Repairable liquid crystal type organic silicon heat conduction material as well as preparation method and application thereof

Abstract

The invention relates to an organic silicon heat conduction material, in particular to a repairable liquid crystal type organic silicon heat conduction material and a preparation method and application thereof. P-hydroxybenzaldehyde, potassium carbonate, potassium iodide and halogenated olefin are used for preparing a monomer M1; then reacting the monomer M1 with aromatic diamine to prepare a diene liquid crystal monomer M2; and finally, reacting the diene liquid crystal monomer M2 with hydrogen-containing silicone oil to prepare the organic silicon heat-conducting material. The repairable liquid crystal type organic silicon heat conduction material has excellent heat conduction performance and electrical performance, can repair damaged materials in a proper temperature range through an exchange reaction of imine bonds, and is suitable for preparation of heat conduction components and / or heat conduction packaging of circuit boards.

Description

Technical Field

[0001] The present invention relates to a silicone thermal conductive material, and particularly to a repairable liquid crystal type silicone thermal conductive material, its preparation method and application. Background Art

[0002] With the rapid development of 5G technology, electronic devices and semiconductor chips are gradually developing towards integration, miniaturization and multi-functionality. The power density of electronic devices and the heat output per unit volume have been significantly improved. If effective heat dissipation treatment cannot be carried out, it will have a huge negative impact on the overall performance and service life of electronic devices. Silicone materials have excellent weather resistance and electrical insulation, and liquid crystallinity is the property that mesogenic units can exhibit both the fluidity of liquids and the anisotropy of crystals under certain physical conditions. Therefore, by achieving the ordered orientation of mesogenic units under certain conditions, the mechanical properties and thermal conductivity of liquid crystal polymers can be greatly improved.

[0003] CN202411221129.5 provides a self-healing silicone thermal conductive gel, which is composed of thiocyanated polydimethylsiloxane, thiocyanated boron nitride and metal salts. The thiocyanic acid groups of thiocyanated polydimethylsiloxane and thiocyanated boron nitride can form dynamic reversible thiocyanato metal salt complexes with metal salts to achieve self-healing. CN202210334222.1 provides a repairable silicone thermal interface material with high repair efficiency and high thermal conductivity, which uses dynamic covalent disulfide bonds to achieve the repairability of the material. CN201580037216.8 provides a side chain type liquid crystalline polymer and its precursor, which can be used as a modifier for thermal conductive agents. Summary of the Invention

[0004] In view of the above problems, the present invention provides a liquid crystal type silicone intrinsic thermal conductive material with repairability. The material can achieve the repairability of the material through reversible dynamic imine bonds. At the same time, the liquid crystallinity is achieved by the ordered orientation of mesogenic units under certain conditions, thereby improving the thermal conductivity of the silicone material.

[0005] Another object of the present invention is to provide a preparation method of the repairable liquid crystal type silicone thermal conductive material.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] A preparation method of a repairable liquid crystal type silicone thermal conductive material, characterized in that the preparation method includes the following steps:

[0008] (1) Synthesis of monomer M1: Mix p-hydroxybenzaldehyde, potassium carbonate and potassium iodide, add acetone for reaction, then add haloalkene, continue heating for reaction, after completion, cool, filter and take the filtrate, rotary evaporate to remove acetone to obtain monomer M1;

[0009] (2) Synthesis of diene liquid crystal monomer M2: Mix monomer M1 with aromatic diamine, add absolute ethanol, heat for reflux reaction, after completion, cool, filter, wash and dry to obtain diene liquid crystal monomer M2;

[0010] (3) Preparation of silicone thermal conductive material: Mix diene liquid crystal monomer M2, solvent and hydrogen-containing silicone oil, add catalyst under heating and stirring, after reaction, pour into a mold and cure to obtain silicone thermal conductive material.

[0011] Preferably, the preparation method comprises the following steps:

[0012] (1) Synthesis of monomer M1: Mix 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate and 0.1 part of potassium iodide, add 30 - 60 parts of acetone, react for 20 - 40 min under magnetic stirring; drop 1 - 1.5 parts of haloalkene into the reaction solution within 60 - 120 minutes, heat to 50 - 80 °C, reflux for 5 - 8 hours, then cool to room temperature, filter and take the filtrate, rotary evaporate to remove acetone to obtain monomer M1;

[0013] (2) Synthesis of diene liquid crystal monomer M2: Add 2 parts of M1 and 1 part of aromatic diamine into a reaction flask, add 50 parts of absolute ethanol, heat to 60 - 80 °C, reflux for 4 - 12 h, cool and filter, wash with absolute ethanol and dry to obtain diene liquid crystal monomer M2;

[0014] (3) Preparation of silicone thermal conductive material: Mix 1 part of M2, solvent and hydrogen-containing silicone oil, heat to 60 - 70 °C, add Karstedt catalyst under stirring, react for 0.5 - 3 h, take out and pour into a mold, cure at 70 °C for 1 hour, then heat to 120 - 140 °C and cure for 2 hours to obtain silicone thermal conductive material.

[0015] Preferably, the haloalkene in step (1) is chloro- or bromo-alkene with 3 - 8 carbon atoms.

[0016] Preferably, the haloalkene in step (1) is at least one of 6-bromo-1-hexene, 3-bromo-1-propene, 4-bromo-1-butene, 5-bromo-1-pentene, 6-chloro-1-hexene, 3-chloro-1-propene.

[0017] Preferably, the aromatic diamine in step (2) is at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminobiphenyl.

[0018] Preferably, the solvent in step (3) is toluene; the hydrogen-containing silicone oil is one or a mixture of two or more of end-hydrogen-containing silicone oil, side-hydrogen-containing silicone oil, and mixed-type hydrogen-containing silicone oil with a total hydrogen content of less than 0.4%.

[0019] The repairable liquid crystal type silicone thermal conductive material prepared by the method of the present invention.

[0020] Preferably, the silicone thermal conductive material realizes the repairability of the material through reversible dynamic imine bonds.

[0021] The application of the repairable liquid crystal type silicone thermal conductive material of the present invention in the field of electronic appliances, for the preparation of thermal conductive components and / or the thermal conductive encapsulation of circuit boards.

[0022] The reaction principle of the present invention is:

[0023] In the first step, p-hydroxybenzaldehyde and haloolefin are synthesized into monomer M1, and the structural formula of M1 is as follows:

[0024]

[0025] In the second step, M1 reacts with aromatic diamine to synthesize diene liquid crystal monomer M2:

[0026]

[0027] In the third step, the diene liquid crystal monomer M2 is mixed with hydrogen-containing silicone oil for catalytic reaction to obtain a product. The partial structural formula of the product is as follows, and both ends represent the access positions of the hydrogen-containing silicone oil chains:

[0028]

[0029] In the above structure, n≥1; R represents at least one of, and the dotted line represents the access position to the main chain.

[0030] The present invention has the following advantages and effects compared with the prior art:

[0031] (1) The repairable liquid crystal type silicone thermal conductive material of the present invention has excellent thermal conductivity and electrical properties.

[0032] (2) The repairable liquid crystal type silicone thermal conductive material of the present invention has good repairability and can repair damaged materials through the exchange reaction of imine bonds in a suitable temperature range. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the self-repair of the material prepared in Example 1 of the present invention.

[0034] Figure 2 1H NMR spectrum of M1 in Example 4 of the present invention 1 1H NMR spectrum

[0035] Figure 3 13C NMR spectrum of M1 in Example 4 of the present invention 13 13C NMR spectrum

[0036] Figure 4 1H NMR spectrum of M2 in Example 4 of the present invention 1 1H NMR spectrum

[0037] Figure 5 Infrared spectrum of M2 and the product in Example 4 of the present invention Detailed implementation manners

[0038] The present invention will be further described in detail below in conjunction with embodiments, but the implementation manners of the present invention are not limited thereto.

[0039] Example 1

[0040] (1) Synthesis of monomer M1: 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate and 0.1 part of potassium iodide were respectively added into a three-necked flask equipped with a magnetic stirrer and a condenser, 30 parts of acetone were added, and the reaction was carried out for 30 min under magnetic stirring. Then, 1 part of 6-bromo-1-hexene was added to the above flask through a dropping funnel within 60 minutes, and the temperature was heated to 70 °C. After refluxing for 6 hours, it was cooled to room temperature, the solid residue was removed by suction filtration, the acetone was removed by rotary evaporation, and the product M1 was obtained after purification.

[0041] (2) Synthesis of diene liquid crystal monomer M2: 2 parts of M1 and 1 part of m-phenylenediamine were successively added into a reaction flask with a reflux device, 50 parts of absolute ethanol were added, the temperature was raised to 60 °C, and the reaction was refluxed for 12 h. After cooling and filtering, it was washed with absolute ethanol and dried to obtain the diene liquid crystal monomer M2.

[0042] (3) Preparation of silicone thermal conductive material: 1 part of M2, toluene and side hydrogen-containing silicone oil with a total hydrogen content of 0.18% were added to a three-necked flask, the temperature was raised to 70 °C, and a catalytic amount of Karstedt catalyst was added under stirring. The reaction was carried out for 0.5 h, then poured into a mold, cured at 70 °C for 1 h, and then cured at 120 °C for 2 h. After taking out, the silicone thermal conductive material HM was obtained, and its thermal conductivity was 0.35 W / (m·K).

[0043] The self-healing performance test steps of HM are as follows: After cutting HM in the middle with a blade, the fracture surfaces were brought into contact with each other and hot-pressed, and it was observed whether the two cross-sections would return to a whole. The test results are as Figure 1 shown, and it can be seen that the repair performance of the material is excellent.

[0044] Example 2

[0045] (1) Synthesis of monomer M1: 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate, and 0.1 part of potassium iodide were respectively added into a three-necked flask equipped with a magnetic stirrer and a condenser. 45 parts of acetone were added, and the reaction was carried out for 30 min under magnetic stirring. Then, 1.5 parts of 3-bromo-1-propene were added to the above flask through a dropping funnel within 80 minutes, and the mixture was heated to 50 °C. After refluxing for 6 hours, it was cooled to room temperature, the solid residue was removed by suction filtration, acetone was removed by rotary evaporation, and the product M1 was obtained after purification.

[0046] (2) Synthesis of diene liquid crystal monomer M2: 2 parts of M1 and 1 part of 4,4'-diaminobiphenyl were successively added into a reaction flask equipped with a reflux device. 50 parts of absolute ethanol were added, the temperature was raised to 80 °C, and the reaction was refluxed for 4 h. After cooling and filtration, it was washed with absolute ethanol and dried to obtain the diene liquid crystal monomer M2.

[0047] (3) Preparation of organosilicon thermal conductive material: 1 part of M2, toluene, and a mixed hydrogen-containing silicone oil with a total hydrogen content of 0.3% were added into a three-necked flask. The temperature was raised to 60 °C, and a catalytic amount of Karstedt catalyst was added under stirring. The reaction was carried out for 3 h, then it was taken out and poured into a mold, cured at 70 °C for 1 hour, and then the temperature was raised to 140 °C and cured for 2 hours. After taking out, the organosilicon thermal conductive material TD was obtained, and its thermal conductivity was 0.38 W / (m·K).

[0048] Example 3

[0049] (1) Synthesis of monomer M1: 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate, and 0.1 part of potassium iodide were respectively added into a three-necked flask equipped with a magnetic stirrer and a condenser. 60 parts of acetone were added, and the reaction was carried out for 30 min under magnetic stirring. Then, 1.5 parts of 6-chloro-1-hexene were added to the above flask through a dropping funnel within 120 minutes, and the mixture was heated to 80 °C. After refluxing for 6 hours, it was cooled to room temperature, the solid residue was removed by suction filtration, acetone was removed by rotary evaporation, and the product M1 was obtained after purification.

[0050] (2) Synthesis of diene liquid crystal monomer M2: 2 parts of M1 and 1 part of diethyltoluenediamine were successively added into a reaction flask equipped with a reflux device. 50 parts of absolute ethanol were added, the temperature was raised to 75 °C, and the reaction was refluxed for 10 h. After cooling and filtration, it was washed with absolute ethanol and dried to obtain the diene liquid crystal monomer M2.

[0051] (3) Preparation of organosilicon thermal conductive material: 1 part of M2, toluene, and side hydrogen-containing silicone oil and end hydrogen-containing silicone oil with a total hydrogen content of 0.3% were added into a three-necked flask. The temperature was raised to 65 °C, and a catalytic amount of Karstedt catalyst was added under stirring. The reaction was carried out for 2 h, then it was taken out and poured into a mold, cured at 70 °C for 1 hour, and then the temperature was raised to 130 °C and cured for 2 hours. After taking out, the organosilicon thermal conductive material HD was obtained, and its thermal conductivity was 0.36 W / (m·K).

[0052] Example 4

[0053] (1) Synthesis of monomer M1: 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate, and 0.1 part of potassium iodide were respectively added into a three-necked flask equipped with a magnetic stirrer and a condenser. 50 parts of acetone were added, and the reaction was carried out for 30 min under magnetic stirring. Then, 1.3 parts of 5-bromo-1-pentene were added dropwise to the above flask within 90 min, and the temperature was raised to 65 °C. After refluxing for 6 h, it was cooled to room temperature, and the solid residue was removed by suction filtration. Acetone was removed by rotary evaporation. After purification, the product M1, the 1 1H NMR spectrum and 13 13C NMR spectrum are as Figures 2 - 3 shown.

[0054] (2) Synthesis of diene liquid crystal monomer M2: 2 parts of M1 and 1 part of 4,4'-diaminodiphenylmethane were successively added into a reaction flask equipped with a reflux device. 50 parts of absolute ethanol were added, and the temperature was raised to 76 °C. The reaction was refluxed for 6 h, cooled and filtered, washed with absolute ethanol, and dried to obtain the diene liquid crystal monomer M2. The 1 1H NMR spectrum is as Figure 4 shown.

[0055] (3) Preparation of organosilicon thermal conductive material: 1 part of M2, toluene, a mixed hydrogen-containing silicone oil and a terminal hydrogen-containing silicone oil with a total hydrogen content of 0.36% were added to a three-necked flask. The temperature was raised to 65 °C, and a catalytic amount of Karstedt catalyst was added under stirring. The reaction was carried out for 1 h, then taken out and poured into a mold, cured at 70 °C for 1 h, and then the temperature was raised to 120 °C and cured for 2 h. After taking out, the organosilicon thermal conductive material LCP was obtained, and its thermal conductivity was 0.39 W / (m·K). The infrared spectrum of LCP is as Figure 5 shown.

[0056] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent substitution methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of a repairable liquid crystal type silicone thermal conductive material, characterized in that, the preparation method comprises the following steps: (1) Synthesis of monomer M1: Mix p-hydroxybenzaldehyde, potassium carbonate and potassium iodide, add acetone and react, then add a halogenated olefin, continue to heat and react, after completion, cool, filter and take the filtrate, and rotary evaporate to remove acetone to obtain monomer M1; (2) Synthesis of diene liquid crystal monomer M2: Mix monomer M1 with an aromatic diamine, add absolute ethanol, heat and reflux, after completion, cool, filter, wash and dry to obtain diene liquid crystal monomer M2; (3) Preparation of the silicone thermal conductive material: Mix diene liquid crystal monomer M2, a solvent and a hydrogen-containing silicone oil, add a catalyst under heating and stirring, react and then pour into a mold and cure to obtain the silicone thermal conductive material.

2. The preparation method of a repairable liquid crystal type silicone thermal conductive material according to claim 1, wherein The preparation method comprises the following steps: (1) Synthesis of monomer M1: Mix 1 part of p-hydroxybenzaldehyde, 1 part of potassium carbonate and 0.1 part of potassium iodide, add 30-60 parts of acetone, and react under magnetic stirring for 20-40 min; Drop 1-1.5 parts of a halogenated olefin into the reaction solution within 60-120 minutes, heat to 50-80 °C, reflux for 5-8 hours, then cool to room temperature, filter and take the filtrate, and rotary evaporate to remove acetone to obtain monomer M1; (2) Synthesis of diene liquid crystal monomer M2: Add 2 parts of M1 and 1 part of an aromatic diamine to a reaction flask, add 50 parts of absolute ethanol, heat to 60-80 °C, reflux for 4-12 h, cool and filter, wash with absolute ethanol, and dry to obtain diene liquid crystal monomer M2; (3) Preparation of the silicone thermal conductive material: Mix 1 part of M2, a solvent and a hydrogen-containing silicone oil, heat to 60-70 °C, add Karstedt catalyst under stirring, react for 0.5-3 h, take out and pour into a mold, cure at 70 °C for 1 hour, then heat to 120-140 °C and cure for 2 hours to obtain the silicone thermal conductive material.

3. The preparation method of a repairable liquid crystal type silicone thermal conductive material according to claim 1 or 2, characterized in that, In step (1), the halogenated olefin is a chloro- or bromo-olefin with 3-8 carbon atoms.

4. The preparation method of a repairable liquid crystal type silicone thermal conductive material according to claim 3, characterized in that, In step (1), the halogenated olefin is at least one of 6-bromo-1-hexene, 3-bromo-1-propene, 4-bromo-1-butene, 5-bromo-1-pentene, 6-chloro-1-hexene, 3-chloro-1-propene.

5. The preparation method of a repairable liquid crystal type silicone thermal conductive material according to claim 1 or 2, characterized in that In step (2), the aromatic diamine is at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminobiphenyl.

6. The preparation method of a repairable liquid crystal type silicone thermal conductive material according to claim 1 or 2, characterized in that, In step (3), the solvent is toluene; the hydrogen-containing silicone oil is one or a mixture of two or more of an end-hydrogen-containing silicone oil, a side-hydrogen-containing silicone oil, and a mixed hydrogen-containing silicone oil with a total hydrogen content of less than 0.4%.

7. A repairable liquid crystal type silicone thermal conductive material prepared by the method according to any one of claims 1 to 6.

8. The repairable liquid crystal type silicone thermal conductive material according to claim 7, characterized in that, The silicone thermal conductive material realizes the repairability of the material through reversible dynamic imine bonds.

9. Use of the reparable liquid crystal type silicone thermal conductive material according to claim 7 or 8 in the field of electronic appliances, characterized in that, For the preparation of thermal conductive components and / or the thermal conductive encapsulation of circuit boards.

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