Environment-friendly wave-absorbing phase-change energy-storage temperature-control coating as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly wave-absorbing phase-change energy-storage temperature-control coating as well as a preparation method and application thereof, and belongs to the technical field of special coatings. The environment-friendly wave-absorbing phase-change energy-storage temperature-control coating comprises the following raw materials in percentage by mass: 28%-32% of a phase-change energy-storage material, 30%-35% of an interior wall paint raw material, 8%-12% of an amphiphilic electromagnetic wave absorbent, 1%-2% of a negative expansion coefficient material, 3%-5% of an emulsifier, 2%-4% of an initiator, 0.2%-0.5% of a pH regulator and 15%-20% of water, and the sum of the mass fractions of all the components is 100%. The phase-change energy storage material comprises at least one phase-change material with the phase-change temperature of 29-45 DEG C and at least one phase-change material with the phase-change temperature of 0-10 DEG C. Heat is absorbed and released through the phase change reaction of the system, indoor temperature balance is automatically regulated and controlled, energy consumption caused by refrigeration in summer and heating in winter is reduced, carbon emission is reduced, intelligent upgrading of buildings is achieved, and green sustainable development is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of special coatings, and in particular to an environmentally friendly wave-absorbing phase-change energy-storage temperature-control coating, a preparation method thereof, and an application thereof. Background Art

[0002] As the world's attention to energy issues and environmental protection continues to increase, energy conservation and carbon emission reduction in the construction industry have become key issues. According to data from the International Energy Agency (IEA), building operating energy consumption accounts for 30% of the world's total, and carbon emissions account for nearly 28% of total emissions; data from the China Building Energy Conservation Association shows that in 2021, the country's building energy consumption and carbon dioxide emissions reached 5.01 billion tons, accounting for 47.1% of the country's total carbon emissions. There are more than 40 billion square meters of buildings in my country, of which high-energy-consuming buildings account for more than 95%, which is 2 to 3 times the number of developed countries with the same latitude and similar climate. Building energy consumption mainly involves six aspects: heating and heating, air conditioning and refrigeration, of which heating and cooling energy consumption accounts for about half of the total building energy consumption.

[0003] The traditional way to save energy is to modify building materials to enhance insulation and heat preservation functions, but the contribution to energy conservation and emission reduction is limited. The combination of phase change energy storage technology and building materials has become a research hotspot. Phase change materials (PCM) can store or release energy through phase changes.

[0004] For example, the Chinese invention application with application number 201010124626.5 discloses a composite phase-change energy storage architectural coating and its preparation method. The phase-change energy storage composite material uses expanded perlite as a matrix material, and is combined with room temperature ionic liquids, linear fatty acids, alkanes and other phase-change materials to form a composite phase-change energy storage material, and then mixed with one or more of styrene-acrylic emulsions, pure acrylic emulsions, and ethylene-propylene emulsions to form a polymer film-forming material in a certain proportion, and after being fully stirred and mixed evenly, the architectural coating with phase-change energy storage function can be obtained by standing.

[0005] For example, the Chinese invention application with application number 202011390441.9 discloses a solar energy storage phase change material and a preparation method, wherein the solar energy storage phase change material includes capric acid, lauric acid, and expanded graphite, wherein the capric acid and lauric acid form a composite eutectic binary system, and the expanded graphite is used to adsorb capric acid and lauric acid to form a composite eutectic binary system, and the phase change temperature of the composite phase change material is 26.32°C, and the phase change latent heat is 103.3J / g. After the expanded graphite is used to adsorb capric acid-lauric acid, the temperature is suitable and the thermal stability is good, and it can be used as a phase change material for solar energy storage.

