CN104693379A - Propylene block-propylene polymer and preparation method thereof - Google Patents

Abstract

The invention provides a propylene block-propylene polymer and a preparation method thereof. The propylene block-propylene polymer contains a powdered polyethylene homopolymer block and a propylene polymer synthesized by using powdered polyethylene homopolymer block as an initiator. The preparation method is that the powdered polyethylene homopolymer block is added to a high-pressure kettle type agitating reactor; the discontinuous or continuous liquid phase bulk polymerization process is adopted; the quantitative liquid phase propylene is adopted under an agitating state; a catalyst, additives and the quantitative liquid phase propylene are sequentially polymerized, so as to prepare propylene block-propylene polymer powder. The propylene block-propylene polymer is outstanding in low temperature impact resistance and high in strength. The preparation method solves the shortage that the discontinuous liquid phase bulk polymerization polypropylene process cannot be used for producing copolymerization block polypropylene; therefore, the preparation method has a good application prospect.

Description

Polyethylene block-propene polymer and preparation method thereof

Technical field

The present invention relates to polyethylene block-propene polymer and preparation method thereof, belong to macromolecular material and synthesis of polymer material technical field.

Background technology

Polyethylene (PE) is one of five large synthetic resins, is the kind that in China's synthetic resins, production capacity is maximum, import volume is maximum.Polyvinyl resin is nontoxic, tasteless white powder or particle, and outward appearance is creamy white, and have the feel of ceraceous, water-intake rate is low, is less than 0.01%.Polyethylene film is transparent, and reduces with the raising of degree of crystallinity.Polyethylene is mainly divided into linear low density polyethylene, Low Density Polyethylene, high density polyethylene(HDPE) three major types erosion resistance, and electrical insulating property (especially high-frequency insulation) is excellent, can chlorination, radiation modification, and available glass fiber strengthens.The fusing point of low pressure polyethylene, rigidity, hardness and intensity higher, water-absorbent is little, has good electrical property and radiation resistance; The flexibility of high-pressure polyethylene, elongation, shock strength and perviousness better; Ultrahigh molecular weight polyethylene(UHMWPE) shock strength is high, and antifatigue is wear-resisting.Low pressure polyethylene is suitable for making corrosion-resistant part and insulating part; High-pressure polyethylene is suitable for making film etc.; Ultrahigh molecular weight polyethylene(UHMWPE) is suitable for making damping, wear-resisting and driving parts.Linear low density polyethylene main application fields is plastic sheeting for farm use, packing film, electric wire, tubing, coated products etc.

Polyethylene polymerization production technique: mainly contain high pressure tubular method and autoclave method two kinds.For reducing temperature of reaction and pressure, tubular process generally adopts low temperature high activity to draw agent initiated polymerization system, take high-purity ethylene as main raw material, with propylene/propane etc. for density adjusting agents, use high reactivity initiator about 200 DEG C ~ 330 DEG C, carry out polyreaction under 150-300MPa condition.The molten polymer of initiated polymerization in reactor, must through high pressure, middle pressure and low pressure cooling, be separated, cycle of higher pressure gas is through overcooling, ultra-high voltage (300MPa) suction port of compressor is sent into after separation, Medium pressure cycle gas is through overcooling, high pressure (30MPa) suction port of compressor is sent into after separation, and low pressure recycle gas is through overcooling, send into low pressure (0.5MPa) compressor cycle after separation to utilize, and molten polyethylene is through high pressure, low pressure sends into tablets press after being separated, carry out pelletizing in water, when granulation, enterprise can according to different application field, add suitable additive, particle dispatches from the factory through packaging.

Polypropylene is the polymkeric substance of nontoxic, odorless, tasteless oyster white height crystallization, and density only has 0.90--, and " 0.91g/cm3 is one of kind the lightest in current all plastics.It is stable especially to water, and the water-intake rate in water is only 0.01%, molecular weight about 80,000 one 15 ten thousand.Good moldability, but because of shrinking percentage large (being 1% ~ 2.5%). thick article easily caves in, and to the higher part of some dimensional precisioies, is difficult to reach requirement, product surface good luster, is easy to painted.

Polypropylene is a kind of thermoplastic resin obtained by propylene polymerization.Isotatic polypropylene, Atactic Polypropelene and syndiotactic polypropylene three kinds is divided into by methyl arrangement position.The same side that methyl is arranged in molecular backbone chain claims isotatic polypropylene, if the chaotic both sides being arranged in molecular backbone chain of methyl claim Atactic Polypropelene, the both sides being arranged alternately in molecular backbone chain when methyl claim syndiotactic polypropylene.In the acrylic resin that general industry is produced, isotactic structural content is about 95%, and all the other are random or syndiotactic polypropylene.Industrial products with isotactic thing for main component.

Polypropylene also comprises the polymkeric substance of propylene and a small amount of ethene.Be generally translucent colorless solid, odorless is nontoxic.The highly crystallized due to compound with regular structure, therefore fusing point can up to 167 DEG C.Heat-resisting, corrosion-resistant, the sterilization of goods used vapour is its outstanding advantages.Density is little, is the lightest general-purpose plastics.

The absolute value of Mechanical Properties of PP higher than polyethylene, but still belongs to kind on the low side in a plastic material, and its tensile strength only can reach 30MPa or slightly high level.The polypropylene that isotactic index is larger has higher tensile strength, but with the raising of isotactic index, the shock strength of material declines to some extent, but no longer changes after dropping to a certain numerical value.Temperature and loading rate very large to polyacrylic Toughness.When temperature is higher than second-order transition temperature, impact fracture is ductile rupture, be brittle rupture, and impact value significantly declines lower than second-order transition temperature.Improve loading rate, the temperature that ductile rupture can be made to change to brittle rupture rises.

Polypropylene has excellent flexural fatigue resistance, its goods bent 106 times and do not damage at normal temperatures.Polypropylene has good thermotolerance, and goods temperature to carry out disinfection sterilizing more than 100 DEG C, and not by under the condition of external force, 150 DEG C also indeformable.Embrittlement temperature is-35 DEG C, embrittlement can occur lower than-35 DEG C, and winter hardiness is not as polyethylene.Under room temperature and low temperature, because the molecular structure regularity of itself is high, so resistance to impact shock is poor.

Polypropylene manufacturing process: 1. slurry process.Polymerization in the thinner (as hexane), is industrialization the earliest, is also the method that turnout is maximum so far.2. liquid phase noumenal method.Under 70 DEG C of conditions with 3MPa, be polymerized in liquid propene.3. vapor phase process.Be polymerized under propylene is gaseous condition.Latter two method does not use thinner, and flow process is short, and energy consumption is low.Liquid phase noumenal method has now demonstrated the advantage of catching up from behind.

Polypropylene copolymer, PolypropyleneCopolymer, being called for short PPC, is the multipolymer of propylene monomer and vinyl monomer; According to the distribution mode of vinyl monomer on molecular chain, copolymerization PP can be divided into random copolymers (PPR) and segmented copolymer (PPB) two kinds.The good rigidly of PPH, but shock-resistance is bad, and especially low-temperature impact resistance is more bad, and creep resistant is poor.The shock-resistance of PPB is good, but creep resistant is the same with PPH poor.The shock-resistance of PPR and creep resistant are then all good.

Copolymer type PP material has lower heat-drawn wire (100 DEG C), low transparency, low-luster, low rigidity, but has stronger resistance to impact shock, and the shock strength of PP increases along with the increase of ethylene content.The vicat softening temperature of PP is 150 DEG C.Because degree of crystallinity is higher, surface rigidity and the anti-scratch characteristic of this material are fine.There is not environmental stress cracking problem in PP.Polyacrylic degree of crystallinity is high, compound with regular structure, thus has excellent mechanical property.

In the polymkeric substance that propylene, ethylene copolymer obtain, because the random distribution of ethene and polypropylene segments makes the degree of crystallinity of thing reduce.The vinyl monomer of block copolymerization 2%-3% can obtain Propylene polymerization rubber, can the low-temperature impact of resistance to-30 DEG C.The features such as then become random copolymers when ethylene content reaches 30%, have degree of crystallinity low, impact property is good, and the transparency is good.

