Composition for modifying one-component thermal conductive gel, one-component thermal conductive gel containing the same, and manufacturing method

Abstract

The present invention relates to a composition for modifying a one-component thermal conductive gel, a one-component thermal conductive gel containing the same, and a manufacturing method. Specifically, the composition for modifying a one-component thermal conductive gel contains: a vinyl-terminated polyorganosiloxane, a hydrogen-containing polyorganosiloxane, and a platinum catalyst. The thermal conductive gel modified with the composition for modifying a one-component thermal conductive gel of the present invention has a relatively low hardness of about 50 to 75 Shore A, can withstand vibration and deformation without cracking and interfacial separation; can be stored at room temperature for 1 year without cryogenic storage; can be cured in situ at room temperature, has good vertical stability, and the single-component packaging is easy for dispensing. In addition, the thermal conductivity of the thermal conductive gel of the present invention can be 1 W / mK to 4 W / mK.

Description

Technical Field

[0001] The present invention relates to a composition for modifying a one-component thermal conductive gel, a one-component thermal conductive gel containing the same, and a manufacturing method. Specifically, the present invention relates to a composition for modifying a one-component thermal conductive gel capable of reducing the hardness of the one-component thermal conductive gel, a pre-crosslinked resin-modified low-hardness one-component moisture-curing thermal conductive gel containing the same, and a manufacturing method of the thermal conductive gel, which can be used in fields such as electronic components of automobiles, electrical appliances, communications, transportation, and aviation. Background Art

[0002] In the automotive industry, there is an increasing demand for miniaturization, integration, and high power of electronic components, followed by a trend of continuous reduction in component size, and the problem of thermal management in circuits has increased sharply. Therefore, the demand for thermal management materials in related fields, such as thermal conductive caulking materials, has grown rapidly in the past few years.

[0003] The main thermal conduction materials between general radiators and heating elements (ICs) are thermal conductive gaskets and thermal conductive gels. Thermal conductive gaskets are a relatively traditional heat transfer medium method, with mature applications and relatively low prices. However, thermal conductive gaskets are used by fitting, and in order to overcome the gap tolerance, a relatively large pressure is required, which has requirements for the bearing capacity of the heating element; at the same time, thermal conductive gaskets are powerless for some irregular heating elements, such as the gaps in DC / DC conversion systems, OBC systems, and battery packs in automobiles, etc., which all require filling with thermal conductive materials. In this case, a thermal conductive gel is often needed. Due to its relatively high thixotropy and suitable extrudability for construction, the thermal conductive gel only needs to be extruded into the gap or contact surface through a packaging tube.

[0004] Commonly used thermal conductive gels can be classified into single-component type and AB two-component type.

[0005] The one-component moisture-curing thermal conductive gel can be stored at room temperature and cured at room temperature, which overcomes the disadvantages of general one-component heat-curing thermal conductive gels. After curing, the one-component moisture-curing thermal conductive gel has good vertical reliability, low oil seepage, and other good properties the same as those of two-component thermal conductive gels.

[0006] Compared with the complex and expensive dispensing equipment used for two-component thermal conductive gels, the moisture-curing thermal conductive gel has a simpler dispensing equipment and is more convenient to use.

[0007] However, the curing material of the moisture-curing thermal conductive gel is over-crosslinked due to its reaction characteristics. The hardness of the curing material containing fillers can usually reach Shore hardness A 80 or even greater than 90. The high hardness of the curing material makes it prone to cracking or interfacial separation when subjected to vibration and deformation, which limits its application. For example, electronic components in automobiles obviously require thermal conductive materials to pass high-temperature and low-temperature cycle vibration tests. This test is used to examine the reliability of the thermal conductive gel in the high and low temperature and high vibration environment of automobiles. The focus of the experiment is whether the thermal conductive gel can remain in its original state and be fixed in position under the test conditions. In case of displacement or fragmentation, the thermal conductive gel cannot help the components dissipate heat.

[0008] There are already some one-component thermal conductive gels in the prior art.

[0009] CN107532001A discloses a thermal conductive composition, which is a thermal conductive composition containing (A) spherical thermal conductive filler and (B) alkoxysilane compound or dimethylpolysiloxane, wherein the component (A) is admixed with a spherical thermal conductive filler having an average particle size of 50 μm or more containing a nitride.

[0010] CN110719939A discloses a thermal conductive polysiloxane composition, which comprises: (A) a thermal conductive filler; (B) a siloxane compound with a specific structure; (C) an alkoxysilane compound with a specific structure; (D) a polyorganosiloxane containing one or more aliphatic unsaturated groups in one molecule; (E) a polyorganohydrogensiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule; and (F) a platinum-based catalyst.

[0011] In addition, as commercially available one-component moisture-curing products, 1) Momentive TIA0260; 2) Momentive TIA0220 can be mentioned. However, the Shore hardness A of TIA0260 is 90, and the thermal conductivity Tc is 2.6 W / mK. The Shore hardness A of TIA0220 is 86, and Tc is 2.2 W / mK. That is to say, their Shore hardness A is greater than 80, and there is a problem of being prone to cracking or interfacial separation when subjected to vibration and deformation.

[0012] In short, if the moisture-curing thermal conductive gel can achieve low hardness after curing, this material is not only comparable to two-component curable thermal conductive gels in terms of performance, but also more convenient to use than two-component thermal conductive gels. It has good market application prospects, especially for the heat conduction of automotive electronic components subjected to vibration. Summary of the Invention

[0013] The general curing materials of one-component moisture-curing thermal conductive gels are over-crosslinked due to their reaction characteristics, which results in a Shore hardness A of 80 or even greater than Shore hardness A 90 after curing, and limits the application of the material in some cases where it needs to withstand vibration and deformation without cracking and interfacial separation.

[0014] The present invention discovers that by adding vinyl polyorganosiloxane to the resin system of one-component moisture-curing thermal conductive gels, heating during the mixing process to crosslink the vinyl polyorganosiloxane, and controlling a lower degree of crosslinking, the goal of reducing the hardness of the one-component moisture-curing thermal conductive gel after curing can be achieved.

[0015] Therefore, the present invention solves the inherent high-hardness problem of cured moisture-curing sealants and makes the material more easily withstand vibration and deformation without cracking and interfacial separation. This broadens the application of one-component moisture-curing thermal conductive dispensing sealants.

[0016] According to one aspect, the present invention provides a composition for modifying a one-component thermal conductive gel, which comprises a vinyl-terminated polyorganosiloxane, a hydrogen-containing polyorganosiloxane, and a platinum catalyst.

[0017] In one embodiment, the composition for modifying the thermal conductive gel is a crosslinked addition-cured polyorganosiloxane, which is a pre-crosslinked resin formed by the addition crosslinking of a vinyl-terminated polyorganosiloxane and a hydrogen-containing polyorganosiloxane under the action of a platinum catalyst.

[0018] In one embodiment, the hydrogen-silicon content of the hydrogen-containing polyorganosiloxane is 1-20 mol% of the vinyl groups of the vinyl-terminated polyorganosiloxane, preferably 2-16 mol%, more preferably 4-10 mol%, still more preferably 5-8 mol%; and

[0019] Based on the platinum in the platinum catalyst, the amount of the platinum catalyst is 3-10 ppm of the total weight of the vinyl-terminated polyorganosiloxane and the hydrogen-containing polyorganosiloxane, preferably 4-8 ppm, more preferably 5-7 ppm.

[0020] In one embodiment, the viscosity of the vinyl-terminated polyorganosiloxane before precuring is 50 cps to 2000 cps, preferably 100 to 1500 cps, more preferably 150 to 1000 cps, still more preferably 200 to 800 cps, still more preferably 300 to 500 cps.

[0021] On the other hand, the present invention relates to a one-component thermal conductive gel, which comprises:

[0022] a polyorganosiloxane terminated with a hydroxyl or alkoxy group;

[0023] A crosslinked addition-curable polyorganosiloxane, which is a composition for modifying the above-mentioned one-component thermal gel;

[0024] A thermal conductive filler;

[0025] A second catalyst; and

[0026] A crosslinking agent.

[0027] In one embodiment, the hydroxyl- or alkoxy-terminated polyorganosiloxane is an alkoxy-terminated polyorganosiloxane. Preferably, the viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 50 cps to 2000 cps, preferably 100 to 1500 cps, more preferably 150 to 1000 cps, still more preferably 200 to 800 cps, and still more preferably 400 to 600 cps.

[0028] In one embodiment, the thermal conductive filler is one or more selected from alumina, aluminum nitride, boron nitride, and zinc oxide; and / or the second catalyst is an organotin catalyst or a titanate catalyst; and / or the crosslinking agent is one or more of methoxysilane and ethoxysilane.

[0029] In one embodiment, based on 100% by weight of the one-component thermal gel,

[0030] The hydroxyl- or alkoxy-terminated polyorganosiloxane is 1 to 10% by weight, preferably 2% to 8% by weight, more preferably 2 to 7% by weight, still more preferably 2 to 5% by weight;

[0031] The crosslinked addition-curable silicone is 5% to 18% by weight, preferably 6% to 15% by weight, still preferably 8% to 10% by weight,

[0032] The thermal conductive filler is 75% to 92% by weight, preferably 80% to 90% by weight, still preferably 85% to 88% by weight;

[0033] The second catalyst is 0.2% to 2% by weight, preferably 0.5% to 1.5% by weight, more preferably 0.8 to 1% by weight;

[0034] The crosslinking agent is 1.5% to 5% by weight, 2% to 4.5% by weight, still preferably 2.5% to 4% by weight.

[0035] In one embodiment, the Shore hardness A of the thermal gel is 50 to 80, and / or the thermal conductivity is 1 W / mK to 4 W / mK.

[0036] In yet another aspect, the present invention provides a method for manufacturing the above-mentioned one-component moisture-curable thermal gel, which includes the following steps:

[0037] A composition for modifying a one-component thermally conductive gel, which comprises a vinyl polyorganosiloxane, a hydrogen-containing polyorganosiloxane, and a platinum catalyst, a polyorganosiloxane capped with a hydroxyl group or an alkoxy group, and a thermally conductive filler are uniformly mixed;

[0038] It is heated at 100 - 120 °C for at least 2 hours under vacuum to remove moisture. During this process, the vinyl polyorganosiloxane and the hydrogen-containing polyorganosiloxane undergo addition crosslinking under the action of the platinum catalyst to form a crosslinked addition-cured polyorganosiloxane;

[0039] While maintaining the vacuum, the temperature is lowered to room temperature, and a second catalyst and a crosslinking agent are sequentially added. After mixing evenly, a low-hardness one-component moisture-cured thermally conductive gel modified with a pre-crosslinked resin of the present invention is obtained.

[0040] In another aspect, the present invention also provides the use of the above composition for modifying a one-component thermally conductive gel in reducing the hardness of the one-component thermally conductive gel.

[0041] Beneficial effects

[0042] The low-hardness one-component moisture-cured thermally conductive gel modified with a pre-crosslinked resin of the present invention has the following advantages:

[0043] 1. It has a relatively low hardness with a Shore hardness A of about 50 - 75, and can withstand vibration and deformation without cracking and interfacial separation.

[0044] 2. It can be stored at room temperature for 1 year without the need for frozen storage.

[0045] 3. It cures in situ at room temperature and has good vertical stability.

[0046] 4. Single-component packaging and dispensing application are convenient.

[0047] 5. The thermal conductivity can be 1 W / mK to 4 W / mK. Specific embodiments

[0048] The present invention will now be described more fully hereinafter.

[0049] The present invention described should not be limited to the specific embodiments disclosed, and modifications and other embodiments are also included within the scope of the present invention. Although specific terms are employed herein, they are used only in a general and descriptive sense and not for purposes of limitation.

[0050] Throughout this specification and the following claims, the singular forms "a", "an", and "the" include plural forms unless the context clearly dictates otherwise.

[0051] The terms and expressions used herein are for the purpose of description and should not be regarded as limiting. The use of the terms "comprising", "including", "having" and "containing" and their variants herein is intended to cover the items listed hereinafter and their equivalents as well as other items.

[0052] 1. Composition for modifying one-component thermal conductive gel

[0053] The composition for modifying one-component thermal conductive gel of the present invention is a composition for reducing the hardness of one-component moisture-curing thermal conductive gel to avoid cracking and interfacial separation of the latter.

[0054] The present invention discovers that by adding vinyl polyorganosiloxane to the resin system of one-component moisture-curing thermal conductive gel, heating during the mixing process to crosslink the vinyl polyorganosiloxane, and controlling a lower degree of crosslinking, the goal of reducing the hardness of one-component moisture-curing thermal conductive gel can be achieved.

[0055] The composition for modifying one-component thermal conductive gel of the present invention contains vinyl-terminated polyorganosiloxane, hydrogen-containing polyorganosiloxane and platinum catalyst, or consists of them. More specifically, the composition for modifying the thermal conductive gel is a crosslinked addition-cured polyorganosiloxane, which is a pre-crosslinked resin formed by the addition crosslinking of vinyl-terminated polyorganosiloxane and hydrogen-containing polyorganosiloxane under the action of a platinum catalyst.

[0056] The crosslinking process of the composition for modifying the thermal conductive gel can be carried out separately, and then the pre-crosslinked resin is added to the resin system of one-component moisture-curing thermal conductive gel. However, preferably, after adding the vinyl-terminated polyorganosiloxane, hydrogen-containing polyorganosiloxane and platinum catalyst of the present invention to the resin system of one-component moisture-curing thermal conductive gel, mixing and heating simultaneously, during which the vinyl polyorganosiloxane crosslinks, and controlling a lower degree of crosslinking, the goal of reducing the hardness of one-component moisture-curing thermal conductive gel can be achieved.

[0057] The heating temperature and heating time can be appropriately selected as needed. For example, the heating temperature can be 100 - 120 °C, preferably 110 °C, and the heating time can be at least 2 hours, such as at least 3 hours, at least 4 hours, 5 hours, etc.

[0058] It should be noted that in the art, vinyl polyorganosiloxane can also be called vinyl silicone oil, and hydrogen-containing polyorganosiloxane can also be called hydrogen-containing silicone oil.

[0059] The viscosity of the vinyl polyorganosiloxane before precuring is 50 cps to 2000 cps, preferably 100 to 1500 cps, more preferably 150 to 1000 cps, still more preferably 200 to 800 cps, and still more preferably 300 to 500 cps. If the viscosity is less than 50 cps, the viscosity of the organosiloxane is too low, and oil leakage is more likely to occur during storage at a low degree of precrosslinking; if the viscosity is greater than 2000 cps, the viscosity of the organosiloxane is too high, which is not conducive to high filling of the heat-conducting filler and affects the final thermal conductivity.

[0060] The viscosity can also be 75 cps, 100 cps, 200 cps, 300 cps, 400 cps, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps, 1000 cps, 1100 cps, 1200 cps, 1300 cps, 1400 cps, 1500 cps, 1600 cps, 1700 cps, 1800 cps, 1900 cps, 2000 cps or the range between any two of them.

[0061] As the vinyl polyorganosiloxane, the vinyl polyorganosiloxane commonly used in the art can be adopted, such as one or more of terminal vinyl polyorganosiloxane, side-chain vinyl polyorganosiloxane, and mono-vinyl polyorganosiloxane. It can be obtained commercially. For example, VS250, VS500, VS1000, VDM 500, MV2000 and so on.

[0062] The hydrogen-containing polyorganosiloxane is a polyorganosiloxane that crosslinks with the vinyl-terminated polyorganosiloxane under the action of a platinum catalyst. In order to control the formed precrosslinked resin to have a low degree of crosslinking, the ratio of the silicon-hydrogen content of the hydrogen-containing polyorganosiloxane to the vinyl content of the vinyl-terminated polyorganosiloxane needs to be 1% to 20 mol%. If the ratio is lower than 1 mol%, the degree of crosslinking may be too low, and it is likely to cause oil leakage in the final product; if the ratio is higher than 20 mol%, the degree of crosslinking may be too high, and the hardness of the precrosslinked resin is also too high, and the effect of reducing the hardness of the one-component moisture-curing thermal conductive gel cannot be achieved.

[0063] In addition, the ratio can also be 1%, 3%, 5%, 7%, 9%, 11%, 13%, 15%, 17%, 20% or the range between any two of them.

[0064] As the hydrogen-containing polyorganosiloxane, the hydrogen-containing polyorganosiloxanes commonly used in the art can be adopted, such as one or more of terminal hydrogen polyorganosiloxane, side hydrogen polyorganosiloxane, and terminal hydrogen and side hydrogen polyorganosiloxane. It can be obtained commercially. For example, Andisil XL12, Andisil XL13, Andisil CE13, Andisil CE500, etc. of Ambient Special Organosilicon Co., Ltd. can be cited.

[0065] In addition, based on the platinum in the platinum catalyst, the amount of the platinum catalyst relative to the total weight of the vinyl-terminated polyorganosiloxane and the hydrogen-containing polyorganosiloxane can be 3 to 10 ppm, preferably 4 to 8 ppm, and more preferably 5 to 7 ppm. If this ratio is lower than 3 ppm, it is possible that when the content of the platinum catalyst is low, too much filler is added, and the catalytic effect may be inhibited, which may cause insufficient pre-crosslinking reaction. If this ratio is higher than 10 ppm, it will increase the pre-crosslinking speed after mixing, and increase the formulation cost, without more substantial effects.

[0066] This ratio can also be 3, 4, 5, 6, 7, 8, 9, 10 ppm or the range between any two of them.

[0067] 2. One-component thermal conductive gel

[0068] In the present invention, the one-component thermal conductive gel refers to a one-component moisture-curing thermal conductive gel.

[0069] The moisture-curing type is an alcohol-eliminating curing type. In order to obtain a low-hardness cured material, the entire resin system is specially designed. On the one hand, a polyorganosiloxane terminated with a hydroxyl group or an alkoxy group is introduced. On the other hand, a crosslinked addition-curing silicone is introduced to reduce the crosslinking density after final curing. The cured product has good flexibility and can withstand vibration and deformation without cracking and interfacial separation.

[0070] The product form is a one-component dispensable material. It can achieve storage for one year at room temperature and curing at room temperature.

[0071] The one-component thermal conductive gel of the present invention comprises: a polyorganosiloxane terminated with a hydroxyl group or an alkoxy group; a crosslinked addition-curing polyorganosiloxane, which is a composition for modifying the above one-component thermal conductive gel; a thermal conductive filler; a second catalyst; and a crosslinking agent.

[0072] In the present invention, the viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 50 cps to 2000 cps, preferably 100 to 1500 cps, more preferably 150 to 1000 cps, still more preferably 200 to 800 cps, and even more preferably 400 to 600 cps. If the viscosity is less than 50 cps, in the case of excessive crosslinking, the crosslinking density is large, which is likely to cause high hardness of the product after final curing; if the viscosity is greater than 2000 cps, the viscosity of the organosiloxane is too high, which is not conducive to high filling of the thermal conductive filler and affects the final thermal conductivity.

[0073] The viscosity can also be 75 cps, 100 cps, 200 cps, 300 cps, 400 cps, 500 cps, 600 cps, 700 cps, 800 cps, 900 cps, 1000 cps, 1100 cps, 1200 cps, 1300 cps, 1400 cps, 1500 cps, 1600 cps, 1700 cps, 1800 cps, 1900 cps, 2000 cps or the range between any two of them.

[0074] Preferably, the hydroxyl- or alkoxy-terminated polyorganosiloxane is an alkoxy-terminated polyorganosiloxane, because in the mixing process, the alkoxy-terminated polyorganosiloxane is less likely to form a viscosity peak and has better storage stability than the hydroxyl-terminated polyorganosiloxane after adding a titanate catalyst.

[0075] As the hydroxyl-terminated polyorganosiloxane, the hydroxyl-terminated polyorganosiloxane commonly used in the art can be adopted. It can be commercially available. For example, Andisil MOH70, Andisil MOH 750, Andisil MOH 1000, Andisil MOH 2000 of Anbiate Special Organosilicon Co., Ltd. can be cited, and so on.

[0076] As the alkoxy-terminated polyorganosiloxane, the alkoxy-terminated polyorganosiloxane commonly used in the art can be adopted. It can be commercially available. For example, RH-FW600, RH-FW1K, etc. of Ningbo Runhe High-Tech Materials Co., Ltd. can be cited.

[0077] The one-component thermal conductive gel of the present invention can be filled with thermal conductive fillers of different particle sizes and types to achieve different thermal conductivities. The thermal conductive fillers that can be filled include one or several of alumina, aluminum nitride, boron nitride, and zinc oxide. The morphology of the fillers includes spherical and non-spherical, and the particle size range is from 0.2 microns to 100 microns. The surface of the fillers can be treated with treatment agents including silane, etc., or not treated.

[0078] The crosslinking agent, also known as the curing agent, is used to cure the resin. In the present invention, the crosslinking agent is one or more of methoxysilane and ethoxysilane. Methoxysilane and ethoxysilane commonly used in the art can be adopted. They can be obtained commercially. For example, methyltriethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, etc. can be cited.

[0079] The second catalyst is an organotin catalyst or a titanate catalyst, which is used to promote the curing reaction of the resin. As the organotin catalyst, the organotin catalysts commonly used in the art can be adopted, such as D80, D82, etc. of Hubei New Blue Sky New Materials Company. As the titanate catalyst, the titanate catalysts commonly used in the art can be adopted, such as D62, D60, NB722, etc. of Hubei New Blue Sky New Materials Company.

[0080] Based on the total weight of the low-hardness one-component moisture-curing thermal conductive gel modified by the pre-crosslinked resin, the content of the hydroxy- or alkoxy-terminated polyorganosiloxane is 1 to 10% by weight, preferably 2% to 8% by weight, more preferably 2 to 7% by weight, and still more preferably 2 to 5% by weight. If the content is less than 1%, the curing of the whole material is not good enough. If the content is greater than 10% by weight, the hardness is too high after the material is cured.

[0081] The content can also be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% by weight or the range between any two of them.

[0082] Based on the total weight of the low-hardness one-component moisture-curing thermal conductive gel modified by the pre-crosslinked resin, the content of the crosslinked addition-cured silicone is 5% to 18% by weight, preferably 6% to 15% by weight, and still preferably 8% to 10% by weight.

[0083] If the content is less than 5%, the effect of reducing the hardness is not obvious. If the content is greater than 18% by weight, the curing of the whole material is not good enough and the vertical reliability is not good enough after the material is cured.

[0084] The content can also be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% by weight or the range between any two of them.

[0085] Based on the total weight of the low-hardness one-component moisture-curing thermal conductive gel modified by the pre-crosslinked resin, the thermal conductive filler is 75% to 92% by weight, preferably 80% to 90% by weight, and still preferably 85% to 88% by weight; if the content is less than 75%, the thermal conductivity is insufficient. If the content is greater than 92% by weight, the viscosity is too high.

[0086] This content may also be 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92% by weight or a range between any two of them.

[0087] Based on the total weight of the low-hardness one-component moisture-curing thermal conductive gel modified with pre-crosslinked resin, the second catalyst is 0.2% to 2% by weight, preferably 0.5% to 1.5% by weight, and more preferably 0.8 to 1% by weight. If the content is less than 0.2%, the crosslinking speed is too low. If the content is greater than 2% by weight, the surface curing speed is too fast, forming a dry film, which affects the internal curing of the adhesive layer.

[0088] This content may also be 0.2%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.5%, 1.6%, 1.8%, 2.0% by weight or a range between any two of them.

[0089] Based on the total weight of the low-hardness one-component moisture-curing thermal conductive gel modified with pre-crosslinked resin, the crosslinking agent is 1.5% to 5% by weight, 2% to 4.5% by weight, and preferably 2.5% to 4% by weight. If the content is less than 1.5%, the stability of room-temperature storage is reduced. If the content is greater than 5% by weight, when curing, the excess crosslinking agent will also undergo polycondensation with each other, resulting in a relatively high hardness.

