High thermal-conductive silicone grease and preparation method thereof
Technical field
The present invention relates to macromolecule interfacial Material Field, refer more particularly to High thermal-conductive silicone grease and preparation method thereof
Background technology
Along with the development of modern science and technology, electronic product presents densification, miniaturization trend.Due to the increase of electronic apparatus power, can produce a large amount of heats in the process used, this has higher requirement to heat dissipation problem.Effectively remove the heat that electronics produces, directly have influence on reliability and the work-ing life of product.
For the heat dissipation problem of large power, electrically sub-element, conventional method is installation of heat radiator on pyrotoxin.Even but between pyrotoxin and scatterer, two planes of any surface finish are contacting with each other, and also inevitably there is a fixed gap, the existence in space is making heat radiation by air, and the thermal conductivity of air only has 0.023W/mK, is the poor conductor of heat.Therefore multiple heat interfacial material is developed and is applied to the thermal resistance reduced between scatterer and pyrotoxin.Heat-conducting silicone grease is exactly wherein a kind of heat-conducting medium the most conventional, and because it has easy to use, good heat conduction effect, the advantage such as is easy to reprocess and obtains widespread use.
Current heat-conducting silicone grease mainly through adding high heat conductive filler to improve its heat conductivility in silicone oil.The thermal conductivity of heat-conducting silicone grease directly has influence on the radiating effect of electronic component, thus has influence on work-ing life and the stability of electronic component.Graphene, a kind of highly heat-conductive material, the thermal conductivity of single-layer graphene can reach 5000W/mK, and multi-layer graphene thermal conductivity is also at more than 1500W/mK.Graphene is except having high thermal conductivity, and the two-dimentional laminated structure that Graphene is special, with tight coupling and the low cost of body material, these all make Graphene become the ideal filler of interface thermally conductive material.Carbon nanotube is also a kind of carbon material of excellent thermal conductivity, and thermal conductivity axially can reach 3000W/mK.The thermal conductivity of heat conduction carbon fiber in its fiber direction exceedes copper simultaneously, can reach 700W/mK.The heat conductivility of heat-conducting silicone grease is finally determined by silicone oil and high heat-conducting filler comprehensive action.Graphene is as the filler of heat-conducting silicone grease, the thermal conductivity of himself is all much larger than the thermal conductivity of body material, with other heat conductive filler, there is good combination, when heat conductive filler amount acquires a certain degree, start there has been interaction between filler, in system, define similar chain and netted form, the thermal conductivity of system will be improved to a large extent.The high heat conduction particle (silver, copper, aluminium nitride etc.) of the Graphene of the carbon nanotube of one dimension, heat conduction carbon fiber, two dimension, three-dimensional grapheme foam and zero dimension effectively can form chain and netted heat conduction network, significantly improves the thermal conductivity of heat-conducting silicone grease.
According to patent of invention, application number is CN102634212A, denomination of invention is a kind of heat conductive silicone grease composition, and it adopts in silicone oil the phase transformation capsule adding Graphene, carbon nanotube and parcel paraffin, and the thermal conductivity of its heat-conducting silicone grease prepared is up to 4.2391W/mK.Application number is CN03114099.8, and denomination of invention is high heat conductive insulating resin and preparation method thereof, and the method describes a kind of silicone grease of high heat conduction, and its heat conductivity of heat conduction silicate prepared is relatively low, generally only has 3W/mK, the poor-performing of product.
Summary of the invention
The object of the invention is heat-conducting silicone grease providing a kind of high thermal conductivity and preparation method thereof.Heat-conducting silicone grease thermal conductivity prepared by the present invention is high, and heat-transfer capability is strong, can increase reliability and the work-ing life of electronic product, and preparation technology is simple.Overcome the deficiency that lower, the relative capacity of heat transmission of heat dissipating silicone grease thermal conductivity in prior art is poor.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is:
A kind of High thermal-conductive silicone grease, is calculated in mass percent, comprises following composition and component:
Silicone oil 2% ~ 50%
Additive 50% ~ 98%.
The mixture that described additive is zero dimension filler, one dimension filler, two-dimentional filler, three-dimensional filler form according to different ratios.
Wherein, described silicone oil is one or more the mixture in dimethyl silicone oil, amido silicon oil, phenyl silicone oil, vinyl silicone oil, hydroxy silicon oil, methyl long-chain alkyl-silicone oil.
Wherein, described silicone oil viscosity 25 DEG C time is 500 ~ 15000cps.
Wherein, in described additive, the mass ratio of each component is:
Zero dimension filler 50% ~ 70%
One dimension filler 0.01% ~ 30%
Two dimension filler 0.01% ~ 20%
Three-dimensional filler 1% ~ 5%.
Wherein, described zero dimension filler is one or more the mixture in boron nitride, aluminium nitride, silicon nitride, aluminum oxide, zinc oxide, titanium oxide, silicon carbide, silver powder, copper powder, aluminium powder, graphite.Wherein, the particle size range of described zero dimension filler is 0.02 μm ~ 200 μm.
Wherein, described one dimension filler is one or both the mixture in carbon nanotube, carbon fiber.
Wherein, described two-dimentional filler is graphene sheet layer.
Wherein, described three-dimensional filler is grapheme foam.Grapheme foam material is prepared through hydrothermal method by graphene oxide water solution, and concrete preparation method is as follows:
(1) graphene oxide water solution loaded in the stainless steel cauldron of polytetrafluoro liner, described concentration of aqueous solution is 0.1 ~ 15mg/ml;
(2) 0.5 ~ 10ml hydrazine hydrate is dripped;
(3) temperature of reaction kettle controls at 80 ~ 120 DEG C, and the reaction times is 1 ~ 12 hour;
(4) reacted mixture after filtration, washing, obtain three-dimensional graphene foam material after lyophilize process.
Wherein, described High thermal-conductive silicone grease also comprises one or more the mixture in optional thickening material, tensio-active agent, stablizer, fire retardant, antioxidant, tinting material, thixotropic agent, catalyzer.
The preparation method of this heat-conducting silicone grease comprises the steps:
(1) silicone oil and additive are added double planetary mixer or small-sized kneader carries out mix and blend 10 ~ 30min;
(2) after stirring on three-roll grinder grinding distribution 1 ~ 3 time, realize densification and the deaeration of heat-conducting silicone grease;
(3) vacuumize stirring 1-3h under vacuum conditions, obtain described heat-conducting silicone grease product;
Preferably, the vacuum tightness of described vacuum state is-0.06 ~-0.099mPa.
Heat-conducting silicone grease thermal conductivity prepared by the present invention is high, and heat-transfer capability is strong, can increase reliability and the work-ing life of electronic product, and preparation technology is simple.Overcome the deficiency that lower, the relative capacity of heat transmission of heat dissipating silicone grease thermal conductivity in prior art is poor.
Embodiment
Be described in further details the present invention below by embodiment, these embodiments are only used for the present invention is described, do not limit the scope of the invention.
Embodiment 1
A kind of High thermal-conductive silicone grease, comprises following component, according to the mass fraction: silicone oil 28.98 parts, aluminium nitride 70 parts, carbon nanotube 0.01 part, grapheme foam 1 part, graphene sheet layer 0.01 part.
Wherein, the particle diameter of aluminium nitride is 3-5 μm, and silicone oil adopts methyl long-chain alkyl-silicone oil, and 25 DEG C of viscosity are 500cps.
Preparation method
Silicone oil and heat conductive filler are added double planetary mixer and carry out mix and blend 20min, after stirring on three-roll grinder grinding distribution 2 times, vacuumize under vacuum conditions afterwards and stir 1h, obtain final silicone grease.After measured, its thermal conductivity is 0.9W/mK.
Embodiment 2
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 2 parts, 50 parts, graphite, 13 parts, carbon fiber, carbon nanotube 10 parts, grapheme foam 5 parts, graphene sheet layer 20 parts.
Wherein, the particle diameter of graphite is 3500 orders, and silicone oil adopts the mixture of phenyl silicone oil, vinyl silicone oil and hydroxy silicon oil, and 25 DEG C of viscosity are 15000cps.
Preparation method
Silicone oil and heat conductive filler are added small-sized kneader and carry out mix and blend 20min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 2h, obtain final silicone grease.After measured, its thermal conductivity is 1.1W/mK.
Embodiment 3
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 25 parts, 50 parts, graphite, 20 parts, aluminum oxide, 0.5 part, carbon fiber, grapheme foam 1 part, graphene sheet layer 2.5 parts, carbon nanotube 1 part; Wherein, graphite adopts crystalline flake graphite, and the particle diameter of graphite is 3500 orders, and the particle diameter of aluminum oxide is 0.02 ~ 20 μm, and wherein, silicone oil adopts the mixture of amido silicon oil and dimethyl silicone oil, and 25 DEG C of viscosity are 1000cps.
Preparation method
Silicone oil and heat conductive filler are added in double planetary mixer and carry out mix and blend 20min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 2h, obtain final silicone grease.After measured, its thermal conductivity is 1.8W/mK.
Embodiment 4
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 50 parts, 0.5 part, carbon fiber, boron nitride 46 parts, grapheme foam 1 part, graphene sheet layer 2.5 parts;
Wherein, the particle diameter of boron nitride is 20 ~ 200 μm, and carbon fiber length is 100 ~ 300 μm, and diameter is 5 ~ 20 μm, and carbon content is greater than 99%.
Wherein, silicone oil adopts hydroxy silicon oil, and 25 DEG C of viscosity are 1500cps.
Preparation method
Silicone oil and heat conductive filler are added small-sized kneader and carry out mix and blend 20min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 2h, obtain final silicone grease.
