Full density polyethylene high-efficiency catalyst by using gas phase method
The present invention relates to a kind of polyolefine high-performance solid catalyzer that can be applicable to low-pressure vapor phase and slurry polymerization process, and the method for preparing this catalyzer.This catalyzer is specially adapted to vapor phase process ethylene homo or copolymerization.
As everyone knows, the Ziegler-natta catalyst of for olefines polymerization comprises a kind of compound (as titanium tetrachloride) of transition metal and the compound (as magnesium chloride) of magnesium, in the presence of promotor organometallic compound triethyl aluminum, can carry out the polymerization of alpha-olefin.
Introduce in the United States Patent (USP) 4438019, magnesium powder, titanium tetrachloride, titanium propanolate and chloro-butane reaction are made the catalyzer that is used for olefinic polymerization, though the initial activity height of this catalyzer, polymerization process tends to cause hot spot, make the polyethylene vitreous clinker, perhaps cause granules of catalyst to pulverize.For head it off, introduce in the United States Patent (USP) 4894424, in catalyst preparation process, add an amount of moisture content, make the suitable passivation of catalyzer, with the initial rate that reduces polyreaction, prevent that focus from producing and block poly generation, reaches the purpose of polyreaction stable operation.This type of catalyst preparation process is complicated, has made active high catalyzer on the one hand, and water destroys part activity again on the one hand.For this reason in the European patent 376559, in unstripped gas, constantly add micro-passivator such as oxygen etc., limiting too high catalyst reaction activity, but because the passivator aequum is few, and the add-on time to time change, so be difficult to detect and control.In the Chinese patent 87100304, because it is very wide with above-mentioned method for preparing catalyst gained granules of catalyst size distribution, the polyethylene form that generates is not good, need prepared catalyzer is eluriated for this reason, remove crossing thick or meticulous catalyst particle, and the elutriation process needs the very long cycle, makes catalyst loss very big.
In United States Patent (USP) 4487346, be to be raw material with dialkyl magnesium, make spherical magnesium chloride support with the chloro-butane reaction, and then transition metal halides such as active ingredient such as titanium tetrachloride are loaded on this magnesium chloride support, though can obtain the magnesium chloride support of narrow distribution of particle sizes, but this starting raw material of dialkyl magnesium is to be difficult to make, so the catalyzer problem of olefinic polymerization is the problem that people thirst for solving always.
The objective of the invention is with the magnesium powder is raw material, generates the solvay-type magnesium halide carrier with reducing power, and the method with dipping prepares catalyzer with active constituent loading on carrier again.This catalyzer has that preparation process is simple, the polyreaction initial activity is low, reacting balance, catalytic activity height, resulting polymers particle shape are good, the characteristics of no fine powder.Solved ethene fluctuation of service in gas-phase polymerization processes, polyethylene product easily lumps, the problem that dust is many.
In order to realize this purpose, the present invention at room temperature adds to the magnesium powder to stir in the alkane solvent that contains a small amount of halogen or aluminum alkyls to carry out the activation of magnesium powder in 1~10 hour, the alkane medium can be aliphatics or aromatic hydrocarbon polymer or its mixture that contains 5~10 carbon atoms, as Skellysolve A, iso-pentane, normal hexane, octane, sherwood oil (60~80 ℃), benzene etc.The halogen that adds in alkane can be an iodine.Aluminum alkyls can be triethyl aluminum, aluminium diethyl monochloride etc.
Magnesium powder after the activation and haloalkane (RX) are in the time of 10~100 ℃, and preferably 20~80 ℃ of initiation reactions make alkyl halide magnesium (RMgX), and R is the alkyl group that contains 3~12 carbon atoms, and X is a halogen, preferably chlorine.Haloalkane can be chloro-propane, chloro-butane, chloro-iso-butane, chloro iso-pentane.The adding of haloalkane is better with the dropping form, and haloalkane slowly is added drop-wise in the hydrocarbon medium of process activatory magnesium under stirring state.The dropping time is 0.5~10 hour, and the best dropping time is 1~8 hour.Dropwise the back and continue reaction 0.5~10 hour, be preferably 1~8 hour.
After generating RMgX, add electron donor ED.In the presence of electron donor, when 10~100 ℃ of temperature of reaction, best temperature of reaction is 20~80 ℃, further generates solvay-type magnesium halide carrier (RMgX) p(MgX with reducing power with the haloalkane reaction
2) q(ED) s.P: q: s=0.01~1: 1: 0.01~2.0 wherein, ED is an electron donor, at least containing the organic compound of a Sauerstoffatom and/or a nitrogen-atoms, be in a liquid state under 25 ℃, can be to contain the aliphatics of 3~8 carbon atoms or aromatic ether, ester, amine, alkylol cpd.As N, N dimethyl formamide, N, N dimethylcyclohexylamine, N, N diethyl cyclohexylamine, N, N dimethyl benzylamine, diethyl ether, tetrahydrofuran (THF), ethyl acetate, ethyl benzoate, butyl alcohol-tert, isopropylcarbinol etc., that best is N, N dimethylcyclohexylamine and tetrahydrofuran (THF).The adding of haloalkane still with the dropping form for well, the time of dropping is 0.5~10 hour, the best dropping time is 1~8 hour.Dropwise the back and continue reaction 0.5~10 hour, be preferably 1~8 hour.The carrier that generates is the solvay-type carrier with reducing power, and its size is even, particle spherical in shape.The carrier of gained washs three times with hydrocarbon medium.
In the presence of electron donor, in solvay-type halo reactive magnesium liquid, add haloalkyl aluminium R ' nAlX
3-N or zinc alkyl(s) R '
2It is the compound of lower valency that Zn, the RMgCl in carrier reduce the maxivalence attitude transistion metal compound that adds later.Temperature of reaction is 10~100 ℃, preferably 20~80 ℃.R ' is the alkyl group that contains 2~8 carbon atoms, and n is 1~3.Electron donor contains the organic compound of an oxygen, sulphur, nitrogen, phosphorus atom at least, can be ether, ester, amine, alcohol, thioether, sulfone, sulfoxide, tertiary phosphine etc.Aluminum alkyls can be triethyl aluminum, aluminium diethyl monochloride, dichloro one aluminium triethyl, sesquialter, triisobutyl aluminium, tri-n-octylaluminium etc.Zinc alkyl(s) can be a zinc ethyl etc.Usage quantity is electron donor/transition metal=0.1~10 mol, Al/ transition metal=0.1~20 grammeatom, zinc/transition metal=0.1~20 grammeatom.
With dipping method one or more IV, V, VI group 4 transition metal halogenide are loaded on the solvay-type magnesium halide carrier with reducing power in liquid hydrocarbon medium then, dipping temperature is 10~130 ℃, and best dipping temperature is 20~80 ℃.In the solid of dipping back gained, transition metal/Mg=0.1~1 grammeatom.Described IV, V, VI group 4 transition metal halogenide are the halogenide that contains titanium or vanadium.To contain titanium halide be Ti(OR ") m Cl
4-M, " be the alkyl group that contains 3~4 carbon atoms, m=0~4 are as titanium tetrachloride, metatitanic acid n-propyl, tetrabutyl titanate, methoxyl group titanous chloride, dibutoxy titanium dichloride, butoxy titanous chloride etc. for R in the formula.The vanadium containing brine thing is VXa, VOXa
-2, X is halogen, a=4~5 in the formula, as vanadium tetrachloride, five vanadium chlorides, vanadium oxytrichloride etc.
It is best with the dropping that transition metal halide adds form, at first transition metal halide and the aliphatics that contains 5~10 carbon atoms or aromatic hydrocarbon polymer such as iso-pentane, normal hexane etc. are mixed mutually, under dipping temperature, one side stirs one side and slowly is added drop-wise in the reaction solution that contains carrier, organometallic compound, electron donor, hydrocarbon medium then.The dropping time is 0.5~10 hour, dropwises the back and continues to stir 0.5~10 hour, and best dipping time is 2~8 hours, and transition metal halide can be loaded on the carrier complex compound with reducing power securely.