[0006] For example, the Chinese invention application with application number 202310123252.2 discloses a phase change energy storage temperature control coating and a preparation method thereof, wherein the phase change energy storage temperature control coating is composed of the following raw materials in weight percentage: 35% of a mixture of paraffin / modified fly ash shaped phase change material and kaolin, wherein the paraffin / modified fly ash shaped phase change material is 20%~30%, and the kaolin is 5%~15%; 45%~61% of an alkaline activator; 4% of a silane coupling agent; 0.15%~0.25% of a defoaming agent; 0.5%~0.7% of a dispersant; 0.1%~0.2% of a film-forming aid; and 0.05%~0.15% of a non-ionic wetting agent. The phase change temperature of the phase change energy storage temperature control coating of the invention is 25.3°C, the phase change latent heat is 3.56 J / g, and the specific heat is 50.08 kJ / (kg·K). It can delay temperature changes to a certain extent within the phase change temperature range.

[0007] However, there are many problems in the application of phase change energy storage technology in building materials: most studies focus on the adaptability of phase change energy storage walls in a single season, and cannot take into account both winter and summer; phase change materials have poor thermal conductivity, and heat absorption and heat release lag; thermal expansion matching is not considered, and interior wall paint is prone to cracks, cracking and shedding when the temperature changes; the packaging of phase change materials is not perfect, resulting in coating leakage or a small number of effective phase change cycles. In addition, with the widespread use of electronic devices, the problem of indoor electromagnetic wave pollution has gradually attracted attention, but so far, no researchers have proposed interior wall paint with electromagnetic wave absorption function. Therefore, the development of a material that can solve the above problems has important market value and social significance. Summary of the invention

[0008] The present invention aims to provide an environmentally friendly wave-absorbing phase-change energy storage temperature-control coating and a preparation method and application thereof, so as to solve the problems of high energy consumption of existing house building materials, inability to automatically control indoor temperature in summer and winter, and easy cracking of walls due to temperature changes.

[0009] The environmentally friendly wave-absorbing phase-change energy storage temperature control coating comprises the following raw materials, measured by mass fraction: 28% to 32% of phase-change energy storage material, 30% to 35% of interior wall paint raw materials, 8% to 12% of amphiphilic electromagnetic wave absorber, 1% to 2% of negative expansion coefficient material, 3% to 5% of emulsifier, 2% to 4% of initiator, 0.2% to 0.5% of pH adjuster, and 15% to 20% of water, and the sum of the mass fractions of each component is 100%; the phase-change energy storage material comprises at least one phase-change material having a phase-change temperature of 29 to 45°C and at least one phase-change material having a phase-change temperature of 0 to 10°C.

[0010] The present invention adopts an in-situ growth-like emulsion polymerization method to prepare the coating, and uses two phase change energy storage materials with different phase change temperatures as in-situ sites and an elastomeric polymer as an outer shell layer to encapsulate the phase change energy storage material; at the same time, an amphiphilic electromagnetic wave absorber is adsorbed on the outer wall of the shell layer of the micro latex particles by physical adsorption; in addition, a negative expansion coefficient material with a matching thermal expansion coefficient is added to the emulsion to reduce the deformation amount of the interior wall paint during the phase change process.

[0011] Preferably, the phase change energy storage material is a solid-liquid phase change material.

[0012] Preferably, the phase change material with a phase change temperature of 29-45°C includes Na 2 SO 4 10H 2 O (phase transition temperature about 33 °C), Na 2 CO 3 10H 2 O (phase transition temperature 35 ℃), LiNO 3 ·3H 2 O (phase transition temperature 29.86 ℃), CaBr 2 6H 2 O (phase transition temperature 32.4 ℃), decanoic acid (phase transition temperature 31.5 ℃), methyl palmitate (phase transition temperature around 30 ℃), C 18 -C 20 Alkane mixed paraffin (phase transition temperature 30~35 ℃), n-docosane (phase transition temperature 40 ℃), PEG1000 (phase transition temperature 35 ℃) or PEG2000 (phase transition temperature 45 ℃).

[0013] Preferably, the phase change material with a phase change temperature of 0-10°C includes Na 2 S 2 O 4 10H 2 O low co-hydrated salt (phase transition temperature 9~10 ℃), or PEG400 (phase transition temperature 4 ℃). 2 S 2 O 4 10H 2 O low hydrate salt is composed of 80% by mass of Na 2 S 2 O 4 10H 2 O, 2%~8% KCl, 5%~10% NH 4 Cl and 1%~5% (NH 4 ) 2 SO 4 composition.

[0014] Preferably, the raw materials of the interior wall paint include polyurethane prepolymer, methylsiloxane, methyl methacrylate or isooctyl acrylate.

[0015] Preferably, the amphiphilic electromagnetic wave absorber is obtained by surface modification of the electromagnetic wave absorber with a coupling agent.

[0016] More preferably, the coupling agent includes KH-560 silane coupling agent.

[0017] Preferably, the amphiphilic electromagnetic wave absorber includes amphiphilic flake carbonyl iron powder, amphiphilic high entropy alloy powder or amphiphilic lightweight carbon-based absorber.

[0018] More preferably, the high entropy alloy powder includes iron, silicon and chromium.

[0019] More preferably, the lightweight carbon-based absorbent comprises graphene nanosheets and carbon nanotubes.

[0020] Preferably, the negative expansion coefficient material includes graphite, oligomers containing aromatic groups, polytetrafluoroethylene, zirconium tungstate or garnet ceramics.

[0021] Preferably, the emulsifier includes anionic emulsifier, nonionic emulsifier, natural emulsifier or solid particulate emulsifier.

[0022] More preferably, the anionic emulsifier comprises sodium lauryl sulfate or sodium stearate; the nonionic emulsifier comprises polysorbate or sorbitan fatty acid; the natural emulsifier comprises gum arabic, gelatin or gum; and the solid particulate emulsifier comprises magnesium hydroxide or silicon dioxide.

[0023] Preferably, the initiator comprises ammonium persulfate, potassium persulfate or sodium persulfate.

[0024] Preferably, the pH adjuster comprises a 5 wt % sodium hydroxide aqueous solution.

[0025] Preferably, the environmentally friendly wave-absorbing phase-change energy storage temperature control coating further includes an additive; the additive is added in an amount of 3% to 5%, and the sum of the mass fractions of each component is 100%; the additive includes a defoaming agent, a leveling agent or an anti-settling agent.

[0026] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control paint is applied to interior wall paint.

[0027] The method for preparing the environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint uses water as a dispersion medium, and uses a phase-change material that is suitable for both winter and summer. The phase-change material is used as the original site for emulsion polymerization, and a negative expansion coefficient material is added. An emulsion polymerization method similar to in-situ growth is used to prepare an outer shell layer of the phase-change material. After the polymerization reaction is completed, phase-change energy-storage latex particles are obtained, and then the phase-change energy-storage latex particles are secondary encapsulated with an amphiphilic electromagnetic wave absorber.

[0028] The method for preparing the environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following steps: S1. Adding a phase change material and an emulsifier into water and stirring with high shear intensity, the phase change material is encapsulated in the spherical latex particles formed by the emulsifier, serving as the original site of the in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2000-3000 r / min, raise the temperature to 60-70°C, mix the interior wall paint raw materials and the initiator, and uniformly add them to the reactor in step S1, mix the pH regulator, the negative expansion coefficient material and the auxiliary agent, and then uniformly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 80-85 °C, the speed is raised to 5000-6000 r / min, and the reaction is kept at this temperature for 2 h; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add an amphiphilic electromagnetic wave absorber, and stir for 5 to 15 minutes to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0029] Preferably, the stirring speed is 10000~13000 r / min.

[0030] Preferably, the spherical latex particles have a particle size of 145-155 nm.

[0031] Compared with the prior art, the beneficial effects of the present invention are: 1. Innovatively introduce phase change materials into building materials, absorb and release heat through their own phase change reaction, automatically adjust the indoor temperature balance, reduce energy consumption caused by cooling in summer and heating in winter, reduce carbon emissions, realize intelligent upgrading of buildings, and move towards green and sustainable development.

[0032] 2. The present invention adopts a quasi-in-situ growth emulsion polymerization method to prepare interior wall paint, using water as a dispersion medium, which is safe and environmentally friendly; two phase change materials with different phase change temperatures are used as in-situ sites, while taking into account the room temperature changes in winter and summer; an elastic polymer material is used as the outer shell layer of the latex particles to encapsulate the phase change material to prevent leakage during the phase change process, and to prevent wall cracking caused by volume change of the wall paint layer during the phase change process; in addition, in order to further solve the problem of wall cracking caused by thermal expansion and contraction after four seasons of common household interior wall paint, the present invention adds a negative expansion coefficient material that matches the thermal expansion coefficient of the interior wall paint to balance the volume change of the material at different temperatures, thereby greatly improving the durability of the wall.

[0033] 3. Creatively introduce electromagnetic wave absorbers into water-based interior wall paints, and use the amphiphilicity of the absorber after surface modification to perform secondary encapsulation of latex particles, improve the overall thermal conductivity of the wall, and provide rapid automatic feedback for room temperature changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 This is a picture of a cement box used in testing the temperature control properties of interior wall paint.

[0035] Figure 2 This is a picture of a cement box used for testing with a thermometer probe installed.

[0036] Figure 3 It is a temperature variation curve diagram in a cement box after the interior wall paint of the present invention is applied. DETAILED DESCRIPTION

[0037] The technical scheme of the present invention is further described below by examples. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the art without creative work are within the scope of protection of the present invention. The raw materials used in the examples can be purchased commercially or prepared by conventional methods.

[0038] Example 1 An environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following raw materials by mass fraction: Inorganic solid-liquid phase change material Na with a phase transition temperature of about 33 °C 2 SO 4 10H 2O 14%, organic solid-liquid phase change material PEG400 with a phase change temperature of about 6 ℃ 14%, polyurethane prepolymer 32%, amphiphilic graphene nanosheets 8%, zirconium tungstate 2%, sodium dodecyl sulfate 4%, ammonium sulfate 3%, 5% sodium hydroxide aqueous solution 0.5%, defoamer 1.5%, leveling agent 1%, anti-settling agent 1% and water 19%; wherein the defoamer is selected from TEGO810, DL-3562, BYK007 or BYK022; the leveling agent is selected from BYK-333, TEGO100 or BYK-354; the anti-settling agent is BYK-410, PYY-009A or F50.

[0039] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint is prepared according to the following steps: S1, Na 2 SO 4 10H 2 O, PEG400 and anionic emulsifier are added into water, and stirred at a speed of 13000 r / min by using a sawtooth disk agitator or homogenizer with high shear strength. Phase change material is coated in spherical latex particles formed by emulsifier, and the particle size is about 150nm, which serves as the original site of in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2500 r / min, raise the temperature to 65 ° C, mix the polyurethane prepolymer and the initiator, and then use a syringe pump to slowly and evenly inject them into the reactor in step S1, and mix 5% sodium hydroxide aqueous solution, zirconium tungstate defoamer, leveling agent and anti-settling agent evenly, and then use another syringe pump to slowly and evenly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 83 °C, the speed is increased to 5200 r / min, and the reaction is kept at this temperature for 2 h; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add amphiphilic graphene nanosheets, and stir for 10 min to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0040] Example 2 An environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following raw materials by mass fraction: Inorganic solid-liquid phase change material Na with a phase transition temperature of about 33 °C 2 SO 4 10H 2O 16%, PEG400, an organic solid-liquid phase change material with a phase change temperature of about 6 ℃ 16%, a polyurethane prepolymer 32%, amphiphilic graphene nanosheets 8%, zirconium tungstate 2%, sodium dodecyl sulfate 4%, ammonium sulfate 3%, 5% sodium hydroxide aqueous solution 0.5%, a defoamer 1.5%, a leveling agent 1%, an anti-settling agent 1% and water 15%; wherein the defoamer is selected from TEGO810, DL-3562, BYK007 or BYK022; the leveling agent is selected from BYK-333, TEGO100 or BYK-354; the anti-settling agent is BYK-410, PYY-009A or F50.

