CA2018521A1

CA2018521A1 - Process for the manufacture of a poly-l-olefin

Info

Publication number: CA2018521A1
Application number: CA002018521A
Authority: CA
Inventors: Rainer Lecht
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1989-06-08
Filing date: 1990-06-07
Publication date: 1990-12-08
Also published as: JP2963493B2; ES2050302T3; DE3918646A1; KR0178979B1; EP0401776B1; EP0401776A2; KR910000819A; EP0401776A3; JPH0326706A; ZA904392B; AU5687090A; DE59004655D1; AU626685B2

Abstract

Abstract of the Disclosure:

Process for the manufacture of a poly-1-olefin Polyolefins with a broad molecular weight distribution are obtained in very high yield, with a catalyst based on a reaction product of a magnesium alcoholate and titanium tetrachloride, by removing part of the soluble reaction products from the hydrocarbon-insoluble reaction product of the magnesium alcoholate and titanium tetrachloride, and then heating said reaction product for 8 to 100 hours at a temperature of 110 to 200°C.

Description

HO~CHS~ AKTIENGESELLSCHAFT HOE 89/F 173 Dr.DA/gm De~cription Proces~ for the manufac~ure of a poly-l-olefin The invention relates to a process for the manufacture S of a poly-1-olefin using a Ziegler ~uppor~ed catalyst based on a magnesium alcoholate and TiC14.

Processes for the ~anufacture of poiy-l olefin~ with a broad molecular weight distribution u~ing Zi~gler ~uppor-ted catalysts based on a magnesium alcoholate and TiCl4 are state of the art.

A process of this type is known which uses a catalyst whose transition metal component was manufactured by re-acting a magnesium alcoholate with titanium tetrachloride at a temperature o~ 50 to 100C, separating off and wa~hing the ~olid, tempering the ~olid at 110 to 20~C
~ with the additîon of TiC14, and ~horoughly washi.ng the ; solid ~q.v. CA 120749g~.

similar proces6 is also known which uses the ~ame re-action product of a magnesium alcoholate and TiCl4, except that it was tempered without further additions rather ~ than with the addition of TiC14. This was follow~d by a ,~ ~ thorough extraction by washing (q,v. US 4.447.587).

' ~ Both known catalyst ~ystems have the disad~antag0 that ' ~ their manufacture involves large amounts of wash solu-tions which have to be worked up. The manufacturing process iB also time-consuming.
,, ~: The ob~ect was to find a possible way o~ manufacturing the knvwn catalysks in a ~horter time while saving raw ~!~ materials and auxiliaries and avoidîng wa~te.

It has been found that the object can be achieved by removing only part of the soluble titanium comp~unds . . .

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contained in the solid, after the first reaction step, and subjecting the solid to a heat ~reatmen~ in a liquid phase with a low titanium content.

The invention thus relates to a process ~ox the manu-facture of a poly-1-olefin by the polymerization of a 1-olefin of the formula R4CH=CH~, in which R" is hydrogen or an alkyl radical having 1 to 10 carbon atoms, in SU8-pension or in the gas phase, at a tempera~ure of 20 to 200C and a pressure of 0.5 to 50 bar, in the pre~nce of a catalyst consisting o~ the reaction product of a mag-: nesium alcoholate and titanium tetrachloride (component a~ and a me~al-organic compound of a metal fr~m group I
- to III of the periodic table (component b~, wherein the ~` pol~merization i8 carried out in the pxesance of a catalyst whose componen~ a has been manufacture~d by reacting a magnesium alcoholate with titanium tetra-~ chloride in a hydrocarbon a~ a temperature o 50 to :: 100C, in a first reaction step, and ~hen separating o~
:~, part of the soluble constituents and subjecting the :~` 20 resulting solid to a heat treatment at a temperature of 110 to 200C for 8 to 100 hour~, in a second re~ction step.

: Component a is manufactured using a magnesium alcoholate.
This magnesium alcoholate can be a ~Isimple~ ma~nesium . 25 alcoholate of the formula Mg~ORl)(OR2), in which R1 and R2 ~:~ are identical or different and are an al~yl radical having 1 to 6 carbon atoms. Examples are Mg(OC2H5)2, Mg(O-i~C3H7)2, Mg(o-n-c3H7)2~ My(o-n-c4H~)2~ Mg~OCH3) (Oc2H5) and Mg(OC2H5)~O-~-C3H7). It i8 al80 possible to use a "~imple" magnesium alcoholate of the formula Mg(OR~X~, in whish ~ = halogen, (SO4)l/2, OH, (CO3)~/2, (PO4)~/3 or Cl~ R
, ~ i8 as defined abo~e and n ~ m = 2.
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A further possibility, however, is to use a "complexl' magnesium alcoholate. "Complex" magnesium alcoholate is understood as meaning a magnesium alcoholate containing :
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2~
~ 3 -at least one metal from main group I to IV of the periodic table, in addition to magnesium. Examples of such complex magnesium alcoholates are: ~Mg~O-i-~3~I7)4]Li2r [Al2t-i-C3H7~83Mg, [si~oc~H5)6]Mg~ tMg(0~2H5)~]1Na/
S [Al2(o-i-c4H~ Mg and tAl2(O-seC- C4Ha)6(C2~Is)2]Mg- The complex magnesium alcohola~es (alkoxide ~alt9 ) are manufactured by known methods. The following example~
may be mentioned for ~he manufacture of the complex magnesium alcoholate:

lQ 1. Two metal alcoholates are allowed l:o react in a suitable ~olvent, for example:
2Al(OR)3 + Mg(OR~2 ~ [Al2(R)s]Mg 2. Magne~ium is dissolved in an alcoholic solution of a metal alcoholate:
2~iOR -~ Mg ~ 2ROH ~ [MgtOR)43Li2 ~ H2 3. Two met~ls are ~imultaneously dissolved in alcohol:
8ROH ~ Mg + 2Al ~ ~Al2(OR)~]Mg ~ 4H2 It is preferred to use the simple magnesium alcoholate~, especially Mg(UC2H5)2, Mg(O-n-C3H7)2 and Mg(O-i-C3H7)2- The magnesium alcoholate i8 used in pure form or attached to a support.

~: Component a is manufactured in two reaGtion steps at different temperatures.

In the first reaction ~tep, the magnesium alcoholate is reacted with titanium tetrachloride at a temperature of 5~ to 100C, preferably 60 to 90C, in the pre ence of an ; iner~ hydrocarbon, with stirring. ~.9 to 5 molt pre-ferably 1.4 to 3.5 mol, of titanium tetrachloride are . ~ used per mol of magnesium alcoholate.

A ~uitable inert hydro~arbon is an aliphatic or cyclo-~ aliphatic hydrocarbon such as butane,. pentane, hexane, ¦~" heptane, isooctane, cyclohexane or methyl~yclohexane, or ;; ~

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an aromatic hydrocarbon such a~ toluene or xylene;
hydrogenated diesel oil fxactions or gasoline fractions from which oxygen~ sulfur compounds and moisture have been carefully removed are also useful.

The reaction time in the first step i8 0.S to 8 hour6, preferably 2 to 6 hours.

In the ~irst reaction step, an extensi~e exchange takes place between the alkoxy groups of the magnesium alco-holate and the chlorine atoms of the titanium tetra~
chloride, the reaction product obtained being a hydrs-carbon-insoluble solid containing magnesium and titanium, and hydrocarbon-soluble titanium ester chlorides.

Part of the unreacted soluble titanium compounds is $hen removed from the hydrocarbon-insoluble reaction product ~:~ 15 of the magnesium alcoholate and the titanium tetra-:~ chloride. Thi~ can be carried out by washing with an inert hydrocarbon. This method leave~ behind, in the ~:~ solid, part of the titanium ester chlorides formed and makes it possible to control the extent to which com-:~ 20 ponent a is coated with titanium. Alternatively, it i~
also possible for all the suspending medium containing the soluble titanium compounds to be removed from the :~ hydrocarbon-insolubl~ reaction product, e.g. ~y fil-tration. In ~his case, the amount of filtrate required ~ 25 to ad~ust the extent to whlch component a i~ coated with - titanium is added be~ore tempering.
:
In a second reaction step, the solid obtained is sub-: ~ected to a heat treatment at a temperature of 100 to 200C, preferably 110 to 160C, with stirring. The re-action time i8 8 to 100 hours, preferably 10 to 40 hours.
In this stepl the solid i8 in a liquid phase with a low titanium content. After this ~empering, the solid phase of the su~pension has the desired titanium content and the liquid phase of the suspension obtained has a suf-ficiently low content of t.itanium-containing compounds.

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It is not necessary to wash the catalyst.

This procedure gives a hydrocarbon-insol~ble solid con-taining ma~nesium and titanium, which is called component a.

The polymerization catalyst to be used according to the invention is manufactured by bringinia component a to-gether with a metal-organic compound of a ~etal from group I to III of the pexiodic table (component b).

Component a can be reacted a~ a suspension direct with oomponent b; however, it can first be i~olated as a solid, stored and resuspended for subsequent u6e.

:~ It is preferred to u~e aluminum-organic compounds as com-pDnent b. Suitable altumintum-organic c~mpounds are chlorinated aluminum-organic compound~, dialkylaluminum monochlorides of the foxmula R3~1Cl or alkylaluminum sesquichloride~ of the ormula R33Al2Cl3~ in which R3 iB an aIkyl radical having 1 to 16 carbon ~tom~. Examples ~ which may be mentioned are (C2H5)~1Cl, (i C4H6)~1Cl and .~ (C2H5~3Al~Cl3. It is also po~sible t~ t~e mlxtures of these compounds.
,~ ~
It is especially preferred to u~e chlorine-free compounds as aluminum-or~anic compounds. Some chlorine-free com-pounds suitable for this purpose are khe reactien products of aluminum trialkyls or altuminum dialkyl hydr~de~ with hydrocarbon radicals ~aving l to 6 carbon , ~ a~oms, preferably Al(i-C4H~)30r Al(i-C4H~)2H, and diol.efin6 ,; containing 4 to 20 carbon atoms, preferably i~opren~. An example which may be mentioned is aluminum i~opren~l.

` ~ Other 3uitable chlorine-free aluminum-oxganic compounds are aluminum trialkyls AlR33 or aluminum dialkyl hydride~
; of the formula AlR32H, i~ which R3 is an alkyl radical ~: having 1 to 16 carbon atoms~ ~xamples are Al~C2H5)3, (C2Hs)2N~ Al(C3H~)3, ~l(C3H7)2H, Al~i-C4Ha~3, Al(i-C4H9)~H, ,, $

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Al(C8H17)3, A1(Cl2H2s)3~ Al(~2H5)(C1~H2s)Z and Al(i-C4H9)-( C12H25 ) 2 -It is also possible to use mixtures of metal-organic com-pounds of me~als from group I to III of the periodic table, in particular mix~ures of different alumi~um-organic compounds.
, The following mix~ures may be mentioned as e~amples:
Al~C~s)3 and Al~i-C4H~)3, Al (C2~5~2Cl an~ Al(Ca~17)3, Al ~CzHs)3 : and Al~C8H1,) 3 ~ Al(C4Hg)2H and Al ( C8~l7 ~ 3~ Al(i-C4H9) 3 and Al(C8H17~3, Al(C2H5)3 and A1(C1aH2s)3~ ~C4Hs)3 and Al(ClaH25~3~ Al(C2H5) 3 and Al~ClsH333 3, Al ~ C3H7 ) 3 and (Cl8H37)2(i-C4Hg), and Al(C2~5)3 and aluminum isoprenyl (reaction product o~ isoprene and Al(i~C4Hg)3 or : Al(i-C4Hg)2~) Component a and component b can be mixed before polymeri-~:~ zation, in a stirred kettle, at a temperature of -30C to :~ 150C, pre~erably -10 t~ 120UC. ~t i~ also possi~le to ,~ bring the two components to~ether direct in the poly-` : merization kettl.~ at a polymerization temperature of 20 ~i 20 to 200C~ ~ow~ver, a further pos~ibility i8 to add com-; ~ ponent b in two 6tep6 by preactivating component a, ~: before the pol~merization reaction, with part of com-;~ ponent b at a temperature of -30C to 150~C and adding the remainder of component b in the polymerization re-~ 25 actor at a temper~ture of 20 to 200~C.
,: ~
, The polymerization catalyst to be employed according to ,; the invention i5 u~ed for the polymerization of 1-olefins of the formula R4CH=CH2, in which R~ is a hydrogen atom or ~:: an alkyl radical having 1 ~o 10 carbon a~oms, examples of said l-olefins being ethylene, propylene, but~1-ene, hex~1-ene, 4-methylpent 1-ane and oct-1-ene.

