CN103788456B

CN103788456B - For the functional master batch and preparation method thereof of modification high-density polyethylene

Info

Publication number: CN103788456B
Application number: CN201410042105.3A
Authority: CN
Inventors: 孙斌; 俞强; 丁永红; 苏中悦; 曹世波
Original assignee: JIANGSU SHENGTONG ENVIRONMENT ENGINEERING Co Ltd
Current assignee: JIANGSU SHENGTONG ENVIRONMENT ENGINEERING Co Ltd
Priority date: 2014-01-28
Filing date: 2014-01-28
Publication date: 2016-04-06
Anticipated expiration: 2034-01-28
Also published as: CN103788456A

Abstract

The invention discloses a kind of functional master batch for modification high-density polyethylene and preparation method thereof, with weight parts, described functional master batch comprises following component: polyolefin elastomer 5 ~ 20; Mineral filler 0 ~ 80; Dispersion agent 3 ~ 10.Described preparation method comprises the following steps: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir; Mixed material is added twin screw extruder and carries out granulation; The material strip extruded sends into dicing machine drying after water-cooled.The present invention can improve environmental stress cracking resistance and the ring stiffness of heavy caliber hdpe pipe; And reduce its production cost.

Description

For the functional master batch and preparation method thereof of modification high-density polyethylene

Technical field

The present invention relates to PE modified method, especially a kind of functional master batch for modified poly ethylene and preparation method thereof.

Background technology

High density polyethylene(HDPE) (HDPE) tubing has excellent physical strength and corrosion resistance nature, have light weight in addition concurrently, tube wall is smooth, price is low and the feature such as easy for installation, has therefore been widely used in upper and lower conduit for building, agricultural irrigation and drainage pipes, gas pipe and blow-off pipe etc.But HDPE is a kind of material very responsive to environmental stress cracking.Tubing, when being subject to combined stress effect or contacting with surrounding medium, easily cracks on surface, rapidly brittle cracking occurs subsequently.In many application field boundary institutes, the destruction of HDPE tubing is all owing to there is crackle in long-term internal pressure situation and cause in tubing bearing.So resisting environmental stress and cracking (ESCR) performance of HDPE tubing directly affects the work-ing life of tubing.

Heavy caliber HDPE tubing refers to the tubing of internal diameter at 500mm, and this kind of tubing has important application in fields such as urban water supply and sewerage engineering, urban engineering project and environmental engineerings.To requiring to include of heavy caliber HDPE tubing use properties: intensity and ring stiffness: the ability of namely bearing load under buried environment; Stopping property: namely do not reveal, prevents environmental pollution; Work-ing life: namely require tubing resistance to chemical attack, resistance to wear, resisting environmental stress and cracking; Be convenient to lay and install.In use needing enough ring stiffness and creep-resistant property to meet heavy caliber HDPE tubing, requiring that polyethylene raw material has higher yield strength and modulus in flexure.In order to meet HDPE tubing Long Service Life (50 years), require that tubing raw material must have excellent environmental stress cracking resistance.

The method of current solution HDPE tubing resisting environmental stress and cracking mainly contains three kinds:

The first, in HDPE resin synthesis process, by improvement of production process, improve the molecular weight of HDPE resin, reduce molecular weight distribution and form side chain on molecular chain, thus improve the environmental stress cracking resistance of HDPE resin.

The second, in molding process by the crystallisation process of controlled cooling model speed control HDPE, reduce degree of crystallinity, and obtain careful crystalline texture, thus improve goods environmental stress cracking resistance.

Aforesaid method, while improving HDPE tubing environmental stress cracking resistance, also brings disadvantageous effect to other performances of goods.Such as, improve molecular weight and HDPE resin treatment mobility can be caused to be deteriorated with the increase degree of branching, products machinery intensity reduces; By regulate melt temperature, cooling temperature and cooling time crystallization control speed, shaping cycle can be made to extend, production cost increase.

Summary of the invention

Goal of the invention: provide a kind of functional master batch for modification high-density polyethylene, to solve the problem.Another object of the present invention is to provide a kind of method preparing above-mentioned functions masterbatch.

Technical scheme: a kind of functional master batch for modification high-density polyethylene, with weight parts, comprises following component: polyolefin elastomer 5 ~ 20; Mineral filler 0 ~ 80; Dispersion agent 3 ~ 10.

Described mineral filler is by fibrous BaSO ₄with spherical CaCO ₃composition.Described dispersion agent comprises ethylene-vinyl acetate copolymer and linear low density polyethylene.Described fibrous BaSO ₄with spherical CaCO ₃weight ratio be 2:1 ~ 1:1.

The preparation method of the above-mentioned functional master batch for modification high-density polyethylene, comprises the steps:

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 5 ~ 15min; Stirring velocity is 700 ~ 1400r/min; Temperature 80 DEG C ~ 90 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 400 ~ 600r/min, the temperature of six heating zones and machine head port mould is respectively: 140 ± 2 DEG C, 180 ± 2 DEG C, 200 ± 2 DEG C, 205 ± 2 DEG C, 205 ± 2 DEG C, 210 ± 2 DEG C, 210 ± 2 DEG C;

S3, pelletizing and drying: the material strip extruded sends into dicing machine drying after water-cooled, drying temperature is 70 ~ 80 DEG C.

Beneficial effect: the present invention can improve the mechanical property such as environmental stress cracking resistance and ring stiffness of heavy caliber hdpe pipe; Reduce its production cost, and do not extend its production cycle.

Embodiment

Embodiment 1

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 10; Mineral filler 20; Dispersion agent 5.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 1:1 composition; Dispersion agent is ethylene-vinyl acetate copolymer.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 10min; Stirring velocity is 1000r/min; Temperature 85 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 500r/min, the temperature of six heating zones and machine head port mould is respectively: 140 DEG C, 180 DEG C, 200 DEG C, 205 DEG C, 205 DEG C, 210 DEG C, 210 DEG C;

S3, pelletizing and drying: the material strip extruded sends into dicing machine drying after water-cooled, drying temperature is 75 DEG C.

Embodiment 2

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 10.5; Mineral filler 50; Dispersion agent 6.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO ₃by weight being 2:1 composition; Dispersion agent is ethylene-vinyl acetate copolymer.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 15min; Stirring velocity is 1400r/min; Temperature 90 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 600r/min, the temperature of six heating zones and machine head port mould is respectively: 142 DEG C, 180 DEG C, 200 DEG C, 205 DEG C, 205 DEG C, 210 DEG C, 212 DEG C;

S3, pelletizing and drying: the material strip extruded sends into dicing machine drying after water-cooled, drying temperature is 80 DEG C.

Embodiment 3

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 20; Mineral filler 80; Dispersion agent 10.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 1.5:1 composition; Dispersion agent is linear low density polyethylene.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 5min; Stirring velocity is 1400r/min; Temperature 80 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 550r/min, the temperature of six heating zones and machine head port mould is respectively: 140 DEG C, 180 DEG C, 200 DEG C, 203 DEG C, 204 DEG C, 212 DEG C, 208 DEG C;

S3, pelletizing and drying: the material strip extruded sends into dicing machine drying after water-cooled, drying temperature is 70 DEG C.

Embodiment 4

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 9; Mineral filler 60; Dispersion agent 8.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 1:1 composition; Dispersion agent is EVA.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 12min; Stirring velocity is 1000r/min; Temperature 90 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 400r/min, the temperature of six heating zones and machine head port mould is respectively: 139 DEG C, 180 DEG C, 202 DEG C, 205 DEG C, 205 DEG C, 208 DEG C, 210 DEG C;

Embodiment 5

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 5; Mineral filler 10; Dispersion agent 3.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 2:1 composition; Dispersion agent is ethylene-vinyl acetate copolymer.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 10min; Stirring velocity is 900r/min; Temperature 85 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 600r/min, the temperature of six heating zones and machine head port mould is respectively: 140 DEG C, 180 DEG C, 200 DEG C, 205 DEG C, 205 DEG C, 210 DEG C, 212 DEG C;

Embodiment 6

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 12; Mineral filler 60; Dispersion agent 4.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 1:1 composition; Dispersion agent is ethylene-vinyl acetate copolymer.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 8min; Stirring velocity is 850r/min; Temperature 90 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 550r/min, the temperature of six heating zones and machine head port mould is respectively: 140 DEG C, 182 DEG C, 202 DEG C, 205 DEG C, 205 DEG C, 212 DEG C, 210 DEG C;

Embodiment 7

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 12; Mineral filler 70; Dispersion agent 9.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 3:2 composition; Dispersion agent is linear low density polyethylene.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 8min; Stirring velocity is 1300r/min; Temperature 85 DEG C;

S2, twin-screw extrusion: mixed material is added twin screw extruder and carries out granulation, extruder screw rotating speed 400 ~ 600r/min, the temperature of six heating zones and machine head port mould is respectively: 140 DEG C, 180 DEG C, 200 DEG C, 205 DEG C, 205 DEG C, 210 DEG C, 210 DEG C;

Embodiment 8

For a functional master batch for modification high-density polyethylene, with weight parts, comprise following component: polyolefin elastomer 16; Mineral filler 12; Dispersion agent 7.Wherein, mineral filler is by fibrous BaSO ₄with spherical CaCO3 by weight being 1:1 composition; Dispersion agent is ethylene-vinyl acetate copolymer.

S1, batch mixing: weigh polyolefin elastomer particle, mineral filler and dispersion agent according to part by weight, put into high-speed mixer and stir, churning time is 15min; Stirring velocity is 1200r/min; Temperature 90 DEG C;

Functional master batch prepared by Example 1 to 8, carry out modification to HDPE, related data is as shown in the table:

	1	2	3	4	5	6	7	8
									Functional master batch content %	20	25	20	30	20	25	30	20
Functional master batch density	1.62	1.7	1.65	1.6	1.63	1.65	1.6	1.7
									Melt flow rate (MFR)	3.0	5.0	4.5	3.5	4.0	3.0	5.0	3.0
Tensile strength	26.5	27.5	28.3	28.1	27.2	25.7	26.5	27.1
									Elongation at break	355	340	365	350	355	360	330	345
Modulus in flexure	830	825	825	840	795	805	825	830
									Shock strength	49.5	48.5	52.2	50.8	51.5	50.8	52.4	53.6
Color	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous
									Outward appearance	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified
Ring stiffness	4	5	4.5	4	6	4	5	5.5
									Ring is flexible	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified
Baking oven is tested	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified	Qualified

Table 1

Note: in table 1, the unit of correlation parameter and measurement standard are as shown in Table 2-4:

Table 2

Table 3

Table 4

Above-described embodiment 1 to 8 and table 1 known to 4: the matrix resin that adopts polyolefin elastomer (POE) to be functional master batch, while carrying mineral filler, improve the toughness of HDPE.The POE of graininess demonstrates the advantages such as thermal deformation is little, good in optical property, easy and other mixed with polymers, good with polyolefine affinity, low-temperature flexibility is good in the above-described embodiments.

Polyolefin elastomer in HDPE external phase, forms " sea-island " structure, when blend is subject to External Force Acting as dispersed phase distribution, elastomerics is as stress concentration thing, cause crazing and shear zone, absorb a large amount of energy, thus the shock strength of blend is improved.POE improves comparatively large to the shock strength of blend, toughness is improved obviously, and LLDPE is relatively low.This is because POE has better elasticity, and with the structural similitude of HDPE, solubility parameter is close, and therefore consistency is good.Blend flexural strength and the rigidity conservation rate of POE modification are better.POE has obvious toughening effect, less on the impact of flexural strength.

Adopt spherical and multiple its coordinated of merga pass of fibrous mineral filler, improve functional master batch to the activeness and quietness effect of HDPE.The Young's modulus of material and resin nature and the reinforcing filler character adopted relevant.Above-described embodiment significantly improves the ring stiffness of tubing by the Young's modulus adopting the excellent mineral filler of reinforced effects and improve tubing, can also reduce production cost.

CaCO ₃powder is nearly spherical-like morphology, CaCO ₃particle diameter less, be more conducive to improving the toughening effect of masterbatch.BaSO ₄there is crystal whisker-shaped structure, fibrous BaSO ₄length-to-diameter ratio larger, be more conducive to improving the reinforced effects of masterbatch.The two is carried out composite use, many performances such as tensile strength, modulus in flexure, heat conductivity of matrix material can improved to a greater extent, make functional master batch better play effect to HDPE activeness and quietness.Using POE as the matrix resin of functional master batch, adopt fibrous BaSO ₄with spherical CaCO ₃two kinds of inorganic powders are composite as mineral filler.Between its surface and polyolefin base resin, form firmly interface cohesion, the intensity of compound system and toughness are increased substantially.By fibrous BaSO ₄with spherical CaCO ₃compound is carried out in mineral filler, can play the larger BaSO of length-to-diameter ratio simultaneously ₄enhancement and spherical CaCO ₃toughening effect, obtain the good matrix material of comprehensive mechanical property.