[0041] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint is prepared according to the following steps: S1, Na 2 SO 4 10H 2 O, PEG400 and anionic emulsifier are added into water, and stirred at a speed of 13000 r / min by using a sawtooth disk agitator or homogenizer with high shear strength. Phase change material is coated in spherical latex particles formed by emulsifier, and the particle size is about 150 nm, which serves as the original site of in-situ growth emulsion polymerization. S2, reduce the stirring speed to 2500 r / min, raise the temperature to 65 ° C, mix the polyurethane prepolymer and the initiator, and then use a syringe pump to slowly and evenly inject them into the reactor in step S1, and mix 5% sodium hydroxide aqueous solution, zirconium tungstate defoamer, leveling agent and anti-settling agent evenly, and then use another syringe pump to slowly and evenly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 83 °C, the speed is increased to 5200 r / min, and the reaction is kept at this temperature for 2 h; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add amphiphilic graphene nanosheets, and stir for 10 min to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0042] Example 3 An environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following raw materials by mass fraction: Inorganic solid-liquid phase change material Na with a phase transition temperature of about 33 °C 2 SO 4 10H 2O 14%, PEG400, an organic solid-liquid phase change material with a phase change temperature of about 6 ℃ 14%, a polyurethane prepolymer 35%, amphiphilic graphene nanosheets 8%, zirconium tungstate 2%, sodium dodecyl sulfate 4%, ammonium sulfate 3%, 5% sodium hydroxide aqueous solution 0.5%, a defoamer 1.5%, a leveling agent 1%, an anti-settling agent 1% and water 16%; wherein the defoamer is selected from TEGO810, DL-3562, BYK007 or BYK022; the leveling agent is selected from BYK-333, TEGO100 or BYK-354; the anti-settling agent is BYK-410, PYY-009A or F50.

[0043] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint is prepared according to the following steps: S1, Na 2 SO 4 10H 2 O, PEG400 and anionic emulsifier are added into water, and stirred at a speed of 13000 r / min by using a sawtooth disk agitator or homogenizer with high shear strength, and the phase change material is coated in the spherical latex particles formed by the emulsifier, which serves as the original site of the in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2500 r / min, raise the temperature to 65 ° C, mix the polyurethane prepolymer and the initiator, and then use a syringe pump to slowly and evenly inject them into the reactor in step S1, and mix 5% sodium hydroxide aqueous solution, zirconium tungstate defoamer, leveling agent and anti-settling agent evenly, and then use another syringe pump to slowly and evenly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 83 °C, the speed is increased to 5000-6000 r / min, and the reaction is kept at this temperature for 2 hours; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add amphiphilic graphene nanosheets, and stir for 10 min to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0044] Example 4 An environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following raw materials by mass fraction: Inorganic solid-liquid phase change material Na with a phase transition temperature of about 33 °C 2 SO 4 10H 2O 14%, PEG400, an organic solid-liquid phase change material with a phase change temperature of about 6 ℃ 14%, a polyurethane prepolymer 32%, amphiphilic graphene nanosheets 12%, zirconium tungstate 2%, sodium dodecyl sulfate 4%, ammonium sulfate 3%, 5% sodium hydroxide aqueous solution 0.5%, a defoamer 1.5%, a leveling agent 1%, an anti-settling agent 1% and water 15%; wherein the defoamer is selected from TEGO810, DL-3562, BYK007 or BYK022; the leveling agent is selected from BYK-333, TEGO100 or BYK-354; the anti-settling agent is BYK-410, PYY-009A or F50.

