Background technology
Along with science and technology development, electron device more and more levels off to densification and miniaturization, thereby the stability of electron device is had higher requirement.In order to prevent moisture, dust and obnoxious flavour slow down vibrations to the intrusion of electronic devices and components, prevent that external force is simultaneously also in order to stablize components and parts.The detrimentally affect in the external world is reduced to minimum, needs carry out embedding and installation electronic devices and components.Because the miniaturization of electron device has caused the superpowerization of unit surface, thereby, very easily form localized hyperthermia, and then may cause the unstable operation of device if the heat that electron device produces in the course of the work can not be derived immediately, even cause components from being damaged, cause the inefficacy of this equipment.
Present employed envelope is irritated and installing material is mainly the synthetic polymer materials, wherein with Resins, epoxy, and being most widely used of urethane and rubber.Silicon rubber can keep elasticity for a long time in very wide temperature range, and do not absorb heat during sulfuration, not heat release, and have good electric property and chemical stability, be the preferred material of electric assembly embedding.
Silicon rubber is a kind of special synthetic rubber, be main chain with the siloxane bond, and general rubber is to be the structure of main chain with the C-C.Because the singularity of its structure has determined the unreactiveness that it has high temperature resistant, low temperature resistant, high voltage withstanding, anti-ozone ageing, radiation resistance, anti-marquis, physiology inertia, highly air-permeable and lubricated wet goods media table is revealed excellence.In addition, use temperature scope (50 ℃~300 ℃) broadness, good springiness, anti creepage trace and galvanic corrosion damage performance are good, especially still have good characteristics such as hydrophobic nature after its surperficial contamination.Can be very poor but victory is produced in unfilled silicon rubber heat conduction, thermal conductivity generally has only 0.165W/ (m.k), can improve its heat conductivility by filling heat conductive filler.At present more for the research of the high heat conduction room temperature vulcanized silicone rubber of filled-type, and the heat conductivility of high temperature vulcanized system is studied seldom.The mineral filler aspect mainly concentrates on fibrous and laminal filler, and less research particulate filler is to the compound system Effect on Performance.
Chinese invention patent (application number 200710103362.3) discloses a kind of preparation method of thermally conductive and electrically insulating silicone rubber composite material, this method technology is: (1) mixes tabular alumina and polyoxyethylene glycol spirituous solution, makes alumina slurry or aluminum oxide dry powder; (2) with high-temperature silicon disulfide rubber, alumina slurry (or aluminum oxide dry powder), light basic silicone oil and vulcanizing agent carry out proportioning on demand, mix; (3) under the corresponding curing temperature, adopt the compression molding sulfidization molding, make the product of respective shapes as required; (4) sample after the one step cure moulding carries out post vulcanization in air dry oven, and the sulfuration system is specifically determined according to practical situation.But adopt invention to adopt the tabular alumina slurry to mix with silicon rubber, the gained matrix material coefficient of expansion is big, after being heated, can not well stablize components and parts, thereby can not effectively prevent moisture, dust and obnoxious flavour be to the intrusion of electronic devices and components, thereby cause the damage of electronic devices and components.
Summary of the invention
Little for the thermal conductivity that overcomes existing high-heat-conductive composite material, thermal expansivity big, stablized aspect such as components and parts weak effect exists many deficiencies, the invention provides a kind of preparation method of filled-type thermally conductive silicone rubber composite material, utilize this method products obtained therefrom can effectively realize high-level efficiency transmission to heat, significantly improved the thermal conductivity of matrix material, reduced the thermal expansivity of matrix material, components and parts have been stablized, more effectively prevented moisture, dust and obnoxious flavour have reduced production cost simultaneously to the intrusion of electronic devices and components.
