A kind of preparation method of high heat stability aluminium hydroxide micro powder
Technical field
The preparation method of a kind of high heat stability aluminium hydroxide micro powder, belongs to new inorganic non-metallic materials environmental protection fire retarding agent technical field.
Background technology
Aluminium hydroxide micro powder is the environmental type fire retardant that a kind of consumption is the biggest.Add in plastics frequently as flame resistant filler material, but a kind of highly polar inorganic material of aluminium hydroxide micro powder, poor with the compatibility of non-polar polyolefinic high polymer in use, and the heat decomposition temperature of aluminium hydroxide micro powder is relatively low, when ambient temperature reaches about 250 DEG C, i.e. dehydration aluminium oxide can be decomposed into.Since the reason of this heat-resisting quantity difference of aluminium hydroxide micro powder, and the field that some temperature are higher cannot be applied to.
Copper-clad plate is the common used material of a kind of electron trade, needs at glass-fiber-fabric surface-coated epoxy-resin systems material in its preparation process.If epoxide resin material adding traditional aluminium hydroxide micro powder because the dehydration temperature of aluminium hydroxide micro powder is low as filler, meeting, causes copper-clad plate to run into high temperature (about 280 DEG C) during welding electronic component and can cause plate bursting.The flame retardant instead using other can increase again production cost or not reach environmental requirement.So, now it is badly in need of a kind of more preferable aluminium hydroxide micro powder of high thermal stability.
Summary of the invention
The purpose of the present invention is aiming at the deficiency that above-mentioned prior art exists, it is provided that the preparation method of a kind of dehydration temperature higher high heat stability aluminium hydroxide micro powder.
The technical solution adopted for the present invention to solve the technical problems is: the preparation method of this high heat stability aluminium hydroxide micro powder, it is characterized in that: during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 40 DEG C ~ 45 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 3h ~ 4h, resolution ratio is made to reach 30% ~ 35%, then sodium aluminate solution carries out, with the heating rate of 8 DEG C/h ~ 10 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 75 DEG C ~ 80 DEG C to decompose, continue constant temperature 2 h ~ 3h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 60r/min ~ 70r/min;Aluminium hydroxide is obtained after the serosity decomposed is implemented solid-liquor separation;Wash aluminium hydroxide, be dried, classification i.e. obtains aluminium hydroxide micro powder.
It is contemplated that obtain a kind of crystal formation rule, the higher aluminium hydroxide micro powder of degree of crystallinity.The alternating temperature decomposition technique that the present invention provides first starts Isothermal Structural Decomposition In Certain at a lower temperature, slowly obtain a small amount of highly active β-Al (OH)3, and with high-speed stirred, make β-Al (OH)3Will also rush at this moment is fully dispersed, then carries out continuous warming decomposition with specific heating rate, makes the generation of crystal formation by β-Al (OH)3It is gradually converted into α-Al (OH)3, and continuation Isothermal Structural Decomposition In Certain prepares α-Al (OH) at relatively high temperatures3, at relatively high temperatures, decomposition rate substantially reduces, β-Al (OH) a small amount of during the slow crystallizing in later stage3At α-Al (OH)3Middle dispersion, obtains β-Al (OH)3With α-Al (OH)3This crystal formation coexisted with special ratios, entirety presents almost spherical or hexagon, thus successfully improves dehydration temperature, makes aluminium hydroxide differential be applicable to more high-end field.The present invention, after decomposition completes, continues constant temperature 2 h ~ 3h and improves crystallization so that degree of crystallinity is higher, and plane of crystal is more smooth, and dehydration temperature is higher.
Preferably, the decomposition temperature that described cryogenic thermostat decomposes is 40 DEG C ~ 42 DEG C.
Preferably, the decomposition temperature that described high temperature constant temperature decomposes is 75 DEG C ~ 77 DEG C.
The decomposition temperature that cryogenic thermostat decomposes and high temperature constant temperature decomposes, determines the ratio of two kinds of crystal formation aluminium hydroxide micro powders and mutual degree of scatter, and Isothermal Structural Decomposition In Certain at low temperature 40 DEG C ~ 42 DEG C, fast decoupled, to improve decomposition rate, obtains β-Al (OH) simultaneously3, the ratio controlling two kinds of crystal formations is more accurate, and dispersion is evenly.
Preferably, described washing process adds silane coupler be modified.Utilize washing process addition silane coupler modified to aluminium hydroxide micro powder, make coupling agent dispersion more uniform.Selecting silane coupler to be combined with aluminium hydroxide micro powder more firm, heat-resisting ability is higher.
It is further preferred that the composite coupler that described silane coupler is VTES and 3-chloropropyl alkoxy silane 1:9 ~ 13 in mass ratio.The present invention provides the formula of a kind of compounding coupling agent; based on chloropropyl alkoxy silane coupling agent; VTES is utilized to allocate; both ensured that the strong absorbability after main coupling agent mistake chlorine was firmly combined with aluminium hydroxide micro powder; polyreaction is there is in the alkylene coupling agent utilizing again auxiliary under alkaline environment; improve surface active degree, there is certain protective effect simultaneously, improve resistance to elevated temperatures.
α-Al (OH) in described aluminium hydroxide micro powder3Shared mass percent is 90% ~ 95%, β-Al (OH)3Shared mass percent is 5% ~ 10%.
5% dehydration temperature of described aluminium hydroxide micro powder is at 285 DEG C ~ 287 DEG C.
In aluminium hydroxide micro powder, the ratio of two kinds of crystal formations is the microcosmic effect that the present invention is obtained by alternating temperature technique, and this crystal formation building form makes crystalline particle present almost spherical or hexagon, and ionic bond combines more firm, is that the present invention improves the basic of dehydration temperature.5% dehydration temperature of the aluminium hydroxide micro powder of present invention performance is at 280 DEG C ~ 287 DEG C.More traditional aluminium hydroxide micro powder improves more than 30 DEG C, meets 280 DEG C of requirements the highest in copper-clad plate welding procedure.Can normally use in copper-clad plate produces, not have plate bursting phenomenon and occur.
Compared with prior art the had the beneficial effect that present invention of preparation method of a kind of high heat stability aluminium hydroxide micro powder of the present invention pass through alternating temperature technique prepare aluminium hydroxide micro powder join copper-clad plate produce epoxy-resin systems material in after, meet production requirement.The present invention passes through β-Al (OH)3With α-Al (OH)3This crystalline forms coexisted with special ratios, it is ensured that the crystal formation rule of aluminium hydroxide micro powder, degree of crystallinity are higher.The entirety of aluminium hydroxide micro powder of present invention performance presents almost spherical or hexagon, thus successfully improves 5% dehydration temperature to 285 DEG C ~ 288 DEG C, makes aluminium hydroxide differential be applicable to more high-end field.The present invention, after decomposition completes, continues constant temperature 2 h ~ 3h and improves crystallization so that degree of crystallinity is higher, and plane of crystal is more smooth, and dehydration temperature is higher.The present invention also utilizes wet processing to carry out surface modification, improves resistance to elevated temperatures further while strengthening dispersibility.
Detailed description of the invention
Being described further the preparation method of a kind of high heat stability aluminium hydroxide micro powder of the present invention below by specific embodiment, wherein embodiment 1 is most preferred embodiment.
