AU601769B2 - Catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, process for the preparation thereof and process for the polymerization of alpha-olefins in the presence thereof - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATIp7

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: I his docum :nt cot~naiv.5 ti.

Published: amendments made und r Section 49 and is correct for Priority printing Related Art: APPLICANT'S REFERENCE: S 86/20 Name(s) of Applicant(s): Solvay Cie Societe Anonyme Address(es) of Applicant(s): Rue du Prince Albert, 33, B-1050 Brussels,

BELGIUM.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: CATALYTIC SOLID WHICH CAN BE USED FOR THE STEREOSPECIFIC POLYMERIZATION OF ALPHA-OLEFINS, PROCESS FOR THE PREPARATION THEREOF AND PROCESS FOR THE POLYMERIZATION OF ALPHA-OLEFINS IN THE PRESENCE THEREOF Our Ref 68388 POP Code: 1659/1659 The following statement is a full description of this invention, including the best method of performing it knom to applicant(s): 6003q/l ul ln* lrair* *r l- iir-L i; ii i 1A- The present invention relates to a catalytic solid which can be used for the stereospecific polymerization of alpha-oLefins, to a process for the preparation of this solid and to a process for the polymerization of alphaolefins in the presence of this solid.

The stereospecific polymerization of alpha-olefins such as propylene using a catalytic system which comprises a titanium trichloride-based solid constituent and an activator which consists of an organometallic compound such as an alkylaluminium chloride is known.

Hyperactive solid catalytic complexes based on

TICL

3 with a high internal porosity which enable propylene polymers with very good stereoregularity to be obtained have been described in patent BE-A-78/0,758 (SOLVAY Cie).

A preactivation treatment of these hyperactive solid catalytic complexes which enables them to be stored under hexane for long periods of time without losing their qualities has been described in patent BE-A-80/3,875 (SOLVAY Cie). The preactivator employed may be chosen from amongst organoaluminium compounds and in particular, depending on formula which specifies their nature, from amongst hydrocarbyl hydrocarbyl oxyhalides of aluminium. However, diethylaluminium chloride, ethylatuminium sesquichloride, ethylaluminium dichloride and triethylaluminium are used in practice.

Unfortunately, the stereospecificity of these catalytic complexes is not adequate under all cenditions of polymerization under which they may be required to be used and is inadequate especially at the relatively high temperatures at which the polymerization of propylene in the gaseous phase is often carried out. In fact, when pol/merization is carried out at relatively Low temperatures, a significant decrease in productivity of the catalyst is observed.

Attempts have been made 'o overcome this disadvantage by carrying out the polymerization of propylene in the presence of catalytic systems which comprise the hyperactive solid catalytic complexes mentioned above, k L' I i r

.C

i'

B

1 I-rc ~urrslL 2 modified by the introduction of a third constituent, which is generally an electron donor compound (Lewis base), into the polymerization medium. A very Large number of electron donor compounds of various types have already been proposed as the third constituents capable of increasing the stereospecificity of these catalytic systems (see for example patent BE-A-82/2,941 Among this very Large number of electron donor compounds which can be employed for this purpose, some phenolic compounds (European Patent Application EP-A-0,036,549 (BASF)) and some hydroxyaromatic compounds (US Patent Application US-A-4,478,989 (SHELL OIL)) have, in particular, been proposed. However, the improvement in stereospecificity obtained by the introduction of such electron donor compounds into the polymerization medium is significant only when the quantity uf the electron donor compound is relatively high (the weight oY electron donor compound is generally at least equal to the weight of the solid catalytic complex present in the medium and often much higher). As a result, deleterious secondary effects such as an unacceptable drop in the productivity of the catalyst and the appearance of interfering colours in the polymer collected, not to mention the complications which may be caused the requirement to remove the residues of the third constituent from the polymer, are observed.

The present invention aims at providing a catalytic solid with a very high stereospecificity, without the need for introducing a third constituent into the polymerization medium.

-To-h i e a ot an,-tha prasa n a nt o te to Gornplexed titanium trichloride-based catalytic olids which can be used for :Le stereospecific poly rization of alpha-olefins, preactivated by bringi them into contact with an organoaluminium preacti tor comprising the product of reaction between an rganoatuminium compound (a) and a compound chos from amongst hydroxyaromatic compounds, the hydr yl group of which is sterically hindered.

1 C~Lha i _i I _ii~l I According to the present invention, there is provided a complexed titanium trichloride-based catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, which has been preactivated by chemical binding with an organoaluminium preactivator, wherein the said preactivator comprises the reaction product prepared by bringing into contact a compound chosen from amongst organoaluminium compounds with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is sterically hindered; I wherein said preactivator does not include the reaction products resulting from the contact of an aluminium alkyl of formula A-Al-B

Z

where A and B are each an alkyl radical of not more than 8 Scarbon atoms and Z is a chlorine atom or an alkyl radical of not more than 8 carbon atoms with a sterically hindered phenolic compound having a tendency to crystallize out of solution with heptane at low temperature in a mole ratio of the aluminium alkyl to the phenolic compound of 1:1 to 1:3.

The present invention also provides a process for the preparation of a complexed titanium trichloride-based catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, preactivated by chemically binding an organoaluminium activator onto a complexed titanium trichloride-based solid precursor, wherein the said preactivator comprises the reaction product prepared by bringing into contact a compound chosen from amongst organoaluminium compounds with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of Swhich is sterically hindered, the reaction products resulting from complexed titanium trichloride-based catalytic' solid which can be used for the stereospecific polymerization of alpha-olefins, which has been preactivated by chemical binding with an organoaluminium preactivator, wherein the said preactivator comprises the reaction product prepared by bringing into contact a -2a- II~LC YL -Li 1 I)O r 0, r oo

C-

o 0/ 9

III

9 4 *Il compound chosen from amongst organoaluminium compounds with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is sterically hindered; wherein said preactivator does not include the reaction products resulting from the contact of an aluminium alkyl of formula A-Al-B

I

Z

where A and B are each an alkyl radical of not more than 8 carbon atoms and Z is a chlorine atom or an alkyl radical of not more than 8 carbon atoms with a sterically hinderedphenolic compound having a tendency to crystallize out of solution with heptane at low temperature in a mole ratio of the aluminium alkyl to the phenolic compound of 1:1 to 1:3.

The present invention further provides a process for the polymerization of alpha-olefins in the presence of a catalytic system containing an organometallic compound of metals of groups la, IIa, Iib and IIIb of the Periodic Table and complexed titanium trichloride-based catalytic solid which has been preactivated by chemically binding with an organoaluminium preactivator, wherein the said polymerization is carried out in the presence of a complexed titanium trichloride-based catalytic solid according to the present invention.