[0045] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint is prepared according to the following steps: S1, Na 2 SO 4 10H 2 O, PEG400 and anionic emulsifier are added into water, and stirred at a speed of 13000 r / min by using a sawtooth disk agitator or homogenizer with high shear strength, and the phase change material is coated in the spherical latex particles formed by the emulsifier, which serves as the original site of the in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2500 r / min, raise the temperature to 65 ° C, mix the polyurethane prepolymer and the initiator, and then use a syringe pump to slowly and evenly inject them into the reactor in step S1, and mix 5% sodium hydroxide aqueous solution, zirconium tungstate defoamer, leveling agent and anti-settling agent evenly, and then use another syringe pump to slowly and evenly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 83 °C, the speed is increased to 5000-6000 r / min, and the reaction is kept at this temperature for 2 hours; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add amphiphilic graphene nanosheets, and stir for 10 min to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0046] Example 5 An environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint comprises the following raw materials by mass fraction: Inorganic solid-liquid phase change material Na with a phase transition temperature of about 33 °C 2 SO 4 10H 2O 14%, organic solid-liquid phase change material PEG400 with a phase change temperature of about 6 ℃ 14%, polyurethane prepolymer 32%, amphiphilic graphene nanosheets 12%, zirconium tungstate 2%, sodium dodecyl sulfate 4%, ammonium sulfate 3%, 5% sodium hydroxide aqueous solution 0.5%, defoamer 1.5%, leveling agent 1%, anti-settling agent 1% and water 19%; wherein the defoamer is selected from TEGO810, DL-3562, BYK007 or BYK022; the leveling agent is selected from BYK-333, TEGO100 or BYK-354; the anti-settling agent is BYK-410, PYY-009A or F50.

[0047] The environmentally friendly wave-absorbing phase-change energy-storage temperature-control interior wall paint is prepared according to the following steps: S1, Na 2 SO 4 10H 2 O, PEG400 and anionic emulsifier are added into water, and stirred at a speed of 13000 r / min by using a sawtooth disk agitator or homogenizer with high shear strength, and the phase change material is coated in the spherical latex particles formed by the emulsifier, which serves as the original site of the in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2500 r / min, raise the temperature to 65 ° C, mix the polyurethane prepolymer and the initiator, and then use a syringe pump to slowly and evenly inject them into the reactor in step S1, and mix 5% sodium hydroxide aqueous solution, zirconium tungstate defoamer, leveling agent and anti-settling agent evenly, and then use another syringe pump to slowly and evenly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 83 °C, the speed is increased to 5000-6000 r / min, and the reaction is kept at this temperature for 2 hours; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add amphiphilic graphene nanosheets, and stir for 10 min to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

[0048] Comparative Example 1 An interior wall paint is basically the same as Example 1, except that: there is only one phase change material, which is an organic solid-liquid phase change material PEG400 with a phase change temperature of about 6° C., and the addition amount is 28%.

[0049] Comparative Example 2 An interior wall paint is basically the same as Example 1, except that no phase change material is added.

[0050] Comparative Example 3 An interior wall paint is basically the same as Example 1, except that no negative expansion coefficient material is added.

[0051] Tests and Results The elongation at break, thermal deformation rate and thermal shock resistance of the coatings after curing and film formation of the samples prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were tested respectively, and the temperature control effect of the coating was tested by simulating a closed house.

[0052] (1) Test method for elongation at break of coating The prepared sample was poured into a polytetrafluoroethylene mold by casting film and cured at 80 °C to form a film. The sample was prepared and tested using a UTM510X universal tensile testing machine in accordance with the GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber" test standard. The results are shown in Table 1.

[0053] (2) Test method for thermal deformation change rate of coating The prepared sample was poured into a polytetrafluoroethylene mold by the cast film method and cured at 80 °C to form a film. The coating was then cut into 100 mm × 100 mm squares and placed in a 40 °C oven. After 1 h, the side length of the coating was measured at an ambient temperature of 40 °C. The results are shown in Table 1.

[0054] Coating thermal deformation change rate S = (L 2 -L 1 ) / L 1 ╳100%. Among them, L 1 is the original side length of the coating, which is 100 mm; L 2 It is the side length of the coating measured at 40°C after being placed in a 40°C oven for 1 h, in mm.

[0055] (3) Test method for thermal shock resistance of coatings The prepared sample was poured into a polytetrafluoroethylene mold by casting film, cured at 80 °C, and then cut into 100 mm × 100 mm squares and placed in a temperature shock box. After the temperature shock test was completed, the sample was taken out and placed at room temperature to observe the coating surface and measure the length of the same side of the coating. The test conditions of temperature shock were: 40 °C, heat preservation for 6 h, then reduced to 0 °C, heat preservation for 6 h, and cycled 100 times. It was used to analogize the use of interior wall paint for 50 years. The results are shown in Table 1.

