UV curing thermal insulation coating and preparation method thereof

Abstract

The invention discloses a UV-curable thermal insulation coating and a preparation method thereof, and relates to the technical field of coatings. The preparation method comprises the following steps: firstly, preparing a UV curing coating by taking 2-ethyl-2-(mercaptomethyl)-1, 3-propanedithiol and pentaerythritol triallyl ether as raw materials, and then adding a modified phase change microcapsule material as a thermal insulation auxiliary agent; the polyfunctional group raw material can form a highly cross-linked polymer network structure, so that the mechanical property of the cured coating is improved; an oxidized foam metal loaded sugar alcohol mixture is used as a core material of the phase-change microcapsule, p-fluorocinnamyl chloride doped modified polyamide is used as a shell material of the phase-change microcapsule, then the modified phase-change microcapsule material is prepared by adopting an interfacial polymerization method, and the modified phase-change material can absorb or release heat more quickly, so that the heat preservation effect is improved, and the service life of the phase-change microcapsule is prolonged. The surface of the fluorocinnamyl chloride modified phase change microcapsule material contains double bonds and can participate in a curing reaction to be directly bonded with a resin network, so that the interfacial strength is enhanced. According to the prepared UV curing thermal insulation coating, the thermal insulation effect of the coating is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly to a UV-curable thermal insulation coating and a preparation method thereof. Background Art

[0002] In the global trend of increasing environmental protection awareness, the coating industry is moving towards sustainability. UV coatings have been widely used in modern society due to their advantages such as environmental protection, convenience, and economy. Ultraviolet (UV)-curable coatings, as a type of radiation-curable coatings, specifically refer to those new coatings that can quickly crosslink and cure into films under light irradiation. Compared with traditional solvent-based coatings, photocurable coatings exhibit many advantages: fast curing speed, no volatile organic solvents, low energy consumption, high cost-effectiveness, and support for automated production processes. Therefore, they are regarded as a coating choice that conforms to the concept of green environmental protection.

[0003] Facing the challenges of continuous growth in energy consumption and the approaching exhaustion of traditional fossil energy, the construction field, as a major energy consumer, has particularly prominent energy consumption in its heating, cooling, and other operation processes. To address this challenge, reduce energy consumption, and reduce greenhouse gas emissions to achieve the goal of sustainable development, improving the energy utilization efficiency of buildings has become an urgent problem to be solved. Against this background, thermal insulation coatings, due to their characteristics of effectively blocking heat transfer, have become one of the key technical means to reduce energy loss during building use.

[0004] Therefore, it is particularly important to develop a new type of coating that combines UV-curing technology and thermal insulation function. This UV-curable thermal insulation coating can not only inherit the common environmental protection characteristics of both, but also further expand its application potential in improving building energy efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a UV-curable thermal insulation coating and a preparation method thereof to solve the problems existing in the prior art.

[0006] To solve the above technical problems, the present invention provides the following technical solution: a UV-curable thermal insulation coating, which is prepared from 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether, and then adding a thermal insulation aid, a diluent, a photoinitiator, a leveling agent, and a solvent;

[0007] The thermal insulation aid is a modified phase change microcapsule material; the modified phase change microcapsule material is prepared by using an oxidized foam metal loaded with a sugar alcohol mixture as the core material, p-fluorocinnamoyl chloride modified polyamide as the shell material, and then adopting an interfacial polymerization method.

[0008] Furthermore, the diluent is one of DVE-3, CHVE, HBVE, or DDVE.

[0009] Further, the photoinitiator is one of 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,2-dimethoxy-2-phenylacetophenone or 2-hydroxy-4-methoxybenzophenone.

[0010] Further, the leveling agent is one of BYK-UV3500, BYK-UV3530 or BYK-UV3570.

