after it dries, lay a 1-2cm thick insulation layer, and lay an aluminum foil reflective layer on the surface of the insulation layer; Coating: Apply the coating by scraping, with the wet film thickness controlled at 1-3mm. Dry at room temperature for 24 hours before scraping and leveling for the second time; Construction of protective layer: After the coating is cured, lay a 0.5-1mm thick epoxy resin wear-resistant layer, and then lay the ceramic tile or wooden floor decorative layer; System assembly: Pre-embed nickel-chromium alloy electrodes between the insulation layer and the coating layer, with an electrode spacing of 80-150cm. Connect the power supply through the temperature control module, which has built-in overheat protection (automatic power off at ≥60℃); The temperature controller or temperature control module includes a temperature sensor, a relay and a single-chip microcomputer. The sensor sampling frequency is 1-5Hz, the temperature control accuracy is ±1°C, and the response time is ≤10 seconds.