The production method of polypropylene copolymer can be divided into two kinds according to the difference of catalyzer, and one is metallocene catalyst, and a kind of is the Ziegler-Natta effective catalyst improved.It only has an active centre to metallocene catalyst compared with Ziegler-Natta catalyst, and Ziegler-Natta catalyst has multiple avtive spot.Use control molecular weight and distribution thereof that metallocene catalyst can be more accurate, co-monomer content and the distribution on polymer molecular chain thereof and crystalline texture.Its advantage of modification by copolymerization that Ziegler-Natta catalyst is applied to PP is that production technique is simple, energy consumption is low, can improves macromolecular one-tenth nuclearity, improves the performance of polymkeric substance.

The features such as having of polypropylene pipe is lightweight, corrosion-resistant, non-scaling, long service life.Homo-polypropylene (PP-H), block copolymerization polypropylene (PP-B) and atactic copolymerized polypropene (PP-R) can be divided into according to different PP polymerization process conditions.Because PP-H tubing fragility at low temperatures limits its use, some Application Areass gradually by PP-B tubing, PP-R pipe replace.

Propylene-ethylene random copolymer, that the mixed gas of propylene and ethene is carried out copolymerization, obtain the random multipolymer being dispersed with propylene and ethene segment in main chain, in Propylene-ethylene random copolymer, ethylene content 1-4%(adopts advanced gas phase copolymerization process, makes ethene random homogeneous polymerization in the molecular chain of propylene).PP-R is obtained by the copolymerization under heating, pressurization and catalyst action of propylene monomer and a small amount of vinyl monomer, and vinyl monomer is random, be distributed in the long-chain of propylene randomly.Ethene random adds the degree of crystallinity that reduces polymkeric substance and the performance of the aspect such as fusing point, the impact improving material, long-term resistance to hydrostatic pressure, long-term heat oxygen aging resistance and tubular object extruding be shaping.

Propylene-ethylene block copolymer, adopt Ziegler-Natta catalyst, mud synthesis technique, after single propylene polymerization, remove unreacted propylene with vinyl polymerization, generation be the mixture of polypropylene, polyethylene and end-blocks multipolymer, the rigidity that this mixture had both maintained to a certain degree turn improves shock strength, but the transparency and glossiness decrease, and the specific performance of segmented copolymer depends on the structure of the content of ethene, copolymerized block.Ethylene content in PP-B is generally 7 ~ 15%.The probability linked together due to two vinyl monomers in PP-B and three monomers is very high, therefore illustrate due to vinyl monomer only exist block mutually in, the regularity of PP-H is not reduced, thus do not reach the object of the performance improving the aspects such as PP-H fusing point, long-term resistance to hydrostatic pressure, long-term heat oxygen aging resistance and tubular object extruding be shaping.

Gap bulk polypropylene production technique be China from last century late nineteen seventies early eighties develop voluntarily, the history of existing three more than ten years so far.The finished product of gap bulk polypropylene are Powdered or spherical polypropylene.The advantage of interval hypoxic training technique: technical process is simple, adopts single still batch operation; Raw material sources are extensive, can be that raw material is produced with crude propylene; Power consumption cost is low; Plant investment is economized, and instant effect is good in economic efficiency; During product can meet, low-grade goods needs; The three wastes are few, environmental pollution is little.There is less investment, the construction period be short, tooling cost is low, (recouping capital outlay) significantly feature of producing effects.

Do not add any other solvent in reaction system, catalyzer is directly dispersed in liquid propylene, carry out liquid phase bulk propylene polymerization reaction.Polymkeric substance is separated out from liquid propylene, be suspended in liquid propylene with fine particulate, along with the growth in reaction times, the concentration of polymkeric substance in liquid propylene increases, when propylene conversion acquires a certain degree, retrieve the propylene monomer be polymerized through flash distillation, namely obtain powder polypropylene product, this is a kind of fairly simple and advanced polypropylene industrial working system.Gap bulk polypropylene device is in China close to 100 covers, and annual production accounts for more than 1/3 of domestic polypropylene ultimate production.