It is preferred to polymerize ethylene on its own or as ~: a mixture of at lea~t 70% by weight of ethylene and at . ~ most 30% by weight of another 1-olefin of the above . :
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formula.

It is especially preferred to polymerize ethylene on its own or a mixture of at least 90% by weight of ethylene and at most 10~ by weight of another l-olefin of the above formula.

In known manner, ~he pol~meri%ation is ~arried out in solutio~, in suspension or in the gas pha~ continuously or batchwise, in ~ne or more steps, at a temperature of 20 to 200CJ preferably 50 to 150C. l~he pres~ure is 0.5 to 50 bar. The polymerization is preferably carried out in the pressure range fro~ 5 ~o 30 bar, which is of par-ticular interest in industry.

In this process, component a is used in a concentration, based on titanium~ of O.OQOl to ~, preferably O.001 to : 15 0.5, mmol of Ti per dm3 of di~persing medium or pex ~m3 of reactor volume. ~he metal-orqanic c~mpound i~ used in a concentration of 0.1 to 5 mmol, preferably O.S to 4 mmol, per dm3 of dispersin~ medium or per dm3 of reactor volume.
In p:cinciple, however, higher concentrations are also possible.
, The ~uspension polymerization i~ carried ~ut in an inert disper~ing medium conventionally used or the %iegler low-pre~sure process I for example in an aliphatic or cycloaliphatic hydrocarbon; butane, pentane, hexane, heptane, isooctane, cyclohe~ane and methylcyclohexane may be mentioned as examples of auch hydrocarbons. It is also possible to usegasoline fractions or hydrogenated diesel oil fractions from which oxygen~ sulfur compounds and moi.sture have been carefully removed.
. ~
$he gas pha~e polymerization can be carried out direct or after pxapolymerization of the catalyst in a suspension process.

The molecular weight of the polymer is regulated in known ,:` ' ' ' . :
.

Z0~ 2~L
~ 8 --manner, hydrogen preferably being used for thi~ purpose.

As a consequence of ~he high activity of the catalyst to be used, the process according to the inventiQn gives polymers with very low titanium and halogen contents and hence excep~ionally good ~alues in the color fastness and corrosion tests. Fur~hermore, said process makes it possible to manufacture polymers with a ~ery broad molecular weight distribution (polydispersity); the Mw/~
values of the polymers are o~er 10.

Another decisive advantage of the process a~cordin~ to the invention can be seen in the fact that it makes it possible to manufac~ure polymers with e~tremely different molecular weights simply by varying the hydrogen con-centrations. For example, polymers with molecular weights of more than 2 million are ormed by polymeriza-:~ tion without hydrogen and polymer6 with molecular weights in the region of 30,000 ars formed by pol~merizatioll with hydrogen contents of 70% by volume in ~he gas space.

The polymers can be processed by the extrusion and extru-sion blowing processes to form hollow bodies, tubes, ; cables and films with smooth surface6, a~ high output rates.

Becau~e they have a particular structure~ the hollow bodies and bottles produced from the polyolefins obtained according to the invention are di~tinguished by a high insensitivity to stress crack formation.
~, ~
Furthermore, in the case of su5pen8ion and gas phase polymerization, the proces~ according to the invention : make~ it po~sible to manufacture free-flowing polymer powders with high bulk densities, so further proces8ing to form moldings can be carried out direct without a j:~ granulation step.

, ~ Finally, in the proce~s according to the invention, the ,:;

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time spent on manufacture of the catalyst and the amount of titani~m-containing hydrocarbon solutions obtained are both reduced by 70%. Moreover, 12% of the expen6ive titanium tetrachloride which has to be uæed in the con-ventional process is saved.

The ~ollowing Examples are intended to illustra~e the invention.

In the Examples, the manufacture of the catalyst and the polymerization were carried out using a hydrogenated diesel oil fraction with a boilin~ range of 130 to 170C.

The titanium content of the catalysts was determined by colorimetry (liter~ture referencet G.O. Muiller, "Praktikum der ~uantitativen chemischen Analyse"
("Laboratory manual of quant.itative chemical analy~
4th edition (1957) p. ~43).

The melt flow index, ~EI, was detenmined according to DIN
53 735 tE)-The ~/M~ values were determined from the fractionationdata ef a gel p~rmeation chromatograph in o-dichloro-benzene ~ODCB] as the solvent and eluent, at 13$C.