Embodiment 1
1) first during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 42 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 3.2h, resolution ratio is made to reach 32%, then sodium aluminate solution carries out, with the heating rate of 8 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 75 DEG C to decompose, continue constant temperature 2.5h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 65r/min;The aluminium hydroxide micro powder of gained after decomposing sodium aluminate solution and decomposition nut liquid are carried out solid-liquor separation;
2) putting in sink by the aluminium hydroxide micro powder filter cake of gained again, addition wash water is made into aluminium hydroxide micro powder slurry and washs, and in slurry, aluminium hydroxide micro powder contains admittedly is 150 grams per liters;In the washing process of aluminium hydroxide micro powder, the VTES adding aluminium hydroxide micro powder filter cake quality 1% in this slip is modified with the composite coupler of 3-chloropropyl alkoxy silane 1:11 in mass ratio;
3) utilizing sucking filtration machine to carry out solid-liquor separation after modification terminates, the filter cake of separation is dried at a temperature of 100 DEG C ~ 110 DEG C;
4) by above-mentioned dried aluminium hydroxide micro powder, carry out classification, obtain modified thin aluminium hydroxide micro powder.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 94%, β-Al (OH)3Shared mass percent is 6%.Measuring 5% dehydration temperature is at 286 DEG C.
Embodiment 2
1) first during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 43 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 3.8h, resolution ratio is made to reach 35%, then sodium aluminate solution carries out, with the heating rate of 9 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 77 DEG C to decompose, continue constant temperature 2.6h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 60r/min;The aluminium hydroxide micro powder of gained after decomposing sodium aluminate solution and decomposition nut liquid are carried out solid-liquor separation;
2) putting in sink by the aluminium hydroxide micro powder filter cake of gained again, addition wash water is made into aluminium hydroxide slurry and washs, and in slurry, aluminium hydroxide contains admittedly is 150 grams per liters;In the washing process of aluminium hydroxide, the VTES adding aluminium hydroxide micro powder filter cake quality 1% in this slip is modified with the composite coupler of 3-chloropropyl alkoxy silane 1:12 in mass ratio;
3) utilizing sucking filtration machine to carry out solid-liquor separation after modification terminates, the filter cake of separation is dried at a temperature of 100 DEG C ~ 110 DEG C;
4) by above-mentioned dried aluminium hydroxide micro powder, carry out classification, obtain modified thin aluminium hydroxide micro powder.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 95%, β-Al (OH)3Shared mass percent is 5%.Measuring 5% dehydration temperature is at 287 DEG C.
Embodiment 3
1) first during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 40 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 4h, resolution ratio is made to reach 30%, then sodium aluminate solution carries out, with the heating rate of 8 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 79 DEG C to decompose, continue constant temperature 2h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 70r/min;The aluminium hydroxide of gained after decomposing sodium aluminate solution and decomposition nut liquid are carried out solid-liquor separation;
2) putting in sink by the aluminium hydroxide micro powder filter cake of gained again, addition wash water is made into aluminium hydroxide micro powder slurry and washs, and in slurry, aluminium hydroxide micro powder contains admittedly is 150 grams per liters;In the washing process of aluminium hydroxide micro powder, the VTES adding aluminium hydroxide micro powder filter cake quality 1.3% in this slip is modified with the composite coupler of 3-chloropropyl alkoxy silane 1:9 in mass ratio;
3) utilizing sucking filtration machine to carry out solid-liquor separation after modification terminates, the filter cake of separation is dried at a temperature of 100 DEG C ~ 110 DEG C;
4) by above-mentioned dried aluminium hydroxide micro powder, carry out classification, obtain modified thin aluminium hydroxide micro powder.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 90%, β-Al (OH)3Shared mass percent is 10%.Measuring 55 dehydration temperature is at 288 DEG C.
Embodiment 4
1) first during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 45 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 3h, resolution ratio is made to reach 35%, then sodium aluminate solution carries out, with the heating rate of 8 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 80 DEG C to decompose, continue constant temperature 3h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 70r/min;The aluminium hydroxide micro powder of gained after decomposing sodium aluminate solution and decomposition nut liquid are carried out solid-liquor separation;
2) putting in sink by the aluminium hydroxide micro powder filter cake of gained again, addition wash water is made into aluminium hydroxide micro powder slurry and washs, and in slurry, aluminium hydroxide contains admittedly is 150 grams per liters;In the washing process of aluminium hydroxide micro powder, the OPEO adding aluminum hydroxide filter cake quality 0.6% in this slip is coupling agent modified;
3) utilizing sucking filtration machine to carry out solid-liquor separation after modification terminates, the filter cake of separation is dried at a temperature of 100 DEG C ~ 110 DEG C;
4) by above-mentioned dried aluminium hydroxide micro powder, carry out classification, obtain modified thin aluminium hydroxide micro powder.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 92%, β-Al (OH)3Shared mass percent is 8%.Measuring dehydration temperature is at 285 DEG C.