EVA and LLDPE makes mineral filler dispersed in HDPE matrix, avoids micromolecule additive to the negative impact of tubing environmental stress cracking resistance.Adding of dispersion resin makes calcium carbonate distribute in resin more evenly, and the bonding force between mineral filler and matrix resin is also enhanced.Dispersion resin consumption increases, and can carry out coated then evenly spreading in matrix resin, so mechanical property improves better to calcium carbonate.

In above-mentioned preparation method, should be noted that following problem:

Batch mixing: the object of batch mixing is to make raw material mix, and dispersion agent is all coated on filler and vector resin.This technique adopts batch production mode.In order to obtain the functional master batch of stable performance, to control mixing time, stirring velocity and reinforced sequencing in batch mixing process.

Mixing time controls to be even more important, and the too short meeting of mixing time makes to disperse between raw material uneven, material foaming easily occurs when extruding, and material strip attenuates; Mixing time is too short also can make filling surface process insufficient, directly affects the quality of product.Mixing time is long, raw material can be made to form bulk, not easily blanking.The change of main detection machine electric current during batch mixing operation, if electric current becomes suddenly large, illustrates that raw material is mixed real, can discharging.Take POE as the filling master batch mixing procedure of vector resin, general mixing time is high-speed mixing 10 minutes.Reinforced order is generally first how rear few, and first granular rear powdery, what batch mixing can be made like this to become is easier, mixes more abundant between raw material.In addition, barrel and the upper cover of high-speed mixer to be checked when starting batch mixing, if having last time batch mixing remain under powder or block, they be cleaned out, otherwise batch mixing quality can be affected.

Twin-screw extrusion: twin screw extruder rotates to implement shear-mixed and transmission effect to material by two screw rods in ∞ font heating cylinder.Screw rod can be divided into engagement and non-engagement type, combination and not combined, rotating Vortex and counter rotating, usually with engagement type in the same way and incorgruous engagement type use more, we adopt engagement type in the same way in the art.

Need to carry out following work before carrying out extruding operation:

A, order according to material characteristic arrangement screw element, for different masterbatch, should take the combination of different screw element, otherwise it is uneven easily to cause material to disperse when extruding, or material cannot can not squeeze out.

Screw element arrangement fundamental principle:

Melt zone: adopt shape dish and kneading disk as hybrid element, they can accelerate melting and the mixing of material.In addition, forward delivery element is generally adopted to separate hybrid element in practice, to avoid producing larger thermograde in melting zone.

Mixing section: adopt arrow gauge and less stagger arrangement angle element to increase the distributed rendering of each component in material; Wide sheet, larger stagger arrangement angle element, left-handed conveying kneading disk or multiple tooth toothed disc is adopted to increase dispersing and mixing.

Exhaust section: arrange left-hand thread element before venting port, forms the shutoff to melt, makes material be full of screw channel.The coarse pitch delivery element of groove depth is set in the middle of exhaust section.

Melt conveying zone: adopt turbine mixing element to improve the homogenizing quality of melt, adapted fine pitch screwing element strengthens forward transport capacity simultaneously.

B, the processing parameter of forcing machine is correctly set

Technique arranges mistake will directly affect the quality of masterbatch, even can make forcing machine overflow or squeeze not discharging.At feeding section, for avoiding the blocking of loading channel, relatively low temperature will be kept.At metering zone, the homogeneity of moiety and temperature be guaranteed.Material should have enough residence time.Another part and parcel is the driving mechanism of forcing machine.It controls the speed of rotation of screw rod, and the speed of rotation of screw rod decides the output of forcing machine.Required power is then determined by the resistance to flow of polymkeric substance.

C, forcing machine to be cleaned out, choose head filtering net

At extruder head, filter screen is installed, impurity is blocked on filter screen.The filtering net of forcing machine is fixed on the protecting sheet of a porous or groove, can make like this to form sealing between forcing machine and mould.The pressure that clean filtering net produces is less, and along with the increase of pressure, the amount of impurities in the resin that filtering net retains just becomes many, thus clog filter screens, when the true pressure of head is soon close to rated pressure, can there is chaser in forcing machine.For avoiding stopping work, filter screen should be able to be changed automatically.When processing the resin with impurity, such as reclaimed materials, this point particularly important.

Woven wire is the most frequently used metal filtration net materials of forcing machine.Generally, filtering net mesh (in other words the wire number of per inch) is 20 ~ 150 or more.The filtering net of 20 meshes is thicker; The filtering net of 40 ~ 60 meshes is thinner; The filtering net of 80 ~ 150 meshes is then very meticulous.The mounting means of filtration unit is: the most coarse filter screen is facing to protecting sheet, and the thinnest filter screen is then in the face of forcing machine.Such as, the filter screen arrangement mode from protecting sheet to forcing machine may be 20 mesh/60, mesh/40 meshes, because this arrangement can prevent filter screen to be blocked, and impurity " can be blown into " in the perforate of protecting sheet.If the thinnest filter screen is the mesh of 80 or more, be melted the rotary motion of material to prevent this filter screen or large impurity blocks, then before a coarse filter screen can being put into (such as the arrangement of 20/100/60/20 mesh).Because this type of device is same from both sides read fortune, so in order to ensure that they can not be reversed, symmetrical decoration form (20 mesh/20, mesh/60, mesh/100, mesh/60 mesh) also can be adopted.

The pressure of head to be noted at any time, if strainer filtering is to large stretch of foreign material, the pressure of forcing machine can be made like this to reach peak value rapidly.So, in order to prevent above-mentioned situation from occurring, the security systems such as such as blowout disk, shearing pin or the warning that is connected with tensimeter must be had.Be also noted that the vacuum condition of forcing machine in addition, if vacuum meter display is lower or without vacuum, material strip can foam, porose, serious time draw not slivering.

Pelletizing and drying: adopt water cooling bracing pelletizing mode, tank temperature is crucial Con trolling index.Tank temperature is too high, and the tangent plane of the particle be cut into has burr, affects product attractive in appearance.Be also noted that the water level in tank in addition, be difficult to pull out bar when water is few, even and if the bar pulled out come also easily to break.

Control dicing machine speed consistent with forcing machine rate of feeding.The blank speed inharmonious material strip that will make of feeding that is too fast and forcing machine attenuates, and the particle cut out is slender type.Pelletizing speed easily blocks the bearing in dicing machine too slowly, and the particle cut out can be elongated, affects granular mass.

The pellet cut is put into dryer and carries out sufficient drying, dryer temperature is set to 90 DEG C, and drying time will be suitable for, can not too short can not be oversize, it is higher that too short meeting makes masterbatch remain moisture content, causes masterbatch to have vesicle to produce when processed finished products, thus affect quality and the outward appearance of product.Drying time is oversize, masterbatch can be caused to turn to be yellow and even lump.The drying time of this technique controls at 0.5 to 2.5 hour, is preferably 1 hour.

More than describe the preferred embodiment of the present invention in detail; but the present invention is not limited to the detail in above-mentioned embodiment, within the scope of technical conceive of the present invention; can carry out multiple equivalents to technical scheme of the present invention, these equivalents all belong to protection scope of the present invention.

It should be noted that in addition, each the concrete technical characteristic described in above-mentioned embodiment, in reconcilable situation, can be combined by any suitable mode.In order to avoid unnecessary repetition, the present invention illustrates no longer separately to various possible array mode.

In addition, also can carry out arbitrary combination between various different embodiment of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.

Claims

1., for a preparation method for the functional master batch of modification high-density polyethylene, it is characterized in that,

With weight parts, the functional master batch for modification high-density polyethylene is composed of the following components: polyolefin elastomer 5 ~ 20; Mineral filler 0 ~ 80; Dispersion agent 3 ~ 10; Described mineral filler is by fibrous BaSO ₄with spherical CaCO ₃composition; Described dispersion agent comprises ethylene-vinyl acetate copolymer and linear low density polyethylene; Described fibrous BaSO ₄with spherical CaCO ₃weight ratio be 2:1 ~ 1:1;

Comprise the steps: