CA2116752A1 - Process for preparing a poly-1-olefin - Google Patents

Abstract

Abstract Process for preparing a poly-1-olefin By means of a highly active spherical Ziegler catalyst based on a dialkylmagnesium, spherical polymers can be obtained in the polymerization of alpha-olefins. A
further advantage of the catalyst of the invention lies in the high catalyst activity, so that only vary small amounts of the catalyst are required for the polymeriza-tion. The residual titanium and/or zirconium content in the polymers prepared according to the invention is less than 10 ppm. Owing to its good responsiveness to hydro-gen, the catalyst is particularly suited to two-stage processes for preparing polymers having a broad bimodal molecular weight distribution. The replacement of sulfur-containing electron donors such as diethyl sulfite by alcohols such as ethanol leads to less odor problems and broadened opportunities for use of the polymer. Owing to the spherical shape of the particles and the associated very good flow behavior of the polymers and copolymers, considerable simplification and advantages in handling, drying and processing are achieved.

Description

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O~CHST ARTIENGES~LLSCHAFT HOE 93/F 065 Dr. DA/wo De3cription Proces~ ~or preparing a poly-1-olefin The in~ention relates to a proces~ for preparing a spherical poly-1-olafin by mean~ of a highly active ~pherical Ziegler cataly~t.
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A large number of cataly~t~ of the Zlegler typo for the , polymerization of alpha-olo~ins are already known. Many of the~e cataly~ts ars ba~ed on a magno~ium chloride support material obtained by reaction of an organo-magnesium compound with a compound R'-Cl, such as tetrachloro-methane (cf. US 4 442 225, US 4 439 539, UE 30 10 202).

However, this reactio~ doe~ not make it po~ible to ;- obtain a magne~iu~ chloride having apherical particle~. :

' it 15 On the other hand, it i~ known that Epher~cal magneeium ~l chloride 1~ formed on reaction of an organomag~3~ium compound R2Mg with an organic chlorino compound R'-Cl in i'~ the pre~ence of an organoaluminu~ compouAd, ~uch a~
~i triethylalu~inum, ~nd an olectron donox co~pou~d, ~uch a~
.~ 20 diisoamyl ether (cf. EP 99 284). R' hias to bo a hydro-carbon radical with thrse or more carbon atom~ and the carbon atom adjacent to the ohlorins ha~ to be either ~econdary or tertiary azrbon ato~.

Proces~es are also known in which spherical Ziegler as catalysts are formed by reaction of an organo~agnesium ~i! compound (e.g. ~BOMAG-A, Witco GmbH) with an organic chlorine compound, an electron donor and a tran~ition metal compound (c~. EP 249 869, WO 9 200 332). In the~e cases, el~ctron donors aro required for binding the transition ~etal component.

It has now been found that highly aGtive spherical . `!
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` ',~, ' ' :;i ,'~- ' . ~ ' - ' ~-~ 1 i i 7 j r~l ~ - 2 -: Ziegler cataly~t c~n be prepared by r~action of the reaction product of an org~nomagnesium compound, an organic chlorine compound and, if de~ired, an organo-~' aluminum compound with alcohols and tran~ition metal aompounds, although the alcohol can al80 be omitted. It has also been found that the catalyat can bo parti~ul~rly ~; advantageously u~ed in a gas-phase polymorization pro-, ce~.
., The invention accordingly providea a process for prepar-ing a polyolefin by polymerization of lpha-olefin~ at a :~ temperature from 50 to 150C and a pre~ure from 1 to : 40 bar in the presence of a catalyst ~ompri~ing a transi-:~i` tion metal component (component A) and an organometallic . compound (component B), eaid component A having boen o~tained by :, ~ a) reaction of an organomagnesium compound of the formula R1~MgR22~, in which Rl and R2 are identical or different : alkyl radicals having from 2 to 12 carbon ato~e and x is a number between 0 and 2, with an filiphatl~ primary .'' 20 chlor~nated hydrocarbon in an amount fro~ 0.5 to 2.5 mol of the chlorinated hydrocarbon per 1 mol of .`, the organomagne~ium compound and, ~f de~lr~d, an organomaluminum co~pound of the formula AlR3n(0R4)3n, `~Jj in which R3 and R~ are identical or difforent al~yl ~"
~:~',!, 25 radical~ having from 1 to 8 carbon atom~ and n ic 0, 1, 2 and 3, or the reaction product of trialkyl~
aluminums or dialkylaluminu~ hydrlde~ wlth diolefins containing from 4 to 20 carbon ato~e~ at a to~perature from 30 to 110C, b) treatment of the solid obtainad with an alcohol in an :l amount fro~ 0.001 to 1 mol per gram atom of ~agne~ium conta~ned in the ~olid at a temperature from -20 to 150C, ~nd c) reaction of the support material thus obtained with ~`' 35 one or more compound~ of the formula MlX~(ORs)~, in .

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~ which M1 i8 titanium or zirconium, Rs ~8 an alkyl radical ha~ing ~rom 2 to 10 carbon atom~, X i~ a haloyen atom and m i~ an intoger from 0 to 4, in an - amount from 0.1 to 5 mol par gram atom of magno~um contained in the support material at a te~perature - from 20 to 180C, '' or by carrying out ~tep~ a and c with omission of b, or ~i by ~imultaneou~ly carrying out atep~ k and c.

First, a i~pherical ~olid i8 formed. For this purpo8e, an i~ 10 organomagne~ium co~pou~d is reacted with an organic chlorine com~ound and, ~f de~ired, an organoaluminum compound.

~l The organomagne~ium compound i~ a dialkylmagnesium of the formula R1iMgR2~, in which Rl a~d R2 are idantical or different alkyl radical~ hi~ving from 2 to 12 carbon tom~
and x i~ a number ~etween 0 and 2. Preference is g~vsn to . ., di-n-butylmagne~ium, di-n-octylmagnesium, n-butyl-n-octylmagne~ium, n-butylethylmagne~l~m, n-butyl-~c-butylmagnesium or mixturo~ of theso compound~. P~rtlcular preference ih given to a dialkylmagne~ium of the formula .~ l(n-C~Hg) 1.2.1.7 (n-C8~l~)0.30.~Mg], in particular [(n-C~Hg)1.s(n-C~Hl7)0.sM~l.

Suita~lo aliphatic primary chlorinatod hydrocarbon~ are, for exa~ple, tetrachloromathn~o, trichloromethano, mothylene chloride, 1-chloroprop~ne or 1,1,1-trichloro-ethane, it al~o being po~lble to use mixture~.
Preference i~ given to u3ing trichloromethane and tetra-chloro~ethane.
i~` ' Suitable organoaluminum co~pound~ aro al~yl- or alkoxy-; 30 aluminum compounds of the formula AlR3n(0R~)3~, in which R3 ~;~ and R~ are identical or diffarent alkyl radical~ ha~ing i~i` from 1 to 8 carbon atom~ and n is 0, l, 2 and 3. Al~o :`i suitable i8 tho reaction product of tr$Alkylaluminums or diAlkylaluminum hydrides with diolefine containing from .il ., ;`~'' ~ . ' . ' . ~ , :
., 7 ~ ~

4 to 20 carbon atoms, prsferably isoprene. An example isoprenylaluminum.

To prepare the ~olid compri~ing spherical particles, the organomagne~ium ~ompound and any organoalum~num compound S uaed are di~olved ~n an inert liquid hydrocarbon under a nitrogen or argon atmo~phere. While ~tirring uniformly at a temperature from 30 to 110C, prefer~bly from 40 to 80C, thi~ solution is combined with a solution of the organic chlorine compound. The reaction can be carried out by adding the organic chlorine compound to the solution of the organomagne~ium compound in the liquid hydrocarbon, or vice ver~a.

In thi~ reaction, both the reaction time and al~o the - degree of dilution of tho reactant~ can be vAried within wide limit~. The reaction time ie from 30 minuto~ to a number of hour~, pre~erably from 1 hour to 5 hour3. The ~ reactants are u~ed as ~olutions having a molarity from ;`;~ 0.5 up to 15.

The reaction mixture contain~ up ~o 2.5 mol, preferably up to 2.0 mol, of the organic chlorine compound p~r mole of the organomagneQium co~pound.
...s ~;, A su~peneion of a ~olid comprising ~pherical particles i~ -~, formed. The suspon~ion i8 f~d to the next reaction step without further wa~hing ~teps. Howev~r, the solld can alao be flr~t isolatod and stored in dried for~ and resu~pended for aub~equont further proce3~ing.
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i An aliphatic alcohol is added to the ~uspen~ion of the ~olid comprising spherical particles. The alcohol is added to the solid in a molar ratio from 0.001 to 1, -30 preferably from 0.01 to 0.5, mol per gram atom of magnesium a~ a temperature from -20 to 150C, preferably from 20 to 90C. Depending on the reactivity of the reactants, the reaction time is from 0.1 to 3 hour~, preferably up to 1 hour.

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Aliphatia or cycloaliphatlc alcohol~ or alcohol~ having - a plurality of hydroxyl functions are ueed. Examplee are methanol, ethanol, n-propanol, i-propanol, n-butanol, sec-butanol, t-butanol, pent~nol~, hexa~ol~, amyl ~5 alcohol, ethylhexanol, glycol, glycarol ~nd cyclohexanol.
:~Particular prefersnce i8 given to using qthanol.

The epherical eupport material obtained in thi~ way i~
reacted u~der a nitrogen or ~rgon atmo~phore with a tran3ition metal compound of the formul~ M1a~(oR5)~, in :10 which Ml ie ti~aniu~ or zlrconium, Rs is an alkyl radical having from 2 to 10 carbon atoms, X ie a halogen atom, ~:.preferably chlorine, and m is an integer ~rom 0 to 4, but i8 preferably 2 or 4. It ie poeeible to uee a ~ixture of `a n~mber of these compounde or to u8e a nu~ber of these ;~-15 compound~ ~ucca~sively. It ie al~o poeeible to add the ~alcohol and one or more compounds of the typa M1X~(oR5)~
j in parallel.

Preferred co~pound~ are, for example, TiCl~, TiCl3(OC2Hs), TiCl3(O-iC3~7), TiCl2(Oc2H5)2~ TiCl~(O-iC3~7)"
,.......... 20 TiCl2(O-CH2C6R5) 2~ TiCl(OC2~)3, Ti(OC2~s)~ and ZrC1~, . .
:?: Very particular preference i~ given to TiCl~.
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In the reaction de~cribod ~bove, the titanium or zirco-~ nium compound i~ ueed in an amount from 0.5 to 5 mol, `~ preferably from 0.8 to 2.5 mol, in particular 1 mol, per gram atom of magnesium in the ~pherical aupport matorial.
The reaction temperature 1B fro~ 20 to 180C, prefer~bly ~ from 60 to 100C, and the reaction time 1B, depending on "` the titanium or zirconium coat$ng roquirad, from ~` 30 minutes to a number of hour~, proferably from 1 to 2 hours.
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The catalyet component A prepared in thi~ way i finally froed of eoluble components euch aa me~al or halogen ~ compounde by repeated washing with an lnert hydrocarbon `, at a temperature from 0 to 100C, preferably from 10 to ':

~" 60C.

~-The cataly~t co~ponent A prepared according to the invention i8 in the ~orm of ~phericail particle~ having an - averase diameter from 20 to lS0 ~m, preferably from 40 to ,~ 5 80 ~m, and having a ratio of ma~s a~erage diameter, D~, to number a~erage diameter, D~, of le~ than 1.5, prefer-ably from 1.02 to 1.3.
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To increa~e the mochani~al 0tability, the cataly~t ~:~component A can bo sub~0cted to a pr~polymerization prior to the actual polymerization. For thi3 purpose, the catalyst component A is transferred into B reactor wh~ch has previously been charged with ~ su~psnaion madiu~ and ;~aluminum alkyl.

The ~u~pen~ion ~edium used i~ a ~aturated hydrocarbon -~
~15 having from 3 to 15 car~on ato~s, such as, for example, ~-'-propane, butane, pentane, hexane~ heptane, octane, nonane, decane, cyclohexane or mixture~ of such compound~
or isomer~ thereof.
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The aluminum alkyl i~ one having fro~ 1 to 20 carbon atoms in the al~yl radicals, a~ de~ribed under componant B.
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~-~The prepolymerization i~ c~irried out at a te~perature from 50 to 110C, preferably from 50 to 95C, a pros~ure from 0.5 to 20 bar, preferably from 0.5 to 8 bar, o~er ~
! "~25 period of time from 0.5 to 6 hour~, preforably from 0.5 to 1.5 hours.

The component A i~ ueed in tho for~ of a ~u~pension in an ~inert hydrocarbon, or el~e in dry form after removal of `~`the susponsion medium, or a~ a prepolymer, for the poly-merization of alpha-ol~fins.
~j Preference ie given to the poly~erization of ethylene or propylene or the copolymerization of ethylene with ;,,' ~ .J~
.
propylene or tho copolymerization of ethylene or propy-lene with an alpha-olefin having from 4 to 10 c~rbon atom~ and one or more double bond~, euch aa 1-butone, isobutene, 4-methylpentene, l-hexene or 1,3-butadione.
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i 5 The polymerization i8 carried out continuou~ly or batch-~ .;
wise ~n su~pen~ion in a ~aturated hydrocarbon having ~rom 3 to 15 carbon atOmH, ~uch as propane, butanes, pent~ne~, c hexane~, heptanes, oct~ne~, nonanaR, cyuclohex~nes or , ~, -, mixtureR of ~uch compounds or i8 carried out continuou~ly ~- 10 in the ga~ pha~e. Preference ~ given to polym~rizat~on " in the ga~ pha~e.

In general, hydrogen $8 ueed a~ ~olecular weight regula-tor.
.,~' AR component B (cocataly~t~, an organometallic compound 15 of groups I to III of the Periodic Table i~ u~ed.
Preference i~ given to using an aluminum compound of the formula AlR6~Y37, in which p i~ 1, 2 or 3 and Rc 1~ an alkyl or aryl radical having fro~ 1 to 20 carbon atom~
;` and Y ie hydrogen, a halogen atom or an al~oxy or aryloxy group each having $rom 1 to 20 carbon atom~.
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Examples are trialkylaluminums, alkylaluminum hydride~, , and halogen-containing organoaluminum co~pounds, such a~
`~ dialkylaluminum halides, alkylaluminum dihalide~ or , alkylaluminum ~e~guichlor~d~, which can be usod alone or '~ 25 as m~xtur~. The organoaluminum compound~ u~od are ~ particularly preferably chlorine-free compounds. Suit~ble ; compound~ for thi~ purpo~e are, on the one hand, trialkylaluminums AlR63 or dialkylal~minum hydrides of the formula AlRs2H, in which R6 i8 ~n alkyl radical having 30 from 1 to 20 carbon atoms. Example~ are Al(CH3)3, ~, (C2Hs)3~ Al ( C2~5) 2~ Al(C3H7)3, Al(C3H7)2H, Al(iC~9)3, Al(iC~Hg)2H, Al(CaH17)3~ Al(C~2~25)3~ Al(C2H5)(Cl2~s) Al(iC~Hg)(Cl2H2s) 2 On the other hand, ~uitable chlorine-free organoaluminum ,, . ' ~ ~ ', ..... . ..
, ~ ,, ~- ~ompound~ are al80 the re~tion produc~l3 of trialkyl-- aluminum~ or dialkylaluminu~ hydrides ha~ing hydrocarbon radicals containing from 1 to 6 ~arbon atom~, preferably Al(iC~Hg)3 or Al(iC~Hg)2H, with diolefin~ containing ~rom 4 to 20 carbon atom~, preferably i~oprene. An example which may be mentioned i~ i~oprenylaluminu~.
~, :
; It is al80 posHible to u~e m~xtures of organometallic compound~ of group~ I to III of the Periodlc Table, in particular mixtures of varioua organoaluminum compound~.

The following mixture~ may be mentioned by way of example:

Al (C2Hs) 3 and Al (iC4Hg) 3, Al (C,Hs) ~Cl and Al (C8Hl7) 3, Al (C2Hs) 3 and Al (C8}Il7) 3, Al (C,,Hg) 2H and Al (C8Hl7) 3, Al (C~Hg) 3 and Al ( C~Hl7 ) 3, Al ( C2H5 ) 3 and Al ( C12}I2s ) 3 ~ Al ( C~H5, ) 3 and Al ( Cl 2}I2s ) 3, Al (C,}Is) 3 and Al (C~6H33) 3, Al (C3H7) 3 and Al (Cl~37) 2 (iC4Hg) and i oprenylaluminum (reaction product of ieoprene with Al (iC~Hg) 3 or Al (iC~Hg) 2~

The component A can be reacted a~ a ~u~pen~ion directly with the conponent ~; howover, it can flr~t bo i~olated and etored a~ a ~olid and re~u~pended for ~ub~eguon~
~, further u~e.
~, ~
. The component A and the component B can be ~ixed prior to polymerization in a ~tirred reactor at a t~mperature ~rom -30 to 150C, prefer~bly fro~ -10 to 120C. It iB al~o pos~ible to combine the two component~ directly in the :~; polymerization r~actor at a polymerization temperature . from 20 to 150C. However, the component B can also be added ln two ~tep~, by, prior to the polymerization r~.
reaction, reacting the component A with part of the component B at a te~psrature from -30 to 150C and adding the ramainder of the componont B in the polymerizat~on 'I reactor at a temperature from 20 to 200C.

;~ The polymerization temperature i~ from 50 to 150C, `
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~:~preferably from 50 to 100C, and ~he pre~sure i8 from l to 40 bar, profarably from 3 to 25 bar.

It i3 particularly ad~antageous to u~e the above-dascribed catalyst in the gae-pha~e polymerization :-5 process depicted in the figure~.
i, De~initione ! ,. .
(l) Reactor or fir~t reactor (2) Second roactor (ll) Ga~ distributor(21) ~as di~trlbutor (12) Fluidized bed(22) Fluidizod bed , lO (13) Circulating gas line(23~ Circulating ga~
i~ line ~: (14) Compre~sor(24) ~o~pre~or .. (15) Heat exchanger(25 heat exchanger (16) Feed line(26) Feod line ~` ~ 15 (17) Waste gas line(27) Waste ga~ line ~- (18) Feed line (l9) Diacharge line(29) Di~charge llno ., (3) Storage hop~er~41] Levelm~a~ur~ment ~, (31) Shut-ofE device142~ Pre~ure .;` 20 measurement (32) Offtake lino143] T-mporature ~sa-~ur~ment (33) Feed line1441 Pree~ure-dif~er-ence mea~urement (34) Wa~to line 145] Yolume flow mea-surement (35) Shut-off devlce t46] Ga8 analysi~

Figure l shows the appara~u~ u~ed for a alngls-stage polymerization proco3~. The roactor (l) ha~ing a gas distributor (ll) ~ pro~ided with a circulztlng gas line (13). In thi0 circulating gae line (13), there i8 arranged a compre~eor (14) with a heat oxcha~gar (15) down~tr~am thereof. Upstream of the comprossor (14), a feed line (16~ lead~ into the circulating gas line (13).

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A ~urther feed line (18) lead~ into the r0actor (1). At the top of the reactor (1~ there i~ a wa~te ga~ line (17~
in the circulating ga~ lin~ (13). Via the discharge l~ne ) and the shut-off device (31), tho reactor (1) oan be : 5 di~charged ~nto a ~torage hopper ~3) which i~ provided with an o4ftake line (32). The ~torage hopper (3) can be flushad with an inert ga~ ~ia the eed llne~ (33) ~nd tho wa~te line (34). The apparatu~ ia equippRd with device~
for level mea~urament ~41], for pre~aure measur~ment 142], for t~mperature measur~ment l43], for pra~sure-difforence ~ea~ure~ont [44], for volume flow moa~urement [451 and for determination of the ga~ compo~itlon (gae analysi~) ~46].
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Figure 2 show~ the apparatuo u~ed for ~ two-stage poly-merization proce~. The apparatu~ descr~bed in Figure 1 upplemented with a aecond reactor (2~ whioh ha~ a ga~
:` distributor (21) ~nd i~ connected to the xoac~or (1) via : the di~charge line (19). The reactor (2) i~ provided with a circulating gas l$ne (23) in which there ia inserted a : 20 compre~sor (24~ with downstreu~ hoa exchanger (25).
Upstream o~ the compre~or (24), a f~ed llne (26) lead~
into the clrculating gae line (23) and a~ the top of the ~! reactor (2) there i~ a waste ga~ e (27). Via a f di~charge line (29) with ~hut-off de~ice (31), the 25 reactor (2) can be di~oharged into the atorage hopper ~l (3). The ~econd reac~or ~1AO is eguipped with daYico~ for lev01 mea~ure~ent [41], or pre~uro moa~urement ~42~, ~; for to~peraturo mea~urement l43l, for pre~sur~-difforence ~ mea3urement [44l, for volumo flow mea~ur~ment l45] and 30 for determ~nation of the ga~ compo~ition (gaa analy~is) ~46].
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A coar~e-grained fluidized bed (12) ~omprising ~pherical particle~ iB introduced into the reactor (1). Near the , bottom of the reactor is the ga~ di~tributor (11) wh$ah 35 oupport~ the fluidizod bed (12) in th~ static state and : under operating condition~ i~ perme~ble to the fine-~ grained polym~r contained in the fluidizing ga~

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7.)~) (airculating ga~). Via the circulating ga~ l~ne (13~, the reaction gas i~ led under the gas di~tributor ~ and, ~: after passing through the ga~ distributor (11), com-pletely fluidizes the fluidized bed (12). However, the mixing of the fluidized bed (12) by the oirculating gas can also be carried out below the "fluidizing point~. In addition, the reactor (1) can be fitted with a ~tirrer ~ which can al~o run along the wall. The circulating gas .- ~low i8 generated by a compre~sor (14). ~ho heat of polymerizatlon i~ conducted away via a heat ~xchanger (15).

The catalyst i8 metered in ~ideway~ ~ia the feed lino (18~ above the ga~ di~tributor (11) as a dry ~olid or ; suspended in a low-boiling hydrocarbon such a8, for example, propane, butane or pentane, or a~ a paste. The catalyst i~ preferably fed in bolow the ~urface of the fluidized bod (12). The line ~18) carrying the catalyst can be flu~hed with ~n in~rt gas.

The reactants ethyleno, hydrogen, comonomer (for example ~ 20 propylene, butene, methylpentons, hoxono) and cocataly~t `1 ($or ex~m~le triethylalum~num, i~oprenylaluminum, trii~o-~i bu~ylaluminu~, ethylaluminum ~esguichlorlde), and al~o ~! the auxiliary nitrogon, ~re fed into the circulating gas up~tream of the compre~or (14) via the line (16). Wa~te ga~ i~ takon off vi~ the line (17). The wa~te ga~ flow ~: rats can, i$ de~ired, be controlled by a regulating devioe.
~`
`~ All mea~ured valuos taken on the apparatus can advan-tageou~ly be fed into a process control system and used for proce~a control.

The free-flowing polymer powder i~ dlschargod via a .:1 d~scharge line (19) into a ~torage hopper (3). The discharge line (19) contains a ahut-off device (31) which ~;~ can compri~e a lock or two pulsed valves in ~erios, ~o that di~harge ta~e3 place continuously or quasi-, i /:
~ 7 ~
; - 12 -continuouEly. The di~charge line (19) i~ con~truct2d with a ~ufficiently large ~lope as a gravity-~all line. The storage hopper (3) can be flushed with an inert ga~, for ;~example nitrogen, via the feed lines (33) and the wa~te line (34) to remove the monomer from the product. In fact it i8 po~ible for the produ~t to be eontinuou~ly pa~ed through and flushed with the inort ga~.

The pro~e~ can be operated in a single ~tage (Figure 1) or in a number of stage~ (Figure 23. Flgure 2 schema-~-10 tically show~ the two-stage m0~hod of operation. A~ can '`~be seen from the diagram, ~he individual stage~ of the multi~tage method of operation e~entially ~orro~pond to jthe single-stage process. The product from the ~irs~
;stage pa~e~ via the line (19) and a ~hut-off device (35) (which corre~pond~ to tho ~hut-off device 31) in the i'-fluidized bad (22) into the reactor (2). In contra~t to ~he fir~t ~tage, there i~ hero no metering-in of cataly~t. The di~charge line (29) i~ constructed a~ a gravity-fall line and lead~ the polymer into tha 0torage hopper (3~. In thiR ca~e the line (29) contains tho ~hut-t~" off device (31).

:' ~3The particle~ of the polymer~ and copolymerH prepared ~according to the proceos of the invantion have a compact ,!uniform ~pherical shape and a vory ~arrow partlcle eize t:'.25 di~tributio~. The ratio of tha ma~ average d~i~mster, D"
to the nu~ber a~erage dii~met~r, D~ le~ th~ 1.5, preferably fro~ 1.02 to 1.3. The ratio D/d lie~ in the " ~
-~range from 1.05 to 1.2. The dlumeter of the poly~er .;particle lies in the range from 100 to 1500 ~m, prefer-30 ably from 300 to 1000 ~m. ~he polymers po~ee~s a hlgh bulk density.
~,,, ;, A further advantage of the cstalyst of the i~ention lies in the high cataly~t act~vity, ~o that only very ~mall ~9; amount~ of the catalyst are required for the polymeri-zation. For this rea~on, the polymers also do not havo to be subjected to a~y additional poQt-treatment such a~, .
.,~
, ~ :

for example, complicated wa~hing or purification opera-: tion~. Furthermore, there is no undesired diecoloration of the product due to catalyst rasidue~.

The residual titanium and/or zirconium content in the : 5 polymera prepared according to the invention i8 le~s than ; 10 ppm, preferably le~ than 3 ppm.

~~ Owing to it~ good re~ponsivenes~ to hydro~en, the cata-ly~t i8 particularly sui~Qd to two~tayo proces~e~ for preparing polymera having a broad bl~odal ~olecular ~ 10 weight distribution.
`~
The replacYment of sulfur-containing electron donors ~uch aE diethyl sulfite by alcohols such au ethanol lead~ to an elimination of odor probl~m~ and to broadened oppor- :
~ tunities for use of the polymer.

; 15 Owing to the ~pherical shape of the particle~ and the :~ ssociated very good flow boha~ior o4 the polymer~ and copolymer~, con~iderablo ~implificatio~ and ~dvantages ln handling, drying and proceeeing are achiev2d.

Embodiments of the invontion will ~ow be more par-ticularly de~cribed by way o~ example.

The melt fl~w index (NFI (190/5) w~ determined ln `.,1 accordance with DIN 53735 ~t 190C and under a load of ~' 5 kp.

`, The rat$o of D~ to D~ was determined in accordance with .~ 25 NF X 11-630 of ~une 1981:

D~ n1(D~)3Dl~/~ n1(Dl) 3]
D~ = t~n~D1l/ n;
!~ nl ~ Number of ~a~ples ha~ing the aame diameter Dl Diameter of the i-th ~amplo 3 0 The particle ~$ze di~tribution D~/D~ of the aomponent A

,~ ' ~ : - "' ~: :
7 ~ ~

4 -- .
~- was determined by means of image analysis.

Exampl~ 1 ~;~ 27.7 cm3 ~285 m~ol) of CCl~ in 140 cm3 of petroleum spirit i~ (boiling range 100/120~C) were added to 306 ~m3 of a ~olution of butyloctylmagne~ium (285 mmol of Mg) of the approximate composition l(n-C~Hg)ls(n-C~Hl7)0.sMg]~ which ~ 8 ;: commercially available ~nder the name ~BOMAG-A, in heptane over a period of 90 minut~ at from 70 to 80C.
The mix~ure was ~ubseguently stirred for 120 minute~ at 85C. The re~ulting ~uspension was adm~xed over a period of 5 minutes at a temperature of 85C with a mixture of 7.6 cm3 (130 mmol) of absolute ethanol and 8.4 cm3 of petroleum op$rit (boiling range 100/120C) and was ~ ~ubsequently otirred for one hour at 85C. 18.9 cm3 i~ 15 (171 mmol) of TiCl~ were then added dropwise at a tem-~- perature from 93 to 97C over a period of 10 ~inute~. ~he su~pen~ion was stirred for 2 hours at 98C and ~ub~e-~', quently wafihed 6 times with 700 cm3 portion~ of petroleum spirit (boiling range 100/120C) ~t from 50 to 60C.
Analysis gave a magne~ium:titanîum:chlorine ratio of ``~ Mg:T~:Cl ~ 1:0.037:2.12. ~-D~/D~ = 1.18. -~

Example 2 306 cm3 of a oolution of butyloctylmagnesium (285 mmol of ~-Mg; as in Exa~ple 1) in heptane wero adm~xod over a period of 90 m$nutes with a ~olution of 49 cm3 (605 mmol) of CHCl3 in 140 c~3 of petroleum spirit (boiling range ~`' 100/120C) and were then stirred for a furthor ,,~; 120 minut~s at fro~ 75 to 77C. The resulting su~pen6ion wa~ admixed at 85C over a period of 15 minute~ with a ~, mixture of 3.6 cm3 (62 m~ol) of absolute ethanol and 12.4 cm3 of petroleum ~pirit (boiling rang~ 100/120C) and wa6 ~ub~eguently ~tirred at 85C for on~ hour.
31.4 cm3 (285 m~ol) of TiCl~ were then added dropwi~e at ~S` 35 a temperature o~ 85C over a period of 25 ~inute~. ~ho . ~

~ . .

~ 1 i ~ 7 . i rJ

~uspen~ion was stirred for 2 hour~ at 94C and ~ubse-quently was washed 6 time~ with 700 cm3 portions o~
f~'~ petroleum spirit (boiling rang~ 100/120C) at from 50 to r 6QC. Analysis gave a m~gnesium:ti~anium:chlorine ratio } 5 of Mg:Ti:Cl = 1:0.031:2.03.
~ D~/Dn = 1.12.
, . . .
Example 3 The procedure was ae in Example 2, but 26.2 cm3 (1.25 ~mol) of tetraethyl orthotitanat~ were added in~tead of ~thanol. Analysis gav~ a ~agno~ium:
~ titanium:chlorine ratio of ; M~:Ti:Cl = 1:0.174: 2.22.
D",/Dn = 1. 08 .

Example 4 ~; 15 The procedur~ wa~ ae in Example 1, but 110 m~ol of tetraethyl orthotitanate were addsd in ~ddition to 15 mmol o~ ethanol. Analy0io gave a magno~ium:
titanium:chlorine ratio o~
~`` Mg:Ti~Cl = 1:0.103:2.18.
~,! 2 0 Dl,~/Dn ~ 1.15 . .

Example S
,~.. 1 .
The proosdure wa~ as in Exa~ple 2, but, in~tead of 3.6 cm3 of ethanol, 5.25 cm3 (90 ~mol) o~ ethanol wer~
mlxod with 10.75 cm3 of petroleum ~pirit (boili~g range 100/120C) and were react~d at room temperature. Analysis gave a magnesium:titaniu~:chlorine ratio of Mg:Ti:Cl =
1:0.003:2.05.
D~/Dn 1.2.

Example 6 The procoduro wa~ as in Example 5, but the ethanol/petroleum spirit mixture was added at 85C.
;

., . ., - 16 - ~ 7 J ~
150 cm3 (corre~ponding to 2.66 mmol of titanium) of the cataly t su~pen~ion were aubsequently taken out and admix~3d with 2~26 cm3 of a 1-molar triethylalu~inum ~olution. The mixture was ~tirred for 2 hour~ at 120C.
Subsequently, 46 % of the titanium (IV) were reduced to titanium ~III). Analysis gave a magneciu~:
~ititanium:chlorine ratio of M~:Ti:Cl 8 1:0.029:2.04. :
Example 7 The procedure wa~ as in ~xumple 6, but 1.33 cm3 of a ~-10 1-molar triethylaluminum ~olution were used. Th~ rea~tion wae carried out over a period of 2 hour~ at room ,~temperature. Subs2quently, 25 % of the titanium (IV) were reduoed to titanium (III). Analy~i~ gave ~ magne3ium:
titanium:chlorino ratio of 15 Mg:Ti:Cl = 1:0.003:2.05.
''' . ~
Example 8 A 1.5 dm3 ~t~el autoclave waa charged with 690 cm3 of ~`` petroleum ~pirit (bolling range (100~120C~, 20 ~mol of triethylaluminum and 93.2 e~3 (corre~ponding to 10 ol of titan~um) of the cataly~t suspe~lon fro~ EXU~P1Q 3.
The autoclave wa~ ~ub~eguently prsssurized with 2 b~r of argon and 1.1 bar of hydrogen; the prepolymerization took place after addition of sthylene at a total pres~ure of ~` 6 bar and a te~perature of 65~ over a period of one hour.
.
Example 9 .
The procedure was a~ in Example 2, but the additio~ o~
~ ethanol wae omitted. Analysi~ gave a magne~ium:tita-,; nium:chlorine ratio of 1O0.018:2.03.
30 D,/D~ s 1.04.
~' :

~ ., . . ~ . ~ - ,. . .
,~.: . .

r:- - 17 ~
Example~ 10 to 22 ~;.
.". An ethyle~e polymerization wa~ carri~d out ln accordance with the Table in 800 cm3 of petrolsum npirit (bo~ling ~:~ rang~ 100/120C) in a 1.5 dm3 ~teel auto~lav~ at a tem-J 5 perature of 85C and a pre~3ure o~ 6 bar. In oach ca3e, , the compon~nt B add~d wa~ 1 mmol of triethylaluminum . (TEA), 5 mmol of trii~obutylal~minum (TIBA) or 5 ~mol of oprenylaluminum (IPRA). Ths proportlon o~ polymor particles ~ 100 ~m was c 0.1 %.
.
10 Table: Ethyl~ne polymerizatio~
. ................................ _ ¦ 13x~ Comp. A Comp. H~ Yl~ld ~5FI dSO BD :~
¦ pl8 Accord- B lb/lr~ ~gP~5/ 190/5 ~ lg/l]
~; . l ing t-~ ~1 Ti 1 tg/lo . l lZx~ple min~ ::
¦ 10 1 T~A 3.85 23 080 12.1 470 290 ., l _ , _ _ .
~ I 11 1 TIBA 1.4 58 200 0.05 1480 320 '.~ I . __ ¦ 12 2 TIBA 3.85 25 620 8.8 480 340 ,'~:,' I , .
i 13 2 IPRA 2.1 36 420 1.4 960 310 ~' .,._ . .. .
, ¦ 14 3 IPRA 4.0 1 940 46.8 340 310 ~3 _ ~ _ _ ~i,i ¦ 15 3 TI8A 3.85 3 200 10.9 570 300 ~Y ~ . ._ ._ , ._ 16 4 ~A 3.a5 11 300 25.3 720 330 ~ .... __ __ 17 4 IPRA 1.9 5 600 0.12 960 290 lB 5 TIBA 3.85 23 250 9.1 410 340 . . ~.......... __ .. ~ 19 6 TIBA 3.85 24 750 8.4 440 310 _ _ .. , _ ~"~ 20 7 T~A 3.85 29 200 9.1 440 300 21 7 TIBA 2.1 54 500 0.3 1230 310 21 8 TRA 3.85 28 300 10.3 530 320 'P~`' . .. .
~ 22 TEA 3.85 21400 8.5 420 310 ~ '- :
. :
"~ ~ ~

,~ `

",~

Example 23 For the ga~-phaEe polymerizatlon, the apparatu~ ~ch~mati-cally shown in Figure 1 wa~ u~ed. Prior to commsncoment of the reaction, the reactor wa~ charged with 20 kg of polyethylene which had an av~rage particle diameter of 500 ~mO At 80C ~nd 20 bar, 45 m3/h of a gas ~lxturo were paseed upward~ through th~ bed. The gas mixture compri~od ethylene, hydrogen and nitrog~n. The re~ctor wa~ con-tinuou~ly supplied wlth 2 kg/h of ethylene and with ~atalyst. For thi~ purpo~e, the catalyst from Examplo 2 wa~ ~ubjected to a prepolymerization a~ in ~x~mplo 8. The ~mount of cataly~t was regulated in such a w~y that the ethylene partial pre~ure romained con~ta~t. The met~ring-in of the hydrogon, as molecular waight regulator, wa~ regulated in auch a way that the ratio o~
the partial pressureo o ethylene ~nd hydrogen rema$ned con~tant. ~e~ide~ the catalyet, triethylPluminum wa~
metered in as cocatalyst in an Al/Ti ratio of 200:1. The poly~er obtained under the~e condition~ po~ee~ed an 20 MFI l90/5 of 3 g/10 mi~, ~ d50 value of 600 ~, a propor-tion of material having d50 ~200 ~m of le~s than 2 % and bul~ d-n~ity of 500 g/d~3.

i ~ . . ... .