[0011] Further, a preparation method of a UV-curable heat-insulating coating includes the following preparation steps:

[0012] (1) Place the sugar alcohol mixture in a drying oven, dry it at 100-105°C for 8-10 h, then place it in a sealed box, heat it up to 200°C, keep it at a constant temperature for 1-2 h, take it out and let it cool naturally to room temperature, then use a planetary ball mill to grind it at a rotation speed of 250 r / min for 15 min, and pass it through a 150-mesh sieve to obtain a pretreated sugar alcohol mixture;

[0013] (2) Dissolve the pretreated sugar alcohol mixture in deionized water with a mass 5-10 times that of the pretreated sugar alcohol mixture, add oxidized foam metal with a mass 0.8-1.0 times that of the pretreated sugar alcohol mixture, and then stir at 80-100°C and 300-400 r / min until the deionized water completely evaporates, and dry it at 100°C for 1.0-1.5 h to obtain a modified phase change material;

[0014] (3) Aqueous phase: Mix polyethylene glycol and deionized water at a mass ratio of 0.05-0.08:1, add the modified phase change material with a volume 0.03-0.05 times that of the mixed solution, and stir at 500-600 r / min for 30-60 min to obtain an aqueous phase;

[0015] Oil phase: Mix p-fluorocinnamoyl chloride and terephthaloyl chloride at a molar ratio of 0.1-0.3:1, then add Tween 80 with a mass 0.01-0.03 times that of terephthaloyl chloride to obtain a mixture, dissolve the mixture in an organic solvent, and stir at 500-600 r / min for 30-60 min to obtain an oil phase;

[0016] Emulsification: At 50°C and 800-1000 r / min, add the oil phase to the aqueous phase and stir for 20-40 min to obtain a stable emulsion, and the volume ratio of the oil phase to the aqueous phase is 1:3;

[0017] Encapsulation: At room temperature and 600 r / min, add an aqueous solution of amine to the stable emulsion, react for 15-30 min, filter and wash to obtain a modified phase change microcapsule material;

[0018] (4) Prepare a UV-curable heat-insulating coating by mixing 20 - 35% 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 20 - 35% trimethylolpropane triallyl ether, 3 - 5% modified phase change microcapsule material, 5 - 10% diluent, 1 - 5% photoinitiator, 0.3 - 1% leveling agent, and 20 - 30% solvent by mass percentage.

[0019] Further, in the step (2), the oxidized foam metal is obtained by cleaning and drying the foam metal with deionized water, and then performing heat treatment in an air atmosphere at 500 - 800 °C for 3 - 5 h, and naturally cooling to room temperature. The foam metal is one of foam iron, foam nickel, or foam copper.

[0020] Further, in the step (3), the organic solvent is prepared by mixing cyclohexane and chloroform in a ratio of 3:2.

[0021] Further, in the step (3), the aqueous solution of amine is prepared by mixing 1,6-hexanediamine and diethylenetriamine in a molar ratio of 1:1 to obtain a mixed solution, and then dissolving the mixed solution in deionized water with a mass 2 - 3 times that of the mixed solution.

[0022] Further, the molar ratio of 1,6-hexanediamine, diethylenetriamine, and terephthaloyl chloride is 1.0 - 1.1:1.0 - 1.1:1.

[0023] Further, in the step (3), the washing is performed by alternately washing with deionized water and ethanol 2 - 3 times.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0025] The present invention uses 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and trimethylolpropane triallyl ether as raw materials to prepare a UV-curable coating, and then adds a modified phase change microcapsule material as a heat-insulating auxiliary to improve the heat-insulating effect of the coating.

[0026] First, a UV-curable coating is prepared using 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether as raw materials; 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether will undergo a thiol-ene click reaction under ultraviolet light and cure rapidly, forming a solid coating film in a short time, which can improve production efficiency, reduce the volatilization time of the coating during curing, reduce the impact on the environment. At the same time, the surface of the phase change microcapsule material modified by para-fluorocinnamoyl chloride contains double bonds as a heat preservation aid, which will also provide active sites during UV curing and can be directly bonded to the resin network through a thiol-ene click reaction to form a "microcapsule-matrix" covalent connection, enhancing the interfacial strength and further improving the mechanical properties of the cured coating; moreover, 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol contains multiple mercapto groups, which can form a highly cross-linked polymer network structure. The dense polymer network can effectively prevent external corrosive substances, such as moisture, oxygen, acids, and alkalis, from penetrating into the interior of the coating film, thereby protecting the substrate from corrosion; the pentaerythritol skeleton provides rigidity, and the ethyl side chain and thioether bond endow toughness to avoid brittle cracking.

[0027] Secondly, a mixture of oxidized foam metal and sugar alcohol is used as the core material of the phase change microcapsule, and para-fluorocinnamoyl chloride-modified polyamide is used as the shell material of the phase change microcapsule. Then, an interfacial polymerization method is used to prepare the modified phase change microcapsule material, and the modified phase change microcapsule material is added as a heat preservation aid to the above raw materials to prepare a UV-curable heat preservation coating; the surface of the oxidized foam metal has oxide active sites, which can form hydrogen bonds with sugar alcohol compounds, thus more firmly loading the sugar alcohol compounds. Moreover, the foam metal has good thermal conductivity, and after loading, it can effectively improve the problem of low thermal conductivity of the sugar alcohol mixture, improve the thermal conductivity of the sugar alcohol mixture and the heat transfer efficiency during the phase change process. When the environmental temperature changes, the modified phase change material can absorb or release heat more quickly, realizing a more efficient phase change and improving the heat preservation effect; the encapsulation of the polyamide resin can effectively prevent the phase change material from directly contacting the environment, playing a protective role, and at the same time can also prevent the leakage of the phase change material during use, further improving the heat preservation performance of the coating; introducing fluorine atoms into the polyamide shell material, the strong hydrophobicity of the fluorine atoms can significantly reduce the water absorption rate of the shell material, reduce the erosion of the phase change material caused by water penetration, avoid the rupture of the microcapsules due to hygroscopic expansion, improve the coating effect of the polyamide shell material, delay the service life of the microcapsule material, and the fluorine group can reduce the surface energy of the shell material, reduce the adhesion between microcapsules, and improve its dispersibility in the UV-curable coating. Specific implementation mode

[0028] The following will describe the technical solutions in the embodiments of the present invention clearly and completely in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0029] In order to more clearly illustrate the method provided by the present invention, the following embodiments are used for detailed description. The test methods for each index of the UV-curable thermal insulation coating prepared in the following embodiments are as follows:

[0030] The UV-curable coatings obtained in the embodiments of the present invention and the comparative examples are subjected to the following process:

[0031] The process sequence is: substrate cleaning → coating dilution → spraying → IR baking → UV curing. The specific process parameters are: spraying the UV-curable thermal insulation coating on the metal surface and baking at 70 °C for 3 - 5 min; then curing it with a UV curing machine with an energy of 1000 - 2100 mJ / cm 2 to form a coating, and the following performance tests are carried out on the obtained coating.

[0032] Adhesion: The adhesion of the UV-curable thermal insulation coatings obtained in the examples and the comparative examples with the same mass is tested according to GB / T9286-1998 "Cross-Cutting Test Method for Paint and Varnish Films".

[0033] Hardness: The hardness of the UV-curable thermal insulation coatings obtained in the examples and the comparative examples with the same mass is tested according to GB / T6739-1996 "Pencil Hardness Test Method".

[0034] Thermal conductivity: The thermal conductivity of the UV-curable thermal insulation coatings obtained in the examples and the comparative examples with the same mass is tested according to GB / T17371-2008 "Silicate Composite Thermal Insulation Coatings".

[0035] Example 1

[0036] A preparation method of a UV-curable thermal insulation coating includes the following preparation steps:

[0037] (1) After cleaning and drying PPI40 nickel foam with deionized water, heat-treat it in an air atmosphere at 500 °C for 3 h, and naturally cool it to room temperature to obtain oxidized nickel foam;

[0038] (2) Place erythritol and mannitol in a drying oven at a mass ratio of 1:1, dry at 100 °C for 8 h, then place it in a sealed box, heat it up to 200 °C, keep it at a constant temperature for 1 h, take it out and naturally cool it to room temperature, then grind it with a planetary ball mill at a rotation speed of 250 r / min for 15 min, and pass through a 150-mesh sieve to obtain a pretreated sugar alcohol mixture;

[0039] (3) Dissolve the pretreated sugar alcohol mixture in deionized water with a mass 5 times that of the pretreated sugar alcohol mixture, add oxidized nickel foam with a mass 0.8 times that of the pretreated sugar alcohol mixture, and then stir at 80 °C and 300 r / min until the deionized water completely evaporates. After drying at 100 °C for 1.0 h, a modified phase change material is obtained;

[0040] (4) Aqueous phase: Mix polyethylene glycol 6000 and deionized water at a mass ratio of 0.05:1, add the modified phase change material with a volume 0.03 times that of the mixed solution, and stir at 500 r / min for 30 min to obtain the aqueous phase;

[0041] Oil phase: Mix p - fluorocinnamoyl chloride and terephthaloyl chloride at a molar ratio of 0.1:1, then add Tween 80 with a mass 0.01 times that of terephthaloyl chloride to obtain a mixture. Dissolve the mixture in an organic solvent, which is prepared by mixing cyclohexane and chloroform at a ratio of 3:2. Stir at 500 r / min for 30 min to obtain the oil phase;

[0042] Emulsification: At 50 °C and 800 r / min, add the oil phase to the aqueous phase and stir for 20 min to obtain a stable emulsion. The volume ratio of the oil phase to the aqueous phase is 1:3;

[0043] Encapsulation: Mix 1,6 - hexanediamine and diethylenetriamine at a molar ratio of 1:1 to obtain a mixed solution, and then dissolve the mixed solution in deionized water with a mass 2 times that of the mixed solution to prepare an aqueous solution of amine. At room temperature and 600 r / min, add the aqueous solution of amine to the stable emulsion, react for 15 min, filter, and wash alternately with deionized water and ethanol 2 times to obtain a modified phase change microcapsule material, where the molar ratio of 1,6 - hexanediamine, diethylenetriamine, and terephthaloyl chloride is 1.0:1.0:1;

[0044] (5) By mass percentage, mix 30% 2 - ethyl - 2 - (mercaptomethyl) - 1,3 - propanedithiol, 30% pentaerythritol triallyl ether, 3% modified phase change microcapsule material, 5% DVE - 3 diluent, 3% 2,4,6 - trimethylbenzoyl diphenylphosphine oxide photoinitiator, 0.3% BYK - UV3500 leveling agent, and 28.7% solvent to obtain a UV - curable thermal insulation coating. The solvent is prepared by mixing acetone and toluene at a volume ratio of 3:1.

[0045] Example 2

[0046] A preparation method of a UV - curable thermal insulation coating, comprising the following preparation steps:

[0047] (1) After cleaning and drying PPI40 nickel foam with deionized water, heat - treat it in an air atmosphere at 700 °C for 4 h, and naturally cool to room temperature to obtain oxidized nickel foam;

[0048] (2) Place erythritol and mannitol in a drying oven at a mass ratio of 1:1, dry at 100 °C for 9 h, then place in a sealed box, heat up to 200 °C, keep the temperature constant for 2 h, take out and let it cool naturally to room temperature, then use a planetary ball mill to grind at a rotational speed of 250 r / min for 15 min, and pass through a 150-mesh sieve to obtain a pretreated sugar alcohol mixture;

[0049] (3) Dissolve the pretreated sugar alcohol mixture in deionized water at 8 times the mass of the pretreated sugar alcohol mixture, add oxidized foam metal at 0.9 times the mass of the pretreated sugar alcohol mixture, and then stir at 90 °C and 350 r / min until the deionized water completely evaporates, and dry at 100 °C for 1.0 h to obtain a modified phase change material;

[0050] (4) Aqueous phase: Mix polyethylene glycol 6000 and deionized water at a mass ratio of 0.06:1, add the modified phase change material at 0.04 times the volume of the mixed solution, and stir at 550 r / min for 45 min to obtain the aqueous phase;

[0051] Oil phase: Mix p-fluorocinnamoyl chloride and terephthaloyl chloride at a molar ratio of 0.2:1, then add Tween 80 at 0.02 times the mass of terephthaloyl chloride to obtain a mixture, dissolve the mixture in an organic solvent, and the organic solvent is prepared by mixing cyclohexane and chloroform at a ratio of 3:2, and stir at 550 r / min for 45 min to obtain the oil phase;

[0052] Emulsification: At 50 °C and 900 r / min, add the oil phase to the aqueous phase and stir for 30 min to obtain a stable emulsion, and the volume ratio of the oil phase to the aqueous phase is 1:3;

[0053] Encapsulation: Mix 1,6-hexanediamine and diethylenetriamine at a molar ratio of 1:1 to obtain a mixed solution, then dissolve the mixed solution in deionized water at 3 times the mass of the mixed solution to obtain an aqueous solution of amine. At room temperature and 600 r / min, add the aqueous solution of amine to the stable emulsion, react for 25 min, filter, and wash alternately with deionized water and ethanol 3 times to obtain a modified phase change microcapsule material, where the molar ratio of 1,6-hexanediamine, diethylenetriamine and terephthaloyl chloride is 1.1:1.0:1;

[0054] (5) By mass percentage, mix 32% 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 32% pentaerythritol triallyl ether, 4% modified phase change microcapsule material, 8% DVE-3 diluent, 3% 2,4,6-trimethylbenzoyl diphenylphosphine oxide photoinitiator, 0.8% BYK-UV3500 leveling agent and 20.2% solvent to obtain a UV-curable thermal insulation coating, and the solvent is prepared by mixing acetone and toluene at a volume ratio of 3:1.

[0055] Example 3

[0056] A preparation method of a UV-curable thermal insulation coating, comprising the following preparation steps:

[0057] (1) After cleaning and drying PPI40 nickel foam with deionized water, it is heat-treated at 800 °C in an air atmosphere for 5 h and naturally cooled to room temperature to obtain oxidized nickel foam.

[0058] (2) Erythritol and mannitol are placed in a drying oven at a mass ratio of 1:1, dried at 105 °C for 10 h, then placed in a sealed box and heated to 200 °C, kept at a constant temperature for 2 h. After taking it out and naturally cooling to room temperature, it is ground for 15 min at a rotation speed of 250 r / min using a planetary ball mill, and then passed through a 150-mesh sieve to obtain a pretreated sugar alcohol mixture.

[0059] (3) The pretreated sugar alcohol mixture is dissolved in deionized water 10 times the mass of the pretreated sugar alcohol mixture, and 1 time the mass of the oxidized foam metal of the pretreated sugar alcohol mixture is added. Then, it is stirred at 100 °C and 400 r / min until the deionized water is completely evaporated, and dried at 100 °C for 1.5 h to obtain a modified phase change material.

[0060] (4) Aqueous phase: Polyethylene glycol 6000 and deionized water are mixed at a mass ratio of 0.08:1, and 0.05 times the volume of the modified phase change material is added to the mixture, and stirred at 600 r / min for 60 min to obtain an aqueous phase.

[0061] Oil phase: p-Fluorocinnamoyl chloride and terephthaloyl chloride are mixed at a molar ratio of 0.3:1, and then 0.03 times the mass of terephthaloyl chloride of Tween 80 is added to obtain a mixture. The mixture is dissolved in an organic solvent, and the organic solvent is prepared by mixing cyclohexane and chloroform at a ratio of 3:2, and stirred at 600 r / min for 60 min to obtain an oil phase.

[0062] Emulsification: At 50 °C and 1000 r / min, the oil phase is added to the aqueous phase and stirred for 40 min to obtain a stable emulsion, and the volume ratio of the oil phase to the aqueous phase is 1:3.

[0063] Encapsulation: 1,6-Hexanediamine and diethylenetriamine are mixed at a molar ratio of 1:1 to obtain a mixed solution. Then, the mixed solution is dissolved in deionized water 3 times the mass of the mixed solution to obtain an aqueous solution of amine. At room temperature and 600 r / min, the aqueous solution of amine is added to the stable emulsion, reacted for 30 min, filtered, and washed alternately with deionized water and ethanol 3 times to obtain a modified phase change microcapsule material, where the molar ratio of 1,6-hexanediamine, diethylenetriamine, and terephthaloyl chloride is 1.1:1.1:1.

[0064] (5) Mix 30% 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 30% pentaerythritol triallyl ether, 5% modified phase change microcapsule material, 10% DVE-3 diluent, 5% 2,4,6-trimethylbenzoyl diphenylphosphine oxide photoinitiator, 1% BYK-UV3500 leveling agent and 19% solvent by mass percentage to obtain a UV-curable thermal insulation coating. The solvent is prepared by mixing acetone and toluene at a volume ratio of 3:1.

[0065] Comparative Example 1

[0066] The difference between Comparative Example 1 and Example 2 lies in step (4). Change 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol in step (5) to 1,2-ethanedithiol; the remaining steps are the same as those in Example 2.

[0067] Comparative Example 2

[0068] The difference between Comparative Example 2 and Example 2 lies in step (2). Change pentaerythritol triallyl ether in step (5) to diallyl ether; the remaining steps are the same as those in Example 2.

[0069] Comparative Example 3

[0070] The difference between Comparative Example 3 and Example 2 is that there is no step (1). Change oxidized foam metal in step (3) to foam metal; the remaining steps are the same as those in Example 2.

[0071] Comparative Example 4

[0072] The difference between Comparative Example 4 and Example 2 is that there are no steps (1) and (3). Change the modified phase change material in step (4) to a pretreated sugar alcohol mixture; the remaining steps are the same as those in Example 2.

[0073] Comparative Example 5

[0074] The difference between Comparative Example 5 and Example 2 lies in step (4). Delete p-fluorocinnamoyl chloride in step (4); the remaining steps are the same as those in Example 2.

[0075] Comparative Example 6

[0076] The difference between Comparative Example 6 and Example 2 is that there is no step (4). Change the modified phase change microcapsule material in step (5) to a modified phase change material; the remaining steps are the same as those in Example 2.

[0077] Effect Example

[0078] The following Table 1 gives the performance analysis results of the UV-curable thermal insulation coatings of Examples 1 to 3 and Comparative Examples 1 to 6 of the present invention.

[0079] Table 1

[0080] Adhesion / level Hardness / H Thermal conductivity (W / m*k) Example 1 0 5 0.21 Example 2 0 5 0.23 Example 3 0 5 0.22 Comparative Example 1 2 2 0.26 Comparative Example 2 2 2 0.25 Comparative Example 3 0 5 0.35 Comparative Example 4 0 5 0.41 Comparative Example 5 1 3 0.32 Comparative Example 6 0 5 0.48

[0081] From the comparison of the experimental data between Example 2 and Comparative Examples 1-2, it can be found that the present invention uses 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether as raw materials to prepare a UV-curable coating; 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether will undergo a thiol-ene click reaction under ultraviolet light and cure rapidly, forming a solid coating film in a short time, which can improve production efficiency, reduce the volatilization time of the coating during curing, reduce the impact on the environment. At the same time, the surface of the phase change microcapsule material modified by fluoro-cinnamoyl chloride contains double bonds, which will also provide active sites during UV curing and can be directly bonded to the resin network through a thiol-ene click reaction to form a "microcapsule-matrix" covalent connection, enhancing the interfacial strength and further improving the mechanical properties of the cured coating; and 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol contains multiple mercapto groups, which can form a highly cross-linked polymer network structure. The dense polymer network can effectively prevent external corrosive substances, such as moisture, oxygen, acids and bases, from penetrating into the interior of the coating film, thereby protecting the substrate from corrosion; the pentaerythritol skeleton provides rigidity, and the ethyl side chain and thioether bond endow toughness to avoid brittle cracking; from the comparison of the experimental data between Example 2 and Comparative Examples 3-4, it can be found that the present invention uses oxidized foam metal to load the phase change material. The surface of the oxidized foam metal has oxide active sites, which can form hydrogen bonds with sugar alcohol compounds, thereby more firmly loading the sugar alcohol compounds. And the foam metal has good thermal conductivity. After loading, it can effectively improve the problem of low thermal conductivity of the sugar alcohol mixture, improve the thermal conductivity of the sugar alcohol mixture and the heat transfer efficiency during the phase change process. When the environmental temperature changes, the modified phase change material can absorb or release heat more quickly, achieve a more efficient phase change, and improve the heat preservation effect; from the comparison of the experimental data between Example 2 and Comparative Example 5, it can be found that the present invention dopes fluoro-cinnamoyl chloride-modified polyamide as the shell material of the phase change microcapsule to introduce fluorine atoms into the polyamide shell material. The strong hydrophobicity of the fluorine atoms can significantly reduce the water absorption rate of the shell material, reduce the erosion of the phase change material caused by water penetration, avoid the rupture of the microcapsule due to moisture absorption and expansion, improve the coating effect of the polyamide shell material, delay the service life of the microcapsule material, and the fluorine group can reduce the surface energy of the shell material, reduce the adhesion between microcapsules, and improve its dispersibility in the UV-curable coating; from the comparison of the experimental data between Example 2 and Comparative Example 6, it can be found that the present invention uses polyamide resin to encapsulate the modified phase change material. The encapsulation of the polyamide resin can effectively prevent the phase change material from directly contacting the environment and play a protective role. At the same time, it can also prevent the leakage of the phase change material during use, further improving the heat preservation performance of the coating.

[0082] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A UV-curable heat-insulating coating, characterized in that, The UV-curable heat-insulating coating is prepared from 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol and pentaerythritol triallyl ether, and then adding a heat-insulating aid, a diluent, a photoinitiator, a leveling agent and a solvent; The heat-insulating aid is a modified phase change microcapsule material; The modified phase change microcapsule material uses an oxidized foam metal loaded with a sugar alcohol mixture as the core material, and p-fluorocinnamoyl chloride-modified polyamide as the shell material, and is then prepared by an interfacial polymerization method.

2. The UV-curable heat-insulating coating according to claim 1, wherein The diluent is one of DVE-3, CHVE, HBVE or DDVE.

3. The UV-curing heat-insulating coating according to claim 2, characterized in that, The photoinitiator is one of 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,2-dimethoxy-2-phenylacetophenone or 2-hydroxy-4-methoxybenzophenone.

4. The UV-curing heat-insulating coating according to claim 3, characterized in that, The leveling agent is one of BYK-UV3500, BYK-UV3530 or BYK-UV3570.

5. A preparation method of a UV-curable heat-insulating coating, characterized in that, It includes the following preparation steps: (1) Place the sugar alcohol mixture in a drying oven, dry it at 100-105°C for 8-10 h, then place it in a sealed box and heat it up to 200°C, keep it at a constant temperature for 1-2 h, take it out and cool it naturally to room temperature, and then use a planetary ball mill to grind it at a speed of 250 r / min for 15 min, and pass through a 150-mesh sieve to obtain a pretreated sugar alcohol mixture; (2) Dissolve the pretreated sugar alcohol mixture in deionized water with a mass 5-10 times that of the pretreated sugar alcohol mixture, add oxidized foam metal with a mass 0.8-1.0 times that of the pretreated sugar alcohol mixture, and then stir at 80-100°C and 300-400 r / min until the deionized water completely evaporates, and dry it at 100°C for 1.0-1.5 h to obtain a modified phase change material; (3) Aqueous phase: Mix polyethylene glycol and deionized water at a mass ratio of 0.05-0.08:1, add the modified phase change material with a volume 0.03-0.05 times that of the mixed solution, and stir at 500-600 r / min for 30-60 min to obtain an aqueous phase; Oil phase: Mix p-fluorocinnamoyl chloride and terephthaloyl chloride at a molar ratio of 0.1-0.3:1, and then add Tween 80 with a mass 0.01-0.03 times that of terephthaloyl chloride to obtain a mixture. Dissolve the mixture in an organic solvent and stir at 500-600 r / min for 30-60 min to obtain an oil phase; Emulsification: At 50°C and 800-1000 r / min, add the oil phase to the aqueous phase and stir for 20-40 min to obtain a stable emulsion, and the volume ratio of the oil phase to the aqueous phase is 1:3; Encapsulation: At room temperature and 600 r / min, add an aqueous solution of amine to the stable emulsion, react for 15-30 min, filter and wash to obtain a modified phase change microcapsule material; (4) By mass percentage, mix 20-35% of 2-ethyl-2-(mercaptomethyl)-1,3-propanedithiol, 20-35% of pentaerythritol triallyl ether, 3-5% of the modified phase change microcapsule material, 5-10% of the diluent, 1-5% of the photoinitiator, 0.3-1% of the leveling agent and 20-30% of the solvent to obtain the UV-curable heat-insulating coating.

6. The preparation method of a UV-curable heat-insulating coating according to claim 5, characterized in that, In the step (2), the oxidized porous metal is obtained by cleaning and drying the porous metal with deionized water, and then performing heat treatment at 500-800 °C for 3-5 h in an air atmosphere and naturally cooling to room temperature. The porous metal is one of porous iron, porous nickel or porous copper.

7. The preparation method of a UV-curable heat-insulating coating according to claim 5, characterized in that In the step (3), the organic solvent is prepared by mixing cyclohexane and chloroform in a ratio of 3:

2.

8. The preparation method of a UV-curable heat-insulating coating according to claim 5, characterized in that, In the step (3), the aqueous solution of amine is prepared by mixing 1,6-hexanediamine and diethylenetriamine in a molar ratio of 1:1 to obtain a mixed solution, and then dissolving the mixed solution in deionized water with a mass 2-3 times that of the mixed solution.

9. The preparation method of a UV-curable thermal insulation coating according to claim 8, wherein, The molar ratio of 1,6-hexanediamine, diethylenetriamine and terephthaloyl chloride is 1.0-1.1:1.0-1.1:

1.

10. The preparation method of a UV-curable heat-insulating coating according to claim 5, characterized in that, In the step (3), the washing is performed by alternately washing with deionized water and ethanol for 2-3 times.