Last resulting solid catalyst with containing liquid hydrocarbon washings such as the aliphatics of 5~10 carbon atoms or aromatic hydrocarbon polymer such as iso-pentane, normal hexane, heptane three times, just makes the high activated catalyst that is applicable to olefinic polymerization.This catalyzer does not need to add the active passivation agent with water treatment or in polymerization process, and it is low just to have initial activity, and polymerization temperature is easy to control, reacting balance, no caking phenomenon.Because temperature is even during polyreaction, and temperature is acutely raise, granules of catalyst can not cause pulverizing because of overheated, thereby produces a large amount of fine powders, does not produce so catalyzer of the present invention has the following fine powder polymkeric substance of 200 orders when being used for olefinic polymerization.
In gas-phase method total density polyolefine method for preparing high-efficient catalyst of the present invention, among the alkyl halide magnesium RMgX, best R is the alkyl group of 3~6 carbon atoms, as chloro-butane, chloro-iso-butane.Solvay-type magnesium halide carrier (RMgX) p(MgX
2) q(ED) among the s, the best proportioning of p: q: s is 0.05~0.3: 1: 0.05~1.0.Best Al/Ti or the grammeatom ratio of Zn/Ti are 0.5~5.Best Ti/Mg grammeatom ratio is 0.15~0.6.
Its compositing range of for olefines polymerization effective catalyst that uses the present invention to make is:
Ti
Thirty0.8~1.0 grammeatom
Total 1 grammeatom of Ti
Mg 2.0~5.0 grammeatom
Cl 7.0~14.0 grammeatom
Owing to catalyzer of the present invention has the certain granules degree, having that load Ti, V compound make on the magnesium chloride complexing carrier of reducing power, so the granularity of catalyzer is narrowly distributing also, this has just been avoided the elutriation technology of catalyzer, simplified catalyst preparation process, and the polyethylene particle form that can obtain again.
By the solid catalyst that the inventive method makes, can select for use one or more organometallic compounds such as organic zinc, organic-magnesium, organo-aluminium compound as promotor.Be directly used in the presence of promotor in the polymerization or copolyreaction of alkene, promotor can be zinc ethyl, magnesium ethide, trimethyl aluminium, triethyl aluminum, three hexyl aluminium, triisobutyl aluminium, aluminium diethyl monochloride, ethyl aluminum dichloride etc.The usage quantity of promotor is metal/transition metal in the promotor=1~100, preferably 2~50.
Solid catalyst of the present invention can be directly used in olefinic polymerization or copolymerization, also can obtain giving the aggressiveness catalyzer through giving polymerization earlier, is used further to polyreaction.Give the polymeric better effects if, so that the reinforced and reaction process when making the particle form of catalyzer more be adapted to gas fluidised bed polymerisation.Giving polyreaction can carry out in inert liquid medium or carry out under drying regime.Temperature is 0~100 ℃, with 10~90 ℃ for better, stagnation pressure is 0.1~0.5MPa.Giving polyreaction is to carry out in the presence of above-mentioned promotor, obtains 5~200 grams usually and gives aggressiveness/gram catalyzer, and preferably 10~100 grams give aggressiveness/gram catalyzer.
Common employed comonomer is the aliphatics alpha-olefin that contains 3~8 carbon atoms, suitable alpha-olefin has propylene, butene-1, amylene-1, hexene-1,4-methylpentene-1, heptene-1 and octene-1, and best alpha-olefin is propylene, butene-1, hexene-1 and 4-methylpentene-1.In vinyl polymerization the usage quantity of comonomer be total gas volume 0.5~50% between adjustable, thereby obtain the polyethylene of various density.It is 0.91~0.96 gram per centimeter that catalyzer of the present invention can make density
3High, medium and low density polyethylene product.
For the melting index of telomerized polymer, can use chain-transfer agent usually, the most frequently used is hydrogen, employed amounts of hydrogen can total gas volume 0.5~80% between adjustable, thereby obtain the polyethylene of various melting index.
