CN112724684B

CN112724684B - Modified heat-conducting silicone grease and preparation method thereof

Info

Publication number: CN112724684B
Application number: CN202011579397.6A
Authority: CN
Inventors: 梁亮; 梁悄; 苏剑; 王刚
Original assignee: SHENZHEN ANPIN SILICONE MATERIAL CO Ltd
Current assignee: SHENZHEN ANPIN SILICONE MATERIAL CO Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2023-01-17
Anticipated expiration: 2040-12-28
Also published as: CN112724684A

Abstract

The invention discloses a modified heat-conducting silicone grease and a preparation method thereof, wherein the heat-conducting silicone grease comprises (A) 5-40 parts of composite base silicone oil and (B) 5-90 parts of heat-conducting filler; the composite base silicone oil (A) is prepared from raw materials including a heat-conducting filler, cyclosiloxane and an end-capping agent. The heat-conducting silicone grease has high heat conductivity coefficient, good insulating property, extremely low oil separation degree and high extrusion rate, and can effectively improve the application performance of the heat-conducting silicone grease and improve the long-term high-temperature aging reliability.

Description

Modified heat-conducting silicone grease and preparation method thereof

Technical Field

The invention belongs to the technical field of organic silicon materials, and relates to modified heat-conducting silicone grease and a preparation method thereof.

Technical Field

In the design of miniaturization and ultra-thinning of the apparatus, heat transfer, sealing, and insulation between the heat generating portion and the heat dissipating portion are one of the key factors to be considered. The heat-conducting silicone grease is commonly called as heat-dissipating paste, and is a heat-conducting silicone grease-like compound prepared by taking basic silicone oil as a main raw material and adding a material with excellent heat resistance and heat-conducting property. The heat-conducting silicone grease is a high-heat-conducting insulating organosilicon material, is almost never cured, can keep a grease state when being used for a long time at the temperature of minus 50-230 ℃, has excellent electrical insulation and heat conductivity, has high and low temperature resistance, water resistance, ozone resistance and weather aging resistance, can be widely applied to contact surfaces between heating bodies (power tubes, silicon controlled rectifiers, electrothermal stacks and the like) and heat dissipation facilities (radiating fins, radiating strips, shells and the like) in various electronic products and electrical equipment, and has the functions of heat transfer media and the performances of moisture resistance, dust prevention, corrosion prevention, shock prevention and the like.

In order to obtain good heat-conducting performance, the heat-conducting silicone grease usually contains a certain proportion of heat-conducting filler, but because the density difference and the compatibility between the base silicone oil and the heat-conducting filler are not good, the heat-conducting silicone grease produces oil after being used for a period of time, namely the base silicone oil and the heat-conducting powder are separated, deposited and layered, so that the heat-conducting silicone grease finally loses uniformity and heat-conducting function, the high-heat-conducting silicone grease is poor in fluidity and low in coating efficiency, and the technical problem to be solved by the product is urgently needed.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the modified heat-conducting silicone grease and the preparation method thereof, and the modified heat-conducting silicone grease has high heat conductivity coefficient, good insulating property, low oil separation degree and high extrusion rate, and can effectively improve the application performance of the heat-conducting silicone grease and improve the long-term high-temperature aging reliability.

The purpose of the invention is realized by the following technical scheme:

a modified heat-conducting silicone grease comprises the following components in parts by weight:

(A) 5 to 40 portions of composite base silicone oil

(B) 5-90 parts of heat-conducting filler;

the composite base silicone oil (A) is prepared from raw materials including a heat-conducting filler, cyclosiloxane and an end-capping agent.

The composite base silicone oil (A) is prepared from raw materials including a heat-conducting filler, cyclosiloxane and a blocking agent, and preferably, the mass percent of the heat-conducting filler is 1-70% by taking the sum of the mass percent of the cyclosiloxane and the heat-conducting filler as 100%.

It is noted that the dosage proportion of the heat-conducting filler in the preparation process of the (A) composite base silicone oil directly affects the viscosity and the extrusion performance of the final product, and more preferably, the mass percent of the heat-conducting filler is 1-60% based on 100% of the sum of the mass percent of the cyclosiloxane and the heat-conducting filler, so that the oil separation value or the oil separation degree of the product can be reduced while the compatibility and the good extrusion effect are improved.

Preferably, the modified heat-conducting silicone grease comprises the following components in parts by weight:

(A) 5 to 40 portions of composite base silicone oil

(B) 40-70 parts of heat-conducting filler;

Preferably, the preparation method of the (A) compound base silicone oil comprises the following steps:

and (2) mixing the cyclosiloxane and the heat-conducting filler, adding an alkali catalyst and an end-capping reagent for reaction, and removing the alkali catalyst and low molecules to obtain the (A) composite base silicone oil.

It is known in the art that cyclic siloxane undergoes a ring-opening polymerization reaction under a base catalysis condition, and the removal of low molecular weight refers to the removal of unreacted reaction raw materials and low molecular weight products generated by the reaction through vacuum pumping, compared with a conventional synthesis process, the reaction in the preparation method of the application is preferably carried out at 80-110 ℃, and too high temperature can affect the synthesis of polysiloxane, so that the molecular weight distribution of polysiloxane is wide, the final silicone grease oil evolution value is increased, the insulating property of the product is reduced, and the application is not facilitated. The reaction time is not particularly limited, and is preferably 5 to 7 hours.

Meanwhile, the alkali catalyst is a catalyst commonly used in the field of silicone synthesis, and can be exemplified by tetramethylammonium hydroxide, sodium hydroxide and the like, and is removed by a corresponding process after the reaction is completed, for example, tetramethylammonium hydroxide can be removed by thermal decomposition, sodium hydroxide can be removed by neutralization and the like, and the influence of the alkali catalyst on the application performance of the silicone grease is avoided. Preferably, the mass of the alkali catalyst is 0.03-0.12% of the sum of the mass of the cyclosiloxane and the mass of the heat-conducting filler.

Preferably, in the preparation method of the composite base silicone oil (A), the temperature of the cyclosiloxane is raised to 80-110 ℃ before the cyclosiloxane is mixed with the heat-conducting filler, so that the reaction efficiency can be improved.

In the preparation method of the (A) composite base silicone oil, the heat-conducting filler can also be other powder or the combination of the heat-conducting filler and other powder, such as flame-retardant powder, conductive powder, reinforcing filler and other commonly used powder types in the material field, and is added according to the actual requirements. The heat-conducting filler interacts with intermediate products and final products in the reaction process, so that the powder holding capacity of a system can be improved, the viscosity is reduced, and the extrusion rate is improved.

Preferably, in the preparation method of the composite base silicone oil (a), the heat conductive filler may be nano graphene, boron nitride, aluminum nitride, magnesium oxide, aluminum powder, copper powder, silver powder, iron powder, nickel powder, gold powder, tin powder, metal silicon powder, boron nitride powder, diamond powder, carbon powder, indium powder, gallium powder, zinc oxide powder, and the like, and among them, one or a combination of several of graphene, boron nitride, aluminum nitride, magnesium oxide, and aluminum oxide is preferred. The heat-conducting filler is preferably spherical heat-conducting filler or nearly spherical heat-conducting filler, the higher the sphericity of the powder is, the smaller the surface energy of the powder is, the better the surface fluidity of the powder is, the better the combination of the powder and organic matters can be ensured, and the influence on the viscosity of a system can be effectively reduced.

Preferably, in the preparation method of the (A) composite base silicone oil, the particle size of the heat-conducting filler is 10-700nm, and the heat-conducting filler is too large to be dispersed sufficiently, so that the interaction between molecules and powder in the organic polymerization reaction process is influenced, the chemical balance in the reaction process is influenced, and the molecular weight of a polymer product, the viscosity of silicone grease and the extrusion performance are influenced finally.

According to the invention, the composite base silicone oil (A) is prepared by a special preparation method, the heat-conducting filler interacts with compounds such as reaction intermediate products and the like in the preparation process, the compatibility of the functional filler and the reaction products can be obviously improved, the Rong Fenliang of the composition is finally improved, and the silicone grease prepared by adopting the composite base silicone oil has good extrusion effect and low oil yield under the condition of the same dosage of the heat-conducting filler.

Said cyclic siloxanes are known in the prior art and are of empirical formula

N may be an integer of 3 to 9, R ₁ 、R ₂ Identical or different are monovalent hydrocarbon radicals having from 1 to 18 carbon atoms. The monovalent hydrocarbon group having 1 to 18 carbon atoms may be an alkyl group such as methyl, ethyl, propyl, hexyl or octyl, a cycloalkyl group such as cyclopentyl or cyclohexyl, an aryl group such as phenyl or tolyl, a 2-phenylethyl group, a 2-methyl-2-phenylethyl group or the likeAralkyl groups, 3,3,3-trifluoropropyl, 2- (perfluorooctyl) ethyl and like halogenated hydrocarbon groups, etc., preferably methyl groups, phenyl groups and alkyl groups having 6 to 14 carbon atoms.

The end-capping agent is an end-capping agent commonly used in organosilicon synthesis and comprises a hydrocarbyl silane end-capping agent, wherein the hydrocarbyl silane end-capping agent is one or more of hexamethyldisiloxane, hexaphenyldisiloxane, hexamethyldisilazane, trimethyl methoxysilane and trimethyl ethoxysilane. Preferably, the mass of the end-capping agent is 0.5 to 4.5% of the sum of the masses of the cyclosiloxane and the thermally conductive filler.

In the preparation method, preferably, the mixing and reaction process of the cyclosiloxane and the heat-conducting filler is carried out by ultrasonic-assisted stirring, so as to improve the dispersion uniformity of the heat-conducting filler, and the specific ultrasonic condition is not particularly limited and can be adjusted according to actual needs.

In the preparation method, the reaction is preferably carried out under the condition of vacuum pumping, and particularly, the reaction is promoted to be carried out by keeping the vacuum degree less than 0.01 MPa.

Preferably, the kinematic viscosity of the compound base silicone oil (A) at 25 ℃ is 100-68000mPa.s, and the viscosity influences the extrusion rate and the smearing use efficiency of the final silicone grease.

In the modified heat-conducting silicone grease, the (B) heat-conducting filler may be nano-graphene, boron nitride, aluminum nitride, magnesium oxide, aluminum powder, copper powder, silver powder, iron powder, nickel powder, gold powder, tin powder, metal silicon powder, boron nitride powder, diamond powder, carbon powder, indium powder, gallium powder, zinc oxide powder, or the like, and among them, one or a combination of several of graphene, boron nitride, aluminum nitride, magnesium oxide, and aluminum oxide is preferable.

Preferably, the average particle diameter of the thermally conductive filler (B) is preferably in the range of 10nm to 50 μm, more preferably 10nm to 20 μm. The (B) heat-conducting filler is preferably spherical heat-conducting filler or approximately spherical heat-conducting filler.

Preferably, the modified heat-conducting silicone grease further contains a coupling agent, specifically a silane coupling agent, titanate, ethyl orthosilicate, hexamethyldisilazane or aluminate, wherein the silane coupling agent is one or more of gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, N-aminoethyl-gamma-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane and methyltrimethoxysilane. More preferably, in the modified heat-conducting silicone grease, the coupling agent is used in an amount of 0.3-5 parts by weight based on 5-40 parts by weight of the (A) composite base silicone oil.

Preferably, in the modified heat-conducting silicone grease, the mass percentage of the heat-conducting filler is 50-95%. Namely, in the modified heat-conducting silicone grease, the mass ratio of the heat-conducting filler in the composite base silicone oil (A) to the heat-conducting filler (B) is 50-95%.

The invention further provides a preparation method of the modified heat-conducting silicone grease, which comprises the following operation steps:

adding the heat-conducting filler (B) into the composite base silicone oil (A) for mixing in several times, stirring for 0.5-2h at 20-80 ℃ to obtain a mixture, and then grinding to obtain the modified heat-conducting silicone grease.

The addition of (B) the thermally conductive filler in a fractional amount is to improve the dispersion uniformity of the filler.

Preferably, the grinding is carried out at 20-80 ℃ to a fineness of 10-30 μm, the test method for the fineness being referred to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

It is to be noted that the viscosity at 25 ℃ according to the present invention is a dynamic viscosity value of a substance at 25 ℃.

The invention has the beneficial effects that: the modified heat-conducting silicone grease is prepared by using the composite base silicone oil, so that the oil-powder compatibility of a system can be effectively improved, the oil output of the silicone grease is reduced, the extrusion rate is improved, and the preparation method is simple and has a good application prospect.

Detailed Description

Specific examples of the modified heat conductive silicone grease of the present invention are given below.

The preparation method of the composite base silicone oil given in the examples 1 and 2 is as follows:

adding cyclosiloxane into a reaction kettle, heating to 90 ℃ under the stirring condition, adding heat-conducting filler for uniform dispersion, vacuumizing to be less than 0.01MPa, stirring for 2 hours under the stirring speed of 500 r/min, adding 0.2g of tetramethylammonium hydroxide catalyst, stirring for 30 min under the conditions of constant temperature of 90 ℃ and vacuumizing to be less than 0.01MPa, adding an end-capping agent, stirring for 5 hours under the constant temperature of 90 ℃, heating to 145 ℃ to decompose and remove the tetramethylammonium hydroxide catalyst, continuously heating to 180 ℃ after 1 hour, removing micromolecules under the condition of vacuum degree of less than 0.01MPa, cooling and discharging to obtain the composite base silicone oil. The types and amounts of cyclosiloxane, heat conductive filler and end-capping agent used to prepare the composite base silicone oil are listed in table 1.

The preparation of the base silicone oils given in comparative examples 1, 2 is as follows:

adding cyclosiloxane into a reaction kettle, heating to 90 ℃, adding tetramethylammonium hydroxide catalyst, stirring for 30 min at the constant temperature of 90 ℃ and the vacuum degree of less than 0.01MPa, adding 2.5g of end-capping reagent, stirring for 5h at the constant temperature of 90 ℃, heating to 145 ℃ to decompose and remove 0.2g of tetramethylammonium hydroxide catalyst, continuously heating to 180 ℃ after 1h, removing small molecules under the condition that the vacuum degree is less than 0.01MPa, cooling and discharging, adding heat-conducting filler, stirring and dispersing uniformly to obtain the comparative base silicone oil. The kinds and amounts of the cyclic siloxane, the heat conductive filler and the blocking agent used for preparing the base silicone oil in the comparative examples are shown in Table 1.

The preparation method of the composite base silicone oil given in the examples 3, 4 and 5 is as follows:

adding cyclosiloxane into a reaction kettle, heating to 100 ℃ under the condition of ultrasonic vibration (1000 w and 20 kz), adding heat-conducting filler for uniform dispersion, vacuumizing to less than 0.01MPa, stirring for 2 hours under the condition of stirring speed of 500 r/min, adding 0.2g of tetramethylammonium hydroxide catalyst, stirring for 30 min under the conditions of constant temperature of 100 ℃ and vacuumizing to less than 0.01MPa, adding an end-capping agent, stirring for 5 hours at constant temperature of 100 ℃, heating to 145 ℃ to decompose and remove the tetramethylammonium hydroxide catalyst, continuously heating to 180 ℃ after 1 hour, removing micromolecules under the condition of vacuum degree of less than 0.01MPa, cooling and discharging to obtain the composite base silicone oil. The types and amounts of cyclosiloxane, heat conductive filler and end-capping agent used to prepare the composite base silicone oil are listed in table 1.

The preparation method of the composite base silicone oil given in the examples 6 and 7 is as follows:

adding cyclosiloxane into a reaction kettle, heating to 90 ℃ under the condition of ultrasonic vibration (1000 w and 20 kz), adding heat-conducting filler for uniform dispersion, vacuumizing to less than 0.01MPa, stirring for 3 hours under the condition of stirring speed of 500 r/min, adding 0.2g of tetramethylammonium hydroxide catalyst, stirring for 30 min under the conditions of constant temperature of 90 ℃ and vacuumizing to less than 0.01MPa, adding an end-capping agent, stirring for 6 hours at constant temperature of 90 ℃, heating to 145 ℃ to decompose and remove the tetramethylammonium hydroxide catalyst, continuously heating to 180 ℃ after 1 hour, removing micromolecules under the condition of vacuum degree of less than 0.01MPa, cooling and discharging to obtain the composite base silicone oil. The types and amounts of cyclosiloxane, heat conductive filler and end-capping agent used to prepare the composite base silicone oil are listed in table 1.

Examples 1 to 7 were prepared to obtain # 1 to 7 composite base silicone oil, and comparative examples 1 to 2 were prepared to obtain # 1 to 2 comparative base silicone oil. The results of performance tests on 1-7# compounded base silicone oil and 1-2# comparative base silicone oil are shown in Table 2, wherein the viscosity test method refers to GB/T2794-1995.

TABLE 1

TABLE 2

Numbering	Dynamic viscosity value at 25 ℃ (mpa.s)
		1	2100
2	12000
		3	1250
4	38300
		5	3080
6	65000
		7	300
Comparative example 1	3000
		Comparative example 2	15000

As can be seen from the data in Table 1 and Table 2, in the preparation of the composite base silicone oil, the base silicone oil with reduced viscosity can be obtained under the condition that powder is added in the preparation process, which is beneficial to improving the application properties of the composition, such as extrusion, and the like.

Examples 8 to 14 below were prepared using the composite base silicone oils of examples 1 to 7, respectively, and the heat conductive filler and the coupling agent to give # 8 to 14 silicone greases, and comparative examples 3 to 4 were prepared using the composite base silicone oils of comparative examples 1 to 2, respectively, to give # 3 to 4 comparative silicone greases, and the amounts of the components in each example are shown in Table 3 in g.

TABLE 3

The specific embodiment is as follows:

example 8

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alpha-spherical alumina with the average particle size of 30 mu m into the composite base silicone oil prepared in the example 1 according to the dosage, adding gamma-aminopropyltriethoxysilane as a coupling agent, stirring for 1h at 40 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 40 ℃ for 2 times until the fineness is 20 mu m to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Example 9

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alpha-spherical alumina with the average particle size of 10 mu m into the composite base silicone oil prepared in the example 2 according to the dosage, adding gamma-aminopropyltriethoxysilane as a coupling agent, stirring for 1h at 50 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 50 ℃ for 2 times until the fineness is 10 mu m to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Example 10

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alpha-spherical alumina with the average particle size of 20 mu m into the composite base silicone oil prepared in the embodiment 3 in portions according to the dosage, adding coupling agent gamma-aminopropyltriethoxysilane, stirring for 1h at 30 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 30 ℃ for 2 times until the fineness is 20 mu m to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Example 11

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alpha-spherical alumina with the average particle size of 10 mu m into the composite base silicone oil prepared in the embodiment 4 in portions according to the dosage, adding coupling agent gamma-aminopropyltriethoxysilane, stirring for 1h at 50 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 50 ℃ for 2 times until the fineness is 20 mu m to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Example 12

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alpha-spherical alumina with the average particle size of 20 mu m into the composite base silicone oil prepared in example 5 in portions according to the dosage, adding gamma-aminopropyltriethoxysilane as a coupling agent, stirring for 1h at 30 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 30 ℃ for 2 times until the fineness is 20 mu m to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Example 13

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding alumina with the average particle size of 500nm into the composite base silicone oil prepared in example 6 in portions according to the dosage, adding coupling agent gamma-aminopropyltriethoxysilane, stirring for 1h at 30 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 30 ℃ for 2 times until the fineness is 10 microns to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to method standards: the test procedure JJG 018-96 & ltScraper fineness tester & gt and GB/T1724-93 standard for instruments special for chemical industry coatings of the people's republic of China.

Example 14

The preparation method of the modified heat-conducting silicone grease comprises the following steps: adding magnesium oxide with the average particle size of 300nm into the composite base silicone oil prepared in example 7 in portions according to the dosage, adding coupling agent gamma-aminopropyltriethoxysilane, stirring for 1h at 40 ℃ to obtain a mixture, grinding the mixture in a three-roll grinder at 40 ℃ for 2 times until the fineness is 10 microns to obtain the modified heat-conducting silicone grease, wherein the test method of the fineness refers to method standards: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Comparative example 3

The preparation method of the comparative heat-conducting silicone grease comprises the following steps: according to the dosage, alpha-spherical alumina with the average particle size of 30 mu m is added into the basic silicone oil prepared in the comparative example 1 in portions, the coupling agent gamma-aminopropyltriethoxysilane is added, the mixture is stirred for 1h at 40 ℃ to obtain a mixture, the mixture is ground for 2 times in a three-roll grinder at 40 ℃ until the fineness is 20 mu m, the modified heat-conducting silicone grease is obtained, and the test method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Comparative example 4

The preparation method of the comparative heat-conducting silicone grease comprises the following steps: according to the dosage, alpha-spherical alumina with the average particle size of 10 mu m is added into the basic silicone oil prepared in the comparative example 2 in portions, the coupling agent gamma-aminopropyltriethoxysilane is added, the mixture is obtained after stirring for 1h at 50 ℃, the mixture is ground for 2 times in a three-roll grinder at 50 ℃ until the fineness is 20 mu m, the modified heat-conducting silicone grease is obtained, and the testing method of the fineness refers to the method standard: the special appliance verification regulation JJJG (chemical industry of the people's republic of China) 018-96 scraper fineness tester and GB/T1724-93 standard thereof.

Test examples

The heat-conductive silicone greases prepared in examples 8 to 14 and comparative examples 3 to 4 were subjected to performance tests, including heat conductivity, penetration, extrusion rate, and oil yield, wherein the oil yield was measured according to HG/T2502-1993 < 5201 > silicone grease, the heat conductivity and penetration test methods are shown in Table 2, and the extrusion rate was measured according to the following method: loading heat-conducting silicone grease into a 30ml syringe (the caliber of a syringe needle opening is 2 mm), placing on an AD-982 dispenser, opening a syringe rear cover, connecting air, turning on a power supply, opening the air, adjusting the air pressure to 90psi, opening the syringe needle opening, keeping the syringe vertical, clicking a start button, stopping after one minute, and weighing the weight of the extruded silicone grease; the test data are shown in Table 4.

TABLE 4 thermal grease Performance data

As can be seen from the data in Table 2, the heat-conducting silicone grease prepared by the invention has the advantages of remarkably reduced oil yield, improved extrusion rate, simple preparation method and good application prospect.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and do not limit the protection scope of the present invention. It will be understood by those skilled in the art that various deductions and equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. The modified heat-conducting silicone grease is characterized by comprising the following components in parts by weight:

(A) 5 to 40 parts of composite base silicone oil

(B) 5-90 parts of heat conducting filler;

the preparation method of the (A) composite base silicone oil comprises the following steps:

mixing cyclosiloxane and heat-conducting filler, adding an alkali catalyst and an end-capping reagent for reaction, and removing the alkali catalyst and low molecules to obtain (A) composite base silicone oil, wherein the sum of the mass percentages of the cyclosiloxane and the heat-conducting filler is 100%, the mass percentage of the heat-conducting filler is 1-70%, and the particle size of the heat-conducting filler is 10-700nm.

2. The modified heat-conductive silicone grease of claim 1, wherein in the preparation method of the (a) complex base silicone oil, the reaction is carried out at 80-110 ℃.

3. The modified heat-conductive silicone grease of claim 1, wherein the kinematic viscosity of the composite base silicone oil (a) at 25 ℃ is 100 to 68000mpa.s.

4. The modified thermally conductive silicone grease as claimed in any one of claims 1 to 3, wherein the (B) thermally conductive filler has an average particle diameter of 10nm to 50 μm.

5. The modified thermal grease as claimed in any one of claims 1 to 3, further comprising a coupling agent, in particular a silane coupling agent, a titanate, ethyl orthosilicate, hexamethyldisilazane or an aluminate.

6. The method for preparing the modified heat-conducting silicone grease as claimed in any one of claims 1 to 3, comprising the following steps: