Phase change material composition, preparation method thereof and electronic device

Abstract

The invention relates to the technical field of phase change energy storage materials. The invention provides a phase change material composition, a preparation method thereof and an electronic device, the phase change material composition provided by the invention comprises a matrix and a filler, the matrix comprises a water-soluble polymer compound; the filler comprises a heat conduction filler and a microcapsule type phase change material, the microcapsule type phase change material comprises a shell layer material and a core located in the shell layer material, the shell layer material comprises an organic polymer material and microcapsule heat conduction particles, and the core comprises a phase change material and microcapsule heat conduction particles. The phase change material composition provided by the invention has a high enthalpy value and good thermal conductivity.

Description

Technical Field

[0001] The present invention relates to the technical field of phase change energy storage materials, and particularly relates to a phase change material composition, a preparation method thereof, and an electronic device. Background Art

[0002] In recent years, the trend of high power density and miniaturization of electronic devices has made the heat dissipation problem of electronic equipment increasingly prominent. The passive electronic device thermal management system has attracted much attention due to its advantages such as simple structure, low energy consumption, and small volume. This system absorbs and temporarily stores the heat conducted from the substrate according to the constant temperature performance of the phase change material, thereby reducing the heating rate of the electronic device. In addition, due to the characteristics of the phase change material such as large heat storage density and the heat storage process being an entropy increase process without external force triggering, this system can also maintain a small volume and low energy consumption, showing good temperature control effects and high applicability for electronic devices, especially intermittent working electronic devices such as outdoor communication and mobile devices.

[0003] Applying phase change temperature control and heat conduction materials to microelectronic components and devices, and using the solid-liquid phase change potential of the phase change material to solve the heat dissipation problem of the heat management system, has advantages such as large energy storage density and approximate isothermal heat storage and release processes, which can extend the service time of electronic devices and equipment and meet the higher and faster operating speeds of electronic devices; and the entire temperature control process is convenient and easy to control, and has been widely studied and applied.

[0004] According to the types of phase change materials, they are mainly divided into inorganic, organic, and composite phase change materials. Different phase change materials are applicable to different temperature ranges: in the low melting point temperature range below 100 °C (such as paraffin), the medium melting point temperature range of 100 - 300 °C (such as hydrates), and the high melting point temperature range above 300 °C phase change range (such as metals, metal alloys). Organic phase change materials have advantages such as no corrosion, no toxicity, good stability, and low supercooling degree. Pure phase change materials often have the disadvantages of leakage and low thermal conductivity, which limit their further application. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an object of the present invention is to provide a phase change material composition, a preparation method thereof, and an electronic device. The phase change material composition proposed by the present invention has a high enthalpy value and good thermal conductivity.

[0006] To this end, a first aspect of the present invention provides a phase change material composition, including: a matrix, the matrix includes a water-soluble polymer compound; a filler, the filler includes a thermal conductive filler and a microencapsulated phase change material, the microencapsulated phase change material includes a shell material and a core located inside the shell material, the shell material includes an organic polymer material and microcapsule thermal conductive particles, and the core includes a phase change material and microcapsule thermal conductive particles.

[0007] The phase change material composition proposed by the present invention has microcapsule heat-conducting particles with a phase change material as the core and an organic polymer material as the shell material. Microcapsule heat-conducting particles are additionally added to the core and shell of the microcapsules. The encapsulation of the phase change material by microencapsulation technology makes the phase change material not easily leak and expand in volume during phase change, having good stability and reliability, so that the phase change material composition can be used as a phase change heat storage and heat-conducting raw material for a thermal management system. Adding microcapsule heat-conducting particles to the core and shell of the microcapsule-type phase change material, as the microcapsule wall material, can effectively prevent the leakage of the phase change material and at the same time realize the construction of the heat-conducting network between the microcapsules and the water-soluble polymer compound matrix; in addition, the addition of the water-soluble polymer compound promotes the compatibility with the microcapsule-type phase change material, making the microcapsule-type phase change material more uniformly dispersed in the matrix and fixed in the three-dimensional network structure of the water-soluble polymer compound matrix, realizing the shaping of the microcapsule-type phase change material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thus effectively improving the heat-conducting performance. In summary, the phase change material composition proposed in this application has a high enthalpy value and good heat conductivity, where the phase change enthalpy is above 160 J / g, the thermal conductivity can reach 1 W / (m·K), and the density is within 0.8 g / cm 3 3.

[0008] In some embodiments of the present invention, in the filler, the mass ratio of the heat-conducting filler to the microcapsule-type phase change material is 1:(1 - 30).

[0009] In some embodiments of the present invention, the mass ratio of the filler to the matrix is (1 - 20):1.

[0010] In some embodiments of the present invention, the mass ratio of the phase change material to the microcapsule heat-conducting particles is (60 - 100):1.

[0011] In some embodiments of the present invention, the water-soluble polymer compound includes at least one of carboxymethyl starch, acetate starch, hydroxymethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol.

[0012] In some embodiments of the present invention, the heat-conducting filler includes at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride.

[0013] In some embodiments of the present invention, the phase change material includes at least one of n-octadecane, n-eicosane, n-docosane, n-tetracosane, n-hexacosane, n-octacosane, n-triacontane, polyethylene glycol, stearyl alcohol, lauryl alcohol, neopentyl glycol, fatty acid adipic acid, capric acid, and stearic acid.

[0014] In some embodiments of the present invention, the microcapsule thermal conductive particles include at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride.

[0015] In some embodiments of the present invention, the organic polymer material includes a polyurea material formed by interfacial polymerization of diisocyanate and polyamine.

[0016] In some embodiments of the present invention, the diisocyanate includes at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate.

[0017] In some embodiments of the present invention, the polyamine includes at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, ethylenediamine, hexamethylenediamine, and urea.

[0018] In some embodiments of the present invention, the mass ratio of the diisocyanate to the polyamine is (10 - 40):(40 - 100).

[0019] In a second aspect of the present invention, the present invention provides a method for preparing the phase change material composition described in the first aspect, including: dissolving a water-soluble polymer compound in water to obtain a water-soluble polymer compound solution; mixing a thermal conductive filler and a microcapsule phase change material, and then mixing with a solvent and the water-soluble polymer compound solution to obtain a mixed slurry; solidifying and molding the mixed slurry to obtain the phase change material composition. Thus, the phase change material composition prepared by the present invention has a high enthalpy value and good thermal conductivity.

[0020] In some embodiments of the present invention, the microcapsule phase change material is prepared by the following method: dissolving an emulsifier in water, heating and stirring, adding a melted phase change material and diisocyanate, and adding a part of the microcapsule thermal conductive particles and stirring to emulsify to obtain an emulsion; adding polyamine to the emulsion, then adding the remaining part of the microcapsule thermal conductive particles, and stirring to obtain a suspension; filtering the suspension to obtain a solid, which is the microcapsule phase change material.

[0021] In some embodiments of the present invention, the mass ratio of the phase change material, diisocyanate, and emulsifier is (60 - 100):(10 - 40):1.

[0022] In some embodiments of the present invention, the emulsifier includes at least one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium stearate, OP-1, Tween 80, and cetylammonium bromide.

[0023] In some embodiments of the present invention, based on the total mass of the water-soluble polymer compound solution, the mass proportion of the water-soluble polymer compound is 1% to 15%.

[0024] In some embodiments of the present invention, the solvent includes at least one of water and ethanol.

[0025] In the third aspect of the present invention, the present invention provides an electronic device, and the electronic device includes the phase change material composition described in the first aspect of the present invention. Thus, the electronic device proposed by the present invention has good thermal conductivity.

[0026] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become apparent from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become clear and easy to understand by combining the description of the embodiments with the drawings, wherein:

[0028] Figure 1 FIG. shows a schematic flow chart of the method for preparing the phase change material composition proposed in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The embodiments of the present invention will be described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as a limitation to the present invention.

[0030] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Further, in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0031] In the first aspect of the present invention, the present invention provides a phase change material composition. The phase change material composition proposed by the present invention includes a matrix and fillers. Among them, the matrix includes a water-soluble polymer compound; the fillers include a thermal conductive filler and a microcapsule-type phase change material. The microcapsule-type phase change material includes a shell material and a core located inside the shell material. The shell material includes an organic polymer material and microcapsule thermal conductive particles. The core includes a phase change material and microcapsule thermal conductive particles.