[0056] The deformation rate of the coating after thermal shock is P = (P 2 -P 1 ) / P 1 ╳100%. Among them, P 1 = is the original side length of the coating, which is 100mm; P 2 It is the side length of the coating after the temperature impact test, in mm.

[0057] The mass loss ratio of the coating after thermal shock is Q = (Q 2 -Q 1 ) / Q 1 ╳100%. Among them, Q 1 Q is the mass of the heat-resistant coating before impact, in g; 2 It is the mass of the coating after temperature impact resistance, in g.

[0058] (4) Coating temperature control test method The cement slurry used for conventional wall materials is poured into the mold by pouring to prepare a cubic cement box with five closed sides and a size of 300 mm ╳ 300 mm ╳ 300 mm. The cement wall thickness is about 30 mm. Figure 1 As shown. The five inner surfaces of the cubic open cement box are sprayed with the environmentally friendly phase-change energy storage temperature-control interior wall paint prepared by the present invention, and the paint film thickness is about 3 mm. The sixth surface is embedded with a PU foam board with a side length of 240 mm and a thickness of 30 mm to pinch into the vacant part of the sixth surface and keep it flush with the edge position. A hole is dug in the middle of the PU foam surface, and the wire connected to the thermometer probe is passed through the small hole, as shown in FIG. Figure 2 As shown; the sealed body was placed in high and low temperature boxes with different temperature settings, one of which was set at 40 ℃ to simulate the summer ambient temperature; the other was set at 0 ℃ to simulate the winter ambient temperature. The temperature values ​​of the sealed body were recorded at 0 min, 3 min, 15 min, 30 min, 60 min, and 120 min after being placed in the high and low temperature boxes. The results are shown in Figure 3 shown.

[0059] Table 1 Performance data of samples

[0060] By comparing Example 1 with Comparative Example 1, it can be found that when only one phase change material is used, the temperature changes in winter and summer cannot be taken into account, that is, Comparative Example 1 cannot regulate the room temperature in summer, which is similar to the performance of Comparative Example 1 in summer.

[0061] By comparing Example 1 with Example 3, it can be found that increasing the proportion of shell material improves the flexibility of the coating, and basically does not affect the coating's controllability of temperature in winter and summer.

[0062] By comparing Example 1 with Example 4, it can be found that when the amount of electromagnetic wave absorber material is increased, the thermal conductivity of the entire coating is increased, and the initial temperature perception rate of the coating is improved. At the same time, the increase in the concentration of powder filler in the coating also sacrifices part of the flexibility of the coating.

[0063] Comparing Example 1 with Example 5, it can be found that the flexibility of the coating is improved by replacing the electromagnetic wave absorber from a lightweight carbon-based material with a high-entropy alloy material with a higher density. However, the latter is far less effective than the former in encapsulating the phase change energy storage material, resulting in a reduction in mass after 100 temperature shocks. This situation is similar to that of Comparative Example 2.

[0064] By comparing Example 1 with Comparative Example 4, it can be found that if the negative expansion coefficient material is not added, the thermal deformation change rate of the coating exceeds 5%, and the coating cracks after being subjected to 100 temperature shocks.

[0065] It can be seen from the above experimental results that Example 2 can show good room temperature self-regulation ability in both experiments simulating summer temperature and winter temperature. The coating has good flexibility and its elongation at break is 66.5%. After the coating was subjected to 100 temperature shocks, its deformation was only 0.48%, and the coating was in good appearance with almost no mass loss, indicating that the encapsulation of phase change energy storage materials is extremely effective.

[0066] It should be understood that the above embodiments are only used to illustrate the present invention and are not used to limit the protection scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims

1. An environmentally friendly microwave-absorbing phase-change energy storage temperature control coating, characterized in that: Calculated by mass fraction, the raw materials include: 28% to 32% of phase change energy storage material, 30% to 35% of interior wall paint raw materials, 8% to 12% of amphiphilic electromagnetic wave absorber, 1% to 2% of negative expansion coefficient material, 3% to 5% of emulsifier, 2% to 4% of initiator, 0.2% to 0.5% of pH adjuster, and 15% to 20% of water, and the sum of the mass fractions of each component is 100%; the phase change energy storage material includes at least one phase change material with a phase change temperature of 29 to 45°C and at least one phase change material with a phase change temperature of 0 to 10°C.

2. The environmentally friendly microwave-absorbing phase-change energy storage temperature control coating according to claim 1, characterized in that: The phase change materials with a phase change temperature of 29-45°C include Na2SO4·10H2O, Na2CO3·10H2O, LiNO3·3H2O, CaBr2·6H2O, methyl palmitate, C 18 -C 20 Alkane mixed paraffin, n-docosane, PEG1000 or PEG2000; the phase change material with a phase change temperature of 0-10°C includes Na2S2O4·10H2O low-compound hydrate salt or PEG400.

3. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 1 is characterized in that: The raw materials of the interior wall paint include polyurethane prepolymer, methylsiloxane, methyl methacrylate or isooctyl acrylate; the emulsifier includes anionic emulsifier, nonionic emulsifier, natural emulsifier or solid particulate emulsifier; the amphiphilic electromagnetic wave absorber includes amphiphilic flaky carbonyl iron powder, amphiphilic high entropy alloy powder or amphiphilic lightweight carbon-based absorber; the negative expansion coefficient material includes graphite, oligomer containing aromatic groups, polytetrafluoroethylene, zirconium tungstate or garnet ceramic; the emulsifier includes anionic emulsifier, nonionic emulsifier, natural emulsifier or solid particulate emulsifier; the initiator includes ammonium persulfate, potassium persulfate or sodium persulfate; the pH adjuster includes 5wt% sodium hydroxide aqueous solution.

4. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 3 is characterized in that: The high entropy alloy powder includes iron, silicon and chromium; the lightweight carbon-based absorbent includes graphene nanosheets and carbon nanotubes; the anionic emulsifier includes sodium dodecyl sulfate or sodium stearate; the nonionic emulsifier includes polysorbate or sorbitan fatty acid; the natural emulsifier includes gum arabic, gelatin or gum; and the solid particulate emulsifier includes magnesium hydroxide or silicon dioxide.

5. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 3 is characterized in that: The amphiphilic electromagnetic wave absorber is obtained by surface modification of the electromagnetic wave absorber with a coupling agent.

6. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 1 is characterized in that: It also includes an auxiliary agent; the addition amount of the auxiliary agent is 3% to 5%, and the sum of the mass fractions of each component is 100%.

7. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 6 is characterized in that: The auxiliary agent includes a defoamer, a leveling agent or an anti-settling agent.

8. A method for preparing the environmentally friendly microwave-absorbing phase-change energy storage temperature control coating according to any one of claims 1 to 7, characterized in that: S1. Adding a phase change material and an emulsifier into water and stirring with high shear intensity, the phase change material is encapsulated in the spherical latex particles formed by the emulsifier, serving as the original site of the in-situ growth emulsion polymerization; S2, reduce the stirring speed to 2000-3000 r / min, raise the temperature to 60-70°C, mix the interior wall paint raw materials and the initiator, and uniformly add them to the reactor in step S1, mix the pH regulator, the negative expansion coefficient material and the auxiliary agent, and then uniformly inject them into the reactor; S3. After the addition is completed, the reaction temperature is raised to 80-85 °C, the speed is raised to 5000-6000 r / min, and the reaction is kept at this temperature for 2 h; S4. After the reaction is completed, cool to room temperature, reduce the speed of the reactor to 3000 r / min, add an amphiphilic electromagnetic wave absorber, and stir for 5 to 15 minutes to obtain the environmentally friendly wave-absorbing phase-change energy storage temperature-control interior wall paint.

9. The method for preparing the environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to claim 8, characterized in that: The stirring speed is 10000-13000 r / min; the particle size of the spherical latex particles is 145-155 nm.

10. The environmentally friendly microwave-absorbing phase-change energy storage temperature-control coating according to any one of claims 1 to 7, characterized in that: The environmentally friendly wave-absorbing phase-change energy-storage temperature-control paint is applied to interior wall paint.

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