Embodiment 5
1) first during kind of a point-score prepares aluminium hydroxide micro powder, at a temperature of 42 DEG C, first carry out cryogenic thermostat after sodium aluminate solution adds crystal seed decompose 3.5h, resolution ratio is made to reach 33%, then sodium aluminate solution carries out, with the heating rate of 8 DEG C/h, the decomposition that heats up, enter high temperature constant temperature when temperature rises to 76 DEG C to decompose, continue constant temperature 2.5h after having decomposed and improve crystallization, whole catabolic process carries out the stirring of 60r/min;The aluminium hydroxide micro powder of gained after decomposing sodium aluminate solution and decomposition nut liquid are carried out solid-liquor separation;
2) putting in sink by the aluminium hydroxide micro powder filter cake of gained again, addition wash water is made into aluminium hydroxide slurry and washs, and in slurry, aluminium hydroxide contains admittedly is 150 grams per liters;
3) washing utilizes sucking filtration machine to carry out solid-liquor separation after terminating, and the filter cake of separation is dried at a temperature of 100 DEG C ~ 110 DEG C;
4) by above-mentioned dried aluminium hydroxide micro powder, carry out classification, obtain modified thin aluminium hydroxide micro powder.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 93.5%, β-Al (OH)3Shared mass percent is 6.5%.Measuring 5% dehydration temperature is at 286 DEG C.
Comparative example 1
Basic craft course and material proportion are with embodiment 1, and except for the difference that the catabolic process of sodium aluminate solution uses the continuous warming decomposition technique from 40 DEG C ~ 75 DEG C.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 76%, β-Al (OH)3Shared mass percent is 24%.Measuring 5% dehydration temperature is at 255 DEG C.α-Al (OH) in the aluminium hydroxide micro powder that the continuous warming technique of visible routine produces3With β-Al (OH)3Ratio irregular, also will not be combined with each other and obtain the crystal grain of special shape, not affect dehydration temperature.
Comparative example 2
Basic craft course and material proportion are with embodiment 1, and the temperature that except for the difference that cryogenic thermostat decomposes is at 55 DEG C.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent accounts for more than 98%.Measuring dehydration temperature is at 250 DEG C.At β-Al (OH)3Amount too small, it is impossible at α-Al (OH)3Middle as crucial junction point, basic expressions is α-Al (OH)3Dehydration temperature.
Comparative example 3
Basic craft course and material proportion are with embodiment 1, and the temperature that except for the difference that high temperature constant temperature decomposes is at 65 DEG C.
α-Al (OH) in X-ray diffraction detection gained aluminium hydroxide micro powder crystal3Shared mass percent is 84%, β-Al (OH)3Shared mass percent is 16%.Measuring dehydration temperature is at 252 DEG C.α-Al(OH)3Formation efficiency low, it is impossible to a small amount of β-Al (OH)3Cocrystallization, it is impossible to obtain the present invention and improve the effect of dehydration temperature.
The above, be only presently preferred embodiments of the present invention, is not the restriction that the present invention makees other form, and any those skilled in the art are changed possibly also with the technology contents of the disclosure above or are modified as the Equivalent embodiments of equivalent variations.But every without departing from technical solution of the present invention content, any simple modification, equivalent variations and remodeling above example made according to the technical spirit of the present invention, still fall within the protection domain of technical solution of the present invention.