[0032] The phase change material composition proposed by the present invention has microcapsule heat-conducting particles with a phase change material as the core and an organic polymer material as the shell material. Microcapsule heat-conducting particles are additionally added to the core and shell of the microcapsules. The phase change material is encapsulated by using the microencapsulation technology, so that the phase change material is not easily leaked and does not expand in volume during phase change, and has good stability and reliability, enabling the phase change material composition to be used as a phase change heat storage and heat-conducting raw material for a thermal management system. Adding microcapsule heat-conducting particles to the core and shell of the microcapsule-type phase change material, as the microcapsule wall material, can effectively block the leakage of the phase change material and at the same time realize the construction of the heat-conducting network between the microcapsules and the water-soluble polymer compound matrix; in addition, the addition of the water-soluble polymer compound promotes the compatibility with the microcapsule-type phase change material, making the microcapsule-type phase change material more uniformly dispersed in the matrix and fixed in the three-dimensional network structure of the water-soluble polymer compound matrix, realizing the shaping of the microcapsule-type phase change material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thus effectively improving the heat-conducting performance. In summary, the phase change material composition proposed in this application has a high enthalpy value and good heat conductivity, with a phase change enthalpy of more than 160 J / g, a thermal conductivity of up to 1 W / (m·K), and a density of 0.8 g / cm 3 or less.

[0033] It can be understood that the microcapsule has a core-shell structure, where the encapsulated substance is called the core material (core), and the polymer material that wraps the core material is called the wall material (shell material). The diameter of the microcapsule is generally 1 - 500 μm.

[0034] In some embodiments of the present invention, the mass ratio of the heat-conducting filler to the microcapsule-type phase change material is 1:(1 - 30), for example, it can be 1:1, 1:5, 1:10, 1:20, 1:30, etc. Controlling the mass ratio of the heat-conducting filler to the microcapsule-type phase change material within the above range can effectively prevent the leakage of the phase change material and at the same time realize the construction of the heat-conducting network between the microcapsules and the water-soluble polymer compound matrix, improve heat transfer, and enable the phase change material composition to have a high enthalpy value and good heat conductivity.

[0035] In some embodiments of the present invention, the mass ratio of the filler to the matrix is (1 - 20):1, for example, it can be 1:1, 5:1, 10:1, 15:1, 20:1, etc. Controlling the mass ratio of the filler to the matrix within the above range makes the microcapsule-type phase change material more uniformly dispersed in the matrix and fixed in the three-dimensional network structure of the water-soluble polymer compound matrix, realizing the shaping of the microcapsule-type phase change material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thus effectively improving the heat-conducting performance.

[0036] In some embodiments of the present invention, the mass ratio of the phase change material to the microcapsule thermal conductive particles is (60 to 100):1. For example, it can be 60:1, 70:1, 80:1, 90:1, 100:1, etc. Controlling the mass ratio of the phase change material to the microcapsule thermal conductive particles within the above range can not only have sufficient phase change material to transfer heat, but also achieve rapid heat transfer, making the phase change material composition have a high enthalpy value and good thermal conductivity.

[0037] In the embodiments of the present application, after preparing microcapsule phase change materials using phase change materials with a relatively high phase change enthalpy, the shaping of the phase change material composition is achieved by adding a relatively small amount of other substances. Adding other substances other than the phase change material will reduce the overall enthalpy value. Due to the small addition amount, the enthalpy value of the obtained product is relatively high.

[0038] It can be understood that in the embodiments of the present application, the microcapsule thermal conductive particles include the shell material and the microcapsule thermal conductive particles in the core.

[0039] In some embodiments of the present invention, the water-soluble polymer compound includes at least one of carboxymethyl starch, acetate starch, hydroxymethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol. The above water-soluble polymer compounds are easily soluble in water, and the above water-soluble polymer compounds can promote the interfacial compatibility of the microcapsule phase change materials. The above water-soluble polymer compounds are polar molecules, making the microcapsule phase change materials more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and fixed in the three-dimensional network structure of the water-soluble polymer compound matrix, achieving the shaping of the microcapsule phase change materials. And because there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is relatively fast, thereby effectively improving the thermal conductivity of the phase change material composition.

[0040] In some embodiments of the present invention, the thermal conductive filler includes at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride. The above thermal conductive fillers have excellent thermal conductivity and relatively fast heat transfer efficiency, thereby effectively improving the thermal conductivity.

[0041] In some embodiments of the present invention, the phase change material includes at least one of n-octadecane, n-eicosane, n-docosane, n-tetracosane, n-hexacosane, n-octacosane, n-triacontane, polyethylene glycol, stearyl alcohol, lauryl alcohol, neopentyl glycol, adipic acid, capric acid, and stearic acid. The above phase change materials have the characteristics of large heat storage density, entropy increase process during heat storage without external force triggering, etc., can maintain a small volume and low energy consumption, and show good temperature control effects and high applicability for electronic devices, especially intermittent working electronic devices such as outdoor communication and mobile devices; in addition, the above phase change materials have advantages such as large energy storage density and approximate isothermal heat storage and release processes, which can extend the service time of electronic devices and equipment and meet the higher and faster operating speeds of electronic devices.

[0042] In some embodiments of the present invention, the microcapsule heat-conducting particles include at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride. The above microcapsule heat-conducting particles can effectively prevent the leakage of the phase change material, and at the same time realize the construction of the heat-conducting network of the microcapsule and the water-soluble polymer matrix, improving the heat-conducting efficiency. Preferably, the microcapsule heat-conducting particles include graphene, which can be adsorbed between the incompletely encapsulated microcapsule shell layer and the core, effectively preventing the leakage problem of the phase change material. At the same time, graphene is added to the whole system as a heat-conducting particle, improving the overall heat-conducting rate and heat dissipation effect of the phase change material composition. Further preferably, carbon-based non-polar graphene is used as the microcapsule heat-conducting particles.

[0043] In some embodiments of the present invention, the organic polymer material includes a polyurea material formed by interfacial polymerization of diisocyanate and polyamine. The above polyurea material is a polar molecule and has good compatibility with water-soluble polymers. The polyurea material is more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and can be fixed in the three-dimensional network structure of the water-soluble polymer compound matrix to realize the shaping of the polyurea material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thus effectively improving the heat-conducting performance.

[0044] In some embodiments of the present invention, the diisocyanate includes at least one of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), and hexamethylene diisocyanate (HDI). Using the above diisocyanate, the polyurea material obtained by interfacial polymerization has good compatibility with water-soluble polymers. The polyurea material is more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and can be fixed in the three-dimensional network structure of the water-soluble polymer compound matrix to realize the shaping of the polyurea material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thus effectively improving the heat-conducting performance.

[0045] In some embodiments of the present invention, the polyamine includes at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, ethylenediamine, hexamethylenediamine, and urea. The polyurea material obtained by interfacial polymerization of the above polyamine and diisocyanate has good compatibility with the water-soluble polymer. The polyurea material is more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and can be fixed in the three-dimensional network structure of the water-soluble polymer compound matrix to realize the shaping of the polyurea material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thereby effectively improving the thermal conductivity.

[0046] In some embodiments of the present invention, the mass ratio of the diisocyanate to the polyamine is (10-40):(40-100). For example, it can be 10:40, 10:80, 10:100, 40:40, 40:80, 40:100, etc. By controlling the mass ratio of the diisocyanate to the polyamine within the above range, the polyamine further reacts with the isocyanate functional group as a nucleophile to form urea bonds. When the added mass of the polyamine is too low, it cannot completely react with the diisocyanate to form urea bonds, resulting in an insufficient thickness of the microcapsule shell layer, which leads to shell layer rupture and phase change material leakage; when the added mass of the polyamine is too high, it causes unnecessary waste and poor economy. The polyurea material obtained by interfacial polymerization of the two monomers has good compatibility with the water-soluble polymer. The polyurea material is more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and can be fixed in the three-dimensional network structure of the water-soluble polymer compound matrix to realize the shaping of the polyurea material. Since there are relatively more voids between the three-dimensional networks, the heat transfer efficiency is faster, thereby effectively improving the thermal conductivity.

[0047] In the second aspect of the present invention, the present invention provides a method for preparing the phase change material composition described in the first aspect. Please refer to Figure 1 , and the method includes:

[0048] S1. Dissolve the water-soluble polymer compound in water to obtain a water-soluble polymer compound solution.

[0049] In this step, dissolving the water-soluble polymer compound in water to obtain a solution facilitates the subsequent addition of the microcapsule-type phase change material, making the microcapsule-type phase change material more uniformly dispersed in the aqueous solution of the water-soluble polymer compound and fixed in the three-dimensional network structure of the water-soluble polymer compound matrix to realize the shaping of the microcapsule-type phase change material.

[0050] In some embodiments of the present invention, based on the total mass of the water-soluble polymer compound solution, the mass proportion of the water-soluble polymer compound is 1% to 15%, for example, it can be 1%, 3%, 5%, 10%, 15%, etc. By controlling the mass proportion of the water-soluble polymer compound in the solution within the above range, if the mass proportion of the water-soluble polymer compound is too low, the phase change material composition will have poor flexibility and excessive rigidity, resulting in cracks during further post-processing, affecting the integrity and thermal conductivity of the composition; if the mass proportion of the water-soluble polymer compound is too high, the mass proportion of the phase change material in the overall phase change material composition will decrease, resulting in a decrease in the overall enthalpy value and affecting the heat dissipation effect.

[0051] S2. After mixing the thermal conductive filler and the microencapsulated phase change material, mix them with the solvent and the water-soluble polymer compound solution to obtain a mixed slurry.

[0052] In this step, the microencapsulated phase change material in the microcapsule state is mixed with the thermal conductive filler and the water-soluble polymer compound solution to obtain a mixed slurry.

[0053] In some embodiments of the present invention, the microencapsulated phase change material is prepared by the following method:

[0054] S21. Dissolve the emulsifier in water, heat and stir, add the melted phase change material and diisocyanate, and add a part of the microcapsule thermal conductive particles and stir to emulsify to obtain an emulsion;

[0055] S22. After adding polyamine to the emulsion, add the remaining part of the microcapsule thermal conductive particles and stir to obtain a suspension;

[0056] In some embodiments, the suspension is continuously stirred in a water bath at 0 - 10 °C for 1 h, then added to an ethanol aqueous solution and left to stand for 1 h, and then filtered using a suction funnel to obtain a gray powder solid polyurea-based microencapsulated phase change material. Due to the relatively low reaction speed, the microcapsules gradually formed in the reaction solution have a relatively large particle size. Through the cooling treatment of the water bath where the reaction solution is located, it is beneficial to the preparation of the microencapsulated phase change material with a low leakage rate.

[0057] S23. Filter the suspension to obtain a solid, which is the microencapsulated phase change material.

[0058] Through the above method, a microencapsulated phase change material with a microcapsule structure with the phase change material and the microcapsule thermal conductive particles as the core and the organic polymer material and the microcapsule thermal conductive particles as the shell material can be prepared.

[0059] In some embodiments of the present invention, the mass ratio of the phase change material, diisocyanate and emulsifier is (60-100):(10-40):1. For example, it can be 60:25:1, 100:25:1, 80:10:1, 80:40:1, etc. Controlling the mass ratio of the three within the above range, the addition of the emulsifier disperses the mixed oil solution of the phase change material and diisocyanate in the aqueous solution to form an oil-in-water microemulsion. At this stage, the hydrophilic groups of the emulsifier are alternately arranged along its hydrophobic chain, so as to combine with water molecules and neatly cover the surface of the phase change material / diisocyanate mixture oil droplets. The hydrophobic chain is oriented inside the oil droplet, and the hydrophilic group is oriented outside the oil droplet, which is beneficial to the polycondensation reaction of diisocyanate and amine at the oil / water interface. In order to ensure the proportion of the phase change material in the microcapsule, the mass proportion of the phase change material is controlled within the above range, ensuring the enthalpy value of the microcapsule while ensuring the thickness of the microcapsule shell layer.

[0060] In some embodiments of the present invention, the emulsifier includes at least one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium stearate, OP-1 (octylphenol polyoxyethylene ether), Tween 80, cetylammonium bromide. The above emulsifier has good emulsifying performance, which is convenient for finally forming a well-dispersed emulsion in step S21, so as to finally generate a complete microcapsule-type phase change material with a phase change material and microcapsule heat-conducting particle core and an organic polymer material and microcapsule heat-conducting particle as the shell material through a polymerization reaction.

[0061] In some embodiments of the present invention, the solvent includes at least one of water and ethanol. The above solvents are cheap and easy to obtain.

[0062] S3. Solidify and mold the mixed slurry to obtain a phase change material composition.

[0063] In summary, the preparation method of the phase change material composition proposed in this application adds the microcapsule-type phase change material and the heat-conducting filler as fillers into the water-soluble polymer compound matrix. The prepared phase change material composition has good heat storage and heat-conducting properties. The phase change material composition has relatively excellent thermal properties, can effectively adjust the temperature of electronic devices, and ensure high efficiency in actual application. It is particularly suitable for passive thermal management systems, which are designed to effectively solve the heat dissipation problem caused by the high-density integration of electronic devices.

[0064] In addition, the composition has excellent thermal properties, good thermal stability, does not require high temperature, high pressure and organic solvents, and can form the microcapsule-type phase change material at room temperature, and the prepared composite phase change material composition maintains a high enthalpy value and thermal conductivity.

[0065] The preparation process of the composite phase change material composition proposed by the present invention is simple. The shaping of the phase change material composition can be achieved at normal temperature and pressure. It has thermal properties such as heat conduction and heat storage, and heat conduction and heat dissipation modules of different specifications can be prepared according to actual needs.

[0066] In the third aspect of the present invention, the present invention proposes an electronic device, and the electronic device includes the phase change material composition described in the first aspect of the present invention. Thus, the electronic device proposed by the present invention has good heat conduction performance.

[0067] The phase change material composition proposed in the embodiments of the present application has thermal properties such as heat conduction and heat storage, and heat conduction and heat dissipation modules of different specifications can be prepared according to actual needs.

[0068] Applying the phase change material composition of the embodiments of the present application to microelectronic components and devices, using the solid-liquid phase change potential of the phase change material to solve the heat dissipation problem of the heat management system, it has advantages such as large energy storage density and approximate isothermal heat storage and heat release processes, which can extend the service time of electronic devices and equipment, meet the higher and faster operating speeds of electronic devices; and the entire temperature control process is convenient and easy to control.

[0069] The solutions of the present disclosure will be explained below with reference to the embodiments. Those skilled in the art will understand that the following embodiments are only for explaining the present disclosure and should not be regarded as limiting the scope of the present disclosure. For those not specified in the embodiments regarding specific techniques or conditions, they shall be carried out according to the techniques or conditions described in the literature in the art or according to the product specifications. Those reagents or instruments not specified as to the manufacturer can be obtained as conventional products through commercial purchase.

[0070] Example 1

[0071] Composition and addition amount of polyurea microcapsule phase change material: sodium dodecyl sulfate (emulsifier) 1.2 g, distilled water 540 g, n - eicosane (phase change material) 96 g, isophorone diisocyanate (diisocyanate) 24 g, triethylenetetramine (polyamine) 74 g, graphene (microcapsule heat conduction particles) 1.2 g, ethanol 60 g.

[0072] Composition and preparation method of polyurea microcapsule phase change material:

[0073] Step 1: Add 1.2 g of sodium dodecyl sulfate to 300 g of distilled water to prepare an aqueous solution. Under a stirring speed of 500 rpm, heat and stir evenly in a 70 °C water bath. Then add 96 g of melted n - eicosane and 24 g of isophorone diisocyanate to the sodium dodecyl sulfate aqueous solution, and then add 0.1 g of graphene, and stir and emulsify for 5 min to obtain a well - dispersed emulsion.

[0074] Step 2: Add 74 g of triethylenetetramine to the above emulsion, stir for 30 min at a stirring speed of 400 rpm, add 1.1 g of graphene to the mixed emulsion system, and then continue to stir for 5 h at a stirring speed of 400 rpm to prepare a suspension of polyurea microcapsule phase change material with certain thermal conductivity. Continue to stir in a water bath at 0 - 10 °C for 1 h, then add it to 300 g of ethanol aqueous solution (60 g of ethanol and 240 g of distilled water), let it stand for 1 h, and then filter it using a suction funnel to obtain a gray powder solid polyurea microcapsule phase change material. Due to the relatively low reaction speed, the microcapsules gradually formed in the reaction solution have a relatively large particle size. Through the cooling treatment of the water bath where the reaction solution is located, it is beneficial to the preparation of microcapsule phase change materials with a low leakage rate.

[0075] Raw materials required for the phase change material composition: 30 g of polyurea microcapsule phase change material, 2 g of polyvinyl alcohol (matrix, water-soluble polymer compound), 0.2 g of polyether defoamer, 1.4 g of graphene (thermal conductive filler), 20 g of solvent (18 g of distilled water, 2 g of ethanol).

[0076] Composition and specific preparation method of the composite phase change material composition:

[0077] Step 1: Add 2 g of polyvinyl alcohol to 18 g of boiling water, stir for 1 h to obtain a 10% polyvinyl alcohol aqueous solution by mass fraction.

[0078] Step 2: Mix 1.4 g of graphene and 30 g of polyurea microcapsule phase change material evenly to obtain a mixed and homogeneous powder mixture.

[0079] Step 3: Add the above powder mixture to 20 g of solvent, 20 g of 10% polyvinyl alcohol aqueous solution, and 0.2 g of polyether defoamer, and mix evenly to obtain a slurry with polyvinyl alcohol as the matrix, containing graphene and polyurea microcapsule phase change material.

[0080] Step 4: Place the above thermal conductive slurry in a mold of 130 mm × 150 mm × 10 mm, and cure and shape it at room temperature to obtain the composite phase change material composition.

[0081] Example 2

[0082] Example 2 is the same as Example 1, except that dicyclohexylmethane diisocyanate is used as the diisocyanate and hexamethylenediamine is used as the polyamine.

[0083] Example 3

[0084] Example 3 is the same as Example 1, except that carbon nanotubes are used as the thermal conductive filler.

[0085] Example 4

[0086] Example 4 is consistent with Example 1, except that an aqueous solution of polyvinyl alcohol with a mass fraction of 8% is used.

[0087] Comparative Example 1

[0088] Comparative Example 2 is consistent with Example 1, except that no thermal conductive filler is added during the preparation of the phase change material composition.

[0089] Comparative Example 2

[0090] Comparative Example 2 is consistent with Example 1, except that no microcapsule thermal conductive particles are added during the preparation of the polyurea microcapsule type phase change material, and no thermal conductive filler is added during the preparation of the phase change material composition.

[0091] The following tests were carried out on the phase change material compositions obtained in Examples 1-4 and Comparative Examples 1-2:

[0092] 1. Phase change enthalpy value test

[0093] Referring to the reference standard JY / T 0589.3-2020, the phase change enthalpy values of the microcapsule type phase change material and the phase change material composition were tested.

[0094] 2. Thermal conductivity test

[0095] Referring to the national standard GB / T 22588-2008, the thermal conductivity of the phase change material composition was tested, and the test results are shown in Table 1.

[0096] 3. Density test

[0097] Referring to the national standard GB / T 5007-2014, the density of the phase change material composition was tested, and the test results are shown in Table 1.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, the enthalpy values of the polyurea microcapsule phase change materials in Examples 1 to 4 can all reach above 180 J / g. After adding the polyvinyl alcohol matrix to shape the microcapsules, the overall enthalpy value decreases. The reason is that the addition of the polyvinyl alcohol matrix and the heat-conducting particles in the composition affects the overall enthalpy value, but it can still reach above 160 J / g; the introduction of heat-conducting particles during the preparation of the phase change material composition can all improve the overall heat-conducting performance; in Comparative Example 1, heat-conducting particles are only introduced during the preparation of the microcapsules, and the overall heat-conducting performance of the phase change material composition decreases significantly. In Comparative Example 2, compared with Comparative Example 1, no heat-conducting particles are introduced during the entire process of preparing the phase change material composition, resulting in the most obvious decrease in heat-conducting performance; after testing the density of the phase change material composition, it can be found that the density of this type of composition is small, all less than 1 g / cm 3 .

[0101] To verify the leakage of the phase change material in the phase change material composition, it is verified from three aspects: the temperature resistance of the microcapsule phase change material, the encapsulation efficiency, and the temperature resistance of the phase change material composition.

[0102] ① Temperature resistance

[0103] Take 1 g of microcapsules in a petri dish and place it in an environment of 60 °C to observe the melting of the sample.

[0104] ② Encapsulation efficiency

[0105] Take 1 g of microcapsules in a petri dish, add 25 ml of toluene, place it at room temperature for 10 min, then perform extraction. After the remaining microcapsule powder is dried, weigh it to obtain the proportion of the remaining microcapsule powder in 1 g of microcapsules, and obtain the encapsulation efficiency. The data obtained after the experiment are shown in Table 2.

[0106] Table 2

[0107] Temperature resistance of microcapsules Microcapsule encapsulation efficiency % Example 1 Not melted 90％ Example 2 Not melted 85％ Example 3 Not melted 82％ Comparative example 2 Not melted 80％

[0108] When the microcapsules are placed in an environment of 60 °C, the microcapsules still show a powdery state after 2 h, 4 h, 6 h, and 8 h; after returning to room temperature, the appearance of the microcapsules still shows a powdery state, and there is no problem of caking due to the melting and re-solidification of the core phase change material, indicating that the phase change material does not leak from the microcapsule core; in addition, when the phase change material compositions prepared according to Examples 1, 2, 3 and Comparative Example 2 are placed on the oil-absorbing paper in an environment of 60 °C for 2 h, 4 h, 6 h, and 8 h, the oil-absorbing paper does not change, indicating that there is no problem of phase change material leakage in the phase change material composition.

[0109] The n-eicosane bulk solid used in Example 1 was placed in a petri dish containing 25 ml of toluene. It was found through experiments that n-eicosane completely dissolved in toluene within 5 minutes. From the test results in Table 2, it was known that the phase change materials encapsulated by the polyurea wall material did not completely dissolve in toluene, and the encapsulation efficiency reached over 80%, indicating that the leakage of the phase change material was not obvious.

[0110] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", "some implementation manners" or "some examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0111] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A phase change material composition, characterized in that, Comprising: A matrix, the matrix comprising a water-soluble polymer compound; A filler, the filler comprising a thermal conductive filler and a microcapsule phase change material, the microcapsule phase change material comprising a shell material and a core located inside the shell material, the shell material comprising an organic polymer material and microcapsule thermal conductive particles, and the core comprising a phase change material and microcapsule thermal conductive particles.

2. The phase change material composition according to claim 1, wherein In the filler, the mass ratio of the thermal conductive filler to the microcapsule phase change material is 1:(1 - 30); and / or, The mass ratio of the filler to the matrix is (1 - 20):1; and / or, The mass ratio of the phase change material to the microcapsule thermal conductive particles is (60 - 100):

1.

3. The phase change material composition according to claim 1 or 2, characterized in that, The water-soluble polymer compound comprises at least one of carboxymethyl starch, acetate starch, hydroxymethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, and polyethylene glycol; and / or, The thermal conductive filler comprises at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride; and / or, The phase change material comprises at least one of n-octadecane, n-eicosane, n-docosane, n-tetracosane, n-hexacosane, n-octacosane, n-triacontane, polyethylene glycol, stearyl alcohol, lauryl alcohol, neopentyl glycol, fatty acid adipic acid, capric acid, and stearic acid; and / or, The microcapsule thermal conductive particles comprise at least one of copper foam, expanded graphite, carbon fiber, carbon nanotube, graphene, alumina, boron nitride, and silicon nitride.

4. The phase change material composition according to claim 1 or 2, characterized in that, The organic polymer material comprises a polyurea material formed by interfacial polymerization of diisocyanate and polyamine.

5. The phase change material composition according to claim 4, characterized in that, The diisocyanate comprises at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate; and / or, The polyamine comprises at least one of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, ethylenediamine, hexamethylenediamine, and urea; and / or, The mass ratio of the diisocyanate to the polyamine is (10 - 40):(40 - 100).

6. A method for preparing the phase change material composition according to any one of claims 1 to 5, characterized in that, Comprising: Dissolving the water-soluble polymer compound in water to obtain a water-soluble polymer compound solution; Mixing the thermal conductive filler and the microcapsule phase change material, and then mixing with a solvent and the water-soluble polymer compound solution to obtain a mixed slurry; Solidifying and molding the mixed slurry to obtain a phase change material composition.

7. The method according to claim 6, wherein The microcapsule phase change material is prepared by the following method: Dissolving an emulsifier in water, heating and stirring, adding the melted phase change material and diisocyanate, and adding a part of the microcapsule thermal conductive particles and stirring to emulsify to obtain an emulsion; Adding polyamine to the emulsion, then adding the remaining part of the microcapsule thermal conductive particles, and stirring to obtain a suspension; Filtering the suspension to obtain a solid, which is the microcapsule phase change material.

8. The method according to claim 7, wherein The mass ratio of the phase change material, diisocyanate, and emulsifier is (60 - 100):(10 - 40):1; and / or, The emulsifier comprises at least one of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium stearate, OP-1, Tween 80, and cetylammonium bromide.

9. The method according to claim 6, wherein Based on the total mass of the water-soluble polymer compound solution, the mass proportion of the water-soluble polymer compound is 1% to 15%; and / or, The solvent includes at least one of water and ethanol.

10. An electronic device, characterized in that, The electronic device includes the phase change material composition according to any one of claims 1-5.

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