The technical solution adopted for the present invention to solve the technical problems is: the preparation method of this filled-type thermally conductive silicone rubber composite material, and this method processing step is:
1) 20~300 mass fraction carbon copper-clad nanoparticles are stirred with 95% ethanolic soln mixing, carbon copper-clad nanoparticle dry powder is made in oven dry then;
2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, it in the carbon copper-clad nanoparticle dry powder heat conductive filler, the mass parts that add 10~300 mass fractions according to the formulating of recipe amount successively 1~3 hydroxy silicon oil, mixing repeatedly to even on roller, thin-pass 5~10 times, adding mass parts then is 1~3.5 vulcanizing agent, mixing more even, sheet under the thin-pass promptly gets silicon rubber gross rubber;
3) silicon rubber that mixes is put into mould, carry out one step cure after the mold filling of colding pressing;
4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven.
The particle diameter of the carbon copper-clad nanoparticle the invention described above processing step 1) is 40~80nm; Oven dry is that the mixture of carbon copper-clad nanoparticle and ethanolic soln is dried 10h down at 120 ℃ earlier, then behind oven dry 1h under 150 ℃; Vulcanizing agent is the organo-peroxide class, comprise peroxidation phenyl-diformyl, xylidene(s), para-totuidine, isopropyl benzene hydroperoxide, dilauroyl peroxide, methyl methacrylate, 2-hydroxyethyl methacrylate, aryl tertiary amine, two 25 of preferred 2.5 mass fractions.
The described one step cure of the invention described above is that the silicon rubber that will mix is 120~190 ℃ in temperature, and pressure is 14MPa~16Mpa, under the condition of curing time 5min~15min, adopts the compression molding sulfidization molding; Post vulcanization technology is earlier room temperature to be warming up to 150~230 ℃, insulation 1h, put in order behind the furnace cooling finished product.
The described carbon copper-clad of the invention described above nanoparticle is a nanometer copper particle outside coating nano carbon; Raw-silastic continuously is a methyl ethylene silica gel; Rubber bag roller is meant that silica gel is coated on the mill roller, so that Synergist S-421 95 can be added in the middle of the silica gel; Mixing repeatedly this mixture that refers to constantly mixes on roller; Thin-pass is meant gets to minimum with the distance between the two rollers of mill, with sizing material by two rollers to reach the finely dispersed purpose of sizing material.
Because carbon copper-clad nanoparticle is a kind of novel high heat conduction, high chemical stability, thermal expansivity is little, the heat conductive filler of low density excellent combination property, the present invention adopts this carbon copper-clad nanoparticle and high temperature silicon rubber mix, make carbon copper-clad nanoparticle be evenly dispersed in the silicon rubber matrix, form complete heat conduction network chain, thereby improved the heat-conductive characteristic of substrate medium, realization has significantly improved the thermal conductivity of matrix material to the high-level efficiency transmission of heat, has reduced the thermal expansivity of matrix material, components and parts have been stablized, more effectively prevented moisture, dust and obnoxious flavour are tensio-active agent with cheap ethanol directly to the intrusion of electronic devices and components simultaneously, not only strengthen the consistency of carbon copper-clad nanoparticle and silicon rubber matrix, also effectively reduced cost.
Embodiment
Describe the present invention for the ease of it will be appreciated by those skilled in the art that below in conjunction with embodiment:
Concrete processing step of the present invention is:
1) 20~300 mass fraction carbon copper-clad nanoparticles are stirred with 95% ethanolic soln mixing, carbon copper-clad nanoparticle dry powder is made in oven dry then;
2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, it in the carbon copper-clad nanoparticle dry powder heat conductive filler, the mass parts that add 10~300 mass fractions according to the formulating of recipe amount successively 1~3 hydroxy silicon oil, mixing repeatedly to even on roller, thin-pass 5~10 times, adding mass parts then is 1~3.5 vulcanizing agent, mixing more even, sheet under the thin-pass promptly gets silicon rubber gross rubber;
3) silicon rubber that mixes is put into mould, carry out one step cure after the mold filling of colding pressing;
4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven.