Interval hypoxic training technique with the main identical point of continuous processing is: overall procedure is identical, namely by part compositions such as feed purification, propylene polymerization, propylene recovery and flash distillation deactivations, this is determined by identical production principle, be propylene under Ziegler-Natta System Catalyst, the tactic polymerization reaction carried out in liquid-phase bulk, and all adopt third generation effective catalyst, therefore the impurity in the raw material such as propylene all has identical disadvantageous effect to reaction, need before polymerization to refine, guarantee that foreign matter content is qualified.

The powder quality of interval hypoxic training technique and continuous processing does not have significant difference in degree of isotacticity, apparent density.But in product ash content, the trade mark and quality stability etc., there is larger difference, cause the larger difference of conforming product rate, high-grade-goods rate, controllable rate.The quality product of continuous processing is highly stable, as MFR can be controlled within the scope of target value ± 0.2g/10min, can ensure the relatively stable of user's processing conditions and smooth operation; Intermittent type PP can not ensure metastable quality product.This species diversity is by the mode of production (continuously with intermittently) and automatic controlling extent is different determined, and then the difference determined in product application, continuous P P technique can produce many trades mark expensive goods, and intermittent type PP technique generally can only produce the low grade products such as woven bag.

Summary of the invention

The present invention is directed to currently available products, the deficiency of technology and interval hypoxic training technique can not the shortcoming of production Co-polypropylene, has invented the preparation method of polyethylene block-propene polymer and polyethylene block-propene polymer.

Technical scheme of the present invention is:

Polyethylene block-propene polymer is the polyethylene block-propene polymer powder comprising powder Natene block and synthesize for initiator with powder Natene block, the preparation method of polyethylene block-propene polymer is characterized in that: Natene powder joins pressure autoclave type and stirs in polymerization reactor, adopt interval liquid-phase bulk polymerization technique or Continuous Liquid Phase bulk technique, at whipped state with quantitative polymerization-grade liquid propylene successively by activator, three components and efficient polypropylene catalyst pour pressure autoclave type and stir in polymerization reactor, catalyzer, activator, three components is adsorbed on Natene powder surface and quantitative polymerization-grade liquid propylene polymerization reaction take place, to reaction end, preparation production polyethylene block-propene polymer powder, reclaim simultaneously and replace unreacting propylene.

Described powder polyethylene block is high density polyethylene(HDPE) homopolymer powder, or low density polyethylene homopolymer powder, or the mixture of low density polyethylene homopolymer powder and high density polyethylene(HDPE) homopolymer powder.

The ratio that described powder polyethylene block add-on accounts for all prods quality is 3%-45%.

Adopt interval liquid-phase bulk polymerization technique, this technique adds quantitative Natene powder to stir in polymerization reactor to pressure autoclave type, add quantitative high-purity hydrogen, add quantitative polymerization-grade liquid propylene again, whipped state with quantitative polymerization-grade liquid propylene successively by activator triethyl aluminum, three components dimethoxydiphenylsilane and CS type or the efficient polypropylene catalyst of N-type pour pressure autoclave type and stir in polymerization reactor, catalyzer, activator, three components is adsorbed on Natene powder surface with quantitative polymerization-grade liquid propylene then through heating up, constant temperature polymerization stage, to reaction end, reclaim unreacting propylene, material spray is to flash vaporization kettle, discharging after flash distillation and displacement unreacting propylene, preparation production polyethylene block-propene polymer powder.

Adopt Continuous Liquid Phase bulk technique; This technique is in batching kettle, add quantitative Natene powder, and a small amount of triethyl aluminum activator, efficient polypropylene catalyst successively pour in batching kettle and mix by the quantitative polymerization-grade liquid propylene of whipped state; Then joining pressure autoclave type continuously stirs in polymerization reactor, Natene powder and quantitative polymerization-grade liquid propylene through constant temperature polyreaction to reaction end, through reclaiming unreacting propylene and recycle, preparation production polyethylene block-propene polymer powder.

The advantage of technical scheme of the present invention is:

1, the feed postition optimization of ethene, changes Natene powder into by the vinyl monomer in past, and make polyethylene block-propene polymer product performance more perfect, product category is abundanter.

2, the feed postition optimization of ethene, changes Natene powder into by the vinyl monomer in past, makes the production control of tank reactor, rolled product variety adjustment, steady quality become and be more prone to carry out, reduces load and the complexity of equipment.

3, the feed postition optimization of ethene, Natene powder is changed into by the vinyl monomer in past, can be applied in the Continuous Liquid Phase bulk technique of tank reactor, the product that tank reactor is produced is more diversified, greatly reduces the quantity of transitional product.

4, adopt powder Natene block and propylene to carry out copolymerization, can give full play to the advantage of batch liquid phase bulk polymerization technique, solving batch liquid phase bulk polymerization technique can not the difficult problem of production Co-polypropylene.

5, adopt powder Natene block and propylene to carry out copolymerization, batch liquid phase bulk polypropylene plant in product diversification, meet client's rapid adjustment in needs especially, obtain better economic benefit.

Embodiment

Describe the present invention in detail below in conjunction with embodiment, but protection scope of the present invention is not limited to embodiment.

Embodiment 1

Polyethylene block-propene polymer special material for tube (melt mass flow rate MFR=1.2-2.0)

Polyethylene block-propene polymer special material for tube (MFR=1.2-2.0) is the Natene powder comprising melt mass flow rate MFR=1.2-2.0 is block, and powder Natene block is the polyethylene block-propene polymer powder of initiator synthesis.

Melt mass flow rate MFR=1.2-2.0 Natene powder is joined pressure autoclave type to stir in polymerization reactor by the preparation method of polyethylene block-propene polymer special material for tube (MFR=1.2-2.0), adopt interval liquid-phase bulk polymerization technique, at whipped state with quantitative polymerization-grade liquid propylene successively by activator triethyl aluminum, three components dimethoxydiphenylsilane and efficient polypropylene catalyst (CS type, or N-type) pour in pressure autoclave type stirring polymerization reactor, catalyzer, activator, other auxiliary agent is adsorbed on Natene powder surface and quantitative polymerization-grade liquid propylene polymerization reaction take place, to reaction end, preparation production polyethylene block-propene polymer powder.

Powder polyethylene block is high density polyethylene(HDPE) homopolymer powder, MFR=1.2-2.0.

The ratio that high density polyethylene(HDPE) homopolymer powder add-on accounts for all prods quality is 3%-7%.

For batch liquid phase bulk 12 cubic metres of polymerization reaction kettles, preparation polyethylene block-propene polymer special material for tube (MFR=1.2-2.0) method is as follows:

1, after getting through flow process, when need feed intake and fine propylene by basin by transferpump, mass flowmeter metering feed intake by normal dosing procedure.

2, stirring is started by polymeric kettle schedule of operation.

3, hydrogenation: first open on polymeric kettle and add valve on hydrogen line, controls hydrogenation to specifying pressure drop with surge flask outlet valve, then closes hydrogenation valve on still.

4, throw propylene: drive valve on activator hopper simultaneously, throw 3m3 propylene and enter polymeric kettle.Valve on the activator hopper of complete pass, leaves standstill 3min, enters after still until liquid propylene, valve under the activator hopper of pass, and activator hopper pressure is let out pipe network.

5, throw three components: tear catalyst hooper plug open, with propylene blowback twice, guarantee unimpeded, add quantitative three components, tighten plug.First drive catalyst hooper propylene feed valve, then drive lower valve simultaneously, rush three components with 1m3 propylene and enter still.Complete, close valve in charging, leave standstill 1 minute, after liquid propylene all enters still, valve under the catalyst hooper of pass, lets out overbottom pressure and enters pipe network.

6, activator is thrown: activator test tank fills smart nitrogen 0.1 ~ 0.2MPa(gauge pressure), open activator hopper activator feed valve, control the quantitative activator material bin of force feed with activator test tank outlet valve, close hopper activator feed valve.Drive valve under activator hopper propylene feed valve and hopper simultaneously, rush activator with 3m3 propylene and enter polymeric kettle.Complete, close propylene feed valve, leave standstill 3min, after liquid propylene all enters still, then pass is descended valve and lets out overbottom pressure to enter pipe network.

7, throw catalyzer: tear catalyst hooper plug open, drive smart nitrogen inlet valve, keep pressure-fired in hopper.Catalyzer sub-bottling, on its mouth, pulls up bottle stopper rapidly, is all added in material bin by bottle inner catalyst, closes smart nitrogen valve, tightens plug, first drives catalyst hooper propylene feed valve, then opens valve under hopper simultaneously, rushes catalyzer enter polymeric kettle with 1m3 propylene.Complete, close propylene feed valve, leave standstill 1min, after liquid propylene all enters still, then pass is descended valve and lets out overbottom pressure to enter pipe network.

8, polymerization heats up

Drive hot water tank steam valve, control hot water tank temperature 75 ~ 80 DEG C.

Close cold water variable valve and drive hot water variable valve, regulate hot water amount, control heating-up time: 30 ~ 50min.Front 15 ~ 20min heats up to hot water, closes hot water variable valve, heat up voluntarily, drive cold water variable valve to control increasing temperature and pressure speed when still temperature reaches 63 DEG C by reaction heat when Jacket outlet water temperature reaches 70 DEG C, counts the reaction times when still temperature reaches 70 DEG C.

9, thermostatic control

Regulate quantity of circulating water, control still temperature 77 ± 1 DEG C, still pressure 3.6 ± 0.1MPa or 3.4 ± 0.1MPa.When pressure rate of growth is very fast, open cycle water by-pass controls, if uncontrollable, then takes urgent recovery or emptying control.

10, reaction end judges

According to following 3 points, comprehensive descision reaction end: the constant and still drops of a still temperature or still temperature rise and still pressure is constant; B stir current obviously increases, about 50 ~ 60A; C reaction times 2 ~ 3.5h.

11, propylene recovery

Reaction reaches terminal, and contact refining post Propylene recovery, drives propylene recovery valve on still, controls to reclaim downstream pressure 1.7 ~ 1.9MPa(gauge pressure), recovery time 15 ~ 25min, as still pressure drop to 1.2 ~ 1.7MPa, closes recovery valve on still.In removal process, regulate recirculated water control valve, controlling still middle portion temperature is 40 ~ 55 DEG C.After the recovery valve of pass in 2min, still internal pressure goes up and is no more than 0.2MPa, and stir current is greater than 60A, represents and reclaims completely.

Tear catalyst hooper plug open, with gas-phase propene blowback in still 2 ~ 3 times, notice flash distillation post material spray.

Material spray is complete, strengthens quantity of circulating water and lowers the temperature to polymeric kettle, prepares next still and produces.

Embodiment 2

Polyethylene block-propene polymer injection moulding PP Pipe Compound (melt mass flow rate MFR=3.0)

Polyethylene block-propene polymer special material for tube (MFR=3.0) is the Natene powder comprising melt mass flow rate MFR=3.0 is block, and powder Natene block is the polyethylene block-propene polymer powder of initiator synthesis.

Melt mass flow rate MFR=1.2-2.0 Natene powder is joined pressure autoclave type to stir in polymerization reactor by the preparation method of polyethylene block-propene polymer special material for tube (MFR=3.0), adopt interval liquid-phase bulk polymerization technique, at whipped state with quantitative polymerization-grade liquid propylene successively by activator triethyl aluminum, three components dimethoxydiphenylsilane and efficient polypropylene catalyst (CS type, or N-type) pour in pressure autoclave type stirring polymerization reactor, catalyzer, activator, other auxiliary agent is adsorbed on Natene powder surface and quantitative polymerization-grade liquid propylene polymerization reaction take place, to reaction end, preparation production polyethylene block-propene polymer powder.

Powder polyethylene block is high density polyethylene(HDPE) homopolymer powder, MFR=3.0.

The ratio that high density polyethylene(HDPE) homopolymer powder add-on accounts for all prods quality is 3%-5%.

For batch liquid phase bulk 12 cubic metres of polymerization reaction kettles, preparation polyethylene block-propene polymer special material for tube (MFR=3.0) method steps is with embodiment 1.

Embodiment 3

Polyethylene block-propene polymer high-impact PP Pipe Compound (melt mass flow rate MFR=20)

Polyethylene block-propene polymer high-impact PP Pipe Compound (MFR=20) is the Natene powder comprising melt mass flow rate MFR=20 is block, and powder Natene block is the polyethylene block-propene polymer powder of initiator synthesis.

Powder polyethylene block is high density polyethylene(HDPE) homopolymer powder, MFR=20.

The ratio that high density polyethylene(HDPE) homopolymer powder add-on accounts for all prods quality is 7%-9%.

Adopt three still Continuous Liquid Phase bulk techniques; This technique is in 2-3 batching kettle, add quantitative melt mass flow rate (MFR)=20 Natene powder, and a small amount of organoaluminum, other auxiliary agent, efficient polypropylene catalyst successively pour in batching kettle and mix by the quantitative polymerization-grade liquid propylene of whipped state; Then joining first, second pressure autoclave type continuously stirs in polymerization reactor, Natene powder and quantitative polymerization-grade liquid propylene through constant temperature polyreaction to reaction end, through reclaiming unreacting propylene and recycle, preparation production polyethylene block-propene polymer high-impact PP Pipe Compound (MFR=20).

Claims (5)

1. polyethylene block-propene polymer and preparation method thereof, is characterized in that: polyethylene block-propene polymer is the polyethylene block-propene polymer powder comprising powder Natene block and synthesize for initiator with powder Natene block, the preparation method of polyethylene block-propene polymer is characterized in that: Natene powder joins pressure autoclave type and stirs in polymerization reactor, adopt interval liquid-phase bulk polymerization technique or Continuous Liquid Phase bulk technique, at whipped state with quantitative polymerization-grade liquid propylene successively by activator, three components and efficient polypropylene catalyst pour pressure autoclave type and stir in polymerization reactor, catalyzer, activator, three components is adsorbed on Natene powder surface and quantitative polymerization-grade liquid propylene polymerization reaction take place, to reaction end, preparation production polyethylene block-propene polymer powder, reclaim simultaneously and replace unreacting propylene.

2. polyethylene block-propene polymer as claimed in claim 1 and preparation method thereof, it is characterized in that: described powder polyethylene block is high density polyethylene(HDPE) homopolymer powder, or low density polyethylene homopolymer powder, or the mixture of low density polyethylene homopolymer powder and high density polyethylene(HDPE) homopolymer powder.

3. polyethylene block-propene polymer as claimed in claim 1, is characterized in that: the ratio that described powder polyethylene block add-on accounts for all prods quality is 3%-45%.

4. the preparation method of polyethylene block-propene polymer as claimed in claim 1, is characterized in that: adopt interval liquid-phase bulk polymerization technique, this technique adds quantitative Natene powder to stir in polymerization reactor to pressure autoclave type, add quantitative high-purity hydrogen, add quantitative polymerization-grade liquid propylene again, whipped state with quantitative polymerization-grade liquid propylene successively by activator triethyl aluminum, three components dimethoxydiphenylsilane and CS type or the efficient polypropylene catalyst of N-type pour pressure autoclave type and stir in polymerization reactor, catalyzer, activator, three components is adsorbed on Natene powder surface with quantitative polymerization-grade liquid propylene then through heating up, constant temperature polymerization stage, to reaction end, reclaim unreacting propylene, material spray is to flash vaporization kettle, discharging after flash distillation and displacement unreacting propylene, preparation production polyethylene block-propene polymer powder.

5. the preparation method of polyethylene block-propene polymer as claimed in claim 1, is characterized in that: adopt Continuous Liquid Phase bulk technique; This technique is in batching kettle, add quantitative Natene powder, and a small amount of triethyl aluminum activator, efficient polypropylene catalyst successively pour in batching kettle and mix by the quantitative polymerization-grade liquid propylene of whipped state; Then joining pressure autoclave type continuously stirs in polymerization reactor, Natene powder and quantitative polymerization-grade liquid propylene through constant temperature polyreaction to reaction end, through reclaiming unreacting propylene and recycle, preparation production polyethylene block-propene polymer powder.