A kind of micro-foaming polypropylene material and preparation method thereof
Technical field
The present invention relates to the field of polymers more particularly to a kind of micro-foaming polypropylene material and preparation method thereof.
Background technique
It is compared with common plastics, Foamex is because its density is low, good heat build-up performance, and high thermal stability is good
Mechanical property, such as the advantages that impact strength, toughness, endurance, in packaging material, auto-parts, adsorbent, mechanical support dress
It is standby that places is waited to have many applications.Wherein, polypropylene, since its is at low cost, high-melting-point, high stretch modulus, low-density, well
Chemical stability, be widely used Foamex industry.According to the difference of foaming aperture size, expanded polypropylene can divide
For the PP and fretting map PP that commonly foams.The common usual abscess naked eyes of expanded polypropylene, can as it can be seen that cell diameter is higher than 100 microns
It is used to prepare packaging material.When cell diameter is lower than 100 microns, then referred to as micro-foaming polypropylene, can be used for the part of car body
The weight of car body is effectively reduced in injection moulded fittings.But preparing micro-foaming polypropylene has two big difficult points, a big difficulty is foaming
The control of size, because comparing with materials such as polyurethane, polystyrene, polyacrylic melt strength is lower, so that foaming
It is extremely difficult, easily there is the problems such as fusion steeped and rupture and generate the bulla of irregular distribution, the second largest difficult point is foaming ruler
Very little homogeneity is difficult to control, and other than being influenced by polypropylene melt strength itself, the homogeneity of polypropylene expanded size is controlled
More difficult mainly to have 2 reasons, reason one is that polypropylene itself is a kind of half hitch polycrystalline macromolecule, whole during forming spherocrystal
A macromolecule internal physical structure is no longer uniform, leads into bubble homogeneity and goes wrong, second reason is foaming agent, microvesicle nucleation
Agent and the mixing of acrylic resin not enough uniformly lead to the size difference that foams.And foaming agent, microvesicle nucleating agent and polypropylene
The mixing of resin is there is also two problems, one is the reunion of foaming agent itself, the second is foaming agent, microvesicle nucleating agent etc. are inorganic
Mixing between particle and acrylic resin.
Currently, difficult for the above foaming of polypropylene fusing point, the bad problem of foaming size distribution uniformity, mainly
Technology path be to improve polyacrylic melt strength, polyacrylic polarity is modified, or use physics supercritical foaming
It is prepared by method.In order to improve polyacrylic melt strength, the first normal method is to use high melt strength, propylene
HMSPP such as introduces a small amount of long chain branched polypropylene using new catalyst or reactor, but it is very high to be generally prepared as this;The
Why the polyolefin (such as polyethylene) of other high fondant-strengths is blended two kinds of modes, but other polyolefin, which are added, to be reduced
The advantages such as the heat resistance of polypropylene itself and good mechanical property;The third mode is to introduce certain cross-linked structure, such as logical
Overshoot crosslinking or chemical cross-linking agent are crosslinked polypropylene segment, but the control of the degree of cross linking is more difficult, and easily deposit
In chemical residual, preparation process is more difficult to control, in some instances it may even be possible to which there are certain risk of explosion.In order to improve polypropylene and inorganic
The mixing of filler, normal method are that use maleic anhydride to modify polypropylene compatible between inorganic filler to improve it
Property, but maleic anhydride higher cost, and it is also unsatisfactory for the control of cell size.In addition, using the overcritical hair of physics
Prepared by bubble method, be to utilize with polymer-gas homogeneous system existing for types of supercritical fluid, using rapidly changing temperature
The mode of degree makes gas solubility change dramatically in the polymer and prepares microvesicle, but supercritical fluid hair method usually needs
Special equipment is wanted, complex process, control of product quality is difficult, and higher cost.
Based on this, inventing one kind can be used for common Melt strength polypropylene resin, without special supercritical fluid
Equipment can be realized polypropylene fretting map, and foaming homogeneity is good, foaming agent soilless sticking and the material technology that cost can be effectively controlled
Become extremely important.
Summary of the invention
The purpose of the present invention is to provide one kind to have low-density, high foamability, abscess uniform pore diameter and main concentration
In material internal, surface has the micro-foaming polypropylene material of excellent appearance and the system of this kind of micro-foaming polypropylene material without trace
Preparation Method.
The present invention is compound in 1-10 microns of foaming agent by blapharoplast and composite foamable agent preparation particle diameter distribution D50 value
Powder makes foaming agent uniform load on blapharoplast, foaming agent composite powder is made with acrylic resin mixing extruding pelletization, injection molding
It is standby to obtain micro-foaming polypropylene material.The micro-foaming polypropylene surfacing being prepared without trace, inside there are uniform pore diameter,
Average-size is the compound microbubble structure that 50-250 microns of the small bubble of microvesicle and aperture less than 10 microns collectively constitutes, or
The ultra micro bubble structure of small bubble of the aperture less than 20 microns.Density of material is 0.8-0.95g/cm3, melt flow rate 2.5-
50g/10min, tensile strength > 8Mpa, elongation at break are higher than 500%, Izod notched impact strength > 5kJ/m2.The present invention
Compared with the preparation process of traditional micro-foaming polypropylene, by preparing NEW TYPE OF COMPOSITE foam powder, without special overcritical
The pore size of polypropylene fretting map and the control of homogeneity can be realized with common Melt strength polypropylene resin in fluid device
System, and solve the problems, such as foaming agent reunion simultaneously.
The present invention provides a kind of micro-foaming polypropylene material, acrylic resin and 0.5- including 50-99.5wt%
The particle diameter distribution D50 value of 50wt% is in 1-10 microns of foaming agent composite powder, and wherein foaming agent composite powder includes following quality hundred
Divide the component of content: blapharoplast 10-95%, composite foamable agent 5-90%, promoter for blowing agent 0-10%.
Wherein, blapharoplast includes but is not limited to: wood powder, diatomite, flyash, dolomite, calcium carbonate, calcium silicates, glass
Glass microballon, titanium dioxide titanium dioxide, sepiolite, concave convex rod, zeolite, quartz, kaolin, silica, bentonite or perlite
One of or it is a variety of.
Composite foamable agent includes the first phase foaming agent of 50-100wt% and the second phase foaming agent of 0-50wt%, wherein
One phase foaming agent is one of p-toluene sulfonylsemicarbazide, azodicarbonamide, Barium azodicarboxylate or 5- phenyl tetrazole
Or it is a variety of, the second phase foaming agent is bicarbonate, such as one of sodium bicarbonate, calcium bicarbonate or calcium bicarbonate or a variety of.
Promoter for blowing agent is sodium bicarbonate, sodium citrate, urea, lactic acid, one of malic acid or a variety of.
The present invention provides a kind of preparation method of micro-foaming polypropylene material, prepares foaming agent composite powder first, by 10-
95wt% blapharoplast, 5-90wt% composite foamable agent, the mixing of 0-10wt% promoter for blowing agent;Again by the poly- of 50-99.5wt%
The foaming agent composite powder of allyl resin and matter 0.5-50wt%, which mix and carries out extruding pelletization, obtains modified polypropene pellet;Finally
Modified polypropene pellet is sent into injection molding machine, injection molding under conditions of injection temperature is 210-250 DEG C is prepared poly-
Propylene micro-foaming material.
Wherein raw material acrylic resin is the acrylic resin particle that melt flow rate is 2-45g/10min.
Wherein being granulated is that melting extrusion granulation is carried out by double screw extruder, and extrusion temperature is 140-180 DEG C, is changed
Property polypropylene granules.
Wherein, blapharoplast includes but is not limited to: wood powder, diatomite, flyash, dolomite, calcium carbonate, calcium silicates, glass
Glass microballon, titanium dioxide titanium dioxide, sepiolite, concave convex rod, zeolite, quartz, kaolin, silica, bentonite or perlite
One of or it is a variety of.
Wherein, composite foamable agent includes the first phase foaming agent of 50-100wt% and the second phase foaming agent of 0-50wt%,
Wherein the first phase foaming agent is p-toluene sulfonylsemicarbazide, azodicarbonamide, Barium azodicarboxylate, in 5- phenyl tetrazole
One or more, the second phase foaming agent is bicarbonate, such as sodium bicarbonate, calcium bicarbonate, one of calcium bicarbonate or a variety of.
Wherein, promoter for blowing agent is sodium bicarbonate, sodium citrate, urea, lactic acid, one of malic acid or a variety of.
Wherein, hybrid mode uses mixed at high speed blender, vibromill, sand mill, air-flow when prepared by foaming agent composite powder
Mill, Ball-stirring mill, honeycomb mill, Raymond mill, ring roll mill, omnipotent impact grinding, high-speed impact airslide disintegrating mill, wet process or dry ball milling
Machine it is one or more, the foaming agent composite powder being prepared is coated on blapharoplast by composite foamable agent, particle diameter distribution D50
Value is at 1-10 microns.
The micro-foaming polypropylene surfacing being prepared is without trace, and there are uniform pore diameters, average-size 50- for inside
The compound microbubble structure that 250 microns of the small bubble of microvesicle and aperture less than 10 microns collectively constitutes, exemplary diagram such as attached drawing 1,
Or the ultra micro bubble structure of small bubble of the aperture less than 20 microns, exemplary diagram such as attached drawing 2.
By the way that composite foamable agent is supported on blapharoplast in advance, asked it is possible to prevente effectively from conventional foaming agents powder ball is poly-
Topic, and can be realized the control of effective dispersibility and foaming dimensional homogeneity of the foaming agent in polypropylene simultaneously, it avoids the occurrence of
Bulla is randomly distributed due to caused by the fusion of bubble, rupture.Further, the aperture of material can be by adjusting foaming agent composite powder
The parameters such as ingredient, constituent mass score, particle diameter distribution be adjusted.The density that material is made is 0.8-0.95g/cm3, melt
Flowing velocity is 2.5-50g/10min, and has good mechanical characteristic, and tensile strength > 8Mpa, elongation at break is higher than
500%, Izod notched impact strength > 5kJ/m2.Compared with traditional fretting map mode, cost of the present invention is lower, sets to special type
Standby requirement is less, and can maximum possible reservation virgin pp itself good characteristic.
Detailed description of the invention
Attached drawing 1 is the compound microbubble structure Fracture scan electron microscope that the present invention is prepared;
Attached drawing 2 is the ultra micro bubble structure Fracture scan electron microscope that the present invention is prepared;
Attached drawing 3 is the scanning electron microscope (SEM) photograph of comparative example.
Specific embodiment
Comparative example
By melt flow rate (MFR) be 38g/min acrylic resin and pure azodicarbonamide according to mass ratio 10:1 most
Carry out extruding pelletization at a temperature of 180 DEG C of high temperature, and 230 DEG C of maximum temperature at a temperature of carry out injection molding, product is made
Density is 0.88g/cm3, there is aperture in 500 microns or more of macroscopical bulla in some areas, and some areas are still, do not steep
Hole aperture seriously affects the mechanical property of material, Izod notched impact strength < 4kJ/m in 10 microns of ultra micro bubbles below2,
Abscess microstructure is as shown in Fig. 3.
Embodiment 1
Using high-speed impact airslide disintegrating mill by mass percent be 95% talcum powder and mass percent be 5%
The compound obtained foaming agent composite powder of composite foamable agent, wherein composite foamable agent selects the first phase foaming agent azodicarbonamide, the
Two-phase foaming agent sodium acid, made foaming agent composite powder particle diameter distribution D50 value are 8.5 microns.It is 2.5 by melt flow rate (MFR)
Acrylic resin and modified foaming agent composite powder according to mass ratio 10:1 180 DEG C of the highest temperature at a temperature of squeeze out and make
Grain, and 230 DEG C of maximum temperature at a temperature of carry out injection molding, be made product density be 0.88g/cm3.Made sample surfaces
Smooth no trace, inside is there are uniform pore diameter, the small bubble of microvesicle and aperture less than 10 microns that average-size is 150 microns
The compound microbubble structure collectively constituted, material melt flowing velocity are 2.5-50g/10min, tensile strength 8.1Mpa, and fracture stretches
Long rate is higher than 500%, Izod notched impact strength 6kJ/m2.Abscess microstructure is as shown in Fig. 1, the foam structure of material
It there are the equally distributed average pore size in bubble aperture is 150-200 microns micro- in 100 micron dimensions mainly in material internal
Pore structure, and there are uniform pore diameter distribution in 1 micron dimension, the micro hole that average pore size is 2 microns.
Embodiment 2
The foaming agent composite powder in acrylic resin and above-described embodiment 1 for being 20 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.91g/cm that product density, which is made,3。
Embodiment 3
The foaming agent composite powder in acrylic resin and above-described embodiment 1 for being 20 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.92g/cm that product density, which is made,3。
Embodiment 4
The foaming agent composite powder in acrylic resin and above-described embodiment 1 for being 38 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.94g/cm that product density, which is made,3。
Embodiment 5
Using high-speed impact airslide disintegrating mill by mass percent be 95% talcum powder and mass percent be 5%
The compound obtained foaming agent composite powder of composite foamable agent, wherein the first phase foaming agent toluene sulfonyl semicarbazide of composite foamable agent selection,
Second phase foaming agent sodium acid, made foaming agent composite powder particle diameter distribution D50 value are 8.5 microns.It is by melt flow rate (MFR)
2.5 acrylic resin and foaming agent composite powder according to mass ratio 10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization,
And 230 DEG C of maximum temperature at a temperature of carry out injection molding, be made product density be 0.92g/cm3.Abscess microstructure is such as
Shown in attached drawing 2.
Embodiment 6
The foaming agent composite powder in acrylic resin and above-described embodiment 5 for being 20 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.94g/cm that product density, which is made,3。
Embodiment 7
Using high-speed impact airslide disintegrating mill by mass percent be 95% talcum powder and mass percent be 5%
The compound obtained foaming agent composite powder of composite foamable agent, wherein composite foamable agent selects the first phase foaming agent Barium azodicarboxylate, the
Two-phase foaming agent sodium acid, made foaming agent composite powder particle diameter distribution D50 value are 8.5 microns.It is 2.5 by melt flow rate (MFR)
Acrylic resin and foaming agent composite powder according to mass ratio 10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and
230 DEG C of maximum temperature at a temperature of carry out injection molding, be made product density be 0.85g/cm3。
Embodiment 8
The foaming agent composite powder in acrylic resin and above-described embodiment 7 for being 20 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.92g/cm that product density, which is made,3。
Embodiment 9
Using high-speed impact airslide disintegrating mill by mass percent be 95% talcum powder and mass percent be 5%
The compound obtained foaming agent composite powder of composite foamable agent, wherein composite foamable agent select the first phase foaming agent for 5- phenyl tetrazole,
Second phase foaming agent sodium acid, made foaming agent composite powder particle diameter distribution D50 value are 8.5 microns.It is by melt flow rate (MFR)
2.5 acrylic resin and foaming agent composite powder according to mass ratio 10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization,
And 230 DEG C of maximum temperature at a temperature of carry out injection molding, be made product density be 0.84g/cm3。
Embodiment 10
The foaming agent composite powder in acrylic resin and above-described embodiment 9 for being 20 by melt flow rate (MFR) is according to mass ratio
10:1 180 DEG C of the highest temperature at a temperature of carry out extruding pelletization, and 230 DEG C of maximum temperature at a temperature of carry out injection molding,
It is 0.90g/cm that product density, which is made,3。
The foregoing is merely better embodiment of the invention, protection scope of the present invention is not with above embodiment
Limit, as long as those of ordinary skill in the art's equivalent modification or variation made by disclosure according to the present invention, should all be included in power
In the protection scope recorded in sharp claim.