Ultrathin breakdown-resistant heat-dissipation insulating film material and preparation method thereof

Abstract

The invention discloses an ultrathin breakdown-resistant heat-dissipation insulating film material and a preparation method thereof. The ultrathin breakdown-resistant heat-dissipation insulating film material comprises the following raw materials in parts by weight: 80-100 parts of a heat-conducting filler, 1-2 parts of a vulcanizing agent, 6-10 parts of vinyl silicone oil, 0.5-1 part of hydrogen silicone oil, 0.5-1 part of organic silicon, 0.5-1 part of a silicon-sensitive adhesive and 0.5-1 part of a silica gel adhesive. The heat-conducting filler comprises modified diamond powder, glass fibers and boron nitride, and the mass ratio of the modified diamond powder to the glass fibers to the boron nitride is 10: 20: 15. Compared with the prior art, the material has higher heat-conducting property and insulating property, the thickness of the material is smaller and can reach 20-50 microns, material glue can be directly used, and heat conduction and breakdown voltage gt resistance are realized by utilizing the high heat-conducting property and insulating property of the material; and the problem of poor heat-conducting property in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat-conducting materials, and particularly to an ultra-thin breakdown-resistant heat-dissipating insulating film material and a preparation method thereof. Background Art

[0002] With the development of technology and to meet the needs of consumers, more and more electronic products are designed for lightweight, making the overall electronic products lighter and thinner. However, for electronic products with built-in batteries, in order to prevent breakdown and meet the heat dissipation requirements, copper foil or graphite is generally used in the market to wrap the batteries at present. Although the heat dissipation effect of copper foil or graphite is relatively good, neither of them can meet the insulation requirements. Therefore, in the prior art, insulating glue is generally used to wrap copper foil or graphite, so as to meet the requirements of both insulation and heat dissipation. However, due to the need to set insulating glue, the volume or thickness of the battery will be too large, and the large thermal resistance of the insulating glue affects the thermal conductivity, unable to meet the lightweight requirements of consumers. The current insulating materials have problems of large thickness and poor thermal conductivity. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an ultra-thin breakdown-resistant heat-dissipating insulating film material and a preparation method thereof, so as to solve the problem of poor thermal conductivity in the past.

[0004] To solve the above technical problem, the present invention discloses an ultra-thin breakdown-resistant heat-dissipating insulating film material, which comprises the following raw materials in parts by weight: 80-100 parts of heat-conducting filler, 1-2 parts of vulcanizing agent, 6-10 parts of vinyl silicone oil, 0.5-1 part of hydrogen silicone oil, 0.5-1 part of silicone, 0.5-1 part of silicon-sensitive glue and 0.5-1 part of silicone adhesive; the heat-conducting filler comprises modified diamond powder, glass fiber and boron nitride, and the mass ratio of modified diamond powder, glass fiber and boron nitride is 10:20:15.

[0005] Among them, the boron nitride is modified boron nitride, and its preparation steps include: adding 40-50 parts of alkaline compound and 20-30 parts of boron nitride into 70-80 parts of ethanol aqueous solution, ultrasonically dispersing for 20-40 min, heating to 90-120 °C and stirring for reaction for 1-2 h, cooling to room temperature, and obtaining the product through grinding and drying.

[0006] Among them, the alkaline compound is a composition of potassium hydroxide and sodium hydroxide.

[0007] Among them, the particle size of the boron nitride is 50-100 nanometers.

[0008] Among them, the preparation steps of the modified diamond powder include: mixing 0.5 - 0.8 parts of silane coupling agent KH570 and 0.7 - 2 parts of ethanol aqueous solution evenly and hydrolyzing them in a constant temperature water bath at 35 - 40°C for 20 - 40 min to obtain a hydrolysis solution; then heating 60 - 80 parts of diamond powder to 90°C, adding it to the hydrolysis solution, stirring for 4 h, and finally obtaining the modified diamond powder through washing and drying.

[0009] Among them, the particle size of the modified diamond powder can be 30 microns, 50 microns, or 90 microns.

[0010] This application also provides a preparation method for an ultra-thin breakdown-resistant heat dissipation insulating film material. Mix 80 - 100 parts of heat-conducting filler, 6 - 10 parts of vinyl silicone oil, 0.5 - 1 part of hydrogen silicone oil, 0.5 - 1 part of silicone, 0.5 - 1 part of silicon-sensitive adhesive, and 0.5 - 1 part of silicone adhesive in a high-temperature environment at 120°C and stir. Then add 1 - 2 parts of vulcanizing agent and stir. After evacuating, roll it into a thickness of 0.2 mm, and finally heat-cure it at 90°C. After cooling and forming, an ultra-thin breakdown-resistant heat dissipation insulating film material is obtained.

[0011] The embodiments of the present invention have the following beneficial effects:

[0012] Compared with the prior art, the ultra-thin breakdown-resistant heat dissipation insulating film material of this application has high heat-conducting performance and insulating performance. The thickness of the material is relatively thin, capable of reaching 20μm - 50μm. The material adhesive can be used directly. Utilizing the high heat-conducting performance and insulating performance of the material, heat conduction and breakdown voltage resistance > 6KV are achieved, solving the problem of poor heat-conducting performance in the past.

[0013] The preparation method of the ultra-thin breakdown-resistant heat dissipation insulating film material of this application has a reasonable process design that can prepare high-quality heat dissipation insulating film materials. The prepared film materials can also be directly compounded with various film materials. Utilizing the high heat-conducting performance and insulating performance of the materials, heat conduction and circuit breakdown voltage resistance are achieved. Detailed implementation manners

[0014] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0015] The terms "first", "second", etc. in the description and claims of the present invention are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, device, product or server that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or servers.

[0016] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0017] Embodiment 1

[0018] One specific embodiment of a super-thin breakdown-resistant heat-dissipating insulating film material disclosed by the present invention, the heat-dissipating insulating film material comprises raw materials in the following parts by weight: 80 parts of a heat-conducting filler, 1 part of a vulcanizing agent, 6 parts of vinyl silicone oil, 0.5 part of hydrogen silicone oil, 0.5 part of silicone, 0.5 part of a silicone-sensitive adhesive, and 0.5 part of a silicone adhesive.

[0019] In this embodiment, the vinyl silicone oil is a resin matrix, which can react with the hydrogen silicone oil to form a polymer network. The silicone is preferably a composition mainly composed of a long-chain silane coupling agent. In combination with the silicone-sensitive adhesive and the silicone adhesive, it can improve the compatibility of the heat-conducting filler with the vinyl silicone oil and the hydrogen silicone oil, promote the dispersion of the heat-conducting filler, and further improve the heat-conducting performance. Among them, the silicone-sensitive adhesive can increase the high-temperature and low-temperature resistance of the material.

[0020] As an improvement, the heat-conducting filler includes modified diamond powder, glass fiber, and boron nitride, and the mass ratio of the modified diamond powder, glass fiber, and boron nitride is 10:20:15. The modified diamond powder and boron nitride as the main heat-conducting fillers can increase the heat-conducting coefficient; the glass fiber can improve the mechanical strength and toughness of the material, increase the tear strength, and even when the material is calendered to 0.2 mm, it is not easily torn.

[0021] In this embodiment, the boron nitride is modified boron nitride, and its preparation steps include: adding 40 parts of an alkaline compound and 20 parts of boron nitride to 70 parts of an ethanol aqueous solution, ultrasonically dispersing for 20 - 40 min, heating to 90 °C and stirring for reaction for 1 - 2 h, cooling to room temperature, and obtaining the product through grinding and drying.

[0022] As a preferred solution, the alkaline compound is a composition of potassium hydroxide and sodium hydroxide. In an ethanol aqueous solution, boron nitride is surface-treated with potassium hydroxide and sodium hydroxide to improve the dispersion performance of boron nitride, so that boron nitride has good dispersibility and crosslinkability during the material forming process, and can further improve the thermal conductivity, insulation and bonding stability of the material. Optionally, the particle size of boron nitride is 50 nanometers. The boron nitride with a fine particle size is stably dispersed in the gaps between the modified diamond powders, so that the thermal conductive filler is denser, and good insulation can be maintained even in a high-voltage environment.

[0023] In this embodiment, the preparation steps of the modified diamond powder include: mixing 0.5 part of silane coupling agent KH570 and 0.7 part of ethanol aqueous solution evenly and hydrolyzing them in a constant temperature water bath at 35°C for 20 min to obtain a hydrolysis solution; then heating 60 parts of diamond powder to 90°C, adding it to the hydrolysis solution and stirring for 4 h, and finally obtaining the modified diamond powder after washing and drying. Among them, the particle size of the modified diamond powder can be 30 microns. The spatial structure of the modified diamond powder is stable, with high thermal conductivity and insulation. The inertness of the surface of the modified diamond is reduced, and it can be fused with silicone oil. With the excellent hardness of the diamond powder, the durability of the insulating material can be further improved.

[0024] In this embodiment, the length of the glass fiber is 600 μm. The glass fiber, in combination with boron nitride and the modified diamond powder, can improve the thermal conductivity, strength and breakdown resistance of the material.

[0025] The insulating film material of this embodiment uses the modified diamond powder, glass fiber and boron nitride as thermal conductive fillers, mixes them into the silicone oil system, and forms a complex and dense three-dimensional thermal conductive network chain by using the different hardness, thermal conductivity and curling degrees among the three, so as to prepare an insulating thermal conductive gasket with good thermal conductivity and insulation performance, mechanical performance and breakdown voltage resistance. Compared with the prior art, the material has high thermal conductivity and insulation performance, the thickness of the material is relatively thin, and can reach 20 μm to 50 μm. The material glue can be used directly. By using the high thermal conductivity and insulation performance of the material, heat conduction and breakdown voltage resistance >6 KV are realized, and the problem of poor thermal conductivity in the past is solved.

[0026] The present invention discloses a preparation method of an ultra-thin breakdown-resistant heat dissipation insulating film material. The thermal conductive filler, vinyl silicone oil, hydrogen silicone oil, silicone, silicon-sensitive glue and silicone adhesive are mixed and stirred in a high-temperature environment of 120°C, then a vulcanizing agent is added and mixed and stirred. After vacuumizing, it is calendered into a thickness of 0.2 mm, and finally heat-cured at 90°C. After cooling and forming, an ultra-thin breakdown-resistant heat dissipation insulating film material is obtained.

[0027] The preparation method of the ultra-thin breakdown-resistant heat-dissipating insulating film material of the present application. Its reasonable process design can prepare high-quality heat-dissipating insulating film materials. The overall steps are simple and easy to operate, suitable for large-scale industrial production. The material can directly wrap the battery with materials such as copper foil with adhesive, aluminum foil with adhesive, etc. The operation is simple and does not affect production; it can also directly wrap the battery with materials such as graphene film with adhesive, copper-plated PET, nickel-plated PET, tin-plated copper, nickel-chromium alloy-plated copper, nickel-chromium alloy-plated aluminum foil, low-temperature phase change alloy, etc. The operation is simple and does not affect production; it can also be a composite material formed by the above materials and artificial / natural graphite (single-layer, double-layer, multi-layer) or copper / aluminum / graphene film + high-viscosity thermal conductive tape, directly wrapping the battery, and the operation is simple and does not affect production.

[0028] Example 2

[0029] The present invention discloses a second specific embodiment of an ultra-thin breakdown-resistant heat-dissipating insulating film material. The heat-dissipating insulating film material comprises the following raw materials in parts by weight: 100 parts of heat-conducting filler, 2 parts of vulcanizing agent, 10 parts of vinyl silicone oil, 1 part of hydrogen silicone oil, 1 part of silicone, 1 part of silicon-sensitive adhesive and 1 part of silicone adhesive.

[0030] Boron nitride is prepared by the following steps: 50 parts of basic compound and 30 parts of boron nitride are added to 80 parts of ethanol aqueous solution, ultrasonically dispersed for 40 min, heated to 120 °C and stirred for reaction for 2 h, cooled to room temperature, and obtained through grinding and drying. The particle size of boron nitride is 100 nanometers.

[0031] Modified diamond powder is prepared by the following steps: 0.8 part of silane coupling agent KH570 and 2 parts of ethanol aqueous solution are mixed evenly and hydrolyzed in a constant temperature water bath at 40 °C for 40 min to obtain a hydrolysis solution; then 80 parts of diamond powder are heated to 90 °C, added to the hydrolysis solution and stirred for 4 h, and finally obtained through washing and drying. The particle size of the modified diamond powder can be 90 microns.

[0032] Example 3

[0033] The present invention discloses a third specific embodiment of an ultra-thin breakdown-resistant heat-dissipating insulating film material. The heat-dissipating insulating film material comprises the following raw materials in parts by weight: 90 parts of heat-conducting filler, 1.5 parts of vulcanizing agent, 8 parts of vinyl silicone oil, 0.8 part of hydrogen silicone oil, 0.8 part of silicone, 0.8 part of silicon-sensitive adhesive and 0.8 part of silicone adhesive.

[0034] Boron nitride is prepared by the following steps: 40 parts of basic compound and 25 parts of boron nitride are added to 75 parts of ethanol aqueous solution, ultrasonically dispersed for 35 min, heated to 110 °C and stirred for reaction for 1.5 h, cooled to room temperature, and obtained through grinding and drying. The particle size of boron nitride is 80 nanometers.

[0035] The modified diamond powder is prepared by the following steps: 0.7 part of silane coupling agent KH570 and 1.5 parts of ethanol aqueous solution are mixed evenly and hydrolyzed in a constant temperature water bath at 37 °C for 35 min to obtain a hydrolysis solution; then 75 parts of diamond powder are heated to 90 °C, added to the hydrolysis solution and stirred for 4 h, and finally the modified diamond powder is obtained after washing and drying. The particle size of the modified diamond powder can be 50 microns.

[0036] The experimental test comparison data of the above three examples are as follows.

[0037] Example 1: Thermal conductivity 6.5 W / (m*k), tensile strength 1.2 Mpa, breakdown voltage resistance 6.1 KV / mm.

[0038] Example 2: Thermal conductivity 6.3 W / (m*k), tensile strength 1.3 Mpa, breakdown voltage resistance 6.15 KV / mm.

[0039] Example 1: Thermal conductivity 6.0 W / (m*k), tensile strength 1.4 Mpa, breakdown voltage resistance 6.20 KV / mm.

[0040] The above experimental tests refer to the method of ASTM D5930 standard, and the steady-state method is used to test the thermal conductivity of the material; referring to the method of ASTM D638 standard, a bench-top universal testing machine is used to perform the tensile strength test; referring to the method of ASTM D149 standard, during the test, the voltage is gradually increased until the material breaks down, and the breakdown voltage and breakdown time are recorded to evaluate the electric shock resistance of the material.

[0041] Finally, it should be noted that: what is disclosed in an ultra-thin breakdown voltage resistant heat dissipation insulating film material and its preparation method disclosed in the embodiments of the present invention is only the preferred embodiments of the present invention, only for explaining the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-thin breakdown-resistant heat-dissipating insulating film material, characterized in that: The invention comprises the following raw materials in parts by weight: 80 to 100 parts of thermal conductive filler, 1 to 2 parts of vulcanizing agent, 6 to 10 parts of vinyl silicone oil, 0.5 to 1 part of hydrogen silicone oil, 0.5 to 1 part of organic silicon, 0.5 to 1 part of silicone sensitive glue and 0.5 to 1 part of silicone adhesive; The thermal conductive filler comprises modified diamond powder, glass fiber and boron nitride, and the mass ratio of the modified diamond powder, glass fiber and boron nitride is 10:20:

15.

2. The ultra-thin breakdown-resistant heat-dissipating insulating film material according to claim 1, characterized in that: The boron nitride is modified boron nitride, and its preparation steps include: adding 40-50 parts of alkaline compounds and 20-30 parts of boron nitride to 70-80 parts of ethanol aqueous solution, ultrasonically dispersing for 20-40 minutes, heating to 90-120° C., stirring and reacting for 1-2 hours, cooling to room temperature, grinding and drying to obtain the modified boron nitride.

3. The ultra-thin breakdown-resistant heat-dissipating insulating film material according to claim 2, characterized in that: The alkaline compound is a combination of potassium hydroxide and sodium hydroxide.

4. The ultra-thin breakdown-resistant heat-dissipating insulating film material according to claim 2, characterized in that: The particle size of the boron nitride is 50 to 100 nanometers.

5. The ultra-thin breakdown-resistant heat-dissipating insulating film material according to claim 1, characterized in that: The preparation steps of the modified diamond powder include: uniformly mixing 0.5-0.8 parts of silane coupling agent KH570 and 0.7-2 parts of ethanol aqueous solution and hydrolyzing them in a constant temperature water bath at 35-40°C for 20-40 minutes to obtain a hydrolyzate; then heating 60-80 parts of diamond powder to 90°C, adding it to the hydrolyzate and stirring for 4 hours, and finally washing and drying to obtain the modified diamond powder.

6. The ultra-thin breakdown-resistant heat-dissipating insulating film material according to claim 1 or 5, characterized in that: The particle size of the modified diamond powder may be 30 microns, 50 microns or 90 microns.

7. A method for preparing an ultra-thin breakdown-resistant heat-dissipating insulating film material, characterized in that: 80-100 parts of thermal conductive filler, 6-10 parts of vinyl silicone oil, 0.5-1 part of hydrogen silicone oil, 0.5-1 part of silicone, 0.5-1 part of silicone sensitive glue and 0.5-1 part of silicone adhesive are mixed and stirred at a high temperature of 120°C, and then 1-2 parts of vulcanizing agent are added and mixed. After vacuuming, calendering is performed to a thickness of 0.2 mm, and finally, it is heated and cured at 90°C, and cooled and formed to obtain an ultra-thin breakdown-resistant heat dissipation insulating film material.