After measured, its thermal conductivity is 3.5W/mK.
Embodiment 5
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 25 parts, carbon nanotube 5 parts, 40 parts, zinc oxide, 26 parts, graphite, grapheme foam 1 part, graphene sheet layer 3 parts.
Wherein, the purity >=95wt% of carbon nanotube, ash content≤0.2wt%, specific surface area is about 40 ~ 300m2/g.
Wherein, the particle diameter of zinc oxide is 10 ~ 100 μm.
Wherein, silicone oil adopts dimethyl silicone oil, and 25 DEG C of viscosity are 2500cps.
Preparation method
Silicone oil and heat conductive filler are added double planetary mixer and carry out mix and blend 30min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 2h, obtain final silicone grease.
After measured, its thermal conductivity is 4.2W/mK.
Embodiment 6
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 28 parts, graphene sheet layer 20 parts, copper powder 30 parts, 40 parts, graphite, grapheme foam 2 parts.
Wherein, graphene sheet layer is the high-quality graphene of the number of plies 10 ~ 20 layers, and the particle diameter of copper powder is 5 ~ 10 μm, and the particle diameter of graphite is 3500 orders.
Wherein, silicone oil adopts amido silicon oil, and 25 DEG C of viscosity are 5000cps.
Preparation method
Silicone oil and heat conductive filler are added small-sized kneader and carry out mix and blend 30min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 3h, obtain final silicone grease.
After measured, its thermal conductivity is 5.3W/mK.
Embodiment 7
A kind of High thermal-conductive silicone grease, comprises following component, by mass: silicone oil 23 parts, graphene sheet layer 40 parts, 5 parts, aluminum oxide, aluminium powder 2 parts, silicon nitride 3 parts, 25 parts, carbon fiber, grapheme foam 2 parts.
Wherein, graphene microchip is the high-quality graphene of the number of plies 10 ~ 20 layers, and the particle diameter of aluminum oxide is 10 ~ 20 μm, and carbon fiber length is 100 ~ 300 μm, and diameter is 5 ~ 20 μm, and carbon content is greater than 99%.
Wherein, silicone oil adopts the mixture of hydroxy silicon oil and amido silicon oil, and ratio is 3:2, and 25 DEG C of viscosity are 10000cps.
After measured, its thermal conductivity is 6.5W/mK.
Embodiment 8
A kind of High thermal-conductive silicone grease, comprises following component, by mass percentage: silicone oil 20 parts, and Graphene 40 parts, 3 parts, silver powder, titanium oxide 3 parts, 4 parts, silicon carbide, carbon nanotube 25 parts, grapheme foam 3 parts, 2 parts, carbon fiber.
Wherein, Graphene adopts the number of plies lower than the high-quality graphene of 5 layers, and the purity >=95wt% of carbon nanotube, ash content≤0.2wt%, the particle diameter of silver powder is 5 ~ 10 μm.
Wherein, silicone oil adopts the mixture of dimethyl silicone oil and hydroxy silicon oil, and ratio is 4:1, and 25 DEG C of viscosity are 12500cps.
Preparation method
Silicone oil and heat conductive filler are added small-sized kneader and carry out mix and blend 30min, after stirring on three-roll grinder grinding distribution 3 times, vacuumize under vacuum conditions afterwards and stir 3h, obtain final silicone grease.
After measured, its thermal conductivity is 8.1W/mK.
Embodiment 9
A kind of High thermal-conductive silicone grease, comprise following component, by mass: silicone oil 2 parts, graphene sheet layer 4 parts, 70 parts, silver powder, titanium oxide 5 parts, 5 parts, silicon carbide, carbon nanotube 4 parts, 4 parts, carbon fiber, grapheme foam 4 parts, thickening material, tensio-active agent, stablizer, fire retardant, antioxidant, tinting material, thixotropic agent, catalyzer totally 2 parts.
Wherein, the particle diameter of aluminium nitride is 3-5 μm, and silicone oil adopts methyl long-chain alkyl-silicone oil, and 25 DEG C of viscosity are 10000cps.
After measured, its thermal conductivity is 9.1W/mK.
Embodiment 10
A kind of High thermal-conductive silicone grease, comprise following component, by mass: silicone oil 2 parts, graphene sheet layer 10 parts, 30 parts, silver powder, 10 parts, aluminum oxide, aluminium powder 10 parts, carbon nanotube 15 parts, 15 parts, carbon fiber, grapheme foam 5 parts, thickening material, tensio-active agent, stablizer, fire retardant, antioxidant, tinting material, thixotropic agent, catalyzer totally 3 parts.
Wherein, the particle diameter of aluminium nitride is 3-5 μm, and silicone oil adopts methyl long-chain alkyl-silicone oil, and 25 DEG C of viscosity are 10000cps.
After measured, its thermal conductivity is 10.5W/mK.
The above embodiment only have expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.