阅读说明：本技术 相变隔热材料及其制备方法和应用 (Phase-change heat-insulating material and preparation method and application thereof ) 是由 黄烁 吴昊 张静 钟毅斌 于 2021-09-17 设计创作，主要内容包括：本申请提供一种相变隔热材料,包括按重量份计混合的如下组分：相变微胶囊20份～50份、气凝胶1份～10份和基质40份～70份,所述基质包括甲基丙烯酸改性有机硅、活性稀释剂、光引发剂、催化剂和硅烷偶联剂。本申请所述相变隔热材料固化速度快、固化深度深且空间利用率高,既能防止元器件局部过热,又能降低元器件产热对终端的影响。本申请还提供一种所述相变隔热材料的制备方法及应用。(The application provides a phase change heat insulation material, which comprises the following components in parts by weight: 20-50 parts of phase change microcapsules, 1-10 parts of aerogel and 40-70 parts of matrix, wherein the matrix comprises methacrylic acid modified organic silicon, an active diluent, a photoinitiator, a catalyst and a silane coupling agent. The application phase change thermal insulation material solidification speed is fast, the solidification degree of depth is dark and space utilization is high, can prevent the local overheat of components and parts, can reduce the influence of components and parts heat production to the terminal again. The application also provides a preparation method and application of the phase-change heat-insulating material.)

1. The phase change heat insulation material is characterized by comprising the following components in parts by weight:

20-50 parts of phase change microcapsules;

1-10 parts of aerogel;

40-70 parts of matrix;

wherein the matrix comprises methacrylic modified silicone, a reactive diluent, a photoinitiator, a catalyst and a silane coupling agent.

2. The phase change thermal insulation material according to claim 1, wherein the mass fraction of the methacrylic modified silicone in the matrix is 60% to 80%, the mass fraction of the reactive diluent is 10% to 30%, the mass fraction of the photoinitiator is 2% to 5%, the mass fraction of the catalyst is 0.2% to 0.5%, and the mass fraction of the silane coupling agent is 5% to 10%.

3. The phase change thermal insulation material according to claim 1, wherein the reactive diluent comprises at least one of 1, 6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, neopentyl glycol diacrylate, tetrahydrofuran acrylate, isobornyl acrylate, 1, 9-nonanediol diacrylate.

4. The phase change thermal insulation material according to claim 1, wherein the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl acetone, ethyl 2,4, 6-trimethylbenzoylphenylphosphonate, 2, 4-dihydroxybenzophenone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, or 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-propanone.

5. The phase change thermal insulation material of claim 1, wherein the catalyst comprises at least one of isopropyl n-titanate, tetrabutyl titanate, diisopropyl bis (ethyl acetoacetate) titanate, or dibutyltin dilaurate.

6. The phase change thermal insulation material of claim 1, wherein the silane coupling agent comprises at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propenyltrimethoxysilane, or propenyltriethoxysilane.

7. The phase-change heat-insulating material according to claim 1, wherein the phase-change microcapsule is of a core-shell structure, the core-shell structure comprises a shell and a core material coated in the shell, the mass ratio of the core material to the shell is 4: 1-6: 1, the shell is a mixture of polyoxyl resin and polyethylene glycol, and the core material is modified phase-change paraffin.

8. The phase change thermal insulation material according to claim 7, wherein the mass ratio of the poly (phenol-oxygen resin) to the polyethylene glycol is 1:3 to 1:7, the molecular weight of the poly (phenol-oxygen resin) is 30000 to 60000, and the molecular weight of the polyethylene glycol is 4000 to 12000.

9. The phase change thermal insulation material according to claim 7, wherein the phase transition temperature of the modified phase change paraffin is 42 ℃ to 46 ℃, the modified phase change paraffin is prepared from long-chain alkyl amine modified or long-chain alkyl carboxylic acid modified long-chain alkane, and the mass of the long-chain alkyl amine or the long-chain alkyl carboxylic acid is 8% to 27% of that of the long-chain alkane.

10. The phase change thermal insulation material of claim 9, wherein the long chain alkane comprises at least one of n-tetradecane, n-pentadecane, n-hexadecane, or n-octadecane, the long chain alkylamine comprises at least one of n-dodecylamine, n-hexadecylamine, or n-octadecylamine, and the long chain alkylcarboxylic acid comprises at least one of palmitic acid, stearic acid, oleic acid, linoleic acid, or palmitic acid.

11. The phase change insulation material according to claim 1, wherein the aerogel has a pore size of 15nm to 20nm and a porosity of 90% to 98%.

12. A method of preparing the phase change insulation material according to any one of claims 1 to 11, comprising the steps of:

mixing methacrylic acid modified organic silicon, phase change microcapsules and aerogel under the conditions of room temperature, light protection and vacuum for 40-60 min;

adding an active diluent, a photoinitiator and a silane coupling agent, and mixing for 20-30 min at room temperature under the conditions of light shielding and vacuum;

adding a catalyst, and mixing for 20-30 min under the conditions of room temperature, light protection and vacuum to obtain the phase change heat insulation material.

13. The application of the phase-change thermal insulation material as claimed in any one of claims 1 to 11 in a battery, wherein the phase-change thermal insulation material is coated on a heating element of the battery by means of dispensing after being heated to 60 ℃ to 65 ℃, and the coating thickness of the phase-change thermal insulation material is greater than or equal to 0.1 mm.

14. The use of the phase-change insulation material in a battery according to claim 13, further comprising a step of irradiating the phase-change insulation material with an ultraviolet lamp for 10 to 30 seconds after coating to tack-dry and shape the phase-change insulation material.

15. The use of the phase change insulation material of claim 14 in a battery, wherein the ultraviolet lamp has a power of 5W to 100W and a wavelength of 254nm to 420 nm.

16. The use of the phase change insulation material of claim 15 in a battery, wherein the ultraviolet lamp has a power of 60W, a wavelength of 365nm, and an irradiation time of 15 s.

Technical Field

The application relates to the technical field of heat insulation materials, in particular to a phase change heat insulation material and a preparation method and application thereof.

Background

With the coming of the 5G era and the development of the quick charging technology, the charging and discharging current and power of the battery are continuously improved, and the heat production quantity is increased rapidly. The heating of the battery not only affects the normal work and the service life of the battery, but also conducts heat to the electronic terminal, thereby affecting the hand feeling of a user, even causing frequent closing of an application program and seriously affecting the user experience. Therefore, how to effectively reduce the influence of battery heat generation on the electronic terminal has become a key research point of the battery heat dissipation technology.

In order to block the conduction of battery heat to electronic terminals (e.g., including but not limited to cell phones), insulating materials are often used. The aerogel has the thermal conductivity coefficient of below 0.02W/m.K, so that the aerogel thermal insulation material is used between the battery heating component and the mobile phone according to the Fourier law, and can achieve a better thermal insulation effect than air. Although the heat conducted from the battery to the mobile phone can be effectively reduced by using the heat insulation material, the heat is blocked near the heating element, so that the temperature of the battery is further increased, the failure rate of the element is increased, and the safety and the service life of the battery are influenced. To solve this problem, a phase change material may be introduced. The phase-change material stores and utilizes heat through the change of the state of the material, and the phase-change heat-insulating material prepared by combining the phase-change material can absorb heat to prevent components from overheating and can reduce the heat conducted from the battery to the mobile phone terminal. Aiming at the limited narrow space of the mobile phone battery, the phase-change heat-insulating material has higher heat-insulating efficiency than the traditional heat-insulating material.

Some existing phase-change heat-insulating materials are prepared by laminating a heat-insulating material and a phase-change material, for example, a phase-change material and aerogel slurry are sequentially coated on a PET (polyethylene terephthalate) substrate to prepare a phase-change heat-insulating film material, but a heat source PCB (battery protection circuit board) of a battery is uneven, a large amount of air gaps are easily remained after the film material is coated, and the space utilization rate is low; and the phase change layer, the heat insulation layer and the substrate have low binding force, and the problems of layering, powder falling and the like are easy to occur in practical use. The phase-change heat-insulating material adopts an aqueous matrix, but the material is solidified by depending on solvent volatilization, the surface drying time is longer, and the productivity is lower; in addition, the existence of the aqueous solvent can cause the corrosion of metal components, and is not suitable for the lithium battery PCB. In addition, the phase-change heat-insulating material needs to be added with a large amount of particle fillers, and the UV curing matrix is difficult to achieve a better curing depth.

Disclosure of Invention

In view of this, the present application provides a phase change insulation material to solve the problems of slow curing speed, insufficient curing depth and low space utilization rate of the phase change insulation material in the prior art.

In addition, a method for preparing the phase-change heat-insulating material is also needed.

In addition, the application of the phase change heat insulation material in a battery is also needed to be provided.

One embodiment of the present application provides a phase change thermal insulation material, including the following components mixed in parts by weight: 20 to 50 parts of phase change microcapsule, 1 to 10 parts of aerogel and 40 to 70 parts of matrix. Wherein the matrix comprises methacrylic acid modified organic silicon, a reactive diluent, a photoinitiator, a catalyst and a silane coupling agent.

The phase-change microcapsule endows the phase-change heat-insulating material with the capacity of absorbing heat and storing energy, can effectively reduce the blockage of aerogel holes and reduce the influence on the heat-insulating property. The aerogel endows the phase change thermal insulation material ability of thermal-insulated, and the thermal conductivity of aerogel can be as low as being close to the air, and the aperture size of aerogel is less than the mean free path (70nm) of air, and the air can't carry out the thermal convection in the aerogel promptly for the gaseous state thermal conductivity of aerogel further reduces. The solid skeleton with extremely low content in the aerogel is composed of nano particles, and the contact area is extremely small, so that the solid heat conductivity coefficient of the aerogel is also extremely small. Based on the special structure, the thermal conductivity coefficient (less than 0.02W/m.K) of the aerogel can be lower than that of normal-temperature static air. Since aerogel has a thermal conductivity of 0.02W/m · K or less, it can have better thermal insulation effect than air when used between a component (e.g., PCB including but not limited to a battery) and an electronic terminal (e.g., including but not limited to a mobile phone) according to fourier law. The combination of the phase-change microcapsule and the aerogel can prevent the local overheating of the components and can reduce the influence of the heat generated by the components on the electronic terminal. The matrix comprises methacrylic acid modified organic silicon, an active diluent, a photoinitiator, a catalyst and a silane coupling agent, the phase-change heat-insulating material is endowed with curing and forming capacity, the phase-change heat-insulating material can be quickly surface-dried and shaped through Ultraviolet (UV) irradiation, and the curing problem of a shadow area and an UV irradiation curing incomplete area can be solved through moisture curing.

In one embodiment, the matrix contains 60 to 80 mass percent of methacrylic acid modified silicone, 10 to 30 mass percent of reactive diluent, 2 to 5 mass percent of photoinitiator, 0.2 to 0.5 mass percent of catalyst and 5 to 10 mass percent of silane coupling agent.

In one embodiment, the reactive diluent comprises at least one of 1, 6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, neopentyl glycol diacrylate, tetrahydrofuran acrylate, isobornyl acrylate, 1, 9-nonanediol diacrylate. The methacrylic acid modified organic silicon and the active diluent are polymerized and crosslinked to form a network structure, so that the phase-change heat-insulating material has an adhesive effect. The reactive diluent can participate in the photocuring reaction, and can dilute and dissolve the methacrylic acid modified organic silicon, adjust the viscosity of the methacrylic acid modified organic silicon and enhance the adhesive force of the phase-change heat-insulating material.

In one embodiment, the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl acetone, ethyl 2,4, 6-trimethylbenzoylphenylphosphonate, 2, 4-dihydroxybenzophenone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, or 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-propanone. The photoinitiator generates active components under the irradiation of ultraviolet light to initiate the polymerization reaction of the methacrylic acid modified organic silicon and the active diluent.

In one embodiment, the catalyst comprises at least one of isopropyl n-titanate, tetrabutyl titanate, diisopropyl bis (ethyl acetoacetate) titanate, or dibutyltin dilaurate. The catalyst can promote the cross-linking reaction of methacrylic acid modified organic silicon and shorten the surface drying and shaping time of the phase-change heat-insulating material.

In one embodiment, the silane coupling agent comprises at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propenyltrimethoxysilane, or propenyltriethoxysilane. After the silane coupling agent is matched with methacrylic acid modified organic silicon for use, the bonding strength of the phase change heat insulation material can be improved, and the water resistance and the durability of the phase change heat insulation material are improved.

In one embodiment, the phase-change microcapsule is of a core-shell structure, the core-shell structure comprises a shell and a core material coated in the shell, the mass ratio of the core material to the shell is 4: 1-6: 1, the shell is a mixture of a polyoxyl resin and polyethylene glycol, and the core material is modified phase-change paraffin.

In one embodiment, the mass ratio of the poly (phenol-oxygen resin) to the polyethylene glycol is 1:3 to 1:7, the molecular weight of the poly (phenol-oxygen resin) is 30000 to 60000, and the molecular weight of the polyethylene glycol is 4000 to 12000.

In one embodiment, the phase transition temperature of the modified phase-change paraffin is 42-46 ℃, the modified phase-change paraffin is prepared from long-chain alkane modified by long-chain alkylamine or long-chain alkyl carboxylic acid, and the mass of the long-chain alkylamine or long-chain alkyl carboxylic acid is 8-27% of the mass of the long-chain alkane. The unmodified paraffin is modified by long-chain alkylamine or long-chain alkyl carboxylic acid so as to improve the compatibility of the unmodified paraffin with other components in the phase-change heat-insulating material and avoid the paraffin from being separated out from the phase-change heat-insulating material.

In one embodiment, the long-chain alkane comprises at least one of n-tetradecane, n-pentadecane, n-hexadecane, or n-octadecane, the long-chain alkylamine comprises at least one of n-dodecylamine, n-hexadecylamine, or n-octadecylamine, and the long-chain alkylcarboxylic acid comprises at least one of palmitic acid, stearic acid, oleic acid, linoleic acid, or palmitic acid.

In one embodiment, the aerogel has a pore size of 15nm to 20nm and a porosity of 90% to 98%. The porosity of the aerogel is 90% -98%, namely the aerogel is mainly composed of air, and this determines that the thermal conductivity of the aerogel can be as low as being close to that of air. The aperture of the aerogel is 15 nm-20 nm and is smaller than the mean free path (70nm) of air, namely, the air cannot carry out thermal convection in the aerogel, so that the gaseous heat conductivity coefficient of the aerogel is further reduced.

An embodiment of the present application provides a method of preparing the phase-change insulation material as described above, including the steps of:

mixing methacrylic acid modified organic silicon, phase change microcapsules and aerogel under the conditions of room temperature, light protection and vacuum for 40-60 min;

adding an active diluent, a photoinitiator and a silane coupling agent, and mixing for 20-30 min at room temperature under the conditions of light shielding and vacuum;

adding a catalyst, and mixing for 20-30 min under the conditions of room temperature, light protection and vacuum to obtain the phase-change heat-insulating material.

One embodiment of the present application provides an application of the phase change thermal insulation material in a battery. The phase-change thermal insulation material is heated to 60-65 ℃ and then coated on a heating element of the battery in a dispensing mode, the coating thickness of the phase-change thermal insulation material is larger than or equal to 0.1mm, and the viscosity of the phase-change thermal insulation material heated to 60-65 ℃ is 2000-6000 mPa. The coating is carried out by adopting a dispensing mode, compared with the pasting of film materials, the thermal contact resistance with a heating source is reduced, and the material space utilization rate is higher. The phase-change heat-insulating material is heated to 60-65 ℃, so that the viscosity of the phase-change heat-insulating material is reduced for dispensing. The coating thickness is greater than or equal to 0.1mm, so that the phase change heat insulation material can simultaneously play a role in heat insulation and heat absorption.

In one embodiment, the step of irradiating for 10-30 s by using an ultraviolet lamp is further included after the coating, so that the phase-change heat-insulating material is surface-dried and shaped.

In one embodiment, the power of the ultraviolet lamp is 5W to 100W, and the wavelength is 254nm to 420 nm.

In one embodiment, the UV lamp is operated at 60W, a wavelength of 365nm, and an exposure time of 15 seconds.

The application has the following beneficial effects: (1) the heat insulation material (aerogel) is combined with the phase change material (phase change microcapsule), so that local overheating of components can be prevented, and the influence of heat generation of the components on an electronic terminal can be reduced; (2) the phase-change heat-insulating material achieves quick surface drying and shaping through UV/moisture dual curing, has high production efficiency, can solve the curing problem of a shadow area and an incomplete UV illumination curing area, and improves the curing speed and the curing depth; (3) the phase-change thermal insulation material is coated in a dispensing mode, and compared with film material pasting, the thermal contact resistance with a heating source can be reduced, and the material space utilization rate is higher.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this application belong. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application.

Some embodiments of the present application will be described in detail below with reference to specific examples and comparative examples. In the following embodiments, features of the embodiments may be combined with each other without conflict.

One embodiment of the present application provides a phase change thermal insulation material, including the following components mixed in parts by weight: 20 to 50 parts of phase change microcapsule, 1 to 10 parts of aerogel and 40 to 70 parts of matrix. Wherein the matrix comprises methacrylic acid modified organic silicon, a reactive diluent, a photoinitiator, a catalyst and a silane coupling agent.

The phase-change microcapsule endows the phase-change heat-insulating material with the capacity of absorbing heat and storing energy, can effectively reduce the blockage of aerogel holes and reduce the influence on the heat-insulating property. The weight part of the phase-change microcapsule is not less than 20 parts, otherwise, the phase-change heat-insulating material absorbs too little heat, and the temperature of components is increased in actual use. The weight portion of the phase-change microcapsule is not higher than 50 portions, otherwise, the heat conductivity coefficient of the phase-change heat-insulating material is larger than 0.1W/m.K, and the heat cannot be effectively insulated.

The aerogel endows the phase change thermal insulation material with thermal insulation capability. The thermal conductivity of the aerogel can be as low as close to that of air, and the pore size of the aerogel is smaller than the mean free path (70nm) of air, namely, the air cannot carry out thermal convection in the aerogel, so that the gaseous thermal conductivity of the aerogel is further reduced. The aerogel contains few solid skeleton particlesThe particle composition and the contact area are extremely small, so that the solid heat conductivity coefficient of the aerogel is also extremely small. Based on the special structure, the thermal conductivity coefficient (less than 0.02W/m.K) of the aerogel can be lower than that of normal-temperature static air. The aerogel has a thermal conductivity coefficient of below 0.02W/m.K, and can be used between a heating component (a battery PCB) and an electronic terminal (a mobile phone) according to the Fourier law, so that the aerogel has a better heat insulation effect than air. The weight portion of the aerogel can not be lower than 1 portion, otherwise, the heat conductivity coefficient of the phase-change heat-insulating material is close to 0.2W/m.K, and the heat-insulating effect is poor as that of a common organic matter. The aerogel may not be higher than 10 parts by weight because of its low density (0.12 g/cm)³) And when the content is more than 10 parts, the volume fraction reaches more than 60 percent, so that the matrix content is low, and the phase change heat insulation material is easy to have the problems of powder falling, cracking and the like.

The heat insulation material (aerogel) is combined with the phase change material (phase change microcapsule), so that local overheating of components can be prevented, and the influence of heat generation of the components on an electronic terminal can be reduced.

The matrix comprises methacrylic acid modified organic silicon, an active diluent, a photoinitiator, a catalyst and a silane coupling agent, the phase-change heat-insulating material is endowed with curing and forming capacity, the phase-change heat-insulating material can be quickly surface-dried and shaped through Ultraviolet (UV) irradiation, and the curing problem of a shadow area and an UV irradiation curing incomplete area is solved through moisture curing.

Further, the structural general formula of the methacrylic acid modified organosilicon is

In the formula, R₁Is CH₃；R₂Is a substituted or unsubstituted C1-C20 alkyl hydrocarbon group; r₃Is a substituted or unsubstituted C1-C20 alkane group. The methacrylic acid modified organic silicon and the active diluent are polymerized and crosslinked to form a network structure, so that the phase-change heat-insulating material has an adhesive effect.

In some embodiments, in the matrix, the mass fraction of the methacrylic acid modified silicone is 60% to 80%, the mass fraction of the reactive diluent is 10% to 30%, the mass fraction of the photoinitiator is 2% to 5%, the mass fraction of the catalyst is 0.2% to 0.5%, and the mass fraction of the silane coupling agent is 5% to 10%.

Further, the reactive diluent includes at least one of 1, 6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, neopentyl glycol diacrylate, tetrahydrofuran acrylate, isobornyl acrylate, 1, 9-nonanediol diacrylate. The reactive diluent can participate in the photocuring reaction, and can dilute and dissolve the methacrylic acid modified organic silicon, adjust the viscosity of the methacrylic acid modified organic silicon and enhance the adhesive force of the phase-change heat-insulating material.

Further, the photoinitiator includes at least one of 2-hydroxy-2-methyl-1-phenyl acetone, ethyl 2,4, 6-trimethylbenzoylphenylphosphonate, 2, 4-dihydroxybenzophenone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, or 2-methyl-2- (4-morpholinyl) -1- [4- (methylthio) phenyl ] -1-propanone. The photoinitiator generates active components under the irradiation of ultraviolet light to initiate the polymerization reaction of the methacrylic acid modified organic silicon and the active diluent.

Further, the catalyst comprises at least one of isopropyl n-titanate, tetrabutyl titanate, diisopropyl bis (ethyl acetoacetate) titanate, or dibutyltin dilaurate. The catalyst can promote the cross-linking reaction of methacrylic acid modified organic silicon and shorten the surface drying and shaping time of the phase-change heat-insulating material.

Further, the silane coupling agent includes at least one of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propenyltrimethoxysilane, or propenyltriethoxysilane. After the silane coupling agent is matched with methacrylic acid modified organic silicon for use, the bonding strength of the phase change heat insulation material can be improved, and the water resistance and the durability of the phase change heat insulation material are improved.

In some embodiments, the phase-change microcapsule is a core-shell structure, the core-shell structure includes a shell and a core material coated in the shell, the mass ratio of the core material to the shell is 4: 1-6: 1, the shell is a mixture of a polyoxyl resin and polyethylene glycol, and the core material is modified phase-change paraffin.

Furthermore, the mass ratio of the poly (phenol-oxygen resin) to the polyethylene glycol is 1: 3-1: 7, the molecular weight of the poly (phenol-oxygen resin) is 30000-60000, and the molecular weight of the polyethylene glycol is 4000-12000.

Further, the phase transition temperature of the modified phase-change paraffin is 42-46 ℃, the modified phase-change paraffin is prepared from long-chain alkyl amine modified or long-chain alkyl carboxylic acid modified long-chain alkane, and the mass of the long-chain alkyl amine or the long-chain alkyl carboxylic acid is 8-27% of that of the long-chain alkane. The unmodified paraffin is modified by long-chain alkylamine or long-chain alkyl carboxylic acid so as to improve the compatibility of the unmodified paraffin with other components in the phase-change heat-insulating material and avoid the paraffin from being separated out from the phase-change heat-insulating material.

Further, the long-chain alkane includes at least one of n-tetradecane, n-pentadecane, n-hexadecane or n-octadecane, the long-chain alkylamine includes at least one of n-dodecylamine, n-hexadecylamine or n-octadecylamine, and the long-chain alkylcarboxylic acid includes at least one of palmitic acid, stearic acid, oleic acid, linoleic acid or palmitic acid.

In some embodiments, the aerogel has a pore size of 15nm to 20nm and a porosity of 90% to 98%. The porosity of the aerogel is 90% -98%, namely the aerogel is mainly composed of air, and this determines that the thermal conductivity of the aerogel can be as low as being close to that of air. The aperture of the aerogel is 15 nm-20 nm and is smaller than the mean free path (70nm) of air, namely, the air cannot carry out thermal convection in the aerogel, so that the gaseous heat conductivity coefficient of the aerogel is further reduced.

Further, the aerogel is SiO₂Aerogel particles, particle size 5 m.

The present application also provides a method of preparing the phase-change thermal insulation material as described above, comprising the steps of:

mixing methacrylic acid modified organic silicon, phase change microcapsules and aerogel under the conditions of room temperature, light protection and vacuum for 40-60 min;

adding an active diluent, a photoinitiator and a silane coupling agent, and mixing for 20-30 min at room temperature under the conditions of light shielding and vacuum;

adding a catalyst, and mixing for 20-30 min under the conditions of room temperature, light protection and vacuum to obtain the phase-change heat-insulating material.

The application also provides an application of the phase change heat insulation material in a battery. The phase-change thermal insulation material is heated to 60-65 ℃ and then coated on a heating element of the battery in a dispensing mode, the coating thickness of the phase-change thermal insulation material is larger than or equal to 0.1mm, and the viscosity of the phase-change thermal insulation material heated to 60-65 ℃ is 2000-6000 mPa. The coating is carried out by adopting a dispensing mode, compared with the pasting of film materials, the thermal contact resistance with a heating source is reduced, and the material space utilization rate is higher. The phase-change heat-insulating material is heated to 60-65 ℃, so that the viscosity of the phase-change heat-insulating material is reduced for dispensing. The coating thickness is greater than or equal to 0.1mm, so that the phase change heat insulation material can simultaneously play a role in heat insulation and heat absorption.

In some embodiments, the step of irradiating for 10-30 s by using an ultraviolet lamp is further included after the coating, so that the phase-change heat-insulating material is surface-dried and shaped.

In some embodiments, the power of the UV lamp is 5W to 100W, and the wavelength is 254nm to 420 nm.

In some embodiments, the power of the UV lamp is 60W, the wavelength is 365nm, and the irradiation time is 15 s.

The present application will be further described with reference to the following specific examples.

Example 1

(1) 39.2 parts of methacrylic acid-modified silicone (commercially available product), 50 parts of phase-change microcapsules and 1 part of SiO₂Mixing the aerogel particles for 50 minutes at room temperature under the conditions of light protection and vacuum;

(2) adding 5.39 parts of isobornyl acrylate (a reactive diluent), 1.568 parts of 1-hydroxycyclohexyl phenyl ketone (a photoinitiator) and 2.695 parts of methyltrimethoxysilane (a silane coupling agent), and mixing at room temperature, in the absence of light and under vacuum for 25 minutes;

(3) and adding 0.147 part of tetrabutyl titanate (catalyst), and mixing for 25 minutes at room temperature under the conditions of light shielding and vacuum to obtain the phase-change heat-insulating material.

Example 2

(1) 48 parts of methacrylic acid modified organic silicon (a commercial product), 35 parts of phase change microcapsules and 5 parts of SiO₂Mixing the aerogel particles for 40 minutes at room temperature under the conditions of light protection and vacuum;

(2) adding 6.6 parts of 1, 6-hexanediol diacrylate (active diluent), 1.92 parts of 2-hydroxy-2-methyl-1-phenyl acetone (photoinitiator) and 3.3 parts of vinyl triethoxysilane (silane coupling agent), and mixing at room temperature, in the absence of light and under vacuum for 30 minutes;

(3) adding 0.18 part of n-isopropyl titanate (catalyst), and mixing for 30 minutes under the conditions of room temperature, light protection and vacuum to obtain the phase-change heat-insulating material.

Example 3

(1) 56 parts of methacrylic acid modified silicone (commercial product), 20 parts of phase change microcapsule and 10 parts of SiO₂Mixing the aerogel particles at room temperature in a dark place under vacuum for 60 minutes;

(2) adding 7.7 parts of tripropylene glycol diacrylate (reactive diluent), 2.24 parts of 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide (photoinitiator) and 3.85 parts of propenyl trimethoxy silane (silane coupling agent), and mixing at room temperature, in the absence of light and under vacuum for 20 minutes;

(3) and adding 0.21 part of dibutyltin dilaurate (catalyst), and mixing for 20 minutes at room temperature under the conditions of light shielding and vacuum to obtain the phase-change heat-insulating material.

Comparative example 1

(1) Mixing 40 parts of methacrylic acid modified organic silicon (a commercial product) and 50 parts of phase change microcapsules for 50 minutes at room temperature under the conditions of light protection and vacuum;

(2) adding 5.5 parts of isobornyl acrylate, 1.6 parts of 1-hydroxycyclohexyl phenyl ketone and 2.75 parts of methyltrimethoxysilane, and mixing for 25 minutes at room temperature under the conditions of light shielding and vacuum;

(3) and adding 0.15 part of tetrabutyl titanate, and mixing for 25 minutes at room temperature under the conditions of light shielding and vacuum to obtain the phase-change material.

Comparative example 2

(1) 72 parts of methacrylic acid-modified organosilicon (commercially available product),10 parts of SiO₂Mixing the aerogel particles at room temperature in a dark place under vacuum for 60 minutes;

(2) adding 9.9 parts of tripropylene glycol diacrylate, 2.88 parts of 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide and 4.95 parts of propenyl trimethoxy silane, and mixing at room temperature, in the absence of light and under vacuum for 20 minutes;

(3) and adding 0.27 part of dibutyltin dilaurate, and mixing for 20 minutes at room temperature under the conditions of light shielding and vacuum to obtain the heat-insulating material.

Comparative example 3

(1) 43 parts of epoxy organic silicon resin HG-43, 2.5 parts of propenyl trimethoxy silane, 20 parts of phase change microcapsule and 10 parts of SiO₂Mixing the aerogel particles at room temperature under vacuum for 60 minutes;

(2) and adding 24.5 parts of 650 polyamide curing agent, and mixing for 40 minutes at room temperature under vacuum conditions to obtain the normal-temperature curing phase-change heat-insulating material.

The selection and content of the components in the above examples and comparative examples are shown in Table 1.

TABLE 1

The phase change heat insulating materials prepared in the above-described examples and comparative examples were subjected to the following performance tests.

Enthalpy value test: testing was performed according to ASTM D3418.

And (3) testing the heat conductivity coefficient: testing was performed according to ASTM D5470.

And (3) testing the cooling effect: in a room with a capacity laboratory and a normal temperature, a lithium battery of a mobile phone is put into an acrylic box with the size of 20cm by 10 cm; respectively coating the phase-change heat-insulating materials prepared in the embodiments and the comparative examples on a lithium battery PCB in a dispensing manner, wherein the coating thickness is 0.3mm, and then irradiating the lithium battery PCB for about 15s by using an ultraviolet lamp with the power of 60W and the wavelength of 365nm to cure the phase-change heat-insulating materials; in addition, no material is coated on a lithium battery PCB as a blank control group; thermocouples are respectively bonded on the surface of a component (lithium battery PCB) and the surface of a phase-change heat insulation material, the temperature change of the battery in the charging and discharging process is recorded, the cooling effect of the heating component is evaluated according to the temperature of the surface of the heating component, and the influence of the heat generation of the lithium battery on a mobile phone terminal is evaluated according to the temperature of the outer surface of the material.

Surface dry time test: the test was carried out according to GB/T13477.5-2002.

The results of the above tests are reported in Table 2.

TABLE 2

The higher the enthalpy value is, the more heat absorbed by the material is, which is beneficial to reducing the temperature of components; however, the enthalpy value is too high, the heat conductivity coefficient of the material is closer to that of a common high polymer material, the heat insulation effect is poor, and the reduction of the temperature of the outer surface of the material is not facilitated. The enthalpy value of the phase change heat insulation material prepared in the embodiment 1-3 is in the range of 40J/g-100J/g, so that the material can absorb more heat to reduce the temperature of components, and the temperature of the outer surface of the material can be reduced. The surface drying time of the phase change heat insulation materials of examples 1 to 3 is 15 seconds, while the surface drying time of comparative example 3 is more than 2 hours, which shows that the matrix in the phase change heat insulation material of the application can remarkably accelerate the solidification forming capability of the material, and the phase change heat insulation material of the application has higher solidification speed. The phase change insulation materials of examples 1-3 all had lower outside surface temperatures, indicating less effect of heat generation on the handset terminal; the phase change heat insulating materials in examples 1 to 3 all had lower component temperatures, indicating that the cooling effect was better. The phase-change heat-insulating material in comparative example 1 lacks an aerogel heat-insulating material, has a high heat conductivity, has a high temperature (67.96 ℃) on the outer surface of the phase-change heat-insulating material, and has a large influence on the mobile phone terminal. The phase-change heat-insulating material of comparative example 2 lacks phase-change microcapsules, and although the heat conductivity coefficient is small, the heat conducted from the lithium battery to the mobile phone terminal can be effectively reduced, but the heat is blocked near the heating element (lithium battery), so that the temperature of the element is higher (73.51 ℃) and even higher than that of a blank control group (70.32 ℃) without coating materials.

The above description is a few specific embodiments of the present application, but in practical applications, the present application is not limited to these embodiments. Other modifications and variations to the technical concept of the present application should fall within the scope of the present application for those skilled in the art.