阅读说明：本技术 一种绝缘超高导热复合材料的制造方法 (Manufacturing method of insulating ultrahigh heat conduction composite material ) 是由 胡黎明 肖扬华 陈武洲 缪宗倍 于 2021-06-29 设计创作，主要内容包括：本发明公开了一种绝缘超高导热复合材料的制造方法,包括：剪切强度控制微纳粉体分散与复合工艺、颗粒表面分子当量叠层改性工艺、流体介质置换工艺三道工序；三道工序合并在一个反应器中进行,或将三道工序任意分组在两个反应器中进行,或者将三道工序分别在三个反应器中进行。本发明能够将纳米和微米粉体分散为“一次粒径”,并达到微纳颗粒复合和级配效果；粉体体积添加分数可达到85.3％；绝缘导热界面材料(STIM)的导热系数均大于6W/(m.K)、达到11.03W/(m.K)；工艺过程简单、设备具有通用性、制造成本低,适于工业化应用。(The invention discloses a manufacturing method of an insulating ultrahigh heat conduction composite material, which comprises the following steps: three procedures of a micro-nano powder dispersion and compounding process, a particle surface molecular equivalent lamination modification process and a fluid medium replacement process are controlled by shear strength; the three processes are combined and carried out in one reactor, or the three processes are arbitrarily grouped and carried out in two reactors, or the three processes are respectively carried out in three reactors. The invention can disperse the nano and micron powder into primary particle size and achieve the compounding and grading effect of the micro-nano particles; the volume addition fraction of the powder can reach 85.3 percent; the thermal conductivity coefficients of the insulating and heat-conducting interface material (STIM) are both greater than 6W/(m.K) and up to 11.03W/(m.K); simple technological process, universal equipment and low manufacturing cost, and is suitable for industrial application.)

1. A manufacturing method of an insulating ultrahigh heat-conducting composite material is characterized by comprising the following steps: three procedures of a micro-nano powder dispersion and compounding process, a particle surface molecular equivalent lamination modification process and a fluid medium replacement process are controlled by shear strength; and sequentially combining the three processes in one reactor, or randomly grouping the three processes in two reactors, or respectively carrying out the three processes in three reactors.

2. The manufacturing method of the insulating ultrahigh heat-conducting composite material according to claim 1, wherein the shear strength control micro-nano powder dispersion and compounding process comprises: controlling the shearing strength of the stator and the rotor in a suspension system of a fluid medium, depolymerizing and dispersing the nano agglomerated powder into primary particle size nano slurry, or depolymerizing and dispersing the submicron agglomerated powder into primary particle size submicron slurry, or synchronously depolymerizing, dispersing and mixing the nano powder, the submicron powder and the micron powder into primary particle size micro-nano composite slurry; the three steps are carried out in one reactor, or in two reactors, or in three reactors respectively; the shear strength control comprises the steps of replacing the diameters of the stator and the rotor and adjusting the rotating speed, and the shear strength is controlled to be (1200-233000) s^-1Controlling the temperature of the slurry within the range of (0-175) DEG C and maintaining the temperature for (0.1-6) hours; the shear strength is controlled according to equation (1),

in the formula (1), the reaction mixture is,

S_sshear strength, unified or converted units of "1/second" or s^-1，

V-the rotational linear velocity of the outer diameter of the rotor, or the relative rotational linear velocity of the outer diameter of an adjacent pair of rotors, is unified or converted into units of "m/s" or m/s,

delta-the minimum clearance between adjacent stators and rotors, or between adjacent rotors and rotors, either in unity or scaled units of "meters" or m.

3. The insulating ultrahigh thermal conductive composite material of claim 1The manufacturing method is characterized in that the lamination modification process of the particle surface molecular equivalent comprises the following steps: after the dispersion and compounding process of the micro-nano powder is controlled by the shear strength, the shear strength is reduced to (120-40000) s^-1To (c) to (d); adding a modifier, controlling the temperature of the slurry to be in the range of (0-175) DEG C in the reactor under negative pressure or normal pressure or positive pressure, and continuously stirring and mixing the modifier and the powder for (0.1-6) h by means of a stator and a rotor or a stirring paddle; drawing by taking the sedimentation volume of powder in the slurry or the thickness of a fluid medium adsorbed on the surface of powder particles as a vertical coordinate (function) and taking the addition amount of a modifier as a horizontal coordinate (independent variable), and connecting the two into a wavy line or an L-shaped curve or regressing an associated equation of the function and the independent variable; on the wavy line or the L-shaped curve or in the correlation equation, the addition amount of the modifier corresponding to the first valley is taken as the modification addition amount of the monolayer, the addition amount of the modifier corresponding to the first peak is taken as the modification addition amount of the bilayer, the addition amount of the modifier corresponding to the second valley is taken as the modification addition amount of the trilayer, the addition amount of the modifier corresponding to the second peak is taken as the modification addition amount of the quarteyer, and the like, so that the equivalent ratio between the surface functional group of the particle and the functional group of the modifier is controlled.

4. The method of claim 1, wherein the fluid medium displacement process comprises: adding liquid or fluid high molecular polymer into the slurry after the lamination modification process of the particle surface molecular equivalent; closing a gate valve entering and exiting the inner cavity of the reactor, keeping a vacuum pipeline to be communicated and closed, and heating to 80-225 ℃; in order to prevent bumping, the pressure in the reactor is controlled within the range of (0 to-0.1) MPa to gradually increase the vacuum degree in a grading manner, when the pressure corresponding to the vacuum degree is within the range of (-0.03 to-0.1) MPa, the stirring is accumulated for 0.5 to 4 hours, the pressure corresponding to the vacuum degree is continuously maintained within the range of (-0.05 to-0.1) MPa, the temperature is reduced while the stirring is carried out, then the stirring is stopped firstly, and the vacuum degree is finally relieved (or the normal pressure is recovered); the pressure is a gauge pressure.

5. The method of claim 1, wherein the fluid medium comprises: the organic solvent (such as but not limited to methanol, ethanol, acetone, methyl ethyl ketone, petroleum ether, ethyl acetate, isopropanol, alkane with 5-8 carbon atoms, D80 solvent and D90 solvent), liquid ammonia, liquid carbon dioxide and water.

6. The method of manufacturing an insulated ultrahigh thermal conductive composite material according to claim 1, wherein the reactor comprises: at least one of a kneader with or without a jacket, a planetary stirrer and a chemical reaction kettle; the material of the reactor comprises at least one of metal, enamel, glass and ceramic; the shape of the inner cavity of the reactor comprises any one of a cuboid, a cylinder, an ellipsoid and a sphere, or a combination formed by connecting any two of the cuboid, the cylinder, the ellipsoid and the sphere.

7. The method of manufacturing an insulated ultrahigh thermal conductive composite material according to claim 2, wherein the stator and the rotor comprise: at least one of comb-shaped, bar-shaped, blade-shaped, and disk-shaped; the comb-shaped stator and the rotor are respectively fixed at the ends of the two sleeve-type concentric shafts, the distance between the comb teeth is 0.5-15 mm, the width of the comb teeth is 0.5-15 mm, and the length of the comb teeth is 5-250 mm; one end of each rod-shaped stator is fixed on the inner wall of the reactor barrel, the axis of each rod-shaped stator is perpendicular to the inner wall of the reactor or forms an included angle of 60-120 degrees, the number of the rod-shaped stators is at least one row, and each row of the rod-shaped stators is at least two; one end of each rod-shaped rotor is fixed on at least one rotating shaft, the axis of each rod-shaped rotor and the axis of each rotating shaft keep a vertical or (60-120) degree included angle, and each rotating shaft is provided with at least one rotor; the blade-shaped stator and the rotor are used for flattening the rod-shaped stator and the rotor in order to save space, and the installation and fixing modes of the blade-shaped stator and the rotor are the same as those of a rod; the disc-shaped stator and the rotor are respectively fixed at the ends of the two shafts, the two shafts are in coaxial butt joint, and the disc-shaped stator and the rotor are controlled by adjusting the distance between the ends of the two shaftsThe gap of (a); the minimum distance between the stator and the rotor is in the range of (0.15-3) mm; the stator and the rotor are made of metal, and titanium nitride (Ti) is infiltrated on the surface of the metal₂N₂) Zirconium dioxide (ZrO)₂) Ceramics, silicon carbide (SiC) ceramics, boron carbide (B)₄C) Ceramic, titanium diboride (TiB)₂) At least one of ceramics.

8. The method for manufacturing the insulating ultrahigh heat-conducting composite material according to claim 1, wherein the chemical components of the powder comprise: aluminum oxide (Al)₂O₃) Magnesium oxide (MgO), silicon dioxide (SiO)₂) Aluminum nitride (AlN), Boron Nitride (BN), zinc oxide (ZnO), silicon nitride (Si)₃N₄) Silicon carbide (SiC), aluminum hydroxide [ Al (OH) ]₃]Magnesium hydroxide [ Mg (OH) ]₂]Ammonium polyphosphate (APP), aluminum hypophosphite [ Al (H)₂PO₂)₃]Calcium carbonate (CaCO)₃) At least one of PVC, diamond (C); the particle morphology of the powder comprises at least one of a sphere, a sphere-like shape, a special-shaped body, a hexagon, a cuboid, a sheet body and a fiber, and is identified by a Transmission Electron Microscope (TEM) or a Scanning Electron Microscope (SEM).

9. The method for manufacturing the insulating ultra-high thermal conductive composite material as claimed in claim 2, wherein: the nano powder has an average particle diameter D₅₀Powder in the range of (1-100) nm; the submicron powder has an average particle diameter D₅₀Powder in the range of (0.11-1.0) mu m; the average particle diameter of the micro powder is D₅₀Powder in the range of (1.1 to 130) mu m.

10. The method of claim 3, wherein the modifier comprises: hexadecyl trimethoxysilane [ CAS: 16415-12-6], hexadecyltriethoxysilane [ CAS: 16415-13-7], gamma- (2, 3-glycidoxy) propyltrimethoxysilane [ CAS: 2530-83-8], gamma- (2, 3-epoxypropoxy) propyltriethoxysilane [ CAS: 2602-34-8], gamma-aminopropyltrimethoxysilane [ CAS: 13822-56-5], gamma-aminopropyltriethoxysilane [ CAS: 919-30-2), n- (β -aminoethyl) - γ -aminopropyltrimethoxysilane [ CAS: 1760-24-3), n- (β -aminoethyl) - γ -aminopropyltriethoxysilane [ CAS: 5089-72-5], gamma- (methacryloyloxy) propyltrimethoxysilane [ CAS: 2530-85-0], gamma- (methacryloyloxy) propyltriethoxysilane [ CAS: 21142-29-0], gamma-diethylenetriaminepropylmethyldimethoxysilane [ CAS: 99740-64-4 ]; or isopropyldioleacyloxy (dioctylphosphatoxy) titanate [ CAS: 61417-49-0], isopropyltris (dioctylphosphonoxy) titanate [ CAS: 65345-34-8], isopropyl triisostearate [ CAS: 61417-49-0], bis (dioctyloxypyrophosphate) ethylene titanate [ CAS: 65467-75-6], tetraisopropylbis (dioctylphosphatoxy) titanate [ CAS: 65460-52-8 ]; or at least one organic acid (for example, but not limited to stearic acid [ CAS: 57-11-4], oleic acid [ CAS: 112-80-1], lauric acid [ CAS: 143-07-7], caprylic acid [ CAS: 124-07-2], ricinoleic acid [ CAS: 141-22-0], abietic acid [ CAS: 514-10-3], salicylic acid [ CAS: 69-72-7], benzoic acid [ CAS: 65-85-0], dodecylbenzenesulfonic acid [ CAS: 27176-87-0], and benzotriazole [ CAS: 95-14-7 ]).

11. The method of claim 4, wherein the liquid or fluid polymer comprises: at least one of polyisocyanate prepolymer, epoxy resin, multi-terminal epoxy ether alkylene alkyl siloxane, multi-terminal amino alkylene siloxane, multi-terminal amino polymer and methyl vinyl silicone oil;

the molecular structural general formula of the polyisocyanate prepolymer is OCN-R₁-NCO；

The general formula of the molecular structure of the epoxy resin is

The general molecular structure formula of the multi-terminal epoxy ether group alkylene alkyl siloxane is shown in the specification

The general molecular structure formula of the multi-terminal amino alkylene siloxane is shown in the specification

The general molecular structure formula of the multi-terminal amino polymer is

The R is₁、R₇Respectively comprises at least one of methyl alkoxy alkylene, phenylene, substituted phenylene, aromatic cyclopropene, substituted aromatic cyclopropene, heterocyclic ring support or substituted heterocyclic ring support; the R is₂At least one alkylene group having 2 to 5 carbon atoms; the R is₃、R₄、R₅、R₆Respectively is at least one of alkyl, phenyl, substituted phenyl, aromatic ring group, substituted aromatic ring group, heterocyclic group or substituted heterocyclic group; m is more than or equal to 0, n is more than or equal to 1, and m and n are integers.

Technical Field

The invention relates to a design and manufacturing technology in the intersection field of polymer-based composite high polymer materials, high-strength bonding structure materials and ultrahigh heat conduction functional materials, in particular to a manufacturing method of an insulating ultrahigh heat conduction composite material formed by shear strength control micro-nano powder dispersion and compounding, particle surface molecular equivalent lamination modification and fluid medium replacement.

Background

In the technical field of rapidly developed miniaturized, highly integrated and functionally diversified 5G/6G electronic chips and application equipment thereof, the heat flux density generated by the chips in the operation process of the equipment is increasingly high. In the visible future, the use of insulating ultra-high thermal interface materials (STIM) to solve the heat dissipation problem of the chip is still the preferred technical approach. However, the thermal conductivity of the insulating and heat conducting interface materials used in large scale in the conventional thermal management system technology is below 6W/(m.k), and most of the materials are below 5W/(m.k), so that the materials cannot meet the requirements of higher and higher heat dissipation loads.

For example, in 5G/6G equipment, the heat dissipation of the chip requires that the heat conductivity coefficient of the heat-conducting interface material is between 6 and 10W/(m.K); on a civil unmanned aerial vehicle chip, the heat conductivity coefficient is required to be 7-9W/(m.K) by using heat-conducting gel; some military equipment has higher requirements on the heat conductivity coefficient of the heat-conducting interface material.

These constitute market demands for high-end insulating and thermally conductive interface materials.

Although the heat conductivity coefficient of some heat-conducting gels on the market reaches 11W/(m.K), the comprehensive physical, chemical and electrical properties of the heat-conducting gels cannot meet the requirements of field application, so that the heat-conducting gels are difficult to popularize and apply on a large scale. For example, the sag resistance difference may be lost in summer, or a pressure may be applied to the wafer to increase its viscosity, which may damage the wafer, or the cost may be too high.

At present, the insulating and heat-conducting interface material is formed by compounding heat-conducting powder and a liquid organic polymer material and adopts two application forms of solidification or non-solidification. The organic polymer material has good insulation property, but the heat conductivity coefficient is mostly below 0.25W/(m.K), the task of improving the heat conductivity coefficient of the composite material falls to the aspect of improving the filling amount of the heat-conducting powder in unit volume, the volume fraction of the heat-conducting powder needs to be added to (61-85)% to greatly improve the heat conductivity coefficient, but the ultrahigh volume addition amount of the heat-conducting powder not only can cause the product to have overlarge viscosity and be unusable, but also is difficult to process on a production line. Although researchers at home and abroad develop various researches on the method, up to now, the results that the method can be industrialized in a large scale through technical feasibility and economic feasibility evaluation are not reported, and the method still stays in the state of high cost, small-scale exploration or unpublished technical details.

In general, the current research directions at home and abroad mainly include five aspects, such as: the method comprises the following steps of selecting the existing powder chemical material, developing a homogeneous material with higher heat conductivity coefficient, modifying the surface of powder particles, grading micron powder particles, compounding micro-nano powder particles and grading:

1) the selection of the existing powder chemical materials comprises element selection, crystal form selection and particle morphology selection. The aluminum oxide is the heat-conducting powder which has the highest cost performance and the widest application at present, but because the heat conductivity coefficient of the aluminum oxide is lower than 20-39W/(m.K), when the addition amount of the aluminum oxide is less than 75% of the micron-sized volume fraction, the improvement of the heat conductivity coefficient of the heat-conducting interface material is limited, and the aim of more than 6W/(m.K) cannot be achieved, and the addition amount of the volume fraction is difficult to be improved to more than 75% in the prior art; the bulk thermal conductivity of boron nitride is higher than 60-125W/(m.K), but the boron nitride is difficult to organically modify on the surface, so that the boron nitride is poor in compatibility with an organic polymer material, the addition amount of the boron nitride in the organic polymer material is difficult to increase, and the thermal conductivity is difficult to increase to more than 6W/(m.K); the heat conductivity coefficient of the aluminum nitride is 80-320W/(m.K), but the aluminum nitride is expensive, easy to hydrolyze and poor in weather resistance, and although some enterprises call hydrolysis resistance, the test result of the aluminum nitride powder product at home and abroad is basically hydrolyzed after an aging test (300-500) h at 85 ℃ and 85% humidity at present; although the diamond or diamond-like powder has high heat conductivity coefficient, the price is too high, and the diamond or diamond-like powder is economically difficult to popularize and apply on a large scale; as for materials such as graphene, carbon nanotubes, graphite flakes, copper powder, aluminum powder, silver powder, etc., the insulation problem is difficult to solve. Therefore, the selection route of the existing powder chemical material is close to the limit.

2) The development of homogeneous materials with higher heat conductivity coefficient comprises the development of heat-conducting powder and resin, but the development of the novel heat-conducting powder is difficult to break through the heat conductivity coefficient of the single crystal diamond so far, the cost is extremely high, and the large-scale industrialization is difficult in the visible future; the development of new heat-conducting resins has not been a breakthrough or is far from industrialization.

3) Powder particle surface modification, including dry modification and wet modification, compared with dry modification, wet modification has higher powder surface coating rate, but in the later period of wet modification, the powder needs grinding and depolymerization processes after drying, the powder surface modification layer is damaged, and the method does not solve the agglomeration problem of the nano powder. Although there are many mature powder surface modification technologies, the technologies are concentrated on the micrometer scale section, and the marginal utility is greatly reduced, the potential is limited, and the prospect is close to the limit.

4) Grading of micron powder particles from experience to theory^[1，2]The method is relatively mature, the marginal utility of the micron-sized particle grading technology is remarkably reduced, and the development prospect is close to the limit; if the particle size distribution needs to be extended to the nanometer scale, the world-level problem of secondary agglomeration of the nanometer powder needs to be solved first, and the method is also one of the main attack directions of research.

5) The micro-nano powder particle compounding and grading, namely dispersing and compounding nano particles on the surface of micro powder particles, increasing the number of particle size grading levels and needing to be cooperated with a comprehensive means of nano powder surface modification. On the premise of feasible process viscosity and processability, the volume addition amount of the heat-conducting powder in the heat-conducting interface material can be increased to the maximum extent. However, no dispersed nano powder product with 'primary particle size' exists in the market at present, only the agglomerated nano powder is sold, and the agglomerated nano powder still belongs to micron-scale powder, so that the grading effect can not be realized, and the nano effect can not be realized; or special equipment can be used for depolymerizing the aggregated nano powder, but the depolymerized nano powder is effective only when being used along with the decomposition, and the storage and transportation process is about to reunite and fail after exceeding a certain time period, so that not only is too much additional cost added to production, but also the micro-nano powder particle compounding and grading cannot be accurate.

For example, chinese patent CN107603224 "a high thermal conductivity, low viscosity thermal conductive silicone grease composition and preparation method". Although the method introduces the technology of improving the addition of material powder and modifying the surface of the powder by compounding nano powder, submicron powder and micron powder in multiple stages, the method also adopts a conventional planetary stirring mode, the patent cannot disperse the nano powder and the submicron powder into primary particle size and mix uniformly, the effects of micro-nano compounding and precise grading cannot be achieved, and the prepared heat-conducting silicone grease has a heat conductivity coefficient of only about 4W/(m.K), and cannot meet the requirements of the high-end market.

For another example, chinese patent CN 110713692a "preparation method of micro-nano co-doped composite insulating dielectric material, composite filler for insulating dielectric material, and insulating dielectric material", refers to the steps of: and uniformly mixing the epoxy resin, the first filler, the second filler and the curing agent, and curing to obtain the epoxy resin. This patent application also does not address the problem of deagglomerating the agglomerated nanoparticles to a "primary particle size" and dispersing in the interstices or on the surface of the micropowder particles, and also fails to address the needs of the high-end market mentioned above.

Therefore, a three-dimensional integrated manufacturing process of micro-nano powder dispersion and compounding, particle surface molecular equivalent lamination modification and fluid medium replacement needs to be invented, so that secondary agglomeration of nano particles can be avoided, the effects of precise gradation and obvious viscosity reduction are achieved, the volume fraction addition amount of the heat-conducting powder in the heat-conducting interface material is increased to the maximum extent on the premise of processability, and finally the heat conductivity coefficient of the heat-conducting interface material is increased to more than 6W/(m.K) at low cost.

Reference to the literature

[1] Xiaoyanghua, "particle grading optimization research-rolling grading method", advanced technology, 1993, 4: 60-67.

[2] Li Yonghong et al, "study of process performance of composite propellant slurry-gradient particle grading model", the proceedings of the fifth national chemical propellant academic conference of the Chinese chemical society, 2011-09-15.

Disclosure of Invention

The invention aims to provide a three-in-one integrated manufacturing process for controlling dispersion and compounding of micro-nano powder, stacking modification of particle surface molecular equivalent and replacement of fluid medium by shear strength so as to prepare a cheap insulating ultrahigh heat-conducting interface material and ensure that the heat conductivity coefficients of a curing type heat-conducting interface material and a non-curing type heat-conducting interface material can reach more than 6W/(m.K).

In order to achieve the above object, the present invention provides a method for manufacturing an insulating ultrahigh thermal conductive composite material, comprising: three procedures of a micro-nano powder dispersion and compounding process, a particle surface molecular equivalent lamination modification process and a fluid medium replacement process are controlled by shear strength; and sequentially combining the three processes in one reactor, or randomly grouping the three processes in two reactors, or respectively carrying out the three processes in three reactors.

Further, the shear strength control micro-nano powder dispersion and compounding process comprises the following steps: controlling the shearing strength of the stator and the rotor in a suspension system of a fluid medium, depolymerizing and dispersing the nano agglomerated powder into primary particle size nano slurry, or depolymerizing and dispersing the submicron agglomerated powder into primary particle size submicron slurry, or synchronously depolymerizing, dispersing and mixing the nano powder, the submicron powder and the micron powder into primary particle size micro-nano composite slurry; the three steps are carried out in one reactor, or in two reactors, or in three reactors respectively; the shear strength control comprises the steps of replacing the diameters of the stator and the rotor and adjusting the rotating speed, and the shear strength is controlled to be (1200-233000) s^-1Controlling the temperature of the slurry within the range of (0-175) DEG C and maintaining the temperature for (0.1-6) hours; the shear strength is controlled according to equation (1),

in the formula (1), the reaction mixture is,

S_sshear strength, unified or converted units of "1/second" or s^-1，

V-the rotational linear velocity of the outer diameter of the rotor, or the relative rotational linear velocity of the outer diameter of an adjacent pair of rotors, is unified or converted into units of "m/s" or m/s,

delta-the minimum clearance between adjacent stators and rotors, or between adjacent rotors and rotors, either in unity or scaled units of "meters" or m.

Further, the particle surface molecular equivalent lamination modification process comprises the following steps: after the dispersion and compounding process of the micro-nano powder is controlled by the shear strength, the shear strength is reduced to (120-40000) s^-1To (c) to (d); adding a modifier, controlling the temperature of the slurry to be in the range of (0-175) DEG C in the reactor under negative pressure or normal pressure or positive pressure, and continuously stirring and mixing the modifier and the powder for (0.1-6) h by means of a stator and a rotor or a stirring paddle; drawing by taking the sedimentation volume of powder in the slurry or the thickness of a fluid medium adsorbed on the surface of powder particles as a vertical coordinate (function) and taking the addition amount of a modifier as a horizontal coordinate (independent variable), and connecting the two into a wavy line or an L-shaped curve or regressing an associated equation of the function and the independent variable; on the wavy line or the L-shaped curve or in the correlation equation, the addition amount of the modifier corresponding to the first valley is taken as the modification addition amount of the monolayer, the addition amount of the modifier corresponding to the first peak is taken as the modification addition amount of the bilayer, the addition amount of the modifier corresponding to the second valley is taken as the modification addition amount of the trilayer, the addition amount of the modifier corresponding to the second peak is taken as the modification addition amount of the quarteyer, and the like, so that the equivalent ratio between the surface functional group of the particle and the functional group of the modifier is controlled.

Further, the fluid medium replacement process comprises: adding liquid or fluid high molecular polymer into the slurry after the lamination modification process of the particle surface molecular equivalent; closing a gate valve entering and exiting the inner cavity of the reactor, keeping a vacuum pipeline to be communicated and closed, and heating to 80-225 ℃; in order to prevent bumping, the pressure in the reactor is controlled within the range of (0 to-0.1) MPa to gradually increase the vacuum degree in a grading manner, when the pressure corresponding to the vacuum degree is within the range of (-0.03 to-0.1) MPa, the stirring is accumulated for 0.5 to 4 hours, the pressure corresponding to the vacuum degree is continuously maintained within the range of (-0.05 to-0.1) MPa, the temperature is reduced while the stirring is carried out, then the stirring is stopped firstly, and the vacuum degree is finally relieved (or the normal pressure is recovered); the pressure is a gauge pressure.

Further, the fluid medium includes: the organic solvent (such as but not limited to methanol, ethanol, acetone, methyl ethyl ketone, petroleum ether, ethyl acetate, isopropanol, alkane with 5-8 carbon atoms, D80 solvent and D90 solvent), liquid ammonia, liquid carbon dioxide and water.

Further, the reactor comprises: at least one of a kneader with or without a jacket, a planetary stirrer and a chemical reaction kettle; the material of the reactor comprises at least one of metal, enamel, glass and ceramic; the shape of the inner cavity of the reactor comprises any one of a cuboid, a cylinder, an ellipsoid and a sphere, or a combination formed by connecting any two of the cuboid, the cylinder, the ellipsoid and the sphere.

Wherein the stator and the rotor include: at least one of comb-shaped, bar-shaped, blade-shaped, and disk-shaped; the comb-shaped stator and the rotor are respectively fixed at the ends of the two sleeve-type concentric shafts, the distance between the comb teeth is 0.5-15 mm, the width of the comb teeth is 0.5-15 mm, and the length of the comb teeth is 5-250 mm; one end of each rod-shaped stator is fixed on the inner wall of the reactor barrel, the axis of each rod-shaped stator is perpendicular to the inner wall of the reactor or forms an included angle of 60-120 degrees, the number of the rod-shaped stators is at least one row, and each row of the rod-shaped stators is at least two; one end of each rod-shaped rotor is fixed on at least one rotating shaft, the axis of each rod-shaped rotor and the axis of each rotating shaft keep a vertical or (60-120) degree included angle, and each rotating shaft is provided with at least one rotor; the blade-shaped stator and the rotor are used for flattening the rod-shaped stator and the rotor in order to save space, and the installation and fixing modes of the blade-shaped stator and the rotor are the same as those of a rod; the disc-shaped stator and the rotor are respectively fixed at the ends of the two shafts, the two shafts are in coaxial butt joint, and the gap between the disc-shaped stator and the rotor is controlled by adjusting the distance between the ends of the two shafts; minimum distance between the stator and the rotorIn the range of (0.15-3) mm; the stator and the rotor are made of metal, and titanium nitride (Ti) is infiltrated on the surface of the metal₂N₂) Zirconium dioxide (ZrO)₂) Ceramics, silicon carbide (SiC) ceramics, boron carbide (B)₄C) Ceramic, titanium diboride (TiB)₂) At least one of ceramics.

Wherein the chemical composition of the powder comprises aluminum oxide (Al)₂O₃) Magnesium oxide (MgO), silicon dioxide (SiO)₂) Aluminum nitride (AlN), Boron Nitride (BN), zinc oxide (ZnO), silicon nitride (Si)₃N₄) Silicon carbide (SiC), aluminum hydroxide [ Al (OH) ]₃]Magnesium hydroxide [ Mg (OH) ]₂]Ammonium polyphosphate (APP), aluminum hypophosphite [ Al (H)₂PO₂)₃]Calcium carbonate (CaCO)₃) At least one of PVC, diamond (C); the particle morphology of the powder comprises at least one of a sphere, a sphere-like shape, a special-shaped body, a hexagon, a cuboid, a sheet body and a fiber, and is identified by a Transmission Electron Microscope (TEM) or a Scanning Electron Microscope (SEM).

Wherein the nano powder has an average particle diameter D₅₀Powder in the range of (1-100) nm.

Wherein the submicron powder has an average particle diameter D₅₀A powder having a particle size of (0.11 to 1.0) μm.

Wherein the micron powder has an average particle diameter D₅₀Powder in the range of (1.1 to 130) mu m.

Wherein the modifier comprises: hexadecyl trimethoxysilane [ CAS: 16415-12-6], hexadecyltriethoxysilane [ CAS: 16415-13-7], gamma- (2, 3-glycidoxy) propyltrimethoxysilane [ CAS: 2530-83-8], gamma- (2, 3-epoxypropoxy) propyltriethoxysilane [ CAS: 2602-34-8], gamma-aminopropyltrimethoxysilane [ CAS: 13822-56-5], gamma-aminopropyltriethoxysilane [ CAS: 919-30-2), n- (β -aminoethyl) - γ -aminopropyltrimethoxysilane [ CAS: 1760-24-3), n- (β -aminoethyl) - γ -aminopropyltriethoxysilane [ CAS: 5089-72-5], gamma- (methacryloyloxy) propyltrimethoxysilane [ CAS: 2530-85-0], gamma- (methacryloyloxy) propyltriethoxysilane [ CAS: 21142-29-0], gamma-diethylenetriaminepropylmethyldimethoxysilane [ CAS: 99740-64-4 ]; or isopropyldioleacyloxy (dioctylphosphatoxy) titanate [ CAS: 61417-49-0], isopropyltris (dioctylphosphonoxy) titanate [ CAS: 65345-34-8], isopropyl triisostearate [ CAS: 61417-49-0], bis (dioctyloxypyrophosphate) ethylene titanate [ CAS: 65467-75-6], tetraisopropylbis (dioctylphosphatoxy) titanate [ CAS: 65460-52-8 ]; or at least one organic acid (for example, but not limited to stearic acid [ CAS: 57-11-4], oleic acid [ CAS: 112-80-1], lauric acid [ CAS: 143-07-7], caprylic acid [ CAS: 124-07-2], ricinoleic acid [ CAS: 141-22-0], abietic acid [ CAS: 514-10-3], salicylic acid [ CAS: 69-72-7], benzoic acid [ CAS: 65-85-0], dodecylbenzenesulfonic acid [ CAS: 27176-87-0], and benzotriazole [ CAS: 95-14-7 ]).

Wherein the liquid or fluid state high molecular polymer comprises: at least one of polyisocyanate prepolymer, epoxy resin, multi-terminal epoxy ether alkylene alkyl siloxane, multi-terminal amino alkylene siloxane, multi-terminal amino polymer and methyl vinyl polysiloxane;

the molecular structural general formula of the polyisocyanate prepolymer is OCN-R₁-NCO；

The general formula of the molecular structure of the epoxy resin is

The general molecular structure formula of the multi-terminal epoxy ether group alkylene alkyl siloxane is shown in the specification

The general molecular structure formula of the multi-terminal amino alkylene siloxane is shown in the specification

The general molecular structure formula of the multi-terminal amino polymer is

The liquid or fluid state high molecular polymer is as follows: methyl vinyl polysiloxane with the structural formula

n＝8～10，m＝1；

The R is₁、R₇Respectively comprises at least one of methyl alkoxy alkylene, phenylene, substituted phenylene, aromatic cyclopropene, substituted aromatic cyclopropene, heterocyclic ring support or substituted heterocyclic ring support; the R is₂At least one alkylene group having 2 to 5 carbon atoms; the R is₃、R₄、R₅、R₆Respectively is at least one of alkyl, phenyl, substituted phenyl, aromatic ring group, substituted aromatic ring group, heterocyclic group or substituted heterocyclic group; m is more than or equal to 0, n is more than or equal to 1, and the number average polymerization degree is m-0-1, n-8-22.

The manufacturing method of the insulating ultrahigh heat conduction composite material has the beneficial technical effects that:

1) the nano and micron powder can be dispersed into primary particle size, so that the effect of compounding and grading micro-nano particles is achieved;

2) the volume addition fraction of the powder can reach 85.3 percent;

3) the thermal conductivity coefficients of the insulating and heat-conducting interface materials (STIM) are all larger than 6W/(m.K) and 11W/(m.K);

4) the process is simple, the equipment has universality and the manufacturing cost is low.

Drawings

Fig. 1 shows a comb-shaped stator and a rotor used in the first, second, third, fourth and sixth embodiments of the present invention.

Fig. 2 shows a blade-shaped stator and a rotor used in the fifth embodiment of the present invention.

In fig. 1 and 2, the same reference numerals are used for the same functional and same structural elements, and the reference numerals for symmetrical or identical series of elements are omitted for the sake of simplicity in the drawings:

1.1-rotor, 1.2-stator, 2.1-rotating shaft, 2.2-blade.

Detailed Description

The following further describes the manufacturing method of the insulating ultrahigh thermal conductive composite material according to the present invention with reference to six embodiments and drawings thereof, in terms of technical content, structural features of components, and achieved objects and effects. The implementation mode of the invention comprises four parts of raw material selection, formula design table, preparation process and heat conductivity coefficient test, which are described as follows.

Firstly, the method comprises the following steps of,selecting raw materials

Six embodiments of the invention, relating to the raw material form, include: powder, fluid medium, modifier, liquid or fluid high molecular polymer;

wherein, the powder is: aluminum oxide, boron nitride, see table 1;

wherein the fluid medium is: ethanol;

wherein, the modifier is: titanium triisostearate isopropyl ester.

Wherein, the liquid or fluid state high molecular polymer is: methyl vinyl polysiloxane.

Secondly, the first step of the method is to perform the following steps,recipe design table

The formulations of the six examples are shown in table 1.

In order to further verify the thermal conductivity coefficient of the insulating and thermal conducting interface material, the grading and formula ranges of the powder are measured according to the mass fraction:

average particle diameter D₅₀The mass fraction of the nano-scale powder is (0-5)%, within the range of (10-100) nm;

average particle diameter D₅₀The mass fraction (1-8)% of the submicron powder in the range of (0.2-0.6) mu m;

average particle diameter D₅₀The mass fraction of the micron-sized powder is (8-30)%, within the range of (1.1-15) mu m;

average particle diameter D₅₀The mass fraction of the micron-sized powder is (8-30)%, within the range of (20-50) mu m;

average particle diameter D₅₀The mass fraction of the micron-sized powder is (30-75)%, within the range of (60-130) mu m;

the mass fraction of the liquid or fluid high polymer is (2-15)%;

the mass fraction of the modifier is (0.1-5)%.

Thirdly, the step of feeding the mixture to a water tank,preparation process

The preparation process of six embodiments of the invention, as shown in table 2, comprises: three procedures of a micro-nano powder dispersion and compounding process, a particle surface molecular equivalent lamination modification process and a fluid medium replacement process are controlled by shear strength; the three processes are carried out in two reactors respectively.

The shear strength control micro-nano powder dispersion and compounding process comprises the following steps: in a fluid medium, firstly, depolymerizing and dispersing nano powder into nano slurry by virtue of shearing of a stator and a rotor, then dispersing the nano slurry and submicron powder into micro-nano slurry, and then adding micron-sized powder for mixing; the two steps are carried out in one reactor; the shear strength is controlled by replacing three different diameters, intervals and lifting rotating speeds of a stator or a rotor, so that the shear strength is controlled to be (1200-233000) s^-1To (c) to (d); automatically controlling the temperature of the slurry to be within the range of 45-60 ℃ by equipment, and shearing and dispersing for 0.5 h; the shear strength is calculated according to equation (1),

in the formula (1), the reaction mixture is,

ss-shear Strength, s^-1，

V-the rotational linear velocity of the outer diameter of the rotor, m/s,

δ -minimum gap between adjacent stator and rotor, m.

Wherein, the lamination modification process of the molecular equivalent on the surface of the particle comprises the following steps: after the dispersion and compounding process of the micro-nano powder is controlled by the shear strength, the shear strength is reduced to (120-40000) s^-1To (c) to (d); adding a modifier and controlling the temperature of the slurry at (A) under normal pressure in the reactorStirring or dispersing the modifier and the powder for 2.75 hours by means of a stator and a rotor within the temperature range of 25-66); in a 100ml measuring cylinder with a plug (a miniature glass reactor), the powder sedimentation volume in the slurry is taken as the ordinate, the modifier addition amount is taken as the abscissa, and a wave linear curve is formed by drawing connection; and taking the addition amount of the modifier corresponding to the first valley as the modification addition amount of the monolayer so as to control the equivalent modification of 1: 1 between the functional groups on the surface of the particle and the functional groups of the modifier.

Wherein, the fluid medium replacement process comprises the following steps: adding liquid or fluid high molecular polymer into the micro-nano slurry after the lamination modification procedure of the particle surface molecular equivalent; closing a gate valve entering and exiting an inner cavity of the reactor, keeping a vacuum pipeline to be communicated and closed, heating to 80-160 ℃, controlling the pressure in the reactor within the range of (0-minus 0.1) MPa to gradually improve the vacuum degree in a grading manner in order to prevent bumping, accumulating and stirring for 2.0h when the pressure corresponding to the vacuum degree is within the range of (-0.08-minus 0.1) MPa, continuously maintaining the pressure corresponding to the vacuum degree within the range of (-0.05-minus 0.1) MPa while stirring and cooling to below 60 ℃, stopping stirring at first and finally relieving the vacuum degree (or recovering the normal pressure); the pressure is a gauge pressure.

Wherein the reactor adopts a planetary stirrer and a kneader; the reactor is made of 304 stainless steel and is provided with a heat-conducting oil circulation constant-temperature device.

Wherein, rotor and stator adopt two kinds of structures of pectination and blade form: the comb shape is shown in figure 1, the distance between a rotor 1.1 and a stator 1.2 is 1.0mm, the distance between comb teeth is 3mm, the width of the comb teeth is 3mm, the length of the comb teeth is 15mm, and the comb rotor and the stator are made of zirconia ceramics; the blade-shaped stator and the rotor are shown in figure 2, the rotating shaft is 2.1, the blades are 2.2, and the minimum distance between the blades between different shafts is 0.3 mm; the number of each rotating shaft 2.1 blade reaches 6, all rotating shafts simultaneously rotate clockwise or anticlockwise in work, and the blades 2.2 are made of hard tool steel-infiltrated titanium nitride.

Fourthly, the step of mixing the raw materials,thermal conductivity test

The thermal coefficients for the six examples were measured using a thermal conductivity tester model DRL-V, performed according to standard ASTM 5470, and the results are shown in Table 3.

Table 1 table of formulation design for six examples

Table 2 preparation of six examples

TABLE 2 preparation of six examples

Table 3 test results of six examples

The manufacturing method of the insulating ultrahigh heat-conducting composite material has the following beneficial technical effects:

comparing the first embodiment with the fifth embodiment, it can be seen that the thermal conductivity coefficients of the equal thermal interface materials prepared by using different rotors and stators are significantly different, and the first embodiment is superior to the fifth embodiment.

Comparing the first phase, the second phase and the third phase, it can be seen that when the addition amount of the powder is the same, the thermal conductivity of the five-level powder is greater than that of the four-level powder and greater than that of the three-level powder.

Comparing the first embodiment with the sixth embodiment, it can be seen that the heat conductivity coefficient of the fluid medium replacement process is better than that of the wet modification process.