AU612277B2

AU612277B2 - Process for the manufacture of 1-olefin polymers

Info

Publication number: AU612277B2
Application number: AU39056/89A
Authority: AU
Inventors: Martin Antberg; Volker Dolle; Jurgen Rohrmann; Walter Spaleck; Andreas Winter
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1988-07-29
Filing date: 1989-07-28
Publication date: 1991-07-04
Anticipated expiration: 2009-07-28
Also published as: ZA895770B; JPH0275605A; DE3825814A1; AU3905689A; EP0355439A3; EP0355439A2

Description

Form COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

6122 77 Class I t. Class Application Number: Lodged: Complete Specification Lorlged: rs Oo 0 0 Accepted: Published: Prioility Related Art: 0 HOECHST AKTIENGESELLSCHAFT .Nome of Applicant: Address of Applicant Actual Inventor: *Ad~ess for Service: 50 Bruningstrasse, D-6230 Frankfurt/Main Germany 80, Federal 1kepublic of ANDREAS WINTER, VOLKER D-OLLE, MARTIN ANTBERG, JURXGEN WALTER SPALECK ROH-RMANN and RXVNXM~kM8GXX0WaterarkPatent Trademark Attorneys 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: PROCESS FOR THE MANUFACTURE OF 1-OLEFIN POLYMERS The following statement is a full description of this invention, including the best method of performing it known to HOECHST AKTIENGESELLSCHAFT Dr.DA/gm HOE 88/F 186 Description Process for the manufacture of 1-olefin polymers The invention relates to a process for the manufacture of 1-olefin polymers with a molecular weight distribution of adjustable breadth and with a high isotacticity.

Soluble metallocene catalysts based on bis(cyclopentadienyl)zirconium dialkyl or bis(cyclopentadienyl)zirconium dihalide in combination with oligomeric aluminoxanes are 6 c known. This system can be used to polymerize ethylene 15 and propylene with moderate activity, although no iso- "o tactic polypropylene is obtained.

tc Isotactic polypropylene can be manufactured with the aid t E I of ethylene-bis(4,5,6,7-tetrahydroinden-1-yl)zirconium dichloride together with an aluminoxane by suspension polymerization European patent application A 185 918). The polymer has a narrow molecular weight distribution (Mw/Mn of 1.6 to which is advantageous for certain applications, for example for high-performance injection molding.

A special method has also been proposed for preactivating the metallocene with an aluminoxene, which results in a considerable increase in the activity of the catalyst .I 30 system and in a marked improvement in the morphology of the polymer particles German patent 37 28 067).

'hese polmers Blso have a narrow molecular weight distribution (Mw/Mn of 1.9 to 2.2).

Furthermore, catalysts based on ethylene-bis(indenyl)hafnium dichloride and ethylene-bis(4,5,6,7-tetrahydroinden- 1-yl)hafnium dichloride and methylaluminoxane are known which can be used to manufacture higher-molecular polypropylenes by suspension polymerization J.A. Ewen '1 2 et al., J. Am. Chem. Soc. 1.0 (1987) 6544).

With Mw/Mn values of 2.1 to 2.4, the polymer products manufactured by this process also have a narrow m6lecular weight distribution.

9u-A- 3 2 21 7 The same applies to the polymers manufactured in f= I "B -&8/F-87 0] with rac-dimethylsilyl-bis(indenyl)hafnium dichloride and rac-phenylmethyl-bis(indenyl)hafnium dichloride and methylaluminoxane (Mw/Mn 2.0 to 2.7).

While narrow molecular weight distributions are advantageous for applications such as injection molding, pre- Scision injection molding and fiber production, a medium t 15 to broad molecular weight distribution has advantages for c applications such as deep drawing, extrusion, hollow body St C t e blow molding and film and sheet production. It is known that simultaneous polymerization by means of two or more metallocene catalyst systems produces polyethylene with a broad molecular weight distribution (Mw/Mn up to 7.8) European patent application A 128 045). Because several catalyst systems are used, however, such a material has a reduced homogeneity. In liticn, the achiral catalysts described produce only atactic polypropylene in the polymerization of propylene, which is not of great V. interest to industry.

It is known to manufacture stereoblock polypropylene with a molecular weight distribution Mw/Mn of 13-15 using a 30 tetramethylethylene-bis(cyclopentadienyl)titanium dichioride and methylaluminoxane German patent 3640924].

However, this achiral catalyst system is not capable of producing highly isotactic polymer.

Moreover, the molecular weights obtained at the high polymerization temperatures relevant to industry are comparatively low.

-J

r 3 The object was therefore to find an industrially applicable process which made it possible to manufacture highly isotactic polymer with a broad molecular weight distribution using a single metallocene catalyst.

It has been found that the use of hafnocene systems at particular polymerization temperatures makes it possible to manufacture polymers with broad molecular weight distributions.

The invention thus relates to a process for the manufacture of a 1-olefin polymer by the polymerization of a 1olefin of the formula R-CH=CH2, wherein R is an alkyl group having 1 to 28 C atoms, or by the copolymerization of these olefins with one another or with ethylene at a temperature of -60 to 200°C, at a pressure of 0.5 to 100 bar, in solution, in suspension or in the gas phase, in the presence of a catalyst consisting of a hafnocene of formula o 8 C a Cr 1 4t C 48cC @888, 1 8C 8 1 C 8 8 a f o 8 s o t* t t 6

R

3

R

R Hf I I R2 R7-'4 nn wherein

R

1 and R 2 are identical or different and are a hydrogen atom, a halogen atom, a Ci-Cio-alkyl &roup, a Ci-Cio- 30 alkoxy group, a Ce-Cio-aryl group, a Ca-Cio-aryloxy group, a C2-Cio-alkenyl group, a CT-C4o-arylalkyl group, a C7-C4o-alkylaryl group or a Ca-C4o-arylalkenyl group,

R

3 and R 4 are identical or different and msononuclear or polynuclear hydrocarbon radical which can form a sandwich structure with the central atom,

R

5 is i: r

'K

Re 19

R

Re Re I I -M M 1.9 19 Re 19 1

R

Re -0-M0- Re Re I I 0-M-

R

9

R

9 Re Re R R 9 Re

I

-0-M- 19

R

8 =BRB, =AlRB, =S02, =NR8, =PRB, =C=0 or =P(0)Rs, wherein Re, R9 and RIO are identical or different and are a hydrogen atom, a halogen 0:60 atom, a Ci-Cio-alkyl group, a Ci-Cio-fluoroalkyl group, a a 15 Ci-Cio-alkoxy group, a Ce-Cio-aryl group, a Cs-Cio- .4:::fluoroaryl group, a Cs-Cio-aryloxy group, a C2-CIOalkenyl group, a C7-C4o-arylalkyl group, a CB-C4o-arylalkenyl group or a C7-C4o-alkylaryl group, or Rs and R 9 or RB and RIO in each case form a ring together with the atoms to which they are bonded, M1 is silicon, germanium or tin and p is 1, 2 or 3, R8 and R 7 are identical or di'ferent and are a group 6 =CR8R9, wherein R8 and R9 are as defined above, and m and n are identical or different and are zero,- 1 or 2, rn-in being zero, 1 or 2, and of an aluminoxane of formuia (11): 60 B a a 9 tO at t 30 I OS Ri I A 0 -Al 01_q AlK for the linear typa and/or of formula (III): [R1 0 J

(II)

(III)

for the cyclic type, in which formulae (II) and (III) R11 is a Ci-Ce-alkyl group and q is an integer from 2 to in which process the polymerization is carried out at a temperature at which the polymer obtained has a bimodal molecular weight distribution.

A variety of transition metal components can be used for the process according to the invention.

These are stereorigid chiral hafnocenes of formula

RR

3 R -R 3 SRf

R

5 Hf"I) 15 2 Rn R 4 4 1

R

1 and R 2 are identical or different and are a hydrogen atom, a Ci-Cio-, preferably Ci-C3-alkyl group, a Ci-Cio-, preferably Ci-Cs-alkoxy group, a Ce-Cio-, preferably Cs- Cs-aryl group, a Ce-Cio-, preferably Ce-Ce-aryloxy group, a C2-C1o-, preferably C2-C4-alkenyl group, a C7-C40-, preferably C7-Cio-arylalkyl group, a C7-C4o-, preferably C7-C1i-alkylaryl group, a Cs-C4o-, preferably Cs-C12arylalkenyl group or a halogen atom, preferably chlorine.

R

3 and R 4 are identical or different, preferably identical, and are a mononuclear or polynuclear hydrocarbon radical which can form a sandwich structure together with 30 the central atom. Examples of such radicals are the indenyl, tetrahydroindenyl or cyclopentadienyl group and heteroaromatic ligands.

R

5 is R R 8

R

8

R

8 8 I I I 10 1 -M 0- R R R R R

KL;

6 8

R

8 1 10 1 (CR2 )p-M 19 19 R R

R

8

R

8 I I -M-0-M- 19 19 R R R8

I

19

R

8

-C-

=BRe, =AIR s =S02,

=NR

8

=PR

s =C=O or =P(O)RL, wherein Re, Re and Rio are identical or different and are a hydrogen atom, a halogen atom, preferably fluorine, a C1-Cio-, preferably Ci-C4alkyl group, a Ci-Cio-, preferably Ci-C-fluoroalkyl group, a Ci-Cio-, preferably C1-C3-alkoxy group, a Ce- Cio-, preferably Ce-Ce-aryl group, a Ce-Cio-, preferably Ce-Ce-fluoroaryl group, a Ce-Cio-, preferably Ce-Ce-aryloxy group, a C2-Cio-, preferably C2-C4-alkenyl group, a C7-C40-, preferably CT-Clo-arylalkyl group, a Cs-C4o-, preferably Ce-C12-arylalkenyl group or a C7-C4o-, t preferably CT-C12-alkylaryl group, or RB and Re or R e and Rio in each case form a ring together with the atoms to U which they are bonded. M is Si, Ge or Sn and p is 1, 2 or 3. R5 is preferably =SiR8R9, =S=0 or =PRB.

R

e and R 7 are identical or different and are a group =CReR 9 wherein R 8 and R 9 are as defined above.

m and n are identical or different and are zero, 1 or 2, m+n being zero, 1 or 2. m and n are preferably zero or 25 1.

1.

4. 4i 4. 4.

1c 4.

i iI 4. 44 The hafnocenes are used as the racemate for the manufacture of highly isotactic poly-1-olefins, but it is also possible to use the R or S form. Optically active poly- 30 mer can be manufactured with these pure stereoisomZric forms. The meso form of the metallocenes must be separated off, however, because the center in these cou.pounds which is active in polymerization (the metal atom) is no longer chiral, due to mirror symmebL., at the central metal, and is therefore unable to produce highly isotactic polymer. This does not apply, however, if the meso form can be converted to a chiral specie; under polymerization conditions.

/i 7 It is known in principle how to separate the stereoisomers.

The metallocenes described above can be prepared according to the following reaction scheme:

H

2

R

3 ButylLi 4HR 3

L

H

2

R

4 ButylLi H R 4

L

(X Cl, Br, J, O-Tosyl)

X-R

6

-R

5

-R

7

-X

M n

HR

3 R6-R 5 -R7-R 4

H

3 _R6_R 5 _R7_R 4 H 2 ButylLi 4+ LiR 3

-R

6

-R

5

-R

7

-R

4 Li In n o t 4

I

'it I I ti~ it I I C ft it

I

LiR 3

-R

6

-R

5

-R

7

-R

4 Li in n

R-R

4 R5 Hf owl C l 1n *41* 4 41 14 4 44 a a I II 44 .4 0

R

6

-R

3 I ~Cl R Hf RiLi>- R6-R3 I

R

->R

5 7 R7_ R4 n 4, 0 0 .4 30 4 44 It 'Is especially preferred to use the following metallocene compounds: rac-bis( indenyl) (dialkylsilyl)hafnium dichlorides, rac-bis(indenyl) (arylalkylsilyl)hafnium dichlorides and rac-biB(indenyl) (alkylene)hafnium dichlorides.

The activator is an aluxninoxane of formula (II): 8 R11 R11 R 1 1 Al 0 Al 0 Al I I for the linear type and/or of formula (III): 1 1 Ii

(III)

Al 0 -(I o q+2 o t 0 0 t for the cyclic type. In these formulae, R 1 1 is a Ci-Csalkyl group, preferably methyl, ethyl or isobutyl, in particular methyl, and q is an integer from 2 to 50, preferably 15 to The aluminoxane can be prepared in a variety of ways.

60,, O 0 e 0 In one process, finely pohdered copper sulfate pentahydrate is suspended in toluene and, in a glass flask, 25 aluminum trialkyl is added, under inert gas at about in an amount such that about 1 mol of CuSO4*5H20 is avai.' ble for every 4 Al atoms. After slow hydrolysis with alkane elimination, the reaction mixture is left for 24 to 48 hours at room temperature, during which time it must be cooled, if necessary, to prevent the temperature from rising about 30*C. The aluminoxane dissolved in the toluene is then separated from the copper sulfate by filtration and the solution is concentrated under vacuum.

It is assumed that, in this preparative process, the lowmolecular aluminoxanes condense to form higher-molecular oligomers with the elimination of aluminum trialkyl.

t- Furthermore, aluminoxanes are obtained when aluminum trialkyl, preferably aluminum trimethyl, dissolved in an I r a Ii a I t I tt II i I I I 1- I -7 9 inert aliphatic or aromatic solvent, preferably heptane or toluene, is reacted, at a temperature of -20 to 100*C, with aluminum salts containing water of crystallization, preferably aluminum sulfate. The volume ratio of solvent to aluminum alkyl used is 1:1 to 50:1 preferably 5:1 and the reaction time, which can be monitored by means of the alkane eliminated, is 1 to 200 hours preferably to 40 hours.

Aluminum salts containing water of crystallization which are used in particular are those with a high content of water of crystallization. Alum.num sulfate hydrates are especially preferred, in particular the compounds Al2(SO4)3-18H20 and Al2(SO4)3s16H20 with the especially high contents of water of crystallization of 16 and 18 mol of H0O/mol of Al2(SO4)s respectively.

Another variant for the preparation of aluminoxanes consists in dissolving aluminum trialkyl, preferably alu- 20 minum trimethyl, in the suspending agent, preferably in the liquid monomer or in heptane or toluene, previously placed in the polymerization kettle, and then reacting the aluminum compound with water.

There are other processes for the preparation of aluminoxanes which can be used in addition to those described above. The exact molecular structure of the aluminoxanes is not precisely known, so formulae II and III above only represent an approximate structure.

Before it is used in the polymerization reaction, the metallocene is preferably preactivated with an aluminoxane of formula (II) and/or (III), which markedly increases the polymerization activity.

The preactivation of the transition metal compound is carried out in solution, the metallocene preferably being dissolved in a solution of the aluminoxane in an inert hydrocarbon. An aliphatic or aromatic hydrocarbon is

I

II+t 4 4I4 I I

J

i

I

suitable for this purpose.

Toluene is t-eferably used.

o 94 *9 4 9, C 999 t *t C 9 4 9996 99 99 9 99 The concentration of the aluminoxane in the solution is in the range from approx. 1% by weight to the saturation limit, preferably from 5 to 30% by weight, based in each case on the total solution. The metallocene can be used in the same concentration, although it is preferably used in an amount of 10- 4 1 mol per mol of aluminoxane. The preactivation time is 5 minutes to 60 hours, preferably to 60 minutes. The reaction temperature is -78°C to 100*C, preferably 0 to 15 A substantially longer preactivation t.me is possible, although normally its effect is neither to increase nor to decrease the activity. However, it can be quite useful for storage purposes.

Preferably, the same aluminoxane is used for preactivation as for polymerization.

The catalyst to be used according to the invention is employed for the polymerization of 1-olefins of the formula R-CH=CH2, wheocir R is alkyl radical having 1 to 28 C atoms, preferably 1 to 10 C atoms, in particular one C atom, for example pi 'pylene, but-1-ene, he:-a.n, 4-methylpent-l-ene or oct-1-ene. Propylene is eepeai&lly preferred. Furthermore, the uatalyst is also used for the copolymerization of these olefins with one another and with ethylene, it being possible to copolymerize more than 50% by weight of ethylene.

The polymerization is carried out in known manner in solution, in suspension or in the gas phase, continuously or batchwise, in one or more steps, at a temperature of to 200*C, preferably -20 to 120, in particular 0 to 800C. The breadth of the molecular weight distribution can be adjusted by choosing the polymerization temperaj 11 ture within this range.

Gel permeation chromatography (GPC) tests on polymer samples prepared at a polymerization temperature of 20 to 100°C show that the initially narrow molecular weight distribution of the polymer product becomes broader with increasing polymerization temperature and that further growth of the high-molecular component at a polymerization temperature typical for the particular hafnocene finally produces a distinctly broad, bimodal distribution. At still higher polymerization temperature, the low-molecular component then disappears and the molecular weight distribution becomes monomodal and narrow again.

The polymerization temperature at which the molecular weight distribution of the polymer is of optimum bimodality and hence of maximum breadth must therefore be determined individually for each hafnocene.

Proportionately narrower distributions can then be selected at lower or higher polymerization temperatures. It is preferable to select the higher polymerization temperature as this affords a higher polymerization activity of the hafnocene and a higher molecular weight of the polymer products manufct-red.

The pressure is 0.5 to 100 bar. lymerization prefers ably takes place in the pressure range fro.w 5 to 60 bar, 4 J which is of particular interest to industry.

S. The metallocene compound is used in a concentration of 10-3 to 10-'r mol, preferably 10-4 to 10-6 mol of transition metal per dm 3 of solvent or per dms of reactor volume. The aluminoxane is used in a concentration of 10-4 to 10-1 mol, preferably 10-3 to 10-2 mol per dm 3 of solvent or per dms of reactor volume. In principle, however, higher concentrations are slao possible.

Before the metallocene is introduced into the polymeriza- 12 tion system, it is advantageous first to stir the aluminoxane for a few minutes together with the polymerization medium, e.g. liquid propylene. The stirring time is preferably 10 to 30 minutes, although a shorter stirring time is also possible without making significant sacrifices; a longer stirring time has no notable effect on the polymerization result.

If the polymerization is carried out in suspension, the reaction is performed in an inert solvent conventionally used for the Ziegler low-pressure process, for example in an aliphatic or cycloaliphatic hydrocarbon; examples of C C 'cc such hydrocarbons which may be mentioned are butane, o r pentane, hexane, heptane, isobutane, isooctane, cyclo- 15 hexane and methylcyclohexane. It is also possible to use a naphtha or hyarogenated diesel oil fraction from which /C oxygen, sulfur compounds and moisture have been carefully C removed. Toluene can also be used. Preferably, the monomer to be polymerized is used as the solvent or suspending agent.

The molecular weight of the polymer can be regulated in

SW

known manner, hydrogen preferably being used for this purpose. The polymerization time is arbitrary since the 25 loss of polymerization activity shown by the catalyst system to be used according to the invention is only slightly time-dependent.

00 o *o The polymers manufactured by means of the process according to the invention have a high molecular weight, a high isotacticity and a molecular weight distribution Mw/Mn whose breadth can va-y from 4 to 15, preferably 4 to The following Examples will serve to illustrate the invention. The abbreviations used have the meanings given below: VN viscosity number in cm 3 /g, Mw weight-average molecular weight in g/mol,

(I

i 13 Mn number-average molecular weight in g/mol, Mw/Mn molecular weight distribution determined by gel permeation chromatography (GPC), and II isotacticity index determined by IsC NMR spectroscopy Example 1 A dry 16 dm 3 kuLcle was flushed with nitrogen and filled with 10 dms of liquid propylene. 30 cm s of a toluene solution of methylaluminoxane (corresponding to 68 mmol of Al, average degree of oligomerization n 20) were then added and the reaction mixture was stirred at for 15 minutes. In a parallel procedure, 22.4 mg (0.044 S, 15 mmol) of rac-ethylene-bis(indenyl)hafnium dichloride were cr dissolved in 15 cm 3 of a toluene solution of methylaluminoxane (34 mmol of Al) and preactivated by standing for S" 15 minutes. The solution was then introduced into the kettle. The polymerization v'ystem was brought to a ternperatur of 65°C and kept for 6 h at this temperature.

2.15 kg of polypropylene were -tained. The activity of the metallocene was therefore 12." kg of PP/g of metal- Ot locene x h.

Mw 85,700, Mn 13,400, Mw/Mn 6.4; II 95.7%.

The molecular weight distribution of the polymer sample was bimodal.

Comparative Example A The procedure was the same as in Example 1 except that polymerization was carried out for I h at 70°C. C.4 kg of polypropylene was obtained. The activity of the metallocene was therefore 17.9 kg of PP/g of metallocene x h.

hM 173,000, Mn 54,600, Mw/Mn 3.2; the molecular weight distribution of the polymer sample was monomodal.

I1 L r i i 1 0 14 Comparative Example B The procedure was the same as in Example 1 except that 24.9 mg (0.049 mmol) of the metallocene were used and the polymerization temperature was 60'C. 2.36 kg of polypropylene were obtained. The activity of the metallocene was 11.8 kg of PP/g of metallocene x h.

Mw 65,500, Mn 18,400, Mw/Mn 3.6; the molecular weight distribution of the polymer sample was monomodal.

Comparative Examples C-E Polymerizations were carried out at 50, 40 and analogously to Example 1. The molecular weight distribu- 15 tions were monomodal and the Mw/Mn values were 3.3, 2.9 and 2.6.

Example 2 C C* CC T C C C C C A dry 16 dm 3 kettle was flushed with nitrogen and filled with 10 dm 3 of liquid propylene. At 30°C, 45 cm 3 of a t otoluene solution of methylaluminoxane (corresponding to 102 mmol of Al, average degree of oligomerization n and 53.6 mg (0.11 mmol) of rac-ethylene-bis(indenyl)- 25 hafnium dichloride, dissolved in 50 cm 3 of toluene, were added. The polymerization system was then kept at for 5 h. 0.37 kg of pclypropylene was obtained. The activity of the metallocene was therefore 1.4 kg of PP/g S'i of metallocene x h.

Mw 140,000, Mn 26,300, Mw/Mn 5.3; the molecular weight distribution of the polymer sample was bimodal.

Example 2 differs from Example 1. in that it dispenses with preactivation of the metallocene in the toluene solution of aluminoxane, the total amount of aluminoxane being introduced direct into the polymerization system.

i, a j r Example 3 The. procedure was the same as in Example 1 except that 51 mg (0.095 mmol) of rac-dimethylsilyl-'is(indenyl)hafnium dichloride were used. The polymerization temperature was and the polymerization time was 5 h.

2.1 kg of polypropylene were obtained. The activity of the metallocene was 8.2 kg of PP/g of metallocene x h.

Mw 179,000, Mn 33,770, Mw/Mn 5.3; the molecular weight distribution of the polymer sample was bimodal.

:cc Example 4 c c c The procedure was the same as in Example 1 except that 100 mg (0.168 mmol) of rac-phenylmethylsilyl-bis- (indenyl)hafnium dichloride were used. The polymeriza- Ct r ion temperature was 65*C and the polymerization time was h. 0.45 kg of polypropylene was obtained. The activity of the metallocene was 0.9 kg of PP/g of metallocene x h.

C' L CMw 229,000, Mn 49,400, Mw/Mn 4.6; the molecular weight distribution of the polymer sample was bimodal.

Comparative Example F The procedure waa the same as in Example 4 except that the polymerization temperature was II t 1.28 kg of polypropylene were obtained. The activity of the metallocene was 2.6 kg of PP/g of metallocene x h.

Mw 234,000, 83.600, Mw/Mn 2.8; the molecular weight distribution of the polymer sample was monomodal.

Example A dry 16 dms kettle was flushed with nitrogen and filled with 10 dm s of liquid propylene. 17.6 cm s of a toluene solution of methylaluminoxane (corresponding to 40 mmol r 16 of Al, average degree of oligomerization n 20) were then added and the reaction mixture was stirred at for 15 minutes. In a parallel procedure, 72.5 mg (0.11 mmol) of rac-diphenylsilyl-bis(indenyl)HfCl2 were dissolved in 8.8 cm 3 of a toluene solution of methylaluminoxane mmol of Al) and preactivated by standing for minutes. The solution was then introduced into the kettle. The polymerization system was brought to a temperature of 65°C and kept for 5 h at this temperature. 0.55 kg of polypropylene was obtained. The activity was therefore 1.51 kg of PP/g of metallocene h.

Mw 167,000, Mw/Mn 4.9, Mn 34,100.

occ The molecular weight distribution of the polymer sample 0° 'was bimodal.

C

t t C

Claims

1. A process for the manufacture of a 1-olefin polymer by the polymerization of a 1-olefin of the formula R-CH=CH2, wherein R is an alkyl group having 1 to 28 C atoms, or by the copolymerization of these olefins with one another or with ethylene at a temperature~ of -60 to 200*C, at a pressure of 0.5 to 100 bar, in solution, in suspension or in the gas phase, in the presence of a catalyst consis- ting of a hafnocene of formula I tr: R 5 (I) I R wherein P1 and R 2 are identical or different and are a hydrogen atom, a halogen atom, a Ci-Cio-alkyl group, a Ci-Cio- C v alkoxy group, a Ce-Cio-aryl group, P- Ca-Cio-aryloxy group, a C2-Cio-alkenyl group, a 07-04o-arylalkyl group, a C7-C4o-alkylaryl group or a C8-C4o-arylalkenyl group, R 3 and R 4 are identical or dif ferent and are muno- nuclear or polynuclear hydrocarbon radical which can form a sandiwich structure with the central atom, t t R 5 is Re8Re Re Re R9 R 9 R9 R 9 R Re Re R 8 8 8 I I 1- 110 (CR~ 0 M '9 R19 pR P A r 18 =BR 8 =A1R8, =S02, =NR8, =PR8 or =P(0)R s wherein R e Re and Rio are iden- tical or different and are a hydrogen atom, a halogen atom, a Ci-Cio-alkyl group, a C1-Cio-fluoroalkyl group, a Ci-Cio-alkoxy group, a Ce-Cio-aryl group, a Ce-Cio- fluoroaryl group, a Ce-Cio-aryloxy group, a C2-Cio- alkenyl group, a C7-C4o-arylalkyl group, a Ce-C4o-aryl- alkenyl group or a C7-C4o-alkylaryl group, or RB and R 9 or R 8 and Rio in each case form a ring together with the atoms to which they are bonded, M is silicon, germanium or tin and p is 1, 2 or 3, R e and R7 are identical or different and are a group =CRBR 9 wherein R 8 and R 9 are as defined above, and 0 1L m and n are identical or different and are zero, 1 or 2, *m+n being zero, 1 or 2, and of an aluminoxane of formula (II): R11 11 R11 Al 0- Al Al R O q (II) 4 64 1 t q+2 for the cyclic type, in which formulae (II) and (III) R: is a Ci-Ce-alkyl group and q is an integer from 2 to in which process the polymerization is carried out at a temperature at which the polymer obtained has a bimodal molecular weight distribution.

2. The process according to claim 1, wherein the bulk polymerization is carried out using ethylene-bis- 19

3. The process according to claim 1, wherein th.*&.bulk polymerization is carried out using dimethylsilyl-bis- (indenyl)hafnium dichloride at a temperature of 60 to 700 C.

4. The process according to claim 1, wherein -the bulk polymerization is carried out using phenylmt-3thylsilyl- bis(indenyl)hafnium dichloride at a temperature of 60 to 700C. The process according to claim 1, wherein, before polymerization, the -tcmpnn is pre- 0 op01n 0 activated with an aluminoxane of formula (II) and/or 0 (1 C(III) at a temperature of -78 to 1000C for 5 minutes to 0 V, 060 hours. 04 6. The, process mccording to claim 1, wherein the *t-a- o.,4 Stn2 a .44en-meta&l/qomponent is a rac-bis( indenyl) (alkylene)- hafnium dichloride, rac-bis(indenyl) (arylalkylsilYl)- hafnium, dichloride or rac-bis(indenyl) (dialkylsilyl)- hafnium dichloride and the aluminoxane is a methylaltmin- oxane. a 01 GOO DATED this 27th day of July 1989. HOECHST AKTIENGESELLSCHAFT' a a4 IS WATERMARK PATEN"T TRADEMARK ATTORNEYS 0S 50 QUEEN STREET MELBOURNE. VIEC. 3000.