Use polymerization catalyst of the present invention active high, catalyst activity is 3000~10000 gram polyethylene/gram catalyzer, stable polymerization reaction, and heat release is even, hydrogen is transferred responsive, copolymerization performance is good, the polymkeric substance prevented from caking, and the polymer beads of gained is even, no fine powder produces, not less than 200 purpose powders, the tap density height has the value of suitability for industrialized production.
Illustrate the present invention with embodiment below, but and do not mean that restriction the present invention.
Embodiment 1:
1. Preparation of Catalyst
In 500 milliliters of round bottom glass reactors that have agitator, condenser, liquid-drop machine and a heating unit, add 360 ml n-hexanes, 0.5 gram iodine, 6.5 gram magnesium powder, at room temperature stir 2 hours activating powders then.
Under 60 ℃, 34 milliliters of n-propylcarbinyl chlorides slowly are added drop-wise in the reactor, dropwise the back and add 20 milliliters of tetrahydrofuran (THF)s.Cool to 40 ℃, and then drip 16 milliliters of n-propylcarbinyl chlorides, dropwise the back at 40 ℃ of following isothermal reactions 8 hours, (BuMgCl) that obtains
0.15(MgCl
2)
1(ED)
0.9Support of the catalyst is washed three times with normal hexane.
In reactor, add 17.5 milliliters of tetrahydrofuran (THF)s, 15 milliliters of triethyl aluminums.The mixture that will be dissolved in gram titanium tetrachloride of 12 in 100 ml n-hexanes and 4 gram tetrabutyl titanates slowly is added drop-wise under 30 ℃ in the reactor, reacts 3 hours down at 30 ℃ then.Cooling back with normal hexane with prepared catalyst detergent three times, analyze resulting catalyzer hexane slurry liquid, wherein contain titanous 170 mmoles/liter, total titanium amount 170 mmoles/liter, Mg content 568.7 mmoles/liter, cl content 1642 mmoles/liter, Mg/Ti=3.35 grammeatom, Cl/Ti=9.66 grammeatom.
2. give polymerization
The catalyzer that adds 600 ml n-hexanes, 0.5 milliliter of triethyl aluminum and 7 milliliters of above-mentioned preparations in the stainless steel reactor under a nitrogen protection that has an agitator.Add 0.05MPa nitrogen, 0.1MPa hydrogen and 0.15MPa ethene then.85 ℃ of polyreactions 4 hours, give polymers heat drying under vacuum with what obtain, make and give aggressiveness catalyzer 45 grams.
3. with the butene-1 copolyreaction
Adopt 100 millimeters gas-phase fluidized-bed reactors of ф, recycle gas consists of ethene 0.45MPa, hydrogen 0.45MPa, butene-1 0.28MPa, add 100 gram base-materials in the reactor earlier, above-mentioned aggressiveness catalyzer 4 grams that give that make are joined in the reactor, add polyethylene 9 grams that are loaded with triethyl aluminum again and carry out copolyreaction, polymerization temperature is 90 ℃, and polymerization time is 4 hours, obtains 340 gram multipolymers after copolyreaction finishes.The result who obtains is: catalyst activity 5000 gram polyethylene/gram catalyzer, MI 11.3 grams/10 minutes, density 0.92 grams per milliliter, tap density 0.36 grams per milliliter, product does not lump, less than the fine powder content below 120 orders<0.2%, there is not the following fine powder of 200 orders.
Embodiment 2:
1. Preparation of Catalyst
In 500 milliliters of round bottom glass reactors that have agitator, condenser, Liquid titrator and a heating unit, add 300 ml n-hexanes, 0.5 gram iodine and 6.03 gram magnesium powder, at room temperature stir 2 hours activating powders.
Under 50 ℃, 25.89 milliliters of n-propylcarbinyl chlorides are slowly joined in the reactor, dropwised afterreaction 1 hour, add 14 milliliters of N again, N dimethylcyclohexylamine and then drip 16 milliliters of n-propylcarbinyl chlorides.Dropwise the back at 30 ℃ of reactions 8 hours, (BuMgCl) that obtains having reducing power
0.25(MgCl
2)
1(ED)
0.2Support of the catalyst is washed three times with normal hexane.
Under 30 ℃, in above-mentioned reactor, add 3 milliliters of N, N dimethylcyclohexylamine, 9 milliliters of triethyl aluminums will be dissolved in the gram of 11.96 in 100ml normal hexane titanium tetrachloride and be added drop-wise in the reactor, dropwise the back 30 ℃ of reactions 8 hours.With prepared catalyst detergent three times, analysis of catalyst consists of with normal hexane for cooling back: titanous 152 mmoles/liter, total titanium amount 154 mmoles/liter, Mg content 563.8 mmoles/liter, cl content 1603.4 mmoles/liter, magnesium/titanium=3.66 grammeatom, chlorine/titanium=10.41 grammeatom.
2. give polymerization
In having the stainless steel cauldron of stirring, under nitrogen protection, add 600 ml n-hexanes, 0.5 milliliter of triethyl aluminum and 7 milliliters of above-mentioned catalyzer.Add 0.05MPa nitrogen, 0.1MPa hydrogen and 0.15MPa ethene then.85 ℃ of following polyreactions 4 hours, take out polymerization product, obtain giving aggressiveness catalyzer 50 grams after the drying.
3. with the butene-1 gas phase copolymerization
Adopt the gas-phase fluidized-bed reactor of 100 millimeters of ф to carry out the copolymerization of ethene and butene-1, circulation gas consists of ethene 0.45MPa, hydrogen 0.45MPa, butene-1 0.28MPa, the above-mentioned aggressiveness catalyzer that gives of 4.12 grams is joined in the fluidized-bed reactor, 90 ℃ of following copolyreaction 4 hours obtain 320 gram multipolymers.The result who obtains is: catalyst activity 5500 gram polyethylene/gram catalyzer, MI 9.8 grams/10 minutes, density 0.918 grams per milliliter, tap density 0.39 grams per milliliter.
Product does not lump, no fine powder.
Embodiment 3:
1. Preparation of Catalyst
Obtain having the solvay-type carrier (BuMgCl) of reducing power by embodiment 1 identical method
0.15(MgCl
2)
1(ED)
0.9
In reactor, add 4 milliliters of tetrahydrofuran (THF)s and 6.5 milliliters of zinc ethyls, will be dissolved in the gram of 12 in 100 ml n-hexanes titanium tetrachloride and under 50 ℃, slowly join in the reactor, dropwise the back and continue reaction 3 hours.Cooling back is with normal hexane washing catalyst three times, analyze contain in the resulting catalyzer normal hexane slurry titanous 156.4 mmoles/liter, total titanium amount 160 mmoles/liter, cl content 1503.8 mmoles/liter, Mg content 537 mmoles/liter, magnesium/titanium=3.36 grammeatom, chlorine/titanium=9.40 grammeatom.
2. give polymerization
Giving polymerization by embodiment 1 identical method obtains exsiccant and gives aggressiveness catalyzer 44 gram.
3. vinyl polymerization
Carry out the polyreaction of ethene in 100 millimeters gas-phase fluidized-bed reactors of ф, add the above-mentioned aggressiveness catalyzer 4.1 that gives that makes and restrain.It is 100 ℃, polymerization time 4 hours that circulation gas consists of ethene 0.45MPa, hydrogen 0.65MPa, temperature of reaction.Obtain 369 gram polyethylene products after reaction finishes, its result is: catalyst activity 5400 gram polyethylene/gram catalyzer, MI 10.76 grams/10 minutes, density 0.962 grams per milliliter, tap density 0.45 grams per milliliter.
Embodiment 4:
1. Preparation of Catalyst
Obtain having the solvay-type carrier (BuMgCl) of reducing power by embodiment 1 identical method
0.15(MgCl
2)
1(ED)
0.9
In reactor, add N, 9.2 milliliters, 14 milliliters triethyl aluminums of N dimethyl formamide, to be dissolved in down the gram titanium tetrachloride of 4 in 100 ml n-hexanes and 4.34 gram tetrabutyl titanates slowly are added drop-wise in the reactor at 45 ℃, stirring reaction was continued 4 hours in the dropping back, normal hexane washing catalyst three times of cooling back.Analyze contain in the resulting catalyzer normal hexane slurry titanous 165.6 mmoles/liter, total titanium 166 mmoles/liter, magnesium 546.7 mmoles/liter, chlorine 1484.7 mmoles/liter, magnesium/titanium=3.29 grammeatom, chlorine/titanium=8.94 mmoles/liter.
2. polyreaction
Adopt 100 millimeters gas-phase fluidized-bed reactors of φ, recycle gas consists of ethene 0.5MPa, hydrogen 0.4MPa, butene-1 0.3MPa.Add 100 gram base-materials in the reactor earlier, 0.2 milliliter of the above-mentioned catalyst slurry liquid that makes is carried on the 20 gram polyethylene, join then in the reactor, add polyethylene 10 grams that are loaded with triethyl aluminum again and carry out copolyreaction.Temperature of reaction is that 90 ℃, time are 4 hours.After finishing, copolyreaction obtains polyethylene copolymerization product 298 grams, the result who obtains is: catalyst activity 6000 gram polyethylene/gram catalyzer, MI 10.9 grams/10 minutes, density 0.919 grams per milliliter, tap density 0.37 grams per milliliter, the polyreaction stable operation, product does not lump, less than the fine powder content below 120 orders<0.2%, there is not the following fine powder of 200 orders.
Embodiment 5:
1. Preparation of Catalyst
In 500 milliliters of round bottom glass reactors that have agitator, condenser, liquid-drop machine and a heating unit, add 360 ml n-hexanes, 0.51 gram iodine, 6.3 gram magnesium powder, at room temperature stir 2 hours activating powders then.
Under 60 ℃, 23 milliliters of n-propylcarbinyl chlorides are slowly joined in the reactor, after dropwising, add 27 milliliters of N again, the N dimethyl formamide.Be cooled to 45 ℃, and then drip 20 milliliters of n-propylcarbinyl chlorides, after dropwising,, obtain (BuMgCl) 45 ℃ of following constant temperature 8 hours
0.85(MgCl
2)
1(ED)
1.3Support of the catalyst is washed three times with normal hexane.
In reactor, add 4.5 milliliters of tetrahydrofuran (THF)s, 14.5 milliliters of triethyl aluminums.The mixture that will be dissolved in gram titanium tetrachloride of 12.4 in 100 ml n-hexanes and 4.26 gram tetrabutyl titanates slowly is added drop-wise under 30 ℃ in the reactor, reacts 4 hours down at 30 ℃ then.Cooling back with normal hexane with prepared catalyst detergent three times, analyze resulting catalyzer hexane slurry liquid, wherein contain titanous 172 mmoles/liter, total titanium amount 172 mmoles/liter, Mg content 573.1 mmoles/liter, cl content 1221 mmoles/liter, Mg/Ti=3.33 grammeatom, Cl/Ti=7.10 grammeatom.
2. give polymerization
The catalyzer that adds 600 ml n-hexanes, 0.5 milliliter of triethyl aluminum and 7 milliliters of above-mentioned preparations in the stainless steel reactor under a nitrogen protection that has an agitator.Add 0.05MPa nitrogen, 0.1MPa hydrogen and 0.15MPa ethene then.85 ℃ of following polyreactions 5 hours, give polymers heat drying under vacuum with what obtain, obtain 41 grams and give the aggressiveness catalyzer.
3. with the butene-1 copolyreaction
Adopt the gas-phase fluidized-bed reactor of 100 millimeters of φ, recycle gas consists of ethene 0.45MPa, hydrogen 0.45MPa, butene-1 0.28MPa.Add 100 gram base-materials in the reactor earlier, above-mentioned aggressiveness 4 grams that give that make are joined in the reactor, add polyethylene 8.5 grams that are loaded with triethyl aluminum again and carry out copolyreaction.Polymerization temperature is 90 ℃, and polymerization time is 4 hours.After finishing, copolymerization obtains 220 gram multipolymers.The result who obtains is: catalyst activity 3080 gram polyethylene/gram catalyzer, and MI 7.1 grams/10 minutes, density 0.924 grams per milliliter, tap density 0.32 grams per milliliter, product does not lump, no fine powder.