Background technology
Polyphenylene sulfide (be called for short PPS) claims polyphenylene sulfide, poly-phenylene thioether again, is a kind of thermoplastic engineering plastic of excellent combination property, and its outstanding feature is high temperature resistant, corrosion-resistant, radiation hardness, do not fire, mechanical property and electrical property excellence.Be mainly used in automobile making, electronic apparatus, mechanical industry, chemical industry instrument and space industry etc.But because the PPS rigidity is strong, performance is crisp, impelling strength is not high, application is restricted, and the PPS product of practical application all is to pass through modification.Though the PPS material of modification has certain insulating property, in air, expose to the open air for a long time or (as: hot and humid condition) use in particular environment, resistance value can descend very fast, and for example: PPS matrix material volume specific resistance under normal conditions is 10
17Ω .m, surface resistivity are 10
14Ω, but in the environment of 95 ℃ of temperature, humidity 90% the resistivity several magnitude that descends rapidly, this certainly will influence the PPS matrix material and be applied in hot and humid insulating material field.
At present, it is mainly compound based on machinery to prepare the method for PPS matrix material.The machinery complex method is meant the insulation modified filler is filled in the plastics in the mode of mechanical blending and goes that the main insulation modified filler of using has mica, nano silicon, aluminium nitride, kaolin, nano-calcium carbonate, calcium carbonate crystal whisker, calcium sulfate crystal whiskers, glass microballon etc.The insulating material that this mechanical recombining process is just simply crossed coupling agent treatment adds in the plastics and disperses, fusion in forcing machine then, extrude, obtain the polyphenyl thioether composite material of modification at last, cause product in actual applications, under particularly long-term exposed to air or process high temperature, the super-humid conditions, insulating property significantly descend.
Above shortcoming in view of prior art the objective of the invention is, and studies a kind of high-performance polyphenylene sulfide insulating composite material preparation method, makes it overcome the above shortcoming of prior art.
The present invention also aims to develop a kind of high-performance polyphenylene sulfide insulating composite material, make it to have that mechanical property and insulativity are high and stable, complete processing is easy, material Application Areas advantage widely.
Summary of the invention,
The high-performance polyphenylene sulfide insulating composite material preparation method, its raw material composition is by weight ratio: polyphenylene sulfide 59%, glass fibre 30% is through coupling surface-treated mineral filler 1~10%, hydrophobic nano-silica 1~5%; Technology comprises following key step:
1) the coupling surface treatment of mineral filler: 10~20min is fully soaked in mineral filler in the mixing solutions of coupling agent, dehydrated alcohol, 30~50 ℃ of treatment temps, make and the abundant and inorganic filler surface reaction of coupling agent obtain the mineral filler of described coupling surface-treated through hot-air dry; Wherein three's proportioning is: 70~80% mineral filler, 1~2.5% coupling agent, 10~20% dehydrated alcohol;
2) taking by weighing polyphenylene sulfide and 1 by weight ratio) mineral filler of coupling surface-treated and hydrophobic nano-silica put into high-speed mixer for dry mixing 5~10 minutes together, the control stirring velocity is 1000~2000rpm, and the agitation vat temperature is 30~50 ℃;
3) with step 2) in mixed material put in the loading hopper of twin screw extruder; glass fibre is added by the side spout; control screw speed 70~100rpm; processing is respectively distinguished temperature from 250~330 ℃; residence time 2min; die orifice pressure is 5MPa, through melt extrude, water cooling, be drawn to the dicing machine granulation.
Adopt technical scheme of the present invention, have following beneficial effect:
1, the present invention adopts novel insulating packing p-poly-phenyl thioether matrix material to carry out filling-modified, new insulation material is uniformly dispersed in the polyphenylene sulfide matrix resin, insulativity is high and stable, and characteristics such as addition is few, easily compound, easy processing, Application Areas are extensive.
When 2, the present invention improves insulated with material, also improve the toughness of polyphenylene sulfide, improved the mechanical property such as bending, stretching of matrix material.
3, the preparation technology of the high electric-insulating polyphenyl thioether matrix material of the present invention's proposition is simple, and can satisfy the processing requirement of plastic shapings processing such as injection moulding, extrusion molding or mold pressing repeatedly, can be widely used in fields such as electronic product, Communication Equipment, safety precaution.
Embodiment
Below in conjunction with accompanying drawing process of the present invention is described in further detail.
As shown in Figure 1, the coupling surface treatment of mineral filler: 10~20min is fully soaked in mineral filler in the mixing solutions of coupling agent, dehydrated alcohol, 30~50 ℃ of treatment temps, make and the abundant and inorganic filler surface reaction of coupling agent behind hot-air dry, obtain the mineral filler of described coupling surface-treated; Wherein three's proportioning is: 70~80% mineral filler, 1~2.5% coupling agent, 10~20% dehydrated alcohol; Mineral filler is calcium carbonate crystal whisker or is that calcium carbonate crystal whisker and two kinds of mica powders are compound.Used mica powder is a mica powder of wet process, and radius-thickness ratio is 80~120, and its coupling surface treatment method is consistent with the processing of calcium carbonate crystal whisker.Used calcium carbonate crystal whisker mean length 30~40 μ m, length-to-diameter ratio 20~50.Coupling agent is at least a in titanate coupling agent, aluminate coupling agent, the siloxanes coupling agent, is preferably the siloxanes coupling agent.
Take by weighing polyphenylene sulfide and the mineral filler of above coupling surface-treated and hydrophobic nano-silica by weight ratio and put into high-speed mixer for dry mixing 5~10min together, the control stirring velocity is 1000~2000rpm, and the agitation vat temperature is 30~50 ℃.Wherein, the polyphenylene sulfide weight-average molecular weight is 50000, and chloride ion content is below 1000ppm; As nanometer titanium dioxide silicone content 96% in the hydrophobic nano-silica of new insulation material interpolation, median size is at 13~16nm.
At last above-mentioned mixed material is put in the loading hopper of twin screw extruder; glass fibre (adopting the non-alkali glass macrofiber) adds by extruding the pusher side spout; control screw speed 70~100rpm; processing is respectively distinguished temperature from 250~330 ℃; residence time 2min; die orifice pressure is 5MPa, through melt extrude, water cooling, be drawn to the dicing machine granulation.
Coupling agent all adopts siloxanes coupling agent KH-550 in following examples.
Embodiment 1
In the present embodiment 1, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 10% coupling surface-treated calcium carbonate crystal whisker, 1% hydrophobic nano-silica.Implementing process is as follows:
The coupling surface treatment of mineral filler: calcium carbonate crystal whisker is fully soaked into 15min in the mixing solutions of siloxanes coupling agent KH-550, dehydrated alcohol, 40 ℃ of treatment temps, make and the abundant and calcium carbonate crystal whisker surface reaction of coupling agent KH-550 behind hot-air dry, obtain described coupling surface-treated calcium carbonate crystal whisker; Wherein three's proportioning is: 80% mineral filler, 2% coupling agent, 18% dehydrated alcohol.
Take by weighing polyphenylene sulfide and above coupling surface-treated calcium carbonate crystal whisker and hydrophobic nano-silica by weight ratio and put into high-speed mixer for dry mixing 5min together, the control stirring velocity is 1500rpm, and the agitation vat temperature is 40 ℃.
At last above-mentioned mixed material is put in the loading hopper of twin screw extruder, glass fibre adds by extruding the pusher side spout, control screw speed 90rpm; processing is respectively distinguished temperature and is: a district is 250 ℃, and two districts are 280 ℃, and three districts are 300 ℃; four districts are 300 ℃; five districts are 295 ℃, and six districts are 290 ℃, and head is 285 ℃; residence time 2min; die orifice pressure is 5MPa, through melt extrude, water cooling, be drawn to the dicing machine granulation.
Embodiment 2:
In the present embodiment 2, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 8% coupling surface-treated calcium carbonate crystal whisker, 2% coupling surface-treated mica powder, 1% hydrophobic nano-silica.Implementing process is with described in the embodiment 1.
Embodiment 3:
In the present embodiment 3, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 5% coupling surface-treated calcium carbonate crystal whisker, 5% coupling surface-treated mica powder, 1% hydrophobic nano-silica.Implementing process is with described in the embodiment 1.
Embodiment 4:
In the present embodiment 4, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 5% coupling surface-treated calcium carbonate crystal whisker, 4% coupling surface-treated mica powder, 2% hydrophobic nano-silica.Implementing process is with described in the embodiment 1.
Embodiment 5:
In the present embodiment 5, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 5% coupling surface-treated calcium carbonate crystal whisker, 3% coupling surface-treated mica, 3% hydrophobic nano-silica.Implementing process is with described in the embodiment 1.
Embodiment 6:
In the present embodiment 6, described high-performance PPS insulating composite material has comprised 59% PPS resin, 30% glass fibre, 5% coupling surface-treated calcium carbonate crystal whisker, 2% coupling surface-treated mica powder, 4% hydrophobic nano-silica.Implementing process is with described in the embodiment 1.
Performance test:
Prepared high-performance polyphenylene sulfide insulating composite material, its tensile strength is tested according to GB GB/T 1040; Its flexural strength and modulus in flexure are tested by GB GB 9341/T; Its notched Izod impact strength is tested by GB/T 1043; Its surface resistivity and volume specific resistance are tested according to GB GB/T 1410-2006.
Fig. 2 is seen in the contrast of embodiment 1~6 prescription and material property: go up tabulation embodiment 1~3 as can be seen by figure, the combination of mineral filler can obviously improve the mechanical property of PPS matrix material, increase along with mica powder in the mineral filler, insulating property under the matrix material normality condition improve, but at hot and humid condition lower surface resistivity and volume specific resistance 2~4 orders of magnitude that still will descend.Can see among the embodiment 4~6, raising along with new insulation material hydrophobic nano-silica content, the insulating property of PPS matrix material obviously improve, but the adding of excessive hydrophobic nano-silica causes the mechanical property of matrix material to reduce, and insulating property do not reach optimum value yet.When mineral filler and hydrophobic nano-silica proportioning reached shown in the embodiment 5, the insulating property of matrix material under normality and hot and humid condition reached optimum value, and have kept higher mechanical property.