The viscosity number, VN, was determined accordlng to DIN
: 53 728 sheet 4 with an Ubbelohde vi~cometer in decahydro-naphthalene a~ the ~olvent.

~ he den~ity was determined according to DI~ 53 479 and ~5 the bulk den~ity according ~o DIN 53 46~.
`' `
~ Example 1 3 ~ a) Preparation of com~onent a ?,~ In a 2 dm3 four-necke~ round-bottomed flask with a dropp-~, ing funnel, stirrer, reflux condenser and thermometer, :~ 30 114~3 g of magnesium ethylate wer~ dispersed in 1 dm3 of :; - ` ~ :` ' , - ` , s~

a diesel oil fraction under a blanket of N2. 332 g of TiCl4 were added dropwise to this dispersion over 5.5 h.
After the 501id had settled, 0.5 dm3 of ~he supernatant solution was wi~hdxawn at 60C and 1.1 dm3 of fresh dispersing medium were added. After ~he volume had been made up a total of follr ~imes with 1.1 dm3 of dispersing : medium and a further 1.1 ~m3 of supernatant ~olution had been withdrawn each time, the ~olume was made up with 0.5 dm3 of dispersing medium and the suspenKion wa~ stirred at ~ 10 125~C for 16 h. The supernatant solution then contained : less than 10 mmol of Ti per dm3~ The ~olid (component a) had the following analytical compoRitions Ti 6.2~ by weight Mg 70.8~ by weight Cl 23.0~ by weight b) Preacti~ation of component a 3~ g of component a were made up to 0.150 dm3 of ~uspen sion with diesel oil a~d 36 cm3 of a 1 molar ~olution of ; triethylaluminum were added. The mixture wa~ ~tirred for 2 h at 120C, after which 85% of the titanium(IV) had been reduced to titanium(III).
;

~ c) Polymeri~ation of ethylene in ~u~pen~ion ., 0.75 dm3 of hydrocarbon, 5 mmol of aluminum isoprenyl and 0.8 mg of component a were placed in a 1.5 dm3 ~teel autoclave. 3.2 bar Of ~2 and 3.9 bar of ethylene were then introduced under pre~sure at a polymerization tem-perature of 85C. Ethylene was subsequently metered in 80 as to maintaln the total pre~ure. The experiment was discontlnued after 2 h. The polymer was separated off by :~ 30 filtration and drie~ in a vacuum drying cabinetv 147 g of pol~mqr were obtained. This corresponded to a :; catalyst-time yield of 9.8 kg PE/mmol Ti h. ~he ~ polymer had a melt flow index ~FI 190/5 of 2.S g/10 min ; and a mel~ flow index ratio ~FI 190/21.6 to MFI 190/5 of :

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12.3. The ratio ~,/M~ from the GPC was 9.7.

~ample 2 100 dm3 of a diesel oil fraction, 50 mmol of aluminum triethyl and 8 g of component a treated according to S Example 1 b were placed in a 150 dm3 kettle. 0.~ m3 o ethylene per h and the amount of Hz required to give an H2 concentration of 75% by volume were then introdu~ed at a temperature of 85C. 0.2 dm3 of but~ ene was me~ered in at the ~ame time. After 2.5 h, the polymerization wa8 ~topped a~ a pressure of 8 bar ~y relea~ing the pressure.
In a second stage of the reactionr 0.7 m3 ethylene/h and the amount of H2 required to ~ive an ~2 cQncentratiOn of 2~ were introduced. 1 dm3 of but-lcene wa~ metered in at the same time. The polymerization wa~ di~continued after 3 h. The suspension was filtered and the polymer was dried by having hot nitroyen pa~sed over it. 31 kg o~
~; product were obtained.
:. ~
~he polyethylene powder had a ~N o~ 290 cm3/g. ~he den-~; ~ity was 0.945 g~cm3. At an MFI 190~5 of 0.6 y/10 min, : 20 the ratio MFI 190/21.6 to MFI 190/5 was 22.
ple 3 ~' .
Component a was prepared as in Example 1 a and the sus ~: pendin~ medium was remo~ed. Thi~ ~olid, which wa~ ~table ~; on storage, was ~uspended in a hydrocarbon and treated as ~, ~ 25 in Example 1 b. Polymeri~a~ion as described in Example 1 ~ ga~e 149 g of polymer. ~hi~ corre~ponded to a :1 cataly~t-time yield of 9.9 kg PE/mmol Ti.h. The polymer : . had a melt flow index MFI 190/5 of 5.2 g/10 min an~ a :~ melt flow index ratio M~I 190/21.6 to MFI 190/5 of 11Ø
,,, Comparative E~ample ~J. ' In a 2 dm3 four-necked round-bottomed fla~k with a drop-:,~ ping funnel, stirrer, reflux condenser and thermometer, .. .
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114.3 g of magnesium ethylate were dispersed in 1 dm3 of a diesel oil fraction und~r a blanket of N2. 332 g of TiC14 were added drop~ise to this dispersion o~er 5.5 h.
The suspending medium was repeatedly changed until the liquid phase no longer contained titanium. 6 cm3 of TiC14 were added and the suspension was stirred at 125C. ~he Ti concentration in the liquid phase wa~ 28 mmol/dm3 after 18 h, 27 mmol/dm3 after a further 4 h and ~till 24 mmol/dm3 after tempering for a total of 60 hours. The solid was washed once more wi~h a h~drocarbon and then pretreated and polymerized as described in Example 1.

Analytical composition of the catalyst:

~i 5.3~ by weight Mg 23.5% by weigh~
Cl 71.2~ by weigh~

160 g of polyethylene were obtained ~rom the polymeri2a-tion. The polymer had an MFI 190/5 of 3.1 g/10 min and a melt flow index ratio ~FI l90/21.6 to MFI 190~5 of 11, Example 4 lO0 dm3 of a diesel oil fraction, 40 mmol of aluminum triethyl and 1.2 g of component a treated according to Example 1 b were placed in a 150 dm3 kektle. 6.4 kg ethylene/h and the amount of H2 required to gi~e a con-centration of 36% by ~olume were then introduced at a temperature of 85C. After 4 h, the pol~merization was ~topped at a pressure of 6.6 ~ar by relea~ing the pres-sure. The suspen~ion was filtered and the pol~mer was drie~ by having hot nitrogen passed over it. 25.5 kg of product were obtained, corre~ponding to a catalys~ yield of 21 kg/g cataly~t. The polymer had an MFI 190/5 of 0.8 ; g/10 min and a ratio MFI l90/21.6 to MFI l90/5 of 13.
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Example~ 5 to 7 The copolymerization result~ obtained analogously to Example 4 with butene, propene and hexene as comonomers are listed in Table 1.

Table 1: Copolymer~

Polymeriza- Yield MFI 190~5 MYI 190~21.6 ; tion tLme to MFI 190/5 h kg g/10 min Ex. 5 170 cm3 of but-l-ene 4 25O3 1.3 15 Ex. 6 260 cm3 Of propene 3.7523.6 1.7 17 . .
Ex. 7 620 cm3 Of h~x-l-ene 3.824.3 1.1 12 .

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Claims

1. A process for the manufacture of a poly-1-olefin by the polymerization of a l-olefin of the formula R4CH=CH2, in which R4 is hydrogen or an alkyl radical having 1 to 10 carbon atoms, in suspension or in the gas phase, at a temperature of 20 to 200°C and a pressure of 0.5 to 50 bar, in the presence of a catalysst consisting of the reaction product of a magnesium alcoholate and titanium tetrachloride (component a) and a metal-organic compound of a metal from group I to III of the periodic table (component b), wherein the polymerization is carried out in the presence of a catalyst whose component a has been manufactured by reacting a magnesium alcoholate with titanium tetrachloride in a hydrocarbon at a temperature of 50 to 100°C, in a first reaction step, and then sepa-rating off part of the soluble constituents and subject-ing the resulting solid to a heat treatment at a tempera-ture of 110 to 200°C for 8 to 100 hours, in a second reaction step.

2. A process as claimed in claim 1, wherein component a has been manufactured by reacting a magnesium alcoholate of the formula Mg(OR)2, in which R is identical or different alkyl radicals having 1-6 carbon atoms, with titanium tetrachloride in a hydrocarbon at a temperature of 50-100°C, in the first reaction step, and then sepa-rating of f part of the soluble constituents and subject-ing the resulting solid to a heat treatment at a tempera-ture of 110-200°C for 8 to 100 hours, in a second re-action step.

3. A process for the manufacture of a poly-1-olefin as claimed in claim 1 and substantially as described herein.