Modified hydrogen-containing silicone oil, one-component heat conductive gel and preparation method thereof

Abstract

The application discloses a modified hydrogen-containing silicone oil and a single-component heat-conducting gel prepared from the modified hydrogen-containing silicone oil. The method for preparing the single-component heat-conducting gel is to mix the hydrogen-containing silicone oil with long-chain alkyl and the powder treatment agent with other components organically, so that the obtained single-component heat-conducting gel can effectively improve the extrusion property, the thermal resistance of the single-component heat-conducting gel does not obviously increase during the long-term use in a high-temperature environment, the single-component heat-conducting gel does not become hard and powdery after high-temperature aging, the thermal stability of the heat-conducting gel can be effectively improved, the single-end vinyl silicone oil is introduced to reduce the oil permeation rate of the system, and therefore the service life and cycle of the electronic components using the heat-conducting gel can be greatly improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to thermally conductive gels, and particularly to modified hydrogen-containing silicone oils, single-component thermally conductive gels, and their preparation methods. Background Technology

[0002] In recent years, with the rapid development of new energy vehicles, 5G communications, smartphones, and laptops, heat dissipation has gradually become a focus of attention. Currently, silicone thermal conductive gels, thermal greases, and thermal pads are widely used. Silicone thermal conductive gels can be divided into single-component and two-component types. Single-component gels are similar to thermal putty and thermal grease, while two-component thermal conductive gels, after curing, resemble elastomers similar to thermal pads. Thermal conductive gels are mainly composed of vinyl silicone oil and thermally conductive powders, which mainly include alumina, zinc oxide, aluminum hydroxide, and boron nitride. Currently, there are many performance requirements for single-component thermal conductive gels, among which high extrusion performance, low oil penetration, and good temperature resistance are some of the key properties. However, achieving all these properties simultaneously is quite difficult. While ordinary long-chain alkyl treatment agents can meet the extrusion requirements, they are prone to powdering and hardening during long-term high-temperature aging, resulting in poor temperature resistance. Therefore, how to prepare a thermal conductive gel that meets the requirements of high extrusion performance, low oil penetration, and good temperature resistance is increasingly becoming a key focus of the market.

[0003] CN118879080 A discloses a low-oil-permeability, high-thermal-conductivity thermally conductive gel and its preparation process. The powder and silicone oil form a good bond through a composite coupling agent, thereby achieving higher powder filling and low oil permeability after curing. However, this technology does not address the changes in thermal resistance and pulverization of the thermally conductive gel under high-temperature aging.

[0004] CN118146770 A discloses a low-oil-leakage interface thermally conductive gel and its preparation method. The method employs a two-step process to prepare the low-oil-leakage thermally conductive gel. The preform minimizes the amount of oil-leaking silicone oil in the gel, ensuring maximum reaction between vinyl silicone oil and hydrogen-containing silicone oil. Then, a diluent is added to maintain the extrusion rate of the low-oil-leakage thermally conductive gel. However, while this technology achieves high extrusion speed and low oil leakage, it does not address the issue of temperature resistance.

[0005] The increase in hardness and thermal resistance of thermal conductive gel is mainly related to the powder treatment agent. Although ordinary long-chain alkyl treatment agents can ensure the extrudability of the powder, they are prone to decomposition in long-term high-temperature environments, resulting in a significant increase in both hardness and thermal resistance. In particular, the increase in thermal resistance of thermal conductive gel will directly affect the service life of electronic components.

[0006] Currently available high thermal conductivity gels (≥5.0W) struggle to achieve high extrusion performance, good temperature resistance, and low oil penetration; they essentially sacrifice one property to satisfy others. Developing a thermal conductivity gel that can meet these requirements—high extrusion performance, low oil penetration, and good temperature resistance—is a strong market demand. Summary of the Invention

[0007] Based on this, the purpose of the present invention is to provide a modified hydrogen-containing silicone oil, as well as a thermally conductive gel, its preparation method and application, wherein the thermally conductive gel has good extrudability and oil penetration rate, and also has good temperature resistance.

[0008] A first aspect of the present invention is to provide a modified hydrogen-containing silicone oil.

[0009] The modified hydrogen-containing silicone oil is generated by reacting D4H cyclotetrasiloxane with an olefin, the structural formula of which is:

[0010] Where 20≥q≥6; Vi represents vinyl groups.

[0011] In some embodiments, the molar ratio of the D4H cyclotetrasiloxane to the olefin is 1:2-4, more preferably 1:2.1-2.3.

[0012] In some of these embodiments, the modified hydrogen-containing silicone oil contains a compound with the following structural formula, where 20 ≥ q ≥ 6, and q is an integer;

[0013] In some of these embodiments, the modified hydrogen-containing silicone oil is generated by reacting D4H cyclotetrasiloxane with an olefin, and the reaction principle is as follows;

[0014]

[0015] Where 20≥q≥6; Vi represents vinyl groups.

[0016] In some of these embodiments, 20 ≥ q ≥ 10 is preferred, 18 ≥ q ≥ 12 is more preferred, and 15 ≥ q ≥ 12 is even more preferred.

[0017] In some embodiments, the modified hydrogen-containing silicone oil has a hydrogen content of 0.01 wt% to 0.4 wt% and a viscosity of 10 to 300 mPa·s; preferably, it is a modified hydrogen-containing silicone oil with a hydrogen content of 0.1 wt% to 0.3 wt% and a viscosity of 50 mPa·s to 200 mPa·s; more preferably, it is a modified hydrogen-containing silicone oil with a hydrogen content of 0.12 wt% to 0.2 wt% and a viscosity of 50 mPa·s to 200 mPa·s; and even more preferably, it is a modified hydrogen-containing silicone oil with a hydrogen content of 0.12 wt% to 0.2 wt% and a viscosity of 50 mPa·s to 150 Pa·s.

[0018] The method for preparing the modified hydrogen-containing silicone oil includes the following steps:

[0019] (1) The olefin was slowly dropped into a reactor containing D4H cyclotetrasiloxane and platinum catalyst, with toluene as solvent; after the dropping was completed, the reaction was refluxed at 80-100℃ for 1-3 hours.

[0020] (2) Then, perform vacuum distillation at 80-100℃ for 1-2 hours to remove unreacted small molecules and solvents, and remove the catalyst to obtain modified hydrogen-containing silicone oil.

[0021] In some of these embodiments, the molar ratio of the D4H cyclotetrasiloxane to the olefin is 1:2-4, preferably 1:2.1-2.3.

[0022] A second objective of this invention is to provide a one-component thermally conductive gel prepared from the following raw material components in parts by weight:

[0023] 30-60 parts of vinyl-terminated silicone oil;

[0024] 30-60 parts of single-ended vinyl silicone oil;

[0025] 5-15 parts of powder treatment agent;

[0026] Platinum catalyst 5-15 ppm;

[0027] 10-30 parts of any of the above-mentioned modified hydrogen-containing silicone oils;

[0028] Inhibitor 0.01-0.2 parts;

[0029] 1000-3000 parts of thermally conductive powder;

[0030] The powder treatment agent is prepared by hydrosilylation reaction of D4H cyclotetrasiloxane with vinylsilane, olefin and phenylvinylsilane respectively.

[0031] The vinylsilane structure is as follows:

[0032] Vi-Si-(OR1)3

[0033] Wherein OR1 is one or more of methoxy, ethoxy, formyloxy, and acetoxy, and Vi is vinyl; the olefin structure is as follows:

[0034]

[0035] Where 20≥q≥6, and Vi represents vinyl groups.

[0036] In some of these embodiments, 20 ≥ q ≥ 10 is preferred, 18 ≥ q ≥ 12 is more preferred, and 15 ≥ q ≥ 12 is even more preferred.

[0037] In some of these embodiments, the powder treatment agent contains a compound with the following structure;

[0038]

[0039] Wherein 20 ≥ q ≥ 6, and q is an integer; the substituent OR1 is methoxy, ethoxy, formyloxy, or acetoxy. Preferably, 20 ≥ q ≥ 10, more preferably 18 ≥ q ≥ 12, and even more preferably 15 ≥ q ≥ 12.

[0040] In some embodiments, the one-component thermally conductive gel is prepared from the following raw material components in parts by weight:

[0041] 40-50 parts of vinyl-terminated silicone oil;

[0042] 40-50 parts of single-ended vinyl silicone oil;

[0043] 5-10 parts of powder treatment agent;

[0044] Platinum catalyst 5-10 ppm;

[0045] 10-20 parts of any of the above-mentioned modified hydrogen-containing silicone oils;

[0046] Inhibitor 0.05-0.1 parts;

[0047] 1500-2500 parts of thermally conductive powder.

[0048] Further preferably, the modified hydrogen-containing silicone oil is 10-15 parts, and / or the powder treatment agent is 5-10 parts, or preferably the powder treatment agent is 5-8 parts.

[0049] In some embodiments, the end-vinyl silicone oil has a viscosity of 50-1000 cp and a vinyl content of 0.1% to 2 wt%; more preferably, it has a viscosity of 100-500 cp and a vinyl content of 0.1% to 1 wt%, and even more preferably, it has a viscosity of 100-200 cp and a vinyl content of 0.5% to 1 wt%.

[0050] In some embodiments, the single-ended vinyl silicone oil has a viscosity of 50-1000 cp and a vinyl content of 0.05% to 1 wt%; preferably, it has a viscosity of 100-500 cp and a vinyl content of 0.05% to 0.5 wt%, and more preferably, it has a viscosity of 100-300 cp and a vinyl content of 0.1% to 0.5 wt%.

[0051] In some embodiments, the thermally conductive powder is a spherical powder selected from one or more of alumina, aluminum nitride, magnesium oxide, zinc oxide, or boron nitride, preferably spherical alumina or near-spherical alumina, with a particle size of 1 to 100 μm.

[0052] Further preferred are spherical or near-spherical alumina, with a particle size of 1–50 μm, and preferably a particle size of 20–30 μm.

[0053] In some of these embodiments, the platinum catalyst is one or a combination of chloroplatinic acid, chloroplatinic acid-isopropanol complex, chloroplatinic acid-divinyltetramethyldisiloxane complex.

[0054] In some of these embodiments, the inhibitor is one or a combination of 1-ethynyl-1-cyclohexanol, tetramethyltetravinylcyclotetrasiloxane, 2-methyl-3-butynyl-2-ol, 3-methyl-1-ethynyl-3-ol, 3,5-dimethyl-1-hexynyl-3-ol, and 3-methyl-1-dodecynyl-3-ol.

[0055] In some embodiments, the method for preparing the powder treatment agent includes the following steps:

[0056] (1) In a reactor containing D4H cyclotetrasiloxane, platinum catalyst and toluene solvent, vinylsilane is slowly added dropwise. After the addition is complete, the reaction is refluxed for 1-3 hours to obtain a mixture.

[0057] (2) Slowly add olefins to the above mixture, and after the addition is complete, heat the mixture to 80-100℃ and reflux for 1-3 hours.

[0058] (3) Slowly add phenyl vinylsilane, and after the addition is complete, continue to reflux at 80-100℃ for 1-3 hours. Then, distill under reduced pressure for about 1-2 hours to remove unreacted small molecules and solvents, and remove the catalyst to obtain the powder treatment agent.

[0059] The vinylsilane has the following structure: Vi-Si-(OR1)3, wherein OR1 is one or more of methoxy, ethoxy, formyloxy, and acetoxy, and Vi is vinyl;

[0060] The olefin structure is as follows: Where 20≥q≥6, and Vi represents vinyl groups.

[0061] In some of these embodiments, the molar ratio of the vinylsilane to D4H cyclotetrasiloxane is 1.-1.3:1.

[0062] In some of these embodiments, the molar ratio of the olefin to D4H cyclotetrasiloxane is 1-1.2:1.

[0063] In some of these embodiments, the molar ratio of the phenylvinylsilane to D4H cyclotetrasiloxane is 1-1.3:1.

[0064] The preparation method of the single-component thermally conductive gel includes the following steps:

[0065] (1) Add the vinyl-terminated silicone oil, single-terminated silicone oil, and powder treatment agent to a planetary mixer and mix for 5-15 minutes until homogeneous. Then add the thermally conductive powder and mix for 10-30 minutes until homogeneous.

[0066] (2) Heat to about 100-120℃ and stop stirring. Maintain vacuum for 60-120 minutes and then cool to room temperature.

[0067] (3) After adding inhibitors and hydrogen-containing silicone oil and stirring for about 15-30 minutes, add platinum catalyst and continue vacuum stirring for about 15-30 minutes. Then raise the temperature to 80℃-100℃ and cure for 60-120 minutes to obtain the thermally conductive gel.

[0068] In preparing the thermally conductive gel, this invention starts with modified hydrogen-containing silicone oil and powder treatment agent to prepare hydrogen-containing silicone oil and powder treatment agent with long-chain alkyl groups. These two are organically combined with other components to obtain a single-component thermally conductive gel that not only effectively improves extrudability, but also does not show a significant increase in thermal resistance during long-term use in high-temperature environments. It does not exhibit powdering or hardening during high-temperature aging, effectively improving the thermal stability of the thermally conductive gel. At the same time, the introduction of single-ended vinyl silicone oil reduces the oil seepage rate of the system, thereby greatly improving the service life and cycle of electronic components using the thermally conductive gel described in this invention.

[0069] This invention synthesizes a modified hydrogen-containing silicone oil and uses it in combination with a novel powder treatment agent to construct a single-component thermally conductive gel. We found that introducing long-chain alkyl groups into the hydrogen-containing silicone oil and phenyl groups into the powder treatment agent effectively wets the thermally conductive powder, improving extrudability. Simultaneously, it enhances the temperature resistance of the treatment agent, preventing degradation and volatilization under high-temperature aging, ensuring minimal increase in thermal resistance, and preventing powdering and hardening. The alkoxy groups effectively treat the powder surface. This is likely because the powder treatment agent contains monosilane groups, and these groups are located at the outermost end of the molecule, facilitating reaction and avoiding problems such as hardening after curing due to steric hindrance. It also participates in the cross-linking reaction of the system, enhancing the bonding force between the silicone oil and the powder, reducing the oil seepage rate after curing. Furthermore, the long-chain alkyl groups more effectively wet the thermally conductive powder, improving extrudability. At the same time, using a single-ended vinyl silicone oil effectively reduces the vinyl content of the system, thereby reducing the oil seepage rate. Therefore, the obtained thermally conductive gel has high extrudability, low oil penetration rate, excellent thermal stability, and its thermal resistance does not increase significantly during long-term high-temperature aging. It does not pulverize or harden and has high application stability. Detailed Implementation

[0070] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be construed as limiting the invention.

[0071] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0072] The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps is not limited to the steps or modules listed, but may optionally include steps not listed, or may optionally include other steps inherent to such process, method, product, or device.

[0073] In this invention, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0074] Some embodiments of the present invention involve

[0075] The following are specific examples.

[0076] Unless otherwise specified, the viscosity in the following examples refers to the viscosity at 25°C; unless otherwise specified, "parts" refers to parts by weight.

[0077] I. The preparation method of the modified hydrogen-containing silicone oil used in the following examples is as follows.

[0078] The preparation method of the modified hydrogen-containing silicone oil includes the following steps:

[0079] (1) In a reaction vessel equipped with a stirrer, reflux condenser, dropping funnel and thermometer, add an appropriate amount of D4H cyclotetrasiloxane (1,3,5,7-tetramethylcyclotetrasiloxane), 3-5 ppm (based on Pt content) of Castel platinum catalyst, and toluene solvent and stir evenly.

[0080] (2) Slowly add 1-hexadecene to the above mixture; after the addition is complete, continue the reflux reaction at 80°C for 2 hours. The molar ratio of 1-hexadecene to D4H cyclotetrasiloxane is 2.2:1.

[0081] (3) The modified hydrogen-containing silicone oil is obtained by vacuum distillation at 80℃ for about 1 hour to remove unreacted small molecules and solvents, and the catalyst is removed by activated carbon adsorption.

[0082] The modified hydrogen-containing silicone oil was measured to have a viscosity of approximately 100 cp and a hydrogen content of 0.16 wt%.

[0083] The modified hydrogen-containing silicone oil includes compounds with the following structural formula:

[0084]

[0085] The reaction principle of the modified hydrogen-containing silicone oil is as follows:

[0086] Where q = 13. Infrared detection showed that the characteristic absorption peak of Si-H in the product was still present at 2162 cm-1, and there was no C=C stretching vibration peak at 1643 cm-1, proving that the olefin had basically reacted completely. Furthermore, a symmetrical stretching vibration peak of -CH2 appeared near 2860 cm-1, and the absorption peak of CH bending vibration in -CH2- was at 1372 cm-1.

[0087] II. The preparation method of the powder treatment agent used in the following examples is as follows.

[0088] The preparation method of the powder treatment agent includes the following steps:

[0089] (1) Add D4H cyclotetrasiloxane and 3-5 ppm (based on Pt content) platinum catalyst (Castel catalyst) to a reactor equipped with a stirrer, reflux condenser, dropping funnel and thermometer, and stir until homogeneous.

[0090] (2) Vinyltriacetoxysilane is slowly added dropwise to the reaction vessel. After the addition is complete, the reaction is refluxed for 2 hours. The molar ratio of vinyltriacetoxysilane to D4H cyclotetrasiloxane is 1:1.

[0091] (3) Slowly add 1-hexadecene to the above mixture, and after the addition is complete, heat the mixture to 80°C and reflux for 2 hours. The molar ratio of 1-hexadecene to D4H cyclotetrasiloxane is 1:1.

[0092] (4) Then slowly add phenyl vinyl silane dropwise into the reaction vessel. After the dropwise addition is complete, continue the reflux reaction for 2 hours. The molar ratio of phenyl vinyl silane to D4H is 1:1. Then perform vacuum distillation at 80°C for about 1 hour to remove unreacted small molecules and solvents. Remove the catalyst by activated carbon adsorption to obtain the self-made powder treatment agent.

[0093] The powder treatment agent has the following structure:

[0094]

[0095] Where q = 13; OR1 is an acetoxy group.

[0096] Infrared detection revealed a Si-H absorption peak at 2160 cm⁻¹, where the characteristic Si-H absorption peak is located, while the product showed an absorption peak at 1642.23 cm⁻¹. -1 The absence of a C=C absorption peak at 2860 cm⁻¹ proves that the vinyl groups have reacted completely. -1 A symmetrical stretching vibration peak of -CH2 appears nearby, at 1370 cm⁻¹. -1 An absorption peak appears at 1590 cm⁻¹ due to the CH bending vibration in -CH₂-. -1 and 1460cm -1 Characteristic peaks of the benzene ring appear at 1075 cm⁻¹; -1 and 1090cm -1 Absorption peaks of Si-OC stretching vibrations appeared nearby.

[0097] III. The thermally conductive gel used in the following examples can be prepared by referring to the following method.

[0098] The preparation method of the single-component thermally conductive gel includes the following steps:

[0099] (1) Put the vinyl silicone oil (including terminal vinyl silicone oil and / or single-terminal vinyl silicone oil) and powder treatment agent into a planetary mixer, stir for 10 minutes until uniform, then add the heat-conducting powder, and stir for 15 minutes until uniform.

[0100] (2) Heat to 100℃-105℃ and stop stirring. Maintain vacuum for 110min-120min and then cool to room temperature.

[0101] (3) After adding the inhibitor and the modified hydrogen-containing silicone oil and stirring for about 15 minutes, add the platinum catalyst and continue to stir under vacuum for about 15-20 minutes. Then raise the temperature to 80℃-85℃ and cure for 110-120 minutes to obtain the thermally conductive gel.

[0102] Example 1

[0103] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0104]

[0105] Example 2

[0106] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0107]

[0108]

[0109] Example 3

[0110] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0111]

[0112] Example 4

[0113] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0114]

[0115]

[0116] Example 5

[0117] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0118]

[0119] Comparative Example 1

[0120] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0121]

[0122]

[0123] Comparative Example 2

[0124] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0125]

[0126] Comparative Example 3

[0127] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0128]

[0129]

[0130] Comparative Example 4

[0131] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0132]

[0133] Comparative Example 5

[0134] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0135]

[0136]

[0137] Comparative Example 6

[0138] The single-component thermally conductive gel prepared in this embodiment has the following raw material composition:

[0139]

[0140] The above thermally conductive gels were tested separately:

[0141] 1. Thermal resistance: Measured according to ASTM D 5470-01 Characterization test for thermal conductivity properties of thin thermally conductive solid electrical insulating materials (2 3mm thick alumina fixtures, 0.5mm thick adhesive layer). Unit: °C*in 2 / W.

[0142] 2. Heat aging resistance: The heat aging conditions are 150℃ / 1000h, and it is observed whether it hardens and turns into powder.

[0143] 3. Extrudability test: The gel was loaded into a 30cc single-component tube, vacuumed and centrifuged to remove bubbles. Under a pressure of 90 ps i, the mass of the extruded gel was tested within 60 seconds by the extruder (the inner diameter of the extruder is 2.5 mm).

[0144] 4. Oil seepage rate test: Take 10g of single-component thermal conductive gel, place it on filter paper, and spread it into a circular gel sample with a diameter of 3cm. After baking at 120℃ for 7 days, calculate the oil seepage area (maximum area of ​​oil seepage edge - area of ​​circular gel sample).

[0145]

[0146] As can be seen from the table, the self-made powder treatment agent and the modified hydrogen-containing silicone oil thermal conductive gel used in Examples 1-5 have excellent extrusion properties and oil penetration rate, and the increase in thermal resistance is not significant during baking at 150°C for 1000 hours.

[0147] The increase in thermal resistance in Examples 1-5 remained within 10%. In Comparative Examples 3 and 4, the long-chain coupling agent hexadecyltrimethoxysilane was used, and even when combined with our modified hydrogen-containing silicone oil, its temperature resistance was still poor. The thermal resistance increased significantly by more than 20% during the aging process, and powdering and hardening occurred. After analysis, this may be because our powder treatment agent contains phenyl groups and hydrogen-containing groups that can participate in the reaction to increase the crosslinking density, which can further improve the temperature resistance of the treatment agent. During long-term high-temperature aging, the thermal resistance of the thermally conductive gel will not increase significantly. In addition, due to the presence of hydrogen-containing groups, the oil penetration rate will be reduced to a certain extent due to their participation in the system reaction. Furthermore, the presence of long-chain alkyl groups also ensures the extrudability of the treatment agent.

[0148] As can be seen from Comparative Example 1, which uses only double-ended vinyl silicone oil, its oil penetration rate is significantly lower than that of Example 1, which contains single-ended vinyl silicone oil. This may be because if single-ended vinyl silicone oil is used, it will reduce the vinyl content of the system. Usually, vinyl content is excessive in single-component thermal conductive gel silicone oil systems, which will result in too much vinyl silicone oil not participating in the reaction. This will lead to oil penetration in long-term high-temperature environments.

[0149] As can be seen from Comparative Example 2, the extrusion performance without using the modified hydrogen-containing silicone oil described in this invention is significantly lower than that in Example 1. The introduction of long-chain alkyl groups into the modified hydrogen-containing silicone oil described in this invention can significantly enhance the wettability of powders, thereby improving extrusion performance.

[0150] As can be seen from Comparative Example 5, although the extrusion performance of the single-component thermal conductive gel is still very good when the amount of modified hydrogen-containing silicone oil reaches 10 parts and is used in combination with 5-10 parts of powder treatment agent, the extrusion performance decreases significantly when the amount of modified hydrogen-containing silicone oil is only 8 parts.

[0151] As can be seen from Comparative Example 6, when the amount of powder treatment agent is increased to 18 parts, the extrusion performance actually decreases. This may be because a large number of hydrogen-containing groups in the powder treatment agent participate in the cross-linking reaction of the system, which will increase the cross-linking density of the silicone oil and reduce the oil penetration area.

[0152] This invention starts from system and structural design, using single-ended vinyl silicone oil to reduce the oil penetration rate of the system, improving extrudability by modifying hydrogen-containing silicone oil, and preparing a single-component thermally conductive gel by designing a suitable powder treatment agent, which can improve temperature resistance and oil penetration rate while ensuring extrudability.

[0153] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0154] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A modified hydrogen-containing silicone oil, characterized in that, The modified hydrogen-containing silicone oil is generated by reacting D4H cyclotetrasiloxane with an olefin, the structural formula of which is: ; Where 20 ≥ q ≥ 6; Vi is vinyl group; the molar ratio of D4H cyclotetrasiloxane to olefin is 1:2-4; the modified hydrogen-containing silicone oil contains compounds with the following structural formula: Where 20≥q≥6, and q is an integer; the modified hydrogen-containing silicone oil has a hydrogen content of 0.01wt%~0.4wt% and a viscosity of 10~300mPa·s.

2. The modified hydrogen-containing silicone oil according to claim 1, characterized in that, In the compound, q is 20 ≥ q ≥ 10, where q is an integer.

3. The modified hydrogen-containing silicone oil according to claim 2, characterized in that, In the compound, q is 18 ≥ q ≥ 12, where q is an integer.

4. The modified hydrogen-containing silicone oil according to claim 3, characterized in that, In the compound, q is 15 ≥ q ≥ 12, and q is an integer.

5. The modified hydrogen-containing silicone oil according to claim 1, characterized in that, The molar ratio of D4H cyclotetrasiloxane to olefin is 1:2.1-2.

3.

6. The modified hydrogen-containing silicone oil according to any one of claims 1-5, characterized in that, The modified hydrogen-containing silicone oil has a hydrogen content of 0.01 wt% to 0.4 wt% and a viscosity of 10 to 300 mPa·s.

7. The modified hydrogen-containing silicone oil according to claim 6, characterized in that, The modified hydrogen-containing silicone oil has a hydrogen content of 0.1 wt% to 0.3 wt% and a viscosity of 50 mPa·s to 200 mPa·s.

8. The modified hydrogen-containing silicone oil according to claim 7, characterized in that, The modified hydrogen-containing silicone oil has a hydrogen content of 0.12 wt% to 0.2 wt% and a viscosity of 50 mPa·s to 150 mPa·s.

9. A method for preparing the modified hydrogen-containing silicone oil according to any one of claims 1-8, characterized in that, Includes the following steps: (1) The olefin was slowly dropped into a reactor containing D4H cyclotetrasiloxane and platinum catalyst, with toluene as solvent; after the dropping was completed, the reaction was refluxed at 80-100℃ for 1-3 hours. (2) Then perform vacuum distillation at 80-100℃ for 1-2 hours to remove unreacted small molecules and solvents, remove catalysts, and obtain modified hydrogen-containing silicone oil. The molar ratio of D4H cyclotetrasiloxane to olefin is 1:2-4.

10. The preparation method according to claim 9, characterized in that, The molar ratio of D4H cyclotetrasiloxane to olefin is 1:2.1-2.

3.

11. A one-component thermally conductive gel, characterized in that, It is prepared from the following raw material components in parts by weight: 30-60 parts of vinyl-terminated silicone oil; 30-60 parts of single-ended vinyl silicone oil; 5-15 parts of powder treatment agent; Platinum catalyst 5-15 ppm; 10-30 parts of the modified hydrogen-containing silicone oil according to any one of claims 1-8; Inhibitor 0.01-0.2 parts; 1000-3000 parts of thermally conductive powder; The powder treatment agent was prepared by hydrosilylation reaction of D4H cyclotetrasiloxane with vinylsilane, olefin and phenylvinylsilane respectively. The vinylsilane structure is as follows: Where OR1 is one or more of methoxy, ethoxy, formyloxy, and acetoxy, and Vi is vinyl; The olefin structure is as follows: Where 20≥q≥6, and Vi represents vinyl groups.

12. The single-component thermally conductive gel according to claim 11, characterized in that, It is prepared from the following raw material components in parts by weight: 40-50 parts of vinyl-terminated silicone oil; 40-50 parts of single-ended vinyl silicone oil; 5-10 parts of powder treatment agent; Platinum catalyst 5-10 ppm; 10-20 parts of the modified hydrogen-containing silicone oil; Inhibitor 0.05-0.1 parts; 1500-2500 parts of thermally conductive powder.

13. The single-component thermally conductive gel according to claim 11, characterized in that, The vinyl-terminated silicone oil has a viscosity of 50-1000 cp and a vinyl content of 0.1% to 2 wt%; and / or The viscosity of the single-ended vinyl silicone oil is 50-1000 cp, and the vinyl content is 0.05% to 1 wt%.

14. The single-component thermally conductive gel according to claim 13, characterized in that, The terminated vinyl silicone oil has a viscosity of 100-500 cp and a vinyl content of 0.1% to 1 wt%.

15. The single-component thermally conductive gel according to claim 14, characterized in that, The terminated vinyl silicone oil has a viscosity of 100-200 cp and a vinyl content of 0.5% to 1 wt%.

16. The single-component thermally conductive gel according to claim 13, characterized in that, The viscosity of single-ended vinyl silicone oil is 100-500 cp, and the vinyl content is 0.05% to 0.5 wt%.

17. The single-component thermally conductive gel according to claim 16, characterized in that, Single-ended vinyl silicone oil has a viscosity of 100-300 cp and a vinyl content of 0.1% to 0.5 wt%.

18. The single-component thermally conductive gel according to claim 11, characterized in that, The thermally conductive powder is a spherical powder with a particle size of 1-100 μm, selected from one or more of alumina, aluminum nitride, magnesium oxide, zinc oxide, or boron nitride; and The platinum catalyst is one or a combination of chloroplatinic acid, chloroplatinic acid-isopropanol complex, and chloroplatinic acid-divinyltetramethyldisiloxane complex; and The inhibitor is one or a combination of 1-ethynyl-1-cyclohexanol, tetramethyltetravinylcyclotetrasiloxane, 2-methyl-3-butynyl-2-ol, 3-methyl-1-ethynyl-3-ol, 3,5-dimethyl-1-hexynyl-3-ol, and 3-methyl-1-dodecynyl-3-ol.

19. The single-component thermally conductive gel according to claim 18, characterized in that, The thermally conductive powder is spherical alumina or near-spherical alumina.

20. The single-component thermally conductive gel according to claim 18, characterized in that, The thermally conductive powder is a spherical powder with a particle size of 20-30 μm.

21. The single-component thermally conductive gel according to any one of claims 11-20, characterized in that, The powder treatment agent contains compounds with the following structure: Where 20 ≥ q ≥ 6, and q is an integer; the substituent OR1 is methoxy, ethoxy, formyloxy, or acetoxy.

22. The single-component thermally conductive gel according to claim 21, characterized in that, The preparation method of the powder treatment agent includes the following steps: (1) In a reactor containing D4H cyclotetrasiloxane, platinum catalyst and toluene solvent, vinylsilane is slowly added dropwise. After the addition is complete, the reaction is refluxed for 1-3 hours to obtain a mixture. (2) An olefin is slowly added dropwise to the above mixture. After the addition is complete, the temperature is raised to 80-100℃ and refluxed for 1-3 hours. (3) Slowly add phenyl vinylsilane, and after the addition is complete, continue to reflux at 80-100℃ for 1-3 hours. Then, distill under reduced pressure for 1-2 hours to remove unreacted small molecules and solvents, and remove the catalyst to obtain the powder treatment agent. The molar ratio of the vinylsilane and D4H cyclotetrasiloxane is 1-1.3:1; and The molar ratio of the olefin and D4H cyclotetrasiloxane is 1-1.2:1; and The molar ratio of the phenylvinylsilane to D4H cyclotetrasiloxane is 1-1.3:

1.

23. A method for preparing the single-component thermally conductive gel according to any one of claims 11-22, characterized in that, Includes the following steps: (1) Add the terminal vinyl silicone oil, the single-terminal vinyl silicone oil, and the powder treatment agent into a mixer and stir for 5-15 minutes until they are evenly mixed. Then add the thermally conductive powder in batches and stir for 10-30 minutes until they are evenly mixed. (2) Heat to 100-120℃, stop stirring, maintain vacuum for 60-120 min, and then cool to room temperature; (3) After adding the inhibitor and the modified hydrogen-containing silicone oil and stirring for 15-30 min, add the platinum catalyst and continue vacuum stirring for 15-30 min. Then raise the temperature to 80℃-100℃ and cure for 60-120 min to obtain the single-component thermally conductive gel.

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