A thermally conductive phase change material, its preparation method, and its applications

Abstract

This invention provides a thermally conductive phase change material, comprising, by weight fraction of raw materials, 3-15 parts by weight of a special wax with a melting point of 30-80℃, 5-20 parts by weight of a polyolefin, 0.5-5 parts by weight of an antioxidant, 0.3-3 parts by weight of a dispersant, 0.1-1 parts by weight of a coupling agent, and 40-180 parts by weight of a thermally conductive filler; the special wax with a melting point of 30-80℃ includes alkyl polymethylsiloxane. The high thermal conductivity and anti-pumping thermally conductive phase change material provided by this invention is obtained by mixing special wax, polyolefin, antioxidant, and modified thermally conductive filler through a heating and calendering process. It is environmentally friendly, efficient, and has stable product performance. Furthermore, the use of alumina, aluminum powder, and zinc oxide as the main fillers improves the long-term thermal stability of the material. The raw material price is low, resulting in a significant cost advantage. Moreover, the preparation method is simple and easy to control, which is conducive to its promotion and application in large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of chip thermal interface material technology, and relates to a thermally conductive phase change material and its preparation method and application, especially to an anti-pumping thermally conductive phase change material and its preparation method and application. Background Technology

[0002] In recent years, with the development of AI technology, the power consumption of AI chips has become increasingly higher. Ten years ago, the thermal design power (TDP) of top-tier GPUs was only 235W, but today this parameter has skyrocketed to 600W! This surge in TDP has led to a dramatic increase in chip heat generation. Simultaneously, another change is the increasing size of AI chips. Compared to 561mm² ten years ago, today's top-tier GPUs have reached an area of ​​3000mm². 2 Such a large surface area creates an extremely complex mechanical environment, making the chip itself more fragile and causing reliability issues with the thermal interface material. Currently, thermal grease and thermally conductive phase change materials are used as thermal interface materials for high-power chips. However, thermal grease, being a paste-like fluid, experiences pumping out when subjected to the pressure of a warped bare chip, causing a sharp increase in thermal resistance between the chip and the heatsink, severely impacting heat dissipation. Traditional thermally conductive phase change materials, when used in high-power, large-size chips, are also prone to pumping out during continuous high and low temperature cycling, leading to increased interface thermal resistance and affecting heat dissipation. Furthermore, traditional high thermal conductivity phase change materials are generally obtained by mixing paraffin, alkanes, coupling agents, and thermally conductive fillers, followed by a heating and calendering process. These high thermal conductivity phase change materials often use high thermal conductivity powders such as graphene, aluminum nitride, and boron nitride as thermally conductive fillers, resulting in relatively high material costs.

[0003] Therefore, finding a more suitable thermally conductive phase change material for chip thermal interface heat dissipation and solving the aforementioned technical problems of existing thermally conductive materials has become one of the urgent problems to be solved by many front-line researchers in the industry. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a thermally conductive phase change material, its preparation method, and its application, particularly a pump-out resistant thermally conductive phase change material. The high thermal conductivity and pump-out resistant thermally conductive phase change material provided by the present invention is obtained by mixing special wax, polyolefin, antioxidant, and modified thermally conductive filler through a heating and calendering process. This process is environmentally friendly, efficient, and produces stable products. Furthermore, the process is simple, the conditions are mild, and it is easy to control, which is conducive to its promotion and application in large-scale industrial production.

[0005] This invention provides a thermally conductive phase change material, comprising, by mass fraction of raw materials:

[0006] 3-15 parts by weight of a special wax with a melting point of 30-80℃;

[0007] 5-20 parts by weight of polyolefin;

[0008] Antioxidant 0.5-5 parts by weight;

[0009] Dispersant 0.3~3 parts by weight;

[0010] 0.1 to 1 part by weight of coupling agent;

[0011] 40-180 parts by weight of thermally conductive filler;

[0012] The special waxes with a melting point of 30~80℃ include alkyl polymethylsiloxanes.

[0013] Preferably, the alkyl polymethylsiloxane is a C20-C45 alkyl polymethylsiloxane;

[0014] The polyolefin includes one or more of polybutadiene, polybutadiene monool, hydrogenated polybutadiene monool, polybutadiene diol, hydrogenated polybutadiene diol, polypropylene diol, hydrogenated polypropylene diol, styrene-butadiene rubber, butadiene-styrene copolymer, epoxidized polybutadiene, and maleic anhydride addition polybutadiene.

[0015] The antioxidants include one or more of the following: tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearate pentaerythritol diphosphite, pentaerythritol tetraester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, dodecyl thiodipropionate, bis(1,2,2,6,6)-pentamethyl-4-piperidinyl sebacate, tetramethylpiperidinamine, and N,N-diphenyl-p-phenylenediamine.

[0016] Preferably, the dispersant comprises polyoxyethylene alkyl ether phosphate and / or polyoxyethylene alkyl ether;

[0017] The coupling agent includes one or more of hexadecyltrimethoxysilane, hexadecylmethyldimethoxysilane, hexadecyltriethoxysilane, hexadecylmethyldiethoxysilane, octadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltriethylsilane, and octadecylmethyldiethoxysilane.

[0018] The thermally conductive filler includes one or more of the following: alumina, zinc oxide, aluminum nitride, boron nitride, diamond, boron nitride, silicon nitride, aluminum, copper, silver, indium, and nickel-plated copper.

[0019] Preferably, the thermally conductive filler comprises one or more of alumina, aluminum, zinc oxide, boron nitride, and aluminum nitride;

[0020] The thermally conductive filler includes one or more of the following: thermally conductive filler with an average particle size of 5-18 μm, thermally conductive filler with an average particle size of 1-4 μm, thermally conductive filler with an average particle size of 0.03-2 μm, and thermally conductive filler with an average particle size of 0.03-1 μm.

[0021] The thermally conductive filler includes one or more of the following: thermally conductive filler with an average particle size of 5-18 μm, thermally conductive filler with an average particle size of 5-15 μm, thermally conductive filler with an average particle size of 0.03-2 μm, and thermally conductive filler with an average particle size of 0.03-1 μm.

[0022] The thermally conductive phase change material is specifically an anti-pumping thermally conductive phase change material.

[0023] Preferably, the thermally conductive filler comprises spherical aluminum particles with an average particle size of 5-18 μm, spherical aluminum particles with an average particle size of 1-4 μm, zinc oxide particles with an average particle size of 0.03-2 μm, and alumina particles with an average particle size of 0.03-1 μm.

[0024] The amount of spherical aluminum particles added is 15-160 parts by weight, the amount of zinc oxide particles added is 10-40 parts by weight, and the amount of alumina particles added is 10-40 parts by weight.

[0025] The thermally conductive filler includes aluminum powder with an average particle size of 5-18 μm, aluminum nitride particles with an average particle size of 5-15 μm, zinc oxide particles with an average particle size of 0.03-2 μm, and aluminum oxide particles with an average particle size of 0.03-1 μm.

[0026] The amount of aluminum powder added is 15-40 parts by weight, the amount of aluminum nitride particles added is 10-60 parts by weight, the amount of zinc oxide particles added is 10-40 parts by weight, and the amount of aluminum oxide particles added is 10-40 parts by weight.

[0027] The thermally conductive phase change material includes a thermally conductive phase change material used for chip heat dissipation.

[0028] This invention provides a method for preparing a thermally conductive phase change material as described in any of the above technical solutions, comprising the following steps:

[0029] 1) After homogenizing polyolefin, antioxidant, coupling agent, dispersant and some thermally conductive filler, a masterbatch is obtained;

[0030] 2) After heating and mixing the masterbatch and special wax obtained in the above steps, add the remaining thermally conductive fillers and continue mixing to obtain the prepared material;

[0031] 3) After the materials prepared in the above steps are calendered, thermally conductive phase change materials are obtained.

[0032] Preferably, the homogeneous dispersion rate is 1500~2500 r / min;

[0033] The thermally conductive filler includes zinc oxide particles with an average particle size of 0.03~2μm and aluminum oxide particles with an average particle size of 0.030~1μm.

[0034] The heating temperature is 100~120℃.

[0035] Preferably, the mixing time is 0.5 to 2 hours;

[0036] The remaining thermally conductive fillers include spherical aluminum particles with an average particle size of 5~18μm and spherical aluminum particles with an average particle size of 1~4μm.

[0037] The remaining thermally conductive fillers include aluminum powder with an average particle size of 5-18 μm and aluminum nitride particles with an average particle size of 5-15 μm.

[0038] The method of continued mixing includes mixing under vacuum conditions.

[0039] Preferably, the temperature for continued mixing is 100~120℃;

[0040] The mixing time is 0.5 to 2 hours;

[0041] The rolling temperature is 100~150℃.

[0042] The present invention also provides the application of the thermally conductive phase change material described in any one of the above technical solutions or the thermally conductive phase change material prepared by any one of the above technical solutions in chip heat dissipation materials.

[0043] This invention provides a thermally conductive phase change material, comprising, by mass fraction of raw materials, 3-15 parts by weight of a special wax with a melting point of 30-80°C, 5-20 parts by weight of a polyolefin, 0.5-5 parts by weight of an antioxidant, 0.3-3 parts by weight of a dispersant, 0.1-1 parts by weight of a coupling agent, and 40-180 parts by weight of a thermally conductive filler; wherein the special wax with a melting point of 30-80°C includes alkyl polymethylsiloxane. Compared with existing technologies, this invention argues that while existing thermally conductive phase change materials exhibit good wettability and low thermal resistance under operating conditions, the short-chain structure of their matrix resin limits their long-term thermal stability and resistance to high and low temperature cycling. After repeated high and low temperature cycling, the matrix resin and thermally conductive filler are severely pumped out, resulting in unstable thermal conduction pathways and affecting heat transfer function. This leads to excessively high local temperatures in the thermal chip, causing chip damage. Furthermore, the thermally conductive fillers used in phase change materials generally have low particle sizes, with powders smaller than 2 micrometers easily agglomerating, especially nanofillers. Traditional processes mainly use planetary mixers for heating and stirring, with a maximum stirring rate of only 50 r / min. Therefore, nano-thermal conductive fillers often fail to disperse properly, leading to unstable product performance.

[0044] Based on this, this invention mainly addresses the poor anti-pumping performance of existing thermally conductive phase change materials. Furthermore, by optimizing cost control to achieve ideal results, a novel thermally conductive phase change material with a specific composition and ratio is designed. The high thermal conductivity and anti-pumping thermally conductive phase change material provided by this invention is obtained through a hot calendering process using a mixture of special wax, polyolefin, antioxidant, and modified thermally conductive filler. This process is environmentally friendly, efficient, and produces stable product performance. Moreover, the use of alumina, aluminum powder, and zinc oxide as the main fillers enhances the material's long-term thermal stability. Simultaneously, it avoids using high thermal conductivity powders as the main filler, resulting in lower raw material prices and a significant cost advantage.

[0045] This invention also provides a corresponding preparation method. The method involves first dispersing the nano-thermal conductive filler as a masterbatch using a homogenizer and high-speed stirring at 1500-2500 r / min. This masterbatch is then mixed with large-diameter particle powder and stirred in a planetary mixer. Finally, the product is obtained through a heated calendering process, resulting in more stable performance. The preparation method provided by this invention is simple, operates under mild conditions, and is easy to control, which is conducive to its promotion and application in large-scale industrial production. Detailed Implementation

[0046] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims.

[0047] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0048] There are no particular restrictions on the purity of any raw materials used in this invention. However, this invention preferably uses materials of analytical grade or those meeting the conventional purity requirements in the field of preparing thermally conductive phase change materials for chip heat dissipation.

[0049] All raw materials of this invention are conventional in the field, and each brand name and abbreviation is clear and distinct in its relevant application. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand name, abbreviation and corresponding application.

[0050] This invention provides a thermally conductive phase change material, comprising, by mass fraction of raw materials:

[0051] 3-15 parts by weight of a special wax with a melting point of 30-80℃;

[0052] 5-20 parts by weight of polyolefin;

[0053] Antioxidant 0.5-5 parts by weight;

[0054] Dispersant 0.3~3 parts by weight;

[0055] 0.1 to 1 part by weight of coupling agent;

[0056] 40-180 parts by weight of thermally conductive filler;

[0057] The special waxes with a melting point of 30~80℃ include alkyl polymethylsiloxanes.

[0058] In this invention, the special wax has a melting point of 30~80℃, specifically 40~70℃ or 50~60℃.

[0059] In this invention, the amount of the special wax with a melting point of 30-80°C added is 3-15 parts by weight, or 5-13 parts by weight, or 7-11 parts by weight.

[0060] In this invention, the amount of antioxidant added is 0.5 to 5 parts by weight, or 1 to 4 parts by weight, or 2 to 3 parts by weight.

[0061] In this invention, the amount of polyolefin added is 5 to 20 parts by weight, or 8 to 17 parts by weight, or 11 to 14 parts by weight.

[0062] In this invention, the amount of dispersant added is 0.3 to 3 parts by weight, or 0.8 to 2.5 parts by weight, or 1.3 to 2.0 parts by weight.

[0063] In this invention, the amount of the coupling agent added is 0.1 to 1 part by weight, or 0.3 to 0.8 parts by weight, or 0.5 to 0.6 parts by weight.

[0064] In this invention, the amount of thermally conductive filler added is 40-180 parts by weight, or 60-150 parts by weight, or 80-130 parts by weight.

[0065] In this invention, the alkyl polymethylsiloxane is preferably a C20-C45 alkyl polymethylsiloxane, more preferably a C25-C40 alkyl polymethylsiloxane, and even more preferably a C30-C35 alkyl polymethylsiloxane.

[0066] In this invention, the polyolefin preferably includes one or more of polybutadiene, polybutadiene monool, hydrogenated polybutadiene monool, polybutadiene diol, hydrogenated polybutadiene diol, polypropylene diol, hydrogenated polypropylene diol, styrene-butadiene rubber, butadiene-styrene copolymer, epoxidized polybutadiene, and maleic anhydride-addition polybutadiene, more preferably polybutadiene, polybutadiene monool, hydrogenated polybutadiene monool, polybutadiene diol, hydrogenated polybutadiene diol, polypropylene diol, hydrogenated polypropylene diol, styrene-butadiene rubber, butadiene-styrene copolymer, epoxidized polybutadiene, or maleic anhydride-addition polybutadiene.

[0067] In this invention, the antioxidant preferably includes tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearate pentaerythritol diphosphite, pentaerythritol tetraester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, dodecyl thiodipropionate, bis(1,2,2,6,6)-pentamethyl-4-piperidinyl sebacate, tetramethylpiperidinamine, and N,N-diphenyl-tert-phenylene oxide. One or more of the following amines, more preferably tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearate pentaerythritol diphosphite, pentaerythritol tetraester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, dodecyl thiodipropionate, bis(1,2,2,6,6)-pentamethyl-4-piperidinyl sebacate, tetramethylpiperidinamine, or N,N-diphenyl-p-phenylenediamine.

[0068] In this invention, the dispersant preferably includes polyoxyethylene alkyl ether phosphate and / or polyoxyethylene alkyl ether, more preferably polyoxyethylene alkyl ether phosphate or polyoxyethylene alkyl ether.

[0069] In this invention, the coupling agent preferably includes one or more of hexadecyltrimethoxysilane, hexadecylmethyldimethoxysilane, hexadecyltriethoxysilane, hexadecylmethyldiethoxysilane, octadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltriethylsilane, and octadecylmethyldiethoxysilane, more preferably hexadecyltrimethoxysilane, hexadecylmethyldimethoxysilane, hexadecyltriethoxysilane, hexadecylmethyldiethoxysilane, octadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltriethylsilane, or octadecylmethyldiethoxysilane.

[0070] In this invention, the thermally conductive filler preferably includes one or more of alumina, zinc oxide, aluminum nitride, boron nitride, diamond, boron nitride, silicon nitride, aluminum, copper, silver, indium, and nickel-plated copper, and more preferably alumina, zinc oxide, aluminum nitride, boron nitride, diamond, boron nitride, silicon nitride, aluminum, copper, silver, indium, or nickel-plated copper.

[0071] In this invention, the thermally conductive filler preferably includes one or more of alumina, aluminum, zinc oxide, boron nitride, and aluminum nitride, and more preferably alumina, aluminum, zinc oxide, boron nitride, or aluminum nitride.

[0072] In this invention, the thermally conductive filler preferably includes one or more of the following: thermally conductive filler with an average particle size of 5-18 μm, thermally conductive filler with an average particle size of 1-4 μm, thermally conductive filler with an average particle size of 0.03-2 μm, and thermally conductive filler with an average particle size of 0.03-1 μm; more preferably, thermally conductive filler with an average particle size of 8-15 μm, thermally conductive filler with an average particle size of 1.5-3.5 μm, thermally conductive filler with an average particle size of 0.05-1.5 μm, and thermally conductive filler with an average particle size of 0.05-0.7 μm; even more preferably, thermally conductive filler with an average particle size of 11-12 μm, thermally conductive filler with an average particle size of 2.0-3.0 μm, thermally conductive filler with an average particle size of 0.1-1.0 μm, and thermally conductive filler with an average particle size of 0.1-0.5 μm. Correspondingly, the thermally conductive filler preferably includes spherical aluminum particles with an average particle size of 5~18μm, spherical aluminum particles with an average particle size of 1~4μm, zinc oxide particles with an average particle size of 0.03~2μm, and alumina particles with an average particle size of 0.03~1μm.

[0073] In this invention, the amount of spherical aluminum particles added is preferably 15 to 160 parts by weight, more preferably 30 to 140 parts by weight, more preferably 50 to 120 parts by weight, and even more preferably 60 to 110 parts by weight.

[0074] In this invention, the amount of zinc oxide particles added is preferably 10 to 40 parts by weight, more preferably 15 to 35 parts by weight, and even more preferably 20 to 30 parts by weight.

[0075] In this invention, the amount of alumina particles added is preferably 10 to 40 parts by weight, more preferably 15 to 35 parts by weight, and even more preferably 20 to 30 parts by weight.

[0076] In this invention, the mass ratio between the spherical aluminum particles with an average particle size of 1~4μm and the spherical aluminum particles with an average particle size of 5~18μm is preferably (1~3):1, more preferably (1.2~2.8):1, and even more preferably (1.5~2.5):1.

[0077] In this invention, the thermally conductive filler preferably includes one or more of the following: thermally conductive filler with an average particle size of 5-18 μm, thermally conductive filler with an average particle size of 5-15 μm, thermally conductive filler with an average particle size of 0.03-2 μm, and thermally conductive filler with an average particle size of 0.03-1 μm; more preferably, thermally conductive filler with an average particle size of 8-15 μm, thermally conductive filler with an average particle size of 7-13 μm, thermally conductive filler with an average particle size of 0.08-1.5 μm, and thermally conductive filler with an average particle size of 0.05-0.8 μm; even more preferably, thermally conductive filler with an average particle size of 10-13 μm, thermally conductive filler with an average particle size of 9-11 μm, thermally conductive filler with an average particle size of 0.1-1 μm, and thermally conductive filler with an average particle size of 0.1-0.5 μm. Correspondingly, the thermally conductive filler preferably includes aluminum powder with an average particle size of 5-18 μm, aluminum nitride particles with an average particle size of 5-15 μm, zinc oxide particles with an average particle size of 0.03-2 μm, and alumina particles with an average particle size of 0.03-1 μm.

[0078] In this invention, the amount of aluminum powder added is preferably 15 to 40 parts by weight, more preferably 20 to 35 parts by weight, and even more preferably 25 to 30 parts by weight.

[0079] In this invention, the amount of aluminum nitride particles added is preferably 10 to 60 parts by weight, more preferably 20 to 50 parts by weight, and even more preferably 30 to 40 parts by weight.

[0080] In this invention, the amount of zinc oxide particles added is preferably 10 to 40 parts by weight, more preferably 15 to 35 parts by weight, and even more preferably 20 to 30 parts by weight.

[0081] In this invention, the amount of alumina particles added is preferably 10 to 40 parts by weight, more preferably 15 to 35 parts by weight, and even more preferably 20 to 30 parts by weight.

[0082] In this invention, the thermally conductive phase change material is preferably an anti-pumping thermally conductive phase change material.

[0083] In this invention, the thermally conductive phase change material preferably includes a thermally conductive phase change material for chip heat dissipation.

[0084] The present invention also provides an application of the thermally conductive phase change material described in any one of the above technical solutions in improving the anti-pumping properties of the thermally conductive phase change material.

[0085] This invention provides a method for preparing a thermally conductive phase change material as described in any of the above technical solutions, comprising the following steps:

[0086] 1) After homogenizing polyolefin, antioxidant, coupling agent, dispersant and some thermally conductive filler, a masterbatch is obtained;

[0087] 2) After heating and mixing the masterbatch and special wax obtained in the above steps, add the remaining thermally conductive fillers and continue mixing to obtain the prepared material;

[0088] 3) After the materials prepared in the above steps are calendered, thermally conductive phase change materials are obtained.

[0089] The present invention first homogenizes polyolefin, antioxidant, coupling agent, dispersant and some thermally conductive filler to obtain masterbatch.

[0090] In this invention, the homogeneous dispersion rate is preferably 1500~2500 r / min, more preferably 1700~2300 r / min, and even more preferably 1900~2100 r / min.

[0091] In this invention, the thermally conductive filler preferably comprises zinc oxide particles with an average particle size of 0.03~2μm and alumina particles with an average particle size of 0.030~1μm, more preferably zinc oxide particles with an average particle size of 0.3~1.5μm and alumina particles with an average particle size of 0.1~0.7μm, and even more preferably zinc oxide particles with an average particle size of 0.8~1.0μm and alumina particles with an average particle size of 0.3~0.4μm.

[0092] In this invention, the masterbatch obtained in the above steps is heated and mixed with special wax, and then the remaining thermally conductive fillers are added and mixed again to obtain the prepared material.

[0093] In this invention, the heating temperature is preferably 100~120℃, more preferably 104~116℃, and even more preferably 108~112℃.

[0094] In this invention, the mixing time is preferably 0.5 to 2 hours, more preferably 0.8 to 1.7 hours, and even more preferably 1.1 to 1.4 hours.

[0095] In this invention, the remaining thermally conductive fillers preferably include spherical aluminum particles with an average particle size of 5-18 μm and spherical aluminum particles with an average particle size of 1-4 μm, more preferably spherical aluminum particles with an average particle size of 7-13 μm and spherical aluminum particles with an average particle size of 1.5-3.5 μm, even more preferably spherical aluminum particles with an average particle size of 9-11 μm and spherical aluminum particles with an average particle size of 2.0-3.0 μm.

[0096] In this invention, the method of continuing mixing preferably includes mixing under vacuum conditions.

[0097] In this invention, the temperature for continued mixing is preferably 100~120℃, more preferably 104~116℃, and even more preferably 108~112℃.

[0098] In this invention, the continued mixing time is preferably 0.5 to 2 hours, more preferably 0.8 to 1.7 hours, and even more preferably 1.1 to 1.4 hours.

[0099] Finally, the materials prepared in the above steps are calendered to obtain a thermally conductive phase change material.

[0100] In this invention, the rolling temperature is preferably 100~150℃, more preferably 110~140℃, and even more preferably 120~130℃.

[0101] This invention aims to complete and refine the overall technical solution, better ensure the composition and ratio of the anti-pumping thermally conductive phase change material, and further improve the thermal conductivity, stability, and anti-pumping performance of the anti-pumping thermally conductive phase change material. Specifically, the aforementioned anti-pumping thermally conductive phase change material and its preparation method may include the following:

[0102] The thermally conductive phase change material of this invention comprises:

[0103] (1) Special wax with a melting point of 30-80℃, selected from: C 20-45 Alkyl polymethylsiloxane.

[0104] (2) Polyolefins

[0105] (3) Antioxidants

[0106] (4) Dispersant

[0107] (5) Coupling agent: selected from one or more of hexadecyltrimethoxysilane, hexadecylmethyldimethoxysilane, hexadecyltriethoxysilane, hexadecylmethyldiethoxysilane, octadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltriethylsilane, and octadecylmethyldiethoxysilane.

[0108] (6) The thermally conductive filler may be one or more of the following: alumina, zinc oxide, aluminum nitride, boron nitride, diamond, boron nitride, silicon nitride, aluminum, copper, silver, indium, and nickel-plated copper. Preferably, it may be any combination of any one or more of the group consisting of alumina, aluminum, zinc oxide, boron nitride, and aluminum nitride. More preferably, it may be any combination of any one or more of the following: spherical aluminum particles with an average particle size of 5 μm to 18 μm, spherical aluminum particles with an average particle size of 1 μm to 4 μm, zinc oxide particles with an average particle size of 0.03 μm to 2 μm, and alumina with an average particle size of 0.030 μm to 1 μm.

[0109] (7) Dispersant: Selected from one or two of polyoxyethylene alkyl ether phosphate and polyoxyethylene alkyl ether.

[0110] Preparation process: Polyolefin, antioxidant, coupling agent, dispersant, zinc oxide particles with an average particle size of 0.03μm to 2μm and alumina with an average particle size of 0.030μm to 1μm are added to a material homogenizer and heated and dispersed at high speed at a dispersion rate of 1500~2500r / min.

[0111] Further:

[0112] This product can be achieved through the following steps:

[0113] Mixing:

[0114] Mixing ratio:

[0115] Specialty wax 3-15%

[0116] Polyolefins 5-20%

[0117] Antioxidant 0.5-5%

[0118] Dispersant 0.3-3%

[0119] Coupling agent 0.1-1%

[0120] Alumina filler 10-40%

[0121] Aluminum powder filler (spherical aluminum powder) 15-160%

[0122] Zinc oxide filler 10-40%

[0123] (1) First, add polyolefin, antioxidant, coupling agent, dispersant, zinc oxide particles with an average particle size of 0.03μm to 2μm, and alumina with an average particle size of 0.030μm to 1μm to a material homogenizer and disperse them at a high speed of 1500-2500r / min. After mixing, use it as a masterbatch for later use.

[0124] (2) Add the above masterbatch and special wax to a mixing tank and stir at 100-120℃ for 0.5-2 hours. Add spherical aluminum particles with an average particle size of 5μm to 18μm and spherical aluminum particles with an average particle size of 1μm to 4μm thermally conductive filler. Stir under vacuum at 100-120℃ for 1 hour. After mixing, transfer the material to a calender and wait for the next process.

[0125] (3) Rolling

[0126] [P]Under certain temperature conditions (100~150℃), thermally conductive phase change material sheets or rolls are obtained through a calender (two-roll, three-roll, or four-roll) in conjunction with a winding / unwinding device and a cutting device.[ / P]

[0127] Alternatively, it could also be:

[0128] Mixing:

[0129] Mixing ratio:

[0130] Specialty wax 3-15%

[0131] Polyolefins 5-20%

[0132] Antioxidant 0.5-5%

[0133] Dispersant 0.3-3%

[0134] Coupling agent 0.1-1%

[0135] Alumina filler 10-40%

[0136] Aluminum nitride filler 10-60%

[0137] Aluminum powder filler 15-40%

[0138] Zinc oxide filler content: 10-40%.

[0139] (1) First, add polyolefin, antioxidant, coupling agent, dispersant, zinc oxide particles with an average particle size of 0.03μm to 2μm, and alumina with an average particle size of 0.030μm to 1μm to a material homogenizer and disperse them at a high speed of 1500-2500r / min. After mixing, use it as a masterbatch for later use.

[0140] (2) Add the above masterbatch and special wax to a mixing tank and stir at 100-120℃ for 0.5-2 hours. Add spherical aluminum particles with an average particle size of 5μm to 18μm and aluminum nitride particles with an average particle size of 5μm to 15μm, and stir under vacuum at 100-120℃ for 1 hour. After mixing, transfer the material to a calender and wait for the next process.

[0141] (3) Rolling

[0142] [P]Under certain temperature conditions (100-150℃), thermally conductive phase change material sheets or rolls are obtained through a calender (two-roll, three-roll, or four-roll) in conjunction with a winding / unwinding device and a cutting device.[ / P]

[0143] This invention provides the application of the thermally conductive phase change material described in any one of the above technical solutions or the thermally conductive phase change material prepared by any one of the above technical solutions in chip heat dissipation materials.

[0144] The present invention provides an anti-pumping thermally conductive phase change material, its preparation method, and its application. The high thermal conductivity and anti-pumping thermally conductive phase change material provided by the present invention is obtained by mixing special wax, polyolefin, antioxidant, and modified thermally conductive filler through a heating and calendering process. This process is environmentally friendly, efficient, and produces a stable product. Furthermore, the use of alumina, aluminum powder, and zinc oxide as the main fillers enhances the long-term thermal stability of the material. Simultaneously, it avoids using high thermal conductivity powders as the main filler, resulting in lower raw material prices and a significant cost advantage.

[0145] This invention also provides a corresponding preparation method. The method involves first dispersing the nano-thermal conductive filler as a masterbatch using a homogenizer and high-speed stirring at 1500-2500 r / min. This masterbatch is then mixed with large-diameter particle powder and stirred in a planetary mixer. Finally, the product is obtained through a heated calendering process, resulting in more stable performance. The preparation method provided by this invention is simple, operates under mild conditions, and is easy to control, which is conducive to its promotion and application in large-scale industrial production.

[0146] To further illustrate the present invention, the following detailed description of a thermally conductive phase change material, its preparation method, and its application, in conjunction with embodiments, is provided. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are given only to further illustrate the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0147] Example 1

[0148] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0149] 3 parts of special wax

[0150] 4 parts of polyolefin

[0151] 1 part antioxidant

[0152] 2 parts dispersant

[0153] 1 part coupling agent

[0154] 20 parts of aluminum oxide

[0155] 180 parts aluminum powder

[0156] 2-30 parts aluminum powder

[0157] 30 parts zinc oxide

[0158] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene with a viscosity of 15000cps, the antioxidant is pentaerythritol tetraester of 3-(3,5-di-tert-butyl-4-hydroxy)phenylpropionate, the dispersant is polyoxyethylene alkyl ether phosphate, the coupling agent is hexadecyltriethoxysilane, the alumina is spherical alumina with an average particle size of 1μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 15μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 2μm, and the zinc oxide is needle-shaped with an average particle size of 0.5μm.

[0159] (1) Weigh 4 parts of polybutadiene with a viscosity of 15000cps, 1 part of pentaerythritol tetraester of 3-(3,5,-di-tert-butyl-4,-hydroxy)phenylpropionate, 2 parts of polyoxyethylene alkyl ether phosphate, 1 part of hexadecyltriethoxysilane, 20 parts of spherical alumina with an average particle size of 1μm, and 30 parts of needle-shaped zinc oxide with an average particle size of 0.5μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2000r / min and a dispersion time of 2min to obtain a mixture.

[0160] (2) Transfer the above mixture to a reactor, weigh 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 80 parts of spherical aluminum powder 1 with an average particle size of 15μm, and 30 parts of spherical aluminum powder 2 with an average particle size of 2μm. Stir at 110℃ for 1.5 hours at a stirring rate of 25r / min, and then stir under vacuum at 110℃ for 1 hour at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender and wait for the next process.

[0161] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0162] Example 2

[0163] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0164] 3.5 parts of specialty wax

[0165] 4.5 parts of polyolefin

[0166] 0.5 parts antioxidant

[0167] 1 part dispersant

[0168] 0.5 parts coupling agent

[0169] 40 parts of aluminum oxide

[0170] 160 parts aluminum powder

[0171] 2-30 parts aluminum powder

[0172] 10 parts zinc oxide

[0173] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene diol with a viscosity of 20000cps, the antioxidant is tris(2,4-di-tert-butylphenyl) phosphite, the dispersant is polyoxyethylene alkyl ether, the coupling agent is hexadecylmethyldimethoxysilane, the alumina is spherical alumina with an average particle size of 0.7μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 8μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 1μm, and the zinc oxide is needle-shaped with an average particle size of 0.05μm.

[0174] (1) Weigh 3.5 parts of polybutadiene diol with a viscosity of 20000cps, 0.5 parts of tris(2,4-di-tert-butylphenyl) phosphite, 1 part of polyoxyethylene alkyl ether phosphate, 0.5 parts of hexadecylmethyldimethoxysilane, 40 parts of spherical alumina with an average particle size of 0.7μm, and 10 parts of needle-shaped zinc oxide with an average particle size of 0.05μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 1500r / min and a dispersion time of 3min to obtain a mixture.

[0175] (2) Transfer the above mixture to a reactor, and weigh 3.5 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 60 parts of spherical aluminum powder 1 with an average particle size of 8μm, and 30 parts of spherical aluminum powder 2 with an average particle size of 1μm. Stir at 100℃ for 2 hours at a stirring rate of 20r / min, and then stir under vacuum at 100℃ for 0.8 hours at a stirring rate of 20r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender and wait for the next process.

[0176] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0177] Example 3

[0178] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0179] 4.5 parts of specialty wax

[0180] 4 parts of polyolefin

[0181] 1.5 parts antioxidant

[0182] 2 parts dispersant

[0183] 1 part coupling agent

[0184] 15 parts of aluminum oxide

[0185] 180 parts aluminum powder

[0186] Aluminum powder 2 40 parts

[0187] 25 parts zinc oxide

[0188] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene with a viscosity of 10000cps, the antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, the dispersant is polyoxyethylene alkyl ether phosphate, the coupling agent is octadecyltrimethoxysilane, the alumina is spherical alumina with an average particle size of 0.1μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 10μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 4μm, and the zinc oxide is needle-shaped with an average particle size of 1.5μm.

[0189] (1) Weigh 4 parts of polybutadiene with a viscosity of 10000cps, 1.5 parts of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, 2 parts of polyoxyethylene alkyl ether phosphate, 1 part of octadecyltrimethoxysilane, 15 parts of spherical alumina with an average particle size of 0.1μm, and 25 parts of needle-shaped zinc oxide with an average particle size of 1.5μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2200r / min and a dispersion time of 1.5min to obtain a mixture.

[0190] (2) Transfer the above mixture to a reactor, weigh 4.5 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 80 parts of spherical aluminum powder 1 with an average particle size of 10μm, and 40 parts of spherical aluminum powder 2 with an average particle size of 4μm. Stir at 120℃ for 1 hour at a stirring rate of 25r / min, and then stir under vacuum at 120℃ for 1 hour at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender and wait for the next process.

[0191] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0192] Example 4

[0193] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0194] 3 parts of special wax

[0195] 4.5 parts of polyolefin

[0196] 1 part antioxidant

[0197] 2 parts dispersant

[0198] 1 part coupling agent

[0199] 15 parts of aluminum oxide

[0200] 190 parts aluminum powder

[0201] Aluminum powder 2 40 parts

[0202] 15 parts zinc oxide

[0203] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene with a viscosity of 10000cps, the antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, the dispersant is a mixture of ethylene oxide alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 1:1, the coupling agent is octadecyltriethoxysilane, the alumina is spherical alumina with an average particle size of 0.5μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 12μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 3μm, and the zinc oxide is needle-shaped with an average particle size of 0.2μm.

[0204] (1) Weigh 4.5 parts of polybutadiene with a viscosity of 10000cps, 1 part of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, 2 parts of a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 1:1, 1 part of octadecyltriethylsilane, 15 parts of spherical alumina with an average particle size of 0.5 μm, and 15 parts of needle-shaped zinc oxide with an average particle size of 0.2 μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2200 r / min and a dispersion time of 2 min to obtain a mixture.

[0205] (2) Transfer the above mixture to a reactor, weigh 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 90 parts of spherical aluminum powder 1 with an average particle size of 12μm, and 40 parts of spherical aluminum powder 2 with an average particle size of 3μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25r / min, then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender for the next process.

[0206] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0207] Example 5

[0208] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0209] 3 parts of special wax

[0210] 5 parts of polyolefin

[0211] 0.5 parts antioxidant

[0212] 1.5 parts dispersant

[0213] 0.5 parts coupling agent

[0214] 20 parts of aluminum oxide

[0215] 170 parts aluminum powder

[0216] 245 parts aluminum powder

[0217] 25 parts zinc oxide

[0218] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene monool with a viscosity of 25000cps, the antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, the dispersant is a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, the coupling agent is octadecyltriethoxysilane, the alumina is spherical alumina with an average particle size of 0.5μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 10μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 2μm, and the zinc oxide is needle-shaped with an average particle size of 0.5μm.

[0219] (1) Weigh 5 parts of polybutadiene monool with a viscosity of 25000cps, 0.5 parts of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, 1.5 parts of a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, 0.5 parts of octadecyltriethoxysilane, 20 parts of spherical alumina with an average particle size of 0.5μm, and 25 parts of needle-shaped zinc oxide with an average particle size of 0.5μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2000r / min and a dispersion time of 2min to obtain a mixture.

[0220] (2) Transfer the above mixture to a reactor, weigh 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 70 parts of spherical aluminum powder 1 with an average particle size of 10μm, and 45 parts of spherical aluminum powder 2 with an average particle size of 2μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25r / min, then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender for the next process.

[0221] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0222] Comparative Example 6

[0223] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0224] 3 parts of special wax

[0225] 5 parts of polyolefin

[0226] 0.5 parts antioxidant

[0227] 1.5 parts dispersant

[0228] 0.5 parts coupling agent

[0229] 20 parts of aluminum oxide

[0230] 170 parts aluminum powder

[0231] 245 parts aluminum powder

[0232] 25 parts zinc oxide

[0233] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene monool with a viscosity of 25000cps, the antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, the dispersant is a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, the coupling agent is octadecyltriethoxysilane, the alumina is spherical alumina with an average particle size of 0.5μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 10μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 2μm, and the zinc oxide is needle-shaped with an average particle size of 0.5μm.

[0234] (1) Weigh 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 5 parts of polybutadiene monool with a viscosity of 25000cps, 0.5 parts of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, 1.5 parts of a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, 0.5 parts of octadecyltriethoxysilane, 20 parts of spherical alumina with an average particle size of 0.5μm, and 25 parts of needle-shaped zinc oxide with an average particle size of 0.5μm and add them to the reactor. Stir at 115℃ for 1.5 hours at a stirring rate of 35r / min.

[0235] (2) Weigh 70 parts of spherical aluminum powder 1 with an average particle size of 10 μm and 45 parts of spherical aluminum powder 2 with an average particle size of 2 μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25 r / min, then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25 r / min and a vacuum degree of -0.09 MPa. After mixing, transfer the material to a calender and wait for the next process.

[0236] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0237] Example 7

[0238] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0239] 3 parts of special wax

[0240] 4.5 parts of polyolefin

[0241] 1 part antioxidant

[0242] 2 parts dispersant

[0243] 1 part coupling agent

[0244] 20 parts of aluminum oxide

[0245] 190 parts aluminum powder

[0246] Aluminum powder 2 40 parts

[0247] 20 parts zinc oxide

[0248] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is hydrogenated polybutadiene monool with a viscosity of 20000cps, the antioxidant is distearate pentaerythritol diphosphite, the dispersant is a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 5:1, the coupling agent is octadecyltrimethoxysilane, the alumina is spherical alumina with an average particle size of 2μm, aluminum powder 1 is spherical aluminum powder with an average particle size of 12μm, aluminum powder 2 is spherical aluminum powder with an average particle size of 3μm, and the zinc oxide is needle-shaped with an average particle size of 2μm.

[0249] (1) Weigh 4.5 parts of hydrogenated polybutadiene monool with a viscosity of 20000cps, 1 part of distearate pentaerythritol diphosphite, 2 parts of a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 5:1, 1 part of octadecyltrimethoxysilane, 20 parts of spherical alumina with an average particle size of 2μm, and 20 parts of needle-shaped zinc oxide with an average particle size of 2μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2200r / min and a dispersion time of 2min to obtain a mixture.

[0250] (2) Transfer the above mixture to a reactor, weigh 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 90 parts of spherical aluminum powder 1 with an average particle size of 12μm, and 40 parts of spherical aluminum powder 2 with an average particle size of 3μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25r / min, then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender for the next process.

[0251] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0252] Comparative Example 8

[0253] Conventional thermally conductive phase change materials

[0254] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0255] 3 parts paraffin

[0256] 5 parts of polybutadiene

[0257] 1 part antioxidant

[0258] 0.5 parts dispersant

[0259] 1 part coupling agent

[0260] 10 parts of aluminum oxide

[0261] 70 parts aluminum powder

[0262] 15 parts zinc oxide

[0263] Among them, paraffin wax has a melting point of 45-50℃, polybutadiene has a viscosity of 15000cps, antioxidant is β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionate octadecyl alcohol ester, dispersant is fatty acid polyethylene glycol ester, coupling agent is dodecyltrimethoxysilane, alumina is spherical alumina with an average particle size of 1.5μm, aluminum powder is spherical aluminum powder with an average particle size of 10μm, and zinc oxide is needle-shaped with an average particle size of 2μm.

[0264] (1) Weigh 3 parts of polybutadiene with a viscosity of 15000cps, 1 part of fatty acid polyethylene glycol ester, 0.5 parts of fatty acid polyethylene glycol ester, 1 part of dodecyltrimethoxysilane, 10 parts of spherical alumina with an average particle size of 1.5μm, and 15 parts of needle-shaped zinc oxide with an average particle size of 2μm. Add them to a material homogenizer and disperse them at high speed. The dispersion rate is 2200r / min and the dispersion time is 2min to obtain a mixture.

[0265] (2) Transfer the above mixture to a reactor, weigh 3 parts of paraffin wax with a melting point of 45-50℃ and 70 parts of spherical aluminum powder with an average particle size of 10μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25r / min, then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender for the next process.

[0266] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0267] Example 9

[0268] The anti-pumping thermally conductive phase change material, by weight, is composed of the following components:

[0269] Special wax 3

[0270] Polyolefin 5

[0271] Antioxidant 0.5

[0272] Dispersant 1.5

[0273] Coupling agent 0.5

[0274] Alumina 30

[0275] Aluminum nitride 60

[0276] Aluminum powder 40

[0277] Zinc oxide 30

[0278] Among them, the special wax is C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, the polyolefin is polybutadiene monool with a viscosity of 25000cps, the antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, the dispersant is a mixture of ethylene oxide alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, the coupling agent is octadecyltriethoxysilane, the alumina is spherical alumina with an average particle size of 1μm, the aluminum nitride is spherical aluminum nitride powder with an average particle size of 10μm, the aluminum powder is spherical aluminum powder with an average particle size of 5μm, and the zinc oxide is needle-shaped with an average particle size of 0.5μm.

[0279] (1) Weigh 5 parts of polybutadiene monool with a viscosity of 25000cps, 0.5 parts of bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, 1.5 parts of a mixture of ethylene alkyl ether phosphate and polyoxyethylene alkyl ether phosphate in a weight ratio of 10:1, 0.5 parts of octadecyltriethoxysilane, 30 parts of spherical alumina with an average particle size of 1μm, and 30 parts of needle-shaped zinc oxide with an average particle size of 0.5μm and add them to a material homogenizer for high-speed dispersion at a dispersion rate of 2000r / min and a dispersion time of 2min to obtain a mixture.

[0280] (2) Transfer the above mixture to a reactor, and weigh out 3 parts of C30-45 alkylmethyl silicone oil with a melting point of 73-77℃, 60 parts of spherical aluminum nitride with an average particle size of 10μm, and 40 parts of spherical aluminum powder with an average particle size of 2μm. Stir at 115℃ for 1.5 hours at a stirring rate of 25r / min, and then stir under vacuum at 115℃ for 2 hours at a stirring rate of 25r / min and a vacuum degree of -0.09Mpa. After mixing, transfer the material to a calender for the next process.

[0281] (3) The above materials are placed on a heating platform at 110°C to melt, covered with PET release film on the top and bottom, and calendered by a three-roll calender to obtain thermally conductive phase change material sheets and rolls.

[0282] Performance testing

[0283] Thermal resistance test: Used to evaluate the thermal properties of thermally conductive phase change materials. The thermal resistance of the thermally conductive phase change materials in Examples 1-8 was tested using an LW-9398 interfacial thermal resistance tester, according to ASTM D5470. The thickness of the thermally conductive phase change materials was 0.25 mm. The pressure applied to the thermal interface material was 40 PSI, the test time was 20 minutes, and the temperature was 80°C.

[0284] Thermal conductivity test: used to evaluate the viscosity of thermally conductive phase change materials. The thermal conductivity of thermally conductive phase change materials in Examples 1-8 was tested using a HOTDISK thermal constant analyzer. The test standard was ISO 22007-2, and the thickness of the thermally conductive phase change materials was 4 mm.

[0285] Pump-out test: Used to evaluate the reliability of thermally conductive phase change materials. The test fixture includes a 30*50mm bare chip and a 30*50mm aluminum heat sink. The thermally conductive phase change materials from Examples 1 to 8 are placed on the chip, and the heat sink is placed on top, applying a pressure of 14 psi to the chip. The assembled chip and heat sink fixture is subjected to a temperature cycle of -40 to 125°C, with a heating / cooling rate of 11°C / min, holding at -40°C and 125°C for 15 minutes each, for 1 hour per cycle, for a total of 350 cycles. After the test, the heat sink is removed, and the degradation of the thermally conductive phase change material morphology on both sides of the heat sink and chip assembly is inspected to calculate the pump-out ratio. Pump-out ratio = (pump-out area / chip area) × 100%.

[0286] See Table 1, which shows the statistical results of the test performance of Examples 1 to 9 of the present invention.

[0287] Table 1

[0288]

[0289] Table 1 shows that the thermally conductive phase change materials prepared in Examples 5 and 9 have low thermal resistance and low pumping rates. Comparing Example 5 and Example 6, the thermally conductive phase change material prepared in Example 5 has low thermal resistance and a low pumping rate. The thermally conductive phase change material prepared in Example 6 using a stirring method has high thermal resistance and a high pumping rate. This confirms that poor dispersion of small-particle thermally conductive fillers leads to increased thermal resistance and a higher pumping rate.

[0290] The foregoing has provided a detailed description of the anti-pumping thermally conductive phase change material, its preparation method, and its applications. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A thermally conductive phase change material, characterized in that, Calculated by raw material mass fraction, including: 3-15 parts by weight of a special wax with a melting point of 30-80℃; 5-20 parts by weight of polyolefin; Antioxidant 0.5-5 parts by weight; Dispersant 0.3~3 parts by weight; 0.1 to 1 part by weight of coupling agent; 40-180 parts by weight of thermally conductive filler; The special wax with a melting point of 30~80℃ is a C20~C45 alkyl polymethylsiloxane; The polyolefin includes one or more of polybutadiene, polybutadiene monool, hydrogenated polybutadiene monool, polybutadiene diol, hydrogenated polybutadiene diol, polypropylene diol, hydrogenated polypropylene diol, styrene-butadiene rubber, butadiene-styrene copolymer, epoxidized polybutadiene, and maleic anhydride addition polybutadiene. The antioxidants include one or more of the following: tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, distearate pentaerythritol diphosphite, pentaerythritol tetraester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,2-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, dodecyl thiodipropionate, bis(1,2,2,6,6)-pentamethyl-4-piperidinyl sebacate, tetramethylpiperidinamine, and N,N-diphenyl-p-phenylenediamine; The dispersant includes polyoxyethylene alkyl ether phosphate and / or polyoxyethylene alkyl ether; The coupling agent includes one or more of hexadecyltrimethoxysilane, hexadecylmethyldimethoxysilane, hexadecyltriethoxysilane, hexadecylmethyldiethoxysilane, octadecyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltriethylsilane, and octadecylmethyldiethoxysilane. The thermally conductive filler includes a variety of materials such as alumina, zinc oxide, aluminum nitride, boron nitride, diamond, boron nitride, silicon nitride, aluminum, copper, silver, indium, and nickel-plated copper.

2. The thermally conductive phase change material of claim 1, wherein, The thermally conductive filler includes one or more of alumina, aluminum, zinc oxide, boron nitride, and aluminum nitride.

3. The thermally conductive phase change material of claim 1, wherein, The thermally conductive phase change material is specifically an anti-pumping thermally conductive phase change material.

4. The thermally conductive phase change material according to claim 2, characterized in that, The thermally conductive filler includes spherical aluminum particles with an average particle size of 5-18 μm, spherical aluminum particles with an average particle size of 1-4 μm, zinc oxide particles with an average particle size of 0.03-2 μm, and alumina particles with an average particle size of 0.03-1 μm. The amount of spherical aluminum particles added is 15-160 parts by weight, the amount of zinc oxide particles added is 10-40 parts by weight, and the amount of alumina particles added is 10-40 parts by weight.

5. The thermally conductive phase change material according to claim 2, characterized in that, The thermally conductive filler includes aluminum powder with an average particle size of 5-18 μm, aluminum nitride particles with an average particle size of 5-15 μm, zinc oxide particles with an average particle size of 0.03-2 μm, and aluminum oxide particles with an average particle size of 0.03-1 μm. The amount of aluminum powder added is 15-40 parts by weight, the amount of aluminum nitride particles added is 10-60 parts by weight, the amount of zinc oxide particles added is 10-40 parts by weight, and the amount of aluminum oxide particles added is 10-40 parts by weight. The thermally conductive phase change material includes a thermally conductive phase change material used for chip heat dissipation.

6. A method for preparing a thermally conductive phase change material as described in claim 1, characterized in that, Includes the following steps: 1) After homogenizing polyolefin, antioxidant, coupling agent, dispersant and some thermally conductive filler, a masterbatch is obtained; 2) After heating and mixing the masterbatch and special wax obtained in the above steps, add the remaining thermally conductive fillers and continue mixing to obtain the prepared material; 3) After the materials prepared in the above steps are calendered, thermally conductive phase change materials are obtained.

7. The preparation method according to claim 6, characterized in that, The homogeneous dispersion rate is 1500~2500 r / min; The thermally conductive filler includes zinc oxide particles with an average particle size of 0.03~2μm and alumina particles with an average particle size of 0.030~1μm.

8. The preparation method according to claim 6, characterized in that, The heating temperature is 100~120℃.

9. The preparation method according to claim 6, characterized in that, The temperature for continued mixing is 100~120℃; The mixing time is 0.5 to 2 hours; The rolling temperature is 100~150℃.

10. The application of the thermally conductive phase change material according to any one of claims 1 to 5 or the thermally conductive phase change material prepared by the preparation method according to any one of claims 6 to 9 in chip heat dissipation materials.

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