Claims (9)

1. A process for preparing a polyolefin by polymerization of an alpha-olefin at a temperature from 50 to 150°C
and a pressure from 1 to 40 bar in the presence of a catalyst comprising a transition metal component (component A) and an organometallic compound (compo-nent b), said component A having been prepared by a) reaction of an organomagnesium compound of the formula R1xMgR22-x, in which R1 and R2 are identical or different alkyl radicals having from 2 to 12 carbon atoms and x is n number from 0 to 2, with an aliphatic primary chlorinated hydrocarbon in an amount from 0.5 to 2.5 mol of the chlorinated hydrocarbon per 1 mol of the organomagnesium compound, b) treatment of the solid obtained with an alcohol in an amount from 0.001 to 1 mol per gram atom of magnesium contained in the solid at a temperature from -20 to 150°C, and c) reaction of the support material thus obtained with one or more compounds of the formula M1Xm(OR5)4-m, in which M1 is titanium or zirconium, R5 is an alkyl radical having from 2 to 10 carbon atoms X is a halogen atom and m is an integer from 0 to 4, in an amount from 0.1 to 5 mol per gram atom of magnesium contained in the support material at a temperature from 20 to 180°C.

2. The process as claimed in claim 1, wherefor the reac-tion of the organomagnesium compound with the ali-phatic primary chlorinated hydrocarbon has been carried out in the presence of an organoaluminum compound of the formula AlR3n(OR4)3n, in which R3 and R4 are identical or different alkyl radicals having from 1 to 8 carbon atoms and n is 0, 1, 2 and 3, or in the presence of the reaction product of trialkylaluminums or dialkylaluminum hydrides with diolofins containing from 4 to 20 carbon atoms.

3. The process as claimed in claim 1, wherefor a dialkyl-magnesium of the formula [(n-C4H9)1,2,1,7(n-C8H17)0,3-0.8Mg]
was used.

4. The process as claimed in claim 1, wherefor the alcohol used was ethanol.

5. The process as claimed in claim 1, wherefor the com-pound of the formula M1Xm(OR5)4m, in which M1, R5 and m are as specified in claim 1, was TiCl4.

6. The process as claimed in claim 1, wherefor step b was omitted.

7. The process as claimed in claim 1, wherefor the cata-lyst component A was subjected to a prepolymerization.

8. The process as claimed in claim 1, wherein the poly-merization is carried out continuously in one or more stages in a gas-phase process.

9. A process for preparing a polyolefin by polymerization of an alpha-olefin at a temperature from 50 to 150°C
and a pressure from 1 to 40 bar, in one or more stages in a gas-phase process, which comprises carrying out the polymerization, in the case of a single-stage process, in an apparatus comprising a reactor (1) having a gas distributor (11) and a circulating gas line (13) in which there is arranged a compressor (14) with a heat exchanger (15) downstream thereof upstream m of the compressor (14) a feed line (16) opens into the circulating gas line (13), a further feed line (18) leads into the reactor (1), at the top of the reactor (1) there is a waste gas line (17) in the circulating gas line (13), the reactor (1) can be discharged via a discharge line (19) and a shut-off device (31) into a storage hopper (3) which is provided with an offtake line (32), or, in the case of a two-stage process, in sais apparatus supplemented with a second reactor (2) which has a gas distributor (21) and is connected to the reactor (1) via the discharge line (19), the reactor (2) is provided with a circulating gas line (23) in which there is inserted a compressor (24) and downstream heat exchanger (25), a feed line (26) leads into the circulating gas line (23) upstream of the compressor (24), there is a waste gas line (27) at the top of the reactor (2), the reactor (2) can be discharged via a discharge line (29) with shut-off device (31) into the storage hopper (3), in the presence of a catalyst comprising a transition metal component (component A) and an organometallic compound (component B), said component A having been prepared by a) reaction of an organomagnesium compound of the formula R1xMgRi22-x, in which R1 and R2 are identical or different alkyl radicals having from 2 to 12 carbon atoms and x is a number from 0 to 1, with an aliphatic primary chlorinated hydrocarbon in an amount from 0.5 to 2.5 mol of the chlorinated hydrocarbon per 1 mol of the organomagnesium compound, if desired in the presence of an organoaluminum compound of the formula AlR3n(OR4)3-n, in which R3 and R4 are identical or different alkyl radicals having from 1 to 8 carbon atoms and n is 0, 1, 2 and 3, or in the presence of the reaction product of trialkyl-aluminums or dialkylaluminum hydrides with diolefins containing from 4 to 20 carbon atoms, b) treatment of the solid obtained with an alcohol in an amount from 0.001 to 1 mol per gram atom of magnesium contained in the solid at a temperature from -20 to 150°C, and c) reaction of the support material thus obtained with one or more compounds of the formula M1Xm(OR5)4m, in which M1 is titanium or zirconium, R5 is an alkyl radical having from 2 to 10 carbon atoms, X is a halogen atom and m is an integer from 0 to 4, in an amount from 0.1 to 5 mol per gram atom of magnesium contained in the support material at a temperature from 20 to 180°C.