The particle diameter of the carbon copper-clad nanoparticle the invention described above processing step 1) is 40~80nm; Oven dry is that the mixture of carbon copper-clad nanoparticle and ethanolic soln is dried 10h down at 120 ℃ earlier, then behind oven dry 1h under 150 ℃; Vulcanizing agent is the organo-peroxide class, comprise peroxidation phenyl-diformyl, xylidene(s), para-totuidine, isopropyl benzene hydroperoxide, dilauroyl peroxide, methyl methacrylate, 2-hydroxyethyl methacrylate, aryl tertiary amine, two 25 of preferred 2.5 mass fractions.
The described one step cure of the invention described above is that the silicon rubber that will mix is 120~190 ℃ in temperature, and pressure is 14MPa~16Mpa, under the condition of curing time 5min~15min, adopts the compression molding sulfidization molding; Post vulcanization technology is earlier room temperature to be warming up to 150~230 ℃, insulation 1h, put in order behind the furnace cooling finished product.
The described carbon copper-clad of the invention described above nanoparticle is a nanometer copper particle outside coating nano carbon; Raw-silastic continuously is a methyl ethylene silica gel; Rubber bag roller is meant that silica gel is coated on the mill roller, so that Synergist S-421 95 can be added in the middle of the silica gel; Mixing repeatedly this mixture that refers to constantly mixes on roller; Thin-pass is meant gets to minimum with the distance between the two rollers of mill, with sizing material by two rollers to reach the finely dispersed purpose of sizing material.
Embodiment 1:
(1) the carbon copper-clad nanoparticle with 50 mass fractions stirs with 95% ethanolic soln mixing, dries 10h down at 120 ℃, and the back is behind oven dry 1h under 150 ℃, and it is stand-by to put into moisture eliminator.
(2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, adds the heat conductive filler of 50 mass parts then, the hydroxy silicon oil of 1~3 mass parts.Mixing repeatedly about 40min is extremely even on roller, thin-pass 5~10 times.It is two two or five to add mass parts and be 2.5 vulcanizing agent, mixing more evenly, sheet under the thin-pass promptly gets silicon rubber gross rubber.
(3) silicon rubber that mixes is put into mould, after the mold filling of colding pressing, mould placed carry out one step cure on the vulcanizing press, the one step cure temperature is: 170 ℃ ± 10 ℃, pressure is 14MPa~16Mpa, under curing time 5min~10min condition, adopt the compression molding sulfidization molding, be pressed into the sample of thickness homogeneous;
(4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven, and the technology of post vulcanization is: room temperature is warming up to 180 ℃, insulation 1h, and furnace cooling takes out sample afterwards.
Utilize Hot Disk thermal constant analyser that the heat-conducting silicon rubber thermal conductivity is measured, the blank rubber of measured thermal conductivity ratio has improved 60%.
Embodiment 2:
(1) the carbon copper-clad nanoparticle with 100 mass fractions stirs with 95% ethanolic soln mixing, dries 10h down at 120 ℃, and the back is behind oven dry 1h under 150 ℃, and it is stand-by to put into moisture eliminator.
(2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, adds the heat conductive filler of 100 mass parts then, the hydroxy silicon oil of 1.5 mass parts.Mixing repeatedly to even on roller, thin-pass 5~10 times.It is two two or five to add mass parts and be 2.5 vulcanizing agent, mixing more evenly, sheet under the thin-pass promptly gets silicon rubber gross rubber.
(3) silicon rubber that mixes is put into mould, after the mold filling of colding pressing, mould placed carry out one step cure on the vulcanizing press, the one step cure temperature is: 170 ℃ ± 10 ℃, pressure is 14MPa~16Mpa, under curing time 5min~10min condition, adopt the compression molding sulfidization molding, be pressed into the sample of thickness homogeneous;
(4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven, and the technology of post vulcanization is: room temperature is warming up to 180 ℃, insulation 1h, and furnace cooling takes out sample afterwards.
Utilize Hot Disk thermal constant analyser that the heat-conducting silicon rubber thermal conductivity is measured, the blank rubber of measured thermal conductivity ratio has improved 200%.
Embodiment 3:
(1) the carbon copper-clad nanoparticle with 150 mass parts stirs with 95% ethanolic soln mixing, dries 10h down at 120 ℃, and the back is behind oven dry 1h under 150 ℃, and it is stand-by to put into moisture eliminator.
(2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, adds the heat conductive filler of 150 mass parts then, the hydroxy silicon oil of 1~3 mass parts.Mixing repeatedly to even on roller, thin-pass 5~10 times.It is two two or five to add mass parts and be 2.5 vulcanizing agent, mixing more evenly, sheet under the thin-pass promptly gets silicon rubber gross rubber.
(3) silicon rubber that mixes is put into mould, after the mold filling of colding pressing, mould placed carry out one step cure on the vulcanizing press, the one step cure temperature is: 170 ℃ ± 10 ℃, pressure is 14MPa~16Mpa, under curing time 5min~10min condition, adopt the compression molding sulfidization molding, be pressed into the sample of thickness homogeneous;
(4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven, and the technology of post vulcanization is: room temperature is warming up to 180 ℃, insulation 1h, and furnace cooling takes out sample afterwards.
Utilize Hot Disk thermal constant analyser that the heat-conducting silicon rubber thermal conductivity is measured, the blank rubber of measured thermal conductivity ratio has improved 264%.
Embodiment 4:
(1) the carbon copper-clad nanoparticle with 200 mass parts stirs with 95% ethanolic soln mixing, dries 10h down at 120 ℃, and the back is behind oven dry 1h under 150 ℃, and it is stand-by to put into moisture eliminator.
(2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, adds the heat conductive filler of 200 mass parts then, the hydroxy silicon oil of 1.5 mass parts.Mixing repeatedly to even on roller, thin-pass 5~10 times.It is two two or five to add mass parts and be 2.5 vulcanizing agent, mixing more evenly, sheet under the thin-pass promptly gets silicon rubber gross rubber.
(3) silicon rubber that mixes is put into mould, after the mold filling of colding pressing, mould placed carry out one step cure on the vulcanizing press, the one step cure temperature is: 170 ℃ ± 10 ℃, pressure is 14MPa~16Mpa, under curing time 5min~10min condition, adopt the compression molding sulfidization molding, be pressed into the sample of thickness homogeneous;
(4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven, and the technology of post vulcanization is: room temperature is warming up to 180 ℃, insulation 1h, and furnace cooling takes out sample afterwards.
Utilize Hot Disk thermal constant analyser that the heat-conducting silicon rubber thermal conductivity is measured, the blank rubber of measured thermal conductivity ratio has improved 403%.
Embodiment 5:
(1) the carbon copper-clad nanoparticle with 250 mass parts stirs with 95% ethanolic soln mixing, dries 10h down at 120 ℃, and the back is behind oven dry 1h under 150 ℃, and it is stand-by to put into moisture eliminator.
(2) raw-silastic continuously with 100 mass parts is added on the roller, behind the rubber bag roller, adds the heat conductive filler of 250 mass parts then, the hydroxy silicon oil of 1~3 mass parts.Mixing repeatedly to even on roller, thin-pass 5-10 time.It is two two or five to add mass parts and be 2.5 vulcanizing agent, mixing more evenly, sheet under the thin-pass promptly gets silicon rubber gross rubber.
(3) silicon rubber that mixes is put into mould, after the mold filling of colding pressing, mould placed carry out one step cure on the vulcanizing press, the one step cure temperature is: 170 ℃ ± 10 ℃, pressure is 14MPa~16Mpa, under curing time 5min~10min condition, adopt the compression molding sulfidization molding, be pressed into the sample of thickness homogeneous;
(4) sample after the one step cure moulding is placed on and carries out post vulcanization on the woven fiber glass in air dry oven, and the technology of post vulcanization is: room temperature is warming up to 180 ℃, insulation 1h, and furnace cooling takes out sample afterwards.
Utilize Hot Disk thermal constant analyser that the heat-conducting silicon rubber thermal conductivity is measured, the blank rubber of measured thermal conductivity ratio has improved 834%.