[0090] In the present invention, since a pre-crosslinked resin of vinyl-terminated polyorganosiloxane with a low crosslinking degree is added to the resin system of the one-component moisture-curing thermal conductive gel, the hardness after curing of the thermal conductive gel can be reduced.

[0091] For example, the Shore hardness A of the thermal conductive gel of the present invention after curing is 50 to 75, such as 52 to 73, 64 to 70, etc. Compared with the hardness of 80 to 90 after curing of the thermal conductive silica gel modified without using the pre-crosslinked resin of the present invention, it is significantly reduced.

[0092] Due to the reduction in hardness, after the vibration test according to ISO 19453-3, the curing interface does not detach and there is no material cracking.

[0093] In addition, the thermal conductive silica gel of the present invention maintains good thermal conductivity, and the thermal conductivity is at least 1 W / mK to 4 W / mK, such as 2 W / mK to 3 W / mK. It can be used as a heat dissipation material for electronic components, such as a heat dissipation material for various electronic devices (such as power modules, super LSIs, optical components (optical pickups or LEDs)), home appliances (such as DVD / HDD recorders (players), audiovisual equipment such as FPDs), PC peripheral devices, home game consoles, automobiles, and industrial equipment such as inverters and switching power supplies.

[0094] 3. Manufacturing Method

[0095] The present invention provides a low-hardness one-component moisture-curing thermal conductive gel modified with the above-mentioned pre-crosslinked resin, which can be prepared by the following method: Add an addition-curable vinyl polyorganosiloxane, a hydrogen-containing polyorganosiloxane, a platinum catalyst, a hydroxyl- or alkoxy-terminated polyorganosiloxane, and a thermal conductive filler into a mixing and stirring pot. After mixing evenly, evacuate the air and heat at 100-120°C for at least 2 hours. During the dehumidification process of the mixture, at the same time, the vinyl polyorganosiloxane and the hydrogen-containing polyorganosiloxane are crosslinked by addition under the action of the platinum catalyst to form a pre-crosslinked resin. Keep the vacuum, cool down to room temperature, add a catalyst and a crosslinking agent in sequence, evacuate the air and mix evenly, and then discharge and fill.

[0096] Examples

[0097] The following examples are used to exemplarily show the implementation manners and effects of the present invention.

[0098] In the present invention, for the percentage of the content of each component, if not otherwise specified, it refers to the weight percentage (wt%).

[0099] Preparation of Thermal Conductive Gel:

[0100] Add a vinyl-terminated polyorganosiloxane (including a hydrogen-containing polyorganosiloxane and a platinum catalyst), a hydroxyl- or alkoxy-terminated organosilicon, and a thermal conductive filler into a mixing and stirring pot. After mixing evenly, evacuate the air and heat at 100-120°C for at least 2 hours. Keep the vacuum, cool down to room temperature, add a catalyst and a crosslinking agent in sequence, evacuate the air and mix evenly, and then discharge and fill.

[0101] Measurement of Thermal Conductivity

[0102] Use a thermal conductivity meter of Hot disk company, model: 2500S.

[0103] Measurement of Hardness

[0104] Use a bench-top Shore A hardness tester.

[0105] Vibration Test

[0106] Conduct a vibration test in accordance with ISO 19453-3 to evaluate whether there is interface detachment and cracking in the cured material.

[0107] Example 1

[0108] Hydroxyl-terminated polydimethylsilicone oil Andisil OH 2,000, 2%,

[0109] Vinyl-terminated polydimethylsilicone oil VS 2000 (pre-mixed with platinum catalyst CATALYST OL (containing 1% platinum), the addition amount in terms of platinum is about 7 ppm, based on vinyl-terminated polydimethylsiloxane VS 2000 and the following hydrogen-containing polyorganosiloxane XL12 (total weight) 7.9%,

[0110] Hydrogen-containing polyorganosiloxane XL12 0.1%,

[0111] 10-micron spherical alumina 55%,

[0112] 2-micron spherical alumina 25%,

[0113] 0.6-micron alumina 5%,

[0114] Titanate catalyst D62 1%,

[0115] Crosslinking agent Methyltrimethoxysilane 4%.

[0116] Test results: Thermal conductivity: 1 W / mK,

[0117] Hardness: Shore A 52,

[0118] After vibration test according to ISO 19453-3, there is no interfacial detachment and no material cracking.

[0119] Example 2

[0120] Methoxy-terminated polydimethylsiloxane RH-FW600, 2%;

[0121] Vinyl-terminated polyorganosiloxane VS 500 (pre-mixed with platinum catalyst CATALYST OL (containing 1% platinum), the addition amount in terms of platinum is about 7 ppm, based on methoxy-terminated polydimethylsiloxane RH-FW600 and the following hydrogen-containing polyorganosiloxane XL17 (total weight) 4.97%;

[0122] Hydrogen-containing polyorganosiloxane XL17 0.03%

[0123] 40-micron spherical aluminum nitride 56%

[0124] 5-micron spherical aluminum nitride 30%

[0125] 0.6-micron alumina 5%;

[0126] Titanate catalyst NB722 0.5%,

[0127] Crosslinking agent methyltriethoxysilane 1%,

[0128] Crosslinking agent vinyltrimethylsilane 0.5%

[0129] Test results: Thermal conductivity: 4.0 W / mK,

[0130] Hardness: Shore A 75,

[0131] After vibration test in accordance with ISO 19453-3, there is no interface detachment and no material cracking.

[0132] Example 3

[0133] Methoxy-terminated polydimethylsiloxane RH-FW1K, 3%;

[0134] Vinyl-terminated polyorganosiloxane VS100 (pre-mixed with platinum catalyst CATALYST OL (containing 1% platinum), calculated as platinum, addition amount is about 7 ppm, based on the total weight of methoxy-terminated polydimethylsiloxane RH-FW1K and the following hydrogen-containing polyorganosiloxane XL12), 9.75%;

[0135] Hydrogen-containing polyorganosiloxane XL12 0.25%

[0136] 30-micron boron nitride 8%;

[0137] 30-micron spherical aluminum nitride 30%

[0138] 5-micron spherical aluminum nitride 35%

[0139] 0.6-micron zinc oxide 10%

[0140] Titanate catalyst NB722 1%,

[0141] Crosslinking agent methyltrimethoxysilane 1.5%,

[0142] Crosslinking agent methyltriethoxysilane 1.5%.

[0143] Test results: Thermal conductivity: 2.2 W / mK, Hardness: Shore A 64,

[0144] After vibration test in accordance with ISO 19453-3, there is no interface detachment and no material cracking.

[0145] Comparative Example 1

[0146] Methoxy-terminated polydimethylsiloxane RH-FW600, 5%;

[0147] 50% spherical alumina with a diameter of 40 microns,

[0148] 25% spherical alumina with a diameter of 10 microns

[0149] 5% alumina with a diameter of 0.6 microns

[0150] 10% aluminum nitride with a diameter of 2 microns

[0151] 1% titanate catalyst D62,

[0152] 2% crosslinking agent methyltrimethoxysilane,

[0153] 2% crosslinking agent methyltriethoxysilane.

[0154] Thermal conductivity: 2 W / mK,

[0155] Hardness: Shore A 88,

[0156] After vibration testing according to ISO 19453-3, the interface detached and the material cracked.

[0157] Comparative Example 2

[0158] Hydroxyl-terminated polydimethylsiloxane 4% OH 750;

[0159] 45% spherical alumina with a diameter of 20 microns

[0160] 40% spherical alumina with a diameter of 5 microns;

[0161] 5% zinc oxide with a diameter of 0.6 microns

[0162] 1% titanate catalyst NB722,

[0163] 2% crosslinking agent methyltrimethoxysilane,

[0164] 3% crosslinking agent methyltriethoxysilane.

[0165] Thermal conductivity: 1.6 W / mK, Hardness: Shore A 92,

[0166] After vibration testing according to ISO 19453-3, the interface detached and the material cracked.

[0167] It can be seen from the above Examples 1-3 and Comparative Examples 1-2 that the composition for modifying one-component thermal conductive gel of the present invention can effectively reduce the hardness of the moisture-cured one-component thermal conductive gel after curing, improve toughness, and meet the requirements of vibration testing.

Claims

1. A one-component moisture-curing thermal conductive gel, characterized in that, It comprises: Hydroxyl- or alkoxy-terminated polyorganosiloxane; Crosslinked addition-curable polyorganosiloxane, which is a pre-crosslinked resin formed by the addition crosslinking of vinyl-terminated polyorganosiloxane and hydrogen-containing polyorganosiloxane under the action of a platinum catalyst. Among them, the silicon-hydrogen content of the hydrogen-containing polyorganosiloxane is 1% to 20 mol% of the vinyl groups of the vinyl-terminated polyorganosiloxane, and the viscosity of the vinyl-terminated polyorganosiloxane before pre-curing is 50 cps to 2000 cps; Thermally conductive filler; Second catalyst; and Crosslinking agent.

2. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The hydroxyl- or alkoxy-terminated polyorganosiloxane is alkoxy-terminated polyorganosiloxane.

3. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 50 cps to 2000 cps.

4. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 100 to 1500 cps.

5. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 150 to 1000 cps.

6. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 200 to 800 cps.

7. The one-component moisture-curing thermal conductive gel according to claim 1, wherein, The viscosity of the hydroxyl- or alkoxy-terminated polyorganosiloxane is 400 to 600 cps.

8. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the vinyl-terminated polyorganosiloxane before pre-curing is 100 to 1500 cps.

9. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the vinyl-terminated polyorganosiloxane before pre-curing is 150 to 1000 cps.

10. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the vinyl-terminated polyorganosiloxane before pre-curing is 200 to 800 cps.

11. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The viscosity of the vinyl-terminated polyorganosiloxane before pre-curing is 300 to 500 cps.

12. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The silicon-hydrogen content of the hydrogen-containing polyorganosiloxane is 2% to 16 mol% of the vinyl groups of the vinyl-terminated polyorganosiloxane.

13. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The silicon-hydrogen content of the hydrogen-containing polyorganosiloxane is 4% to 10 mol% of the vinyl groups of the vinyl-terminated polyorganosiloxane.

14. The one-component moisture-curing thermal conductive gel according to claim 1, wherein The silicon-hydrogen content of the hydrogen-containing polyorganosiloxane is 5% to 8 mol% of the vinyl groups of the vinyl-terminated polyorganosiloxane.

15. The one-component moisture-curing thermal conductive gel according to claim 1, wherein Based on the platinum in the platinum catalyst, the amount of the platinum catalyst is 3 to 10 ppm of the total weight of the vinyl-terminated polyorganosiloxane and the hydrogen-containing polyorganosiloxane.

16. The one-component moisture-curing thermal conductive gel according to claim 1, wherein Based on the platinum in the platinum catalyst, the amount of the platinum catalyst is 4 to 8 ppm of the total weight of the vinyl-terminated polyorganosiloxane and the hydrogen-containing polyorganosiloxane.

17. The one-component moisture-curing thermal conductive gel according to claim 1, wherein Based on the platinum in the platinum catalyst, the amount of the platinum catalyst is 5 to 7 ppm of the total weight of the vinyl-terminated polyorganosiloxane and the hydrogen-containing polyorganosiloxane.

18. The one-component moisture-curing thermal conductive gel according to claim 1 or 2, characterized in that, The thermally conductive filler is one or more selected from alumina, aluminum nitride, boron nitride, and zinc oxide; and / or Among them, the second catalyst is an organotin catalyst or a titanate catalyst; and / or Among them, the crosslinking agent is one or more of methoxysilane and ethoxysilane.

19. The one-component moisture-curing thermal conductive gel according to claim 1, wherein Based on 100% by weight of the one-component thermally conductive gel, The hydroxyl- or alkoxy-terminated polyorganosiloxane is 1 to 10% by weight; The crosslinked addition-curable polyorganosiloxane is 5% to 18% by weight, The thermally conductive filler is 75% to 92% by weight; The second catalyst is 0.2% to 2% by weight; The crosslinking agent is 1.5% to 5% by weight.

20. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the hydroxyl or alkoxy-terminated polyorganosiloxane is 2% to 8% by weight.

21. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the hydroxyl or alkoxy-terminated polyorganosiloxane is 2% to 7% by weight.

22. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the hydroxyl or alkoxy-terminated polyorganosiloxane is 2% to 5% by weight.

23. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the crosslinked addition-cured polyorganosiloxane is 6% to 15% by weight.

24. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the crosslinked addition-cured polyorganosiloxane is 8% to 10% by weight.

25. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the thermal conductive filler is 80% to 90% by weight.

26. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the thermal conductive filler is 85% to 88% by weight.

27. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the second catalyst is 0.5% to 1.5% by weight.

28. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the second catalyst is 0.8 to 1% by weight.

29. The one-component moisture-curing thermal conductive gel according to claim 19, characterized in that, Based on 100% by weight of the one-component thermal conductive gel, it is characterized in that the crosslinking agent is 2% to 4.5% by weight.

30. The one-component moisture-curing thermal conductive gel according to claim 19, wherein Based on 100% by weight of the one-component thermal conductive gel, the crosslinking agent is 2.5% to 4% by weight.

31. The one-component moisture-curing thermal conductive gel according to claim 1, characterized in that, The hardness of the thermal conductive gel after curing is Shore hardness A of 50 to 75, and / or the thermal conductivity is 1 W / mK to 4 W / mK.

32. The method for manufacturing the one-component moisture-curing thermal conductive gel according to any one of claims 1-31, which comprises the following steps: Mixing uniformly a one-component thermal conductive gel modifying composition containing vinyl polyorganosiloxane, hydrogen-containing polyorganosiloxane and a platinum catalyst, a hydroxyl or alkoxy-terminated polyorganosiloxane and a thermal conductive filler; Heating at 100 to 120 °C under vacuum for at least 2 hours to remove moisture. During this process, the vinyl polyorganosiloxane and the hydrogen-containing polyorganosiloxane are crosslinked by addition under the action of the platinum catalyst to form a crosslinked addition-cured polyorganosiloxane; While maintaining the vacuum, cooling to room temperature, adding the second catalyst and the crosslinking agent in sequence, and mixing uniformly to obtain the one-component thermal conductive gel.