The present invention still further provides a process for the polymerization of alpha-olefins in the presence of a catalytic system containing an organometallic compound of metals of groups la, lHa, IIb and IIIb of the Periodic Table and complexed titanium trichloride-based catalytic solid which has been preactivated by chemically binding with an organoaluminium preactivator, wherein the said polymerization is carried out in the presence of a complexed titanium trichloride-based catalytic solid prepared according to the process of the present invention.

The complexed titanium trichloride-based solids .2&N -2b- _i i~ l'i_ II 3 C -3employed as precursors for the preparation of the preactivated catalytic solids according to the present invention may be obtained by any known process. The use of solids obtained by processes which involve an initial reduction of titanium tetrachloride is generally preferred.

This reduction may be carried out using hydrogen or metals such as magnesium and preferably aluminium. Best results are obtained starting with solids produced by the reduction of titanium tetrachloride with an organometallic reducing agent. This may, for example, be an organomagnesium reducing agent. However, the best results are obtained with organoaluminium reducing agents The organoaluminium reducing agents which may preferably be employed are compounds which contain at least one hydrocarbon radical directly bound to the I aluminium atom. Examples of compounds of this type are *mono-, di- and trialkylaluminiums, the alkyl radicals S'which contain from 1 to 12, and preferably from 1 to 6, carbon atoms, such as triethylaluminium, isoprenylalu- 4 miniums, diisobutylaluminium hydride and ethoxydiethylaluminium. With compounds of this type, best results are obtained with dialkylaluminium chlorides and, in particular, with diethylaluminium chloride.

In order to obtain the complexed titanium trichloride-based solids (hereinafter called "precursors") which are employed for the preparation of the preactivated catalytic solids according to the present invention, r the reduced solids mentioned above are subjected to a 30 treatment with at least one complexing agent which is generally chosen from amongst organic compounds containing one or more atoms or groups having one or more free electron pairs capable of ensuring the coordination with the titanium or the aluminium atoms present in the titanium or aluminium halides. The complexing agent is preferably chosen from the group consisting of aliphatic ethers, and more particularly from amongst those of which the aliphatic radicals contain from 2 to 8 carbon atoms, and preferably 4 to 6 carbon atoms. A typical example iti_-il.-l~. .Li( 4 of an aLiphatic ether which gives very good results is diisoamyl ether.

These treatments with complexing agents, which are appropriate for stabilizing or for improving the productivity and/or the stereospecificity of catalytic solids, are well known and have been comprehensively described in the literature.

Thus, for the preparation of the precursor, the treatment with the complexing agent may consist of a grinding of the reduced solid in the presence of the complexing agent. It may consist of a thermal treatment of the reduced solid in the presence of the complexing agent. It may also consist of washing the reduced solid extractively, in the presence of mixed solvents containing a Liquid hydrocarbon compound and an auxiliary polar solvent, for example an ether. The reduction of titanium tetrichloride may also be carried out with the organo-aluminium reducing agent in the presence of the complexing agent, for example by adding, to the titanium tetrachloride, a hydrocarbon-containing solution of the reaction product of the complexing agent with this reducing agent, and the reduced solid thus obtained may then be subjected to a thermal treatment in the absence of the complexing agent or in the presence of a fresh quantity of complexing agent, which may be identical to or different from the previous. The treatment with the complexing agent may also be carried out with a quantity of the latter which is sufficient to form a homogeneous solution of the titanium trichloride- S' j3ased solid, and the solid thus dissolved may be reprecipitated by heating.

For the preparation of the precursor, the treatment with the complexing agent may be combined with or fol- Lowed by an activation treatment. These activation treatments are also well known and have also been described in the titerature. They are generally carried out using at least one agent chosen from amongst inorganic halogenated compounds, organic halogenated compounds, interhalogenated compounds and halogens. Among these agents, there may be mentioned: 4 5 as inorganic haLogenated compounds, haLides of metals and non-metals, such as, for example, titanium and silicon halides; as organic halogenated compounds, halogenated hydrocarbons such as, for example, halogenated alkanes and carbon tetrahalides; as interhalogenated compounds, for example iodine chloride and iodine bromide; and as halogen, chlorine, bromine and iodine.

Examples of agents which are very well suited for the activation treatment are titanium tetrachloride, silicon tetrachloride, iodobutane, monochloroethane, hexachloroethane, chloromethylbenzene, carbon tetrachloride, i iodine chloride and iodine. Best results were obtained with titanium tetrachloride.

The physical form of the complexing agents and the agents which are used for the optional activation treatment is not critical for the preparation of the precursor.

These agents may be employed in gaseous form or in Liquid form, the latter being the most common form in which they are present under usual temperature and pressure conditions. The treatment with the complexing agent and the optional activation treatment may also be carried out in the presence of an inert hydrocarbon diluent which is generally chosen from amongst liquid aliphatic, alicyclic and aromatic hydrocarbons such as liquid alkanes and isoalkanes and benzene.

Details on the most commonly used operating conditions for the complexation and activation treatments may be found especially in patent 8E-A-86/4,708 (SUMITOMO CHEMICAL COMPANY LTD), in patent US-A-4,295,991 (EXXON RESEARCH AND ENGINEERING CO) and in the documents mentioned in the latter.

4t any time during its preparation, either after the reduction or the complexation stage, or after the optional activation stage, but preferably after the reduction stage, the precursor may be subjected to a treatment aimed at reducing the friability of the constituent particles thereof. This treatment, which is referred to &i u I 6 as "prepolymerization", consists in bringing the solid into contact with a lower alpha-monoolefin such as ethy- Lene, or preferably propylene, under polymerizing conditions so as to obtain a solid which generally contains between approximately 5 and 500% by weight of "prepolymerized" alpha-monoolefin. This "prepolymerization" may advantageously be carried out in a suspension of the solid in the inert hydrocarbon diluent as defined above for a period sufficient to obtain the desired quantity of the prepolymerized alpha-monoolefin on the solid. The precursor obtained according to this variant is Less friable and enables polymers with good morphology to be obtained even when the polymerization is carried out at a relatively high temperature.

For its conversion into preactivated catalytic solid, as described Later, the precursor may be employed as such, i.e. without separating it from the medium in which it was prepared, or, preferably, after separation and optional washing with an inert hydrocarbon diluent as defined above.

A preferred method for the preparation of complexed titanium trichloride-based solids which can be used as precursors for the preparation of the preactivated catalytic solids accordinq to the present invention has been described in patent 8E-A-78/0,758. This method consists in the reduction of titanium tetrachloride using an organoaluminium reducing agent which, in this case, is preferably a dialkylaluminium chloride, the alkyl chains of which contain from 2 to 6 carbon atoms, under mihd conditions. After an optional thermal treatment of the reduced solid thus obtained, the Latter is subjected to a treatment with a complexing agent as de'fined above.

Finally, a treatment with titanium t.trachloride is carried out and the complexed titanium trichloride-based solid thus formed is separated and it is optionally washed with an inert hydrocarbon diluent as defined above, preferably chosen from amongst liquid aliphatic hydrocarbons containing from 3 to 12 carbon atoms and which is, moreover the diluent which may be employed throughout the .i 7 preparation of the said solid.

The preferred preparation method defined in the preceding paragraph Leads to the compLexed titanium trichLoride-based solid particles which are also described in patent BE-A-78/0,758. These particles are spherical and generally have a diameter of between 5 and 100 microns and most frequently between 10 and 50 microns. They consist of an agglomerate of microparticles, which are also spherical, which have a diameter of between 0.05 and 1 micron, most frequently between 0.1 and 0.3 micron and which are extremely porous. As a result, the particles 2 have a specific surface area greater than 75 m /g and most frequently located between 100 and 250 m 2 /g and a total porosity greater than 0.15 cm 3 /g and most commonly between 0.20 and 0.35 cm The internal porosity of the S microparticles forms the most significant contribution Sto this total porosity of the particles, as evidenced by o* the high value for the pore volume corresponding to pores 1* less than 200 A in diameter, which is greater than 0.11 4 3 3 S 20 cm /g and most commonly between 0.16 and 0.31 cm /g.

The complexed titanium trichloride-based solids (precursors) obtained according to the preparation method described in patent BE-A-78/0,758, choosing the preferred Soperating conditions, correspond to the formula: TiCI 3 .(ALR"CL2)x.Cy in which R" is an alkyl radical containing from 2 to 6 carbon atoms, C is a complexing agent as defined above, x is any number less than 0.20 and y is any number grea- Ster than 0.009 and generally less than 0.20.

As an alternative form of this preparation method, 4a there may be mentioned that, mentioned above, which consists in "prepolymerizing" the reduced solid, after the optional thermal treatment and before treatment with the complexing agent, with a lower alpha-monoolefin (propylene) under polymerizing conditions. This "prepolymerization" is carried out in a suspension of the reduced solid in the inert hydrocarbon diluent as defined above, between approximately 20 and 80 0 C, for a period generally between 1 minute and 1 hour.

~Lr~ I I 8 -I According to the invention, the precursor, which is prepared as described above, is brought into contact with an organoaLuminium preactivator comprising the product of reaction between an organoaluminium compound (a) and a compound chosen from amongst hydroxyaromatic compounds, the hydroxyL group of which is stericalLy hindered.

The organoaLuminium compound is generalLy chosen from amongst compounds of formuLa: AL Rn X3-n in which R represents hydrocarbon radicals, which may be identical or different, containing from 1 to 18 carbon atoms, chosen in particular from amongst alkyl, aryL, aryLaLkyl, aikylaryl, cycloalkyL, aLkoxy and aryloxy radicats; X is a halogen and n is a number such that 0 n 3.

In the above formula, R is preferably a straightchain or branched alkyl radical containing from 2 to 8 carbon atoms, X is preferably chlorine and n is preferably such that 1 n 3.

As examples of compounds there may be mentioned: triaLkylaLuminiums such as trimethyl-, triethyl-, tri-o-propyl-, tri-n-butyl-, tri-isobutyl-, tri-n-hexyL-, tri-isohexyl-, tri-2-methylpentyl- and tri-n-octylaluminium; dialkylaluminium monohalides such as diethyt-, di-n-propyl- and di-iso-butyauminium monochlorides, ethylaluminium monofluorides, monobromides and monoiodides; alkylaluminium di- and sesquihatides such as methyland ethylaluminium sesquichLorides and ethyl- and isobutylaLuminium dichlorides; alkoxyaluminium hatides such as methoxyaluminium and iso-butoxyauminium dichtorides; alkoxyalkylaluminiums such as monoethoxydiethylauminium, diethoxymonoethylatuminium and dihexaneoxymono-n-hexylaluminium.

Very good results were obtained with trialkylaluminiums and dialkylauminium chlorides, in particular with triethylaluminium and diethylaluminium monochtLoride.

The compound is chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is _C w -9 sterically hindered. "Hydroxyaromatic compound, the hydroxyL group of which is stericaLLy hindered" refers to all hydroxyaromatic compounds which contain a secondary or tertiary aLkyl radicaL in the two ortho positions re- Lative to the hydroxyL group.

The compound is generaLLy chosen from amongst substituted mono- or poLycyclic hydroxyaryLenes as mentioned above, in particuLar from amongst hydroxybenzenes, hydroxynaph tha Lenes, hydroxyanthracer-es and hydroxyphenanthrenes thus substituted, and the aromatic rings of which may also carry other substituents.

As examples of compounds there may be ment i o n ed monocycLic monophenols which are di-tert- and disec-aLkyLated in the ortho positions relative to the hydroxyL group, such as 2,6-di-tert-butyLphenoL, 2,6-ditert-butyL-4-methyLphenoL, 3,5-tert-butyL-4--hydroxy-thydroxybenzene, 2,6-di-tert-decyL-4-methoxyphenoL. 2,6d i-tert-butyL-4-isopropyLphenoL, 2,6-dicycLohexyL-4methyLphenoL, 2,6-diisopropyL-4-methioxyphenoL and 2,6di-tert-butyL-4-sec-butyLphenoL; -5'-di-tert-butyL-4-hydroxyphenyL )prop ioni-.

acid monoesters such as methyl, ethyl, n-propyL, n-butyL, I n-octyL, n-dlodecyL and n-octadecyL 3-(3',5'-dli-tertbutyL-4-hydroxyphenyL )propionates; poLyphenots which are di-tert-atkytated -n the ortho positions relative to tt'e hydroxyt groups, such as 2,2-bis(2,6-di-tert-butyLhydroxyphenyt )propane, di-tert-butyL-4-hydroxybenzyt )methane, 4,4'-methyLenebis(2,6-dli-tert-butyl phenoL, 2,21-niethyLene-bis (4-ethyL- 6-tert-butyl~phenot, 1,3,5-tr imethyL-2,4,6-bis(3,S-ditert-butyL-4-hydroxybenzyL )benzene and tr~s(2,6-dli-terthexyihydroxyphenyL )benzene; ,5 '-di-tert-butyL-4-hydroxyphenyt)propionic acid polyesters such as tetrakistmethytene-3-(3',5'-ditert-butyL-4'-hydroxyphenyL)propionatelmethane; potyclc monophenots which are di-tert- and disec-atkytated in the ortho, positions retative to the hydroxyt group, such as 1I,3-di-tert-butyL-2-hydroxyanthratene, 10 1,3-di-tert-hexyl-2-hydroxyphenanthrene, 2,8-di-tert-butylhydroxynaphthalene, 1,3-di-tert-hexyl-2-hydroxynaphthalene and 1,3-diisoa',yl-2-hydroxynaphthalene.

Very good results were obtained with di-tertalkylated monocyclic monophenols, in particular with 2,6di-tert-butyl-4-methyLphenol and with 3-(3',5'-di-tertbutyl-4-hydroxyphenyl)propionic acid monoesters, in particular with n-octadecyl 3-(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate, the us.e of the latter giving an excellent stereospecificity to the catalytic solids prepared using it.

The general conditions under which compound (a) is brought into contact with compound are not critical insofar as they induce a chemical reaction between these compounds. The reaction is generally carried out in the liquid phase, for example by mixing compound (b) and compound in the absence of a liquid diluent, compound often being liquid under normal temperature and pressure conditions. It is also possible to work in the presence of an inert hydrocarbon diluent as defined above.

The molar ratio in which compound and compound are brought into contact with each other may vary to a large extent. In general, 50 to 0.1 moles of compound are employed per mole of compound the quantity of compound employed is preferably between and 0.5 moles per mole of compou.d very good resulta have been recorded for molar ratios of compound to compound of between approximately 3 and 1.

Compounds and may be brought into con- Stact with each other at temperatures generally between approximately 0 and 90°C, preferably at a temperature in the vicinity of ambient temperature (25 0 C) ard the mixture thereof is maintained for a period sufficient for them to chemically react with each other, which is generally between 5 minutes and 5 hours. This reaction is most often accompanied by a gas evolution which enables its progress to be monitored.

The exact chemical structure of the product of L I rra~ a-P 11 reaction between compounds and is not known with certainty. However, it is almost certain that this product corresponds at Least partiaLLy to the empirical formuLa: Rp AL(OR')q X3-(p+q) in which: R, which has the meaning given above, represents the same hydrocarbon radicaL(s) as that (those) contained in the organoaluminium compound OR' represents the aryloxy group derived from compound X is a halogen; p is a number such that 0 p 3, preferanly such that 0.1 p q is a number such that 0 q 2, preferably such that 0.5 q 1.5; and Ott the sum being such that 0 3.

According to the invention, the organoaluminium preactivator obtained as described above is brought into #4 f contact with the precursor.

The operating conditions under which the preactivator is brought into contact with the precursor are not critical insofar as they bring about at least a partial binding of the preactivator to the said precursor.

Providing this condition is met, this contacting may be carried out by any known process. This contacting may be tarried out, for example, by grinding the precursor which is impregnated with a Liquid phase containing the preactivator.

The preactivator is most often employed in the form of a solution of the following in the inert hydroiarbon diluent optionally employed for the preparation thereof: the reaction product of compound with compound possibly accompanied by the unreacted excess of compound or of compound employed.

In this case, it is preferable to introduce the preactivator solution containing ingredient and possibly ingredient into a suspension of the precursor in this jj 1~-~13U3 YUU~ 12 same hydrocarbon diluent. This suspension is then generally maintained at a temperature between O°C and the normal boiling point of the inert hydrocarbon diluent in which the preactivator was dissolved, preferably between approximately 20 and 40 0 C, for a period generally between approximately 5 and approximately 120 minutes, preferably between 15 and 90 minutes. The respective quantities of precursor and preactivator employed are such that the molar ratio between the total initial quantity of compound employed and the quantity of TiCI 3 present in the -3 precursor is generally between 10 and 10, preferably between 10-2 and 1. Very good results are obtained when the molar ratio defined above is between 0.05 an-d At the end of this preactivatio stage, the catalytic solid thus preactivated is separated from the pre- .o activation medium and washed in order to remove the residues of unbound preactivator, preferably using an inert hydrocarbon diluent of the same type as those optionally employed for the preparation of the precursor and the pre- 20 activator solution.

The preactivated, separated and washed catalytic solid may then be dried, if required. For example, it j may be dried until the residual Liquid hydrocarbon diluent content thereof is less than 1% by weight, preferably less than 0.5% by weight relative to the weight of titanium trichloride it contains, according to the operating conditions described in the patent BE-A-84/6,911 (SOLVAY Cie).

The preactivated catalytic solid thus obtained always contains a certain amount of preactivator which is bound to the solid and which cannot be dissociated from the Latter by purely physical separation methods. The quantity of preactivator in this form is generally between 5 and 500 g per kg of TiCL 3 present in the solid and preferably between 50 and 300 g/kg. Consequently, the preactivated catalytic solid according to the invention contains Less TiCL 3 per unit weight than the solid used as precursor for its preparation. Although the preactivated catalytic solid generally contains at aj.J v ai L aG uy al i ly I VUL L IIC PU l.tIInI 1i a L IuIl uI PI upy I llt in the presence of catalytic systems which comprise the hyperactive solid catalytic complexes mentioned above, I 13 Least 50% by weight of TiCl 3 relative to the total weight, it rarely contains more than approximately 80% of the Latter.

The external morphology of the preactivated cata- Lytic solid particles according to the invention is no different from that of the particles of precursor used in their preparation. Thus, when they are prepared starting with spherical particles consisting of an agglomerate of porous spherical microparticles, they have substantially the same structure, the same dimensions and the same shapes as the particles used at the start. However, the preactivated catalytic solid particles are Less porous, i.e. they are no longer characterized by the high specific surface area associated with the high pore volume which characterizes the particles of the precursor.

o* After being washed and optionally dried, the S, preactivated catalytic solids according to the invention may immediatel.' be brought into contact again with an inert hydrocarbon diluent such as those defined above, 20 which can also be used as diluents in suspension polymerii zation. The preactivated caitalytic solids according to the invention may also be subjected to a "prepolymerization" treatment as described above in connection with the precursor. They may be stored in hexane or in the dry form, preferably in the cold state, for long periods of time without losing their qualities.

For polymerization, the preactivated catalytic solid according to the invention is employed together Swith an activator chosen from amongst organometallic com- S 30 pounds of metals of groups la, Ila, lib and IlIb of the Periodic Table (version published in Kirk-Othmer Encyclopedia of Chemical Technology, 2nd completely revised edition, volume 8, 1965, page 94) and preferably from amongst the compounds of formula: Al Y3-m in which is a hydrocarbon radical containing from 1 to 18 carbon atoms and preferably from 1 to 12 carbon atoms, chosen from amongst alkyl, aryl, arylalkyl, alkylaryt and cycloalkyl radicals; best results are obtained I Lo

~,~LUL

14 when R is chosen from amongst alkyL radicaLs containing from 2 to 6 carbon atoms; Y is a halogen chosen from amongst fLuorine, chlorine, bromine and iodine; best results are obtained when Y is chlorine; m is any number such that 0 m 3 and preferably such that 1.5 m 2.5; best results are obtained when m is equal to 2.

Diethylaluminium chloride (DEAC) ensures maximum activity and maximum stereospecificity of the catalytic system.

The catalytic systems thus defined can be applied to the polymerization of oLefins with terminal unsaturation, containing from 2 to 18 and preferably from 2 to 6 carbon atoms in the molecule, such as ethylene, propylene, 1-butene, 1-pentene, methyl-1-butene, 1-hexene, 3and 4-methyl-1-pentenes and vinylcyclohexene. They are particularly useful in the stereospecific polymerization of propylene, 1-butene and 4-methy-1-pentene into highly isotactic, crystalline polymers. They can also be applied to the copolymeritation of these alpha-olefins between one another as well as with diolefins containing from 4 to 18 carbon atoms. The diolefins are preferably unconjugated aliphatic diolefins such as 1,4-hexadiene, unconjugated monocyclic diolefins such as 4-vinyLcyclohexene, alicyclic diolefins having an endocyclic bridge, such as dicyclopentadiene, methylene- and ethylenenorbornene and conjugated aliphatic diolefins such as butadiene or isoprene.

They can also be applied to the manufacture of the so-called block copoLymers which are formed starting with alpha-olefins and dioLtefins. These block copolymers consist of successions of chain segments of variable I lengths; each segment consists of a homopolymer of an aLpha-olefin or of a random copolymer containing an alphaotefin and at le-ast one comonomer chosen from amongst aLpha-oLefins and diolefins. The atpha-olefins and the diotefins are chosen from amongst those mentioned above.

The preactivated catalytic sotids according to .allr L ~i bm r;rLrarli_ n-rur-- I~L;~;(LIJYnP1~ il ~ei ui-u

I

15 the invention are particuLarly weLL suited to the manufacture of homopoLymers of propyLene and copolymers containing in total at Least 50% by weight of propyLene and preferably 75% by weight of propyLene.

The poLymerization may be carried out according to any known process: in solution or in suspension in a solvent or in an inert hydrocarbon diluent, such as those defined in connection with the preparation of the catalytic solid and which is preferably chosen from amongst butane, pentane, hexane, heptane, cycLohexane, methyLcycLohexane or mixtures thereof. The polymerization may also be carried out in the monomer or with one of the monomers maintained in the liquid state or in the Sgaseous phase. The use of the preactivated cataLytic solids according to the invention is very advantageous in polymerization in the gaseous phase. In fact, insofar as the appearance of amorphous and sticky by-products is particularly harmful in this type of polymerization, the technology of which does not enable them to be removed, the use of highly stereospecific catalytic systems is particularly advantageous.

The polymerization temperature is chosen generally between 20 and 2000C and preferably between 50 and 0 C, the best results being obtained between 65 ano 85 0

C.

The pressure is chosen generally between atmospheric pressure and 50 atmospheres and preferably between 10 and atmospheres. This pressure depends, of course, on the temperature employed.

The polymerization may be carried out in continuous or discontinuous fashion.

The preparation of the so-called block copolymers may also be carried out according to known processes.

The use of a two-stage process which consists in polymerizing an alpha-olefin, generally propylene, according to the method described above for homopolymerization, is preferred. The other alpha-olefin and/or diolefin, generally ethylene, is then polymerized in the presence of the homopolymer chain which is still active. This second polymerization may be carried out after the

'I

_i -1 r i 16 complete or the partial removal of the monomer which has not reacted during the first stage.

The organometallic compound and the preactivated catalytic solid may be added separately to the polymerization medium. They may also be brought into contact with each other, at a temperature of between -40 and 80 0 C, for a period which depends on this temperature and which may range from an hour to several days, before introducing them into the polymerization reactor.

The total quantity of organometallic compound employed is not critical; it is generally greater than 0.1 mmol per litre of diluent, of liquid monomer, or of reactor volume, preferably greater than 0.5 mmol per litre.

The quantity of preactivated catalytic solid employed is determined according to the TiCI 3 content thereof. It is generally chosen so that the concentration of the polymerization medium is greater than 0.01 mmol of TiCL 3 per litre of diluent, of liquid monomer or of reactor volume and preferGbly greater than 0.05 mmol per litre.

The ratio between the quantity of organometallic Scompound and that of the preactivated catalytic solid is not critical either. It is generally chosen so that the molar ratio organometallic compound:TiCL 3 present in the solid is between 0.5:1 and 20:1 and preferably between 1:1 an;d 15:1. Best results are obtained when the molar ratio is between 2:1 and 12:1.

The molecular weight of the polymers manufactured according to the process of the invention may be Sadjusted by adding to the polymerization medium one or more molecular weight-adjusting agents such as hydrogen, diethyl zinc, alcohols, ethers and alkyl halides.

The stereospecificity of the preactivated cata- Lytic solids according to the invention is higher than that of the catalytic complexes described in patent BE-A- 78/0,758, when they are prepared from the Latter. Additionally, this stereospecificity remains unchanged over very Long periods of time, even when the preactivated Ir i Lrne Fs5 d lU IurI p ta i i. %UL Yi Iv ill 111 uiiJI L U III I w 4 .i i .1 the aLiphatic radicals contain from 2 to 8 carbon atoms, and preferably 4 to 6 carbon atoms. A typical example if -d 17 catalytic solids are stored at a relatively high temperature. Therefore, when they are employed, there is no Longer any need to add to the polymerization medium a third constituent which is conventionally known as improving this stereospecificity, such as, for example, an ether or an ester. It is self-evident that such addition of a third constituent to the polymerization medium containing a preactivated catalytic solid according to the invention does not constitute a departure from the sc.ope of the latter; however, such an addition leads, at the very most, to only a marginal improvement in stereospecific i ty.

During the homopolymerization of propylene in the presence of the preactivated catalytic solids. acc.ording to the invention, the proportion of amorphous.polypropylene, determined by measuring the weight of polyprot o' pylene soluble in boiling heptane relative to the solid polypropylene manufactured during the polymerization, is almost always less than This property is conferred to the solid polypropylene manufactured, even when the preactivated catalytic solid has been stored at high temperature (45 0 C) for several weeks.

The following examples serve to illustrate the invention.

25 The symbols used in these examples lave the following meanings: I.I isotacticity index of the polymer, determined by I the fraction of the latter, expressed as a percentage relative to the total quantity of solid polymer collected, which is insoluble in boiling heptane.

G torsional modulus of rigidity of the polymer, determined at 100 0 C and at a torsion angle of 600 of arc, the temperature of the mould being fixed at 70 0 C and the period of conditioning at minutes (standards BS 2782 part I method 150A; ISO 458/1, method 8; DIN 53,447 and ASTM D 1043). This modulus is expressed in daN/cm 2 MFI i melt flow index determined under a load of 2.16 kg _i L LiY 'i compounas, orFSanic ia Luy Ia eu iiUi(u iu 1 compounds and halogens. Among these agents, there may be mentioned: 18 at 230 0 C and expressed in g/10 min (ASTM standard D 1238).

AD apparent density of the insoluble polymer fraction, determined by packing and expressed in g/l.

a catalytic activity, usually expressed in grams of insoluble polymer in the polymerization medium, obtained per hour and per gram of TiCL 3 contained in the preactivated catalytic solid.

Example 1 A Preparation of the precursor (complexed titanium trichloride-based solid) ml of dry hexane and 60 ml of pure TiCL 4 are introduced, under a nitrogen atmosphere, into an 800-ml reactor equipped with a twin-blade stirrer, rotating at 400 rpm. This hexane-TiCL 4 solution is cooled to 0 1) 0

C.

Within 4 h, a solution consisting of 190 ml of hexane and ml of diethylaluminium chloride (DEAC) is added thereto, while maintaining a temperature of 0 1)°C in the reactor.

After the addition of the DEAC-hexane solution, the reaction medium consisting of a suspension of fine 3: particles is maintained stirred at 1 1)°C for 15 min and then heated, in the course of 1 h, to 25 0 C and maintained at this temperature for 1 h and then heated, in the course of 1 h, to approximately 65 0 C. The medium is maintained stirred for 2 h at 65 0

C.

The liquid phase is then separated from the solid and the solid product washed with 7 x 200 ml of dry hexane, the solid being resuspended during each washing.

The reduced solid thus obtained is suspended in -456 ml of diluent (hexane) and 86 ml of diisoamyl ether (DIAE) are added thereto. The suspension is stirred for 1 h at 50°C. The solid thus treated is then separated from the liquid phase.

The latter solid is resuspended in 210 ml of hexane and 52 ml of TiCl 4 are added thereto; the suspension is maintained stirred (150 rpm) at 70 0 C for 2 h. The liquid phase is then removed by filtration and the complexed titanium trichloride-based solid is washed with L -LiC 1- 19 19 14 x 270 mL of hexane.

B Preactivation g of the complexed titanium trichloride-based solid (containing approximately 820 g of TiCL3/kg) suspended in 280 mL of hexane are introduced into an 800-mL reactor equipped with a blade-stirrer rotating at 150 rpm.

120 mL of a solution, in hexane, of a preactivator (hereinafter called preactivator prepared beforehand by mixing 80 g of DEAC (compound and 176.2 g of n-octadecyl 3-(3',5'-di-tert-butyL-4-hydroxypheny)propionate, markited under the name Irganox 1076 by CIBA-GEIGY (compound per litre of hexane, are introduced slowly (30 minutes) into this reactor. Thus, the molar ratio between compounds and employed in preparing the preactiva- 15 tor is 2 and the molar ratio between the preactivator A 0 and the complexed titanium trichloride-based solid (expressed as moles of compound initially employed per moLe of TiCL 3 present in the solid) is 0.2.

44 The preactivator solution is introduced into the reactor only after 15 minutes from the time when the gas evolution observed during mixing compound and compound t(b) ceases.

The suspension to which the preactivator A has thus been added is maintained for 1 hour at 30 0 C, with stirring.

After decantation, the resulting preactivated catalytic solid is washed with 5 x 100 mL of dry hexane, the solid being resuspended during each washing, and then dried by sweeping with nitrogen in a fluidized bed for 2 hours at 70 0

C.

The preactivated catalytic solid thus obtained contains 641 g of TiCL 3 12 g of aluminium, 31 g of DIAE and a quantity, which is estimated to be approximatey 250 g, of the preactivator A, per kg.

C Potymerization of prop ylene in suspension in the SLiuid monomer, in the presence of the preactivated ata lytic solid The following are introduced, while being swept with nitrogen, into a 5-Litre autoLtave which has previously I i: i- -I 20 been dried and maintained under a dry nitrogen atmosphere: 400 mg of DEAC (in the form of a 200 solution in hexane) marketed by SCHERING (the CI:AL atom ratio is adjusted to 1.02 by adding ethylaLuminium dichloride); 100 mg of preactivated catalytic solid (the molar ratio between the DEAC and the TiCL 3 present in the solid is thus approximately 8); hydrogen at a partial pressure of 1 bar; and 3 1 of Liquid propylene.

The reactor is maintained at 65 0 C with stirring for 3 hours. The excess propylene is then degassed and the polypropylene (PP) formed, which amounts to 643 g of dry polypropylene, is collected.

The activity a of the preactivated catalytic solid is 3340; the productivity amounts to 6430 g of polypropylene/g of preactivated catalytic solid.

This polypropylene has the following characteristics: 1.1 98.1% S678 daN/cm 2 MFI 3.16 g/10 min AD 510 g/l.

Examples iR to These examples are given by way of comparison.

Example IR A complexed titanium trichloride-based solid is prepared as described in Example 1, part A, without preactivating it as mentioned in part B of this example.

This solid, dried as mentioned in Example 1, contains 811 g of TiCl3, 2.8 g of aluminium and 61 g of O LAE.

A polymerization trial is carried out in the presence of the solid thus obtained, which is not preactivated, under conditions strictly comparable to those defined in Example 1, part C. 785 g of dry PP are collected at the end of this trial.

The activity a is therefore 3230 and the -i i~ -LF i i- Il- ~i~i ~_i----riruu-liri ,1 productivity amounts to 7850 g of PP/g of solid.

This poLypropyLene has the following characteristics: I.I 94.9% G 572 daN/cm 2 MFI 7.3 g/10 min AD 490 g/l.

The significant differences in the fractions insoluble in boiling heptane and in the modules G respectively of the polymers obtained under comparable conditions according to Examples 1 and 1R are proof of the higher stereospecificity of the catalytic system which contains the preactivated catalytic solid of Example 1.

Example 2R A complexed titanium trichloride-based solid prepared as described in Example 1, part A, is preactivated with a solution which contains only compound A partial dissolution of the solid is observed, which solid is, moreover, in the form of very fine particles. The polymerization trial, carried out as mentioned in Example 1, part C, is repeated with a quantity of catalyst such that it contains approximately 70 mg of TiCl 3 535 g of PP are obtained, which corresponds to an activity a of only 2550. This PP is in the form of fine particles and its AD is only 100 g/l, which excludes the possibility of using it.

Example 3R Example 1, parts A and B, are repeated, the only exception being that the suspension of the complexed titanium trichloride-based solid is treated in sequence, ilp first with a solution of compound in hexane and then, 15 minutes after the addition of the solution of compound is complete, with a solution of compound in hexane. The values for the molar ratios between compounds and which are added separately, and between compound and the quantity of TiCt3 present in the solid, are 2:1 and 0.2:1 respectively. The catalytic solid collected contains 757 g/kg of TiCL, The polymeritation trial, carried out as L c _i _1 -1 r, I 1 II Li I CLIIY LQ I LUI IIl 11 III 0 III 1 II7 l L Uiuil11 I II IUIII III II U I I u The compound is chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is -22 mentioned in Example 1, part C, only enables a polypropyLene in the form of blocks, which cannot be used, to be collected with an activity a of 3090.

Example 4R Example 3R is repeated, but reversing the sequence of introduction of the solutions of compounds (a) and The same phenomenon as in Example 2R is observed, i.e. a partial dissolution of the solid.

The polymerization trial, carried out as described in Example 1, part C, only enables a polypropylene in the form of very fine particles, with an AD of only 200 g/l to be collected with an activity a of 3450, which excludes the possibility of using it.

Example The complexed titanium trichloride-based solid prepared as described in Example 1R not preactivated) is employed in a polymerization trial carried out as described in Example 1, part C, with the exception that in addition to DEAC, the solid, hydrogen and propylene, the product Irganox 1076 is introduced into the polymerization medium in a quantity such that the; molar ratio between this product and the TiCl 3 present in the solid is approximately 0.2.

A PP characterized by the following properties is obtained, with an activity a of 3286: 1.I 95.2% G 575 daN/cm MFI 5.2 g/10 min AD 505 g/l.

Example 2 t A preactivated catalytic solid is prepared as mentioned in Example 1, parts A and 8, except that the product Irganox 1076 is replaced with 2,6-di-tert-butyl- 4-methylphenol, marketed under the name lonol CP by SHELL.

The preactivated catlytic solid thus obtained contains 632 g of TiCL3, 14 g of aluminium, 30 g of DIAE and a quantity of preactivator, which is estimated to be approximately 170 g, per kg. It is employed in carrying out a polymerization trial under the conditions _I ir sec-aLkyLated in the ortho positions relative to the hydroxyl group, such as 1,3-di-tert-butyl-2-hydroxyanthracene, 23 of Example 1, part C.

This trial enables a polypropylene with the following characteristics to be collected, with an activity a of 3230: I.I 95.9% G 653 daN/cm 2 MFI 9 g/10 min AD 500 g/L.

Example 3 A preactivated catalytic solid prepared as mentioned in Example 1, parts A and B, is used in a trial for the polymerization of propylene in suspension in hexane under the operation conditions described below.

1 litre of dry and purified hexane is introduced into a 5-litre stainless steel autoclave which has been Spurged several times with nitrogen. 400 mg of DEAC (in the form of a 200 g/l solution in hexane) and a quantity of catalytic solid equivalent to approximately 51 mg of STiCI 3 are then introduced in sequence. The molar ratio DEAC:TiCI3 is therefore approximately Tt autoclave is heated to 65 0 C and the pressure is returned to atmospheric pressure by a slow degassing.

An absolute hydrogen pressure of 0.3 bar is then set up therein and propylene is then introduced into the autoclave until a total pressure, at the temperature concerned, of 11.9 bars is obtained. This pressure is maintained constant during the polymerization by introducing gaseous propylene.

After 3 h, the polymerization is stopped by degassing the propylene.

The contents of the autoclave are poured onto a Bichner fiter, rinsed with 3 x 0.5 I of hexane and dried under reduced pressure at 60 0 C. 251 g of hexane-insoluble PP are collected. 0.75 g of soluble polymer, which corresponds to is found in the hexane used in the polymerization and in the washing. The activity a is 1643.

The productivity amounts to 3157 g of PP/g of preactivated catalytic solid.

The hexane-insoluble PP has the following _i r. -24properties: I.I 98.2% G 654 daN/cm 2 MFI 2.9 g/10 min AD 503 g/l.

Example 6R This example is given by way of comparison.

A polymerization trial is carried out under the same conditions as in Example 3, in the presence of cata- Lytic solid prepared as mentioned in Example 3, but leaving out the preactivation stage, and containing 735 g/kg of TiCI 3 A PP, 1% of which is soluble in the hexane used in the polymerization and in the washing, and the insoluble part of which has the following characteristics, is obtained, with an activity a of 1719: 1.1 95.7% G 591 daN/cm 2 MFI 9.5 g/10 min AD 479 g/l.

Example 4 A preactivated catalytic solid is prepared according to the general conditions described in Example 1, parts A and B. However, after treatment of the suspension of the reduced solid with stirring for 2 hours at 65 0 C, this suspension is cooled to approximately propylere is then introduced into the gaseous atmosphere in the reactor, at a pressure of 2 bars. This introduction is continued for a period sufficient (approximately minutes) to obtain 100 g of polymerized propytlene per kg of solid. The suspension of the solid thus "prepolymerized" is then cooled to 400C and the preparation is then continued as mentioned in Example 1, part A.

The preactivated catalytic solid finally obtained contains 611 g of TiCL3, 9 g of aluminium, 14 g of DIAE and a quantity, which is estimated to be approximateLy 143 g, of preactivator A per kg.

This preactivated catalytic solid is employed in a propylene polymerization trial comprising a first stage which is carried out in the Liquid monomer and a second -L i i- 25 stage which is carried out in the gaseous phase under the operating conditions detailed below.

The following are introduced, under a stream of nitrogen, into the 5-Litre autoclave used according to Examples 1 and 3: 800 mg of DEAC a quantity of catalytic solid equivalent to 100 mg of TiCI3.

The molar ratio DEAC:TiCI 3 is therefore approximately 10:1.

An absolute hydrogen pressure of 0.2 bar is set up in the autoclave. 2 1 of liquid propylene are then introduced, with stirring, and the autoclave is heated to 60 0 C. Polymerization is carried out for 30 min at 15 this temperature. The autoclave is then degassed to a pressure of 15 bars, while heating it to 70 C at the same time. An absolute hydrogen pressure of 1 bar is then set up therein and propylene is then introduced into the autoclave until a total pressure, at the temperature concerned, 20 of 28 bars is obtained. After 3 hours, the polymerization is stopped by degassing the propylene, and the PP formed, which amounts to 1150 g of dry PP, is collected.

The activity a of the preactivated catalytic solid is therefore 3286 and the productivity amounts to 7027 g of PP/g of preactivated catalytic solid. This PP has the following characteristics: I.1 97.9% G 698 daN/cm 2 SMF1 3 g/10 min AD a 520 g/l.

SExample 7R This example is given by way of comparison.

A preactivated catalytic solid is prepared according to the procedure in Example 4, but leaving out the preactivation stage. This solid contains 718 g of TiCl 3 3.8 g of aluminium and 84 g of DIAE per kg. When used in a polymerization trial carried out according to the conditions described in Example 4, it enables a PP, characterized by the following properties, to be obtained, i _L iP L-- _il. 26 with an activity a of 3168: I.I 96.4% G 620 daN/cm 2 MFI 3 g/10 min AD 516 g/L.

Examples 5 to 7 Preactivated catalytic solids are prepared according to the conaitions mentioned in Example 4, except that the molar ratio between compounds and (b) employed in the preparation of the preactivator A (see Example 1, part B) (Examples 5 and 6) and the molar ratio between the preactivator A and the complexed titanium trichloride-based solid (expressed as mole of compound (a) initially employed per mole of TiCl 3 present in the solid) (see Example 1, idem) (Example 7) are modified.

These preactivated catalytic solids are employed in trials for the polymerization of propylene in suspension in hexane according to the general conditions mentioned in Example 3.

o 20 The operating conditions specific to the preparations of the catalytic solids and the results of the polymerization trials are collated in Table 1 which follows.

S*

I

C 4 4 r i -i i Lir 27 TabLe I

I

S

I

Examp Ie 1 6 Preparation of the preactivated cataLytic solids Compound (a)I Co pon-( -(mole/moLe) 50 10 0 Compound (a) (mole/mole) 1 TiCL 3 contained jin the solid ;TiCL 3 content of the preacti- 724 62 709 vated catalytic solid Cg/kg) 17 Results of polymerization Activity a :2160 2160 2130 (g PP/g TiCL 3 x h)I PP solubLe in the hexane 1.1 0.8 1.1I :used in the poLymerization ((as of total PP) I .1 ()97.3j 98.2 97.4 G (daN/cm 2) ~678 68 689 aF g Omn 7.11 5.0 7.7j AO 502 J502 504J

I

28 Example 8 A preactivated catalytic solid is prepared according to the procedure in Example 4 and it is used in a polymerization trial carried out according to the conditions described in part C of Example 1, except that the reactor is maintained at 75 0 C with stirring for 2 hours.

Under these conditions, this preactivated catalytic solid enables a PP characterized by the following properties to be obtained, with an activity a of 5010: I.I 98.1% G 688 daN/cm 2 MFI 5.9 g/10 min AD 510 g/l.

Examples 9 and Preactivated catalytic solids are prepared according to the conditions mentioned in Example 1, parts A and 8, except that triethylaluminium (TEAL) (Example 9) and ethylaluminium dichloride (EADC) (Example 10) are employed as compounds respectively.

These preactivated catalytic solids are used in trials for the polymerization of propylene in suspension in the liquid monomer, under the general conditions mentioned in Example 1, part C.

The characteristics of the preactivated catalytic solids employed and the results of these polymerization trials are collated in Table II which follows.

I

I

IB

ir i I 29 Table II Example 9 Nature of compound empLoyed in TEAL EADC the preparation of the preactivated catalytic solid TiCI 3 content of the preactivated 648 1713 catalytic solid (g/kg) Activity a (g PP/g TiCI 3 x h) 33 27 Properties of the PP 97.7 G (daN/cm 2 645 67 MlFI (g/10 min) 3.4 3.7 IAD (giL) 504 4 490

Claims (28)

1. A complexed titanium trichloride-based catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, which has been preactivated by chemical binding with an organoaluminium preactivator, wherein the said preactivator comprises the reaction product prepared by bringing into contact a compound chosen from amongst organoaluminium compounds S with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is sterically hindered; wherein said preactivator does not include the reaction products resulting from the contact of an aluminium alkyl of formula A-Al-B I where A and B are each an alkyl radical of not more than 8 carbon atoms and Z is a chlorine atom or an alkyl radical of not more than 8 carbon atoms with a sterically hindered phenolic compound having a tendency to crystallize out of solution with heptane at low temperature in a mole ratio of the aluminium alkyl to the phenolic compound of 1:1 to

2. The solid according to claim 1, wherein the compound is chosen from amongst compounds of formula: Al R X. n 3-n in which: R represents hydrocarbon radicals, which may be identical or different, containing from 1 to 18 carbon atoms, X is a halogen, and n is a number such that 0 n 3.

3. The solid according to claim 1 or claim 2, wherein the compound is chosen from amongst trialkylaluminiums and dialkylaluminium halides.

4. The solid according to claim 1, wherein the compound is chosen from amongst mono- or polycyclic hydroxyarylenes containing a secondary or tertiary alky radical in the two ortho positions relative to the A4 9 hydroxyl group.

The solid according to claim 1, wherein the compound is chosen from amongst di-tert-alkylated monocyclic monophenols and that compound and compound are brought into contact with each other in a molar ratio of between 50 and 0.1 moles of compound per mole of compound

6. The solid according to claim 1, wherein the compound is chosen from amongst butyl-4-hydroxyphenyl) propionic acid esters and that compound and compound are brought into contact with each other in a molar ratio of between 50 and 2 moles of compound per mole of compound

7. The solid according to any one of claims 1 to 6, wherein the amount of chemically bound preactivator is comprised between 5 and 500 g per kg of TiCl 3 present in the solid.

8. The solid according to any one of claims 1 to 6, wherein the amount of chemically bound preactivator is comprised between 50 and 300 g per kg of TiC13 present in the solid.

9. The solid according to any one of claims 1 to 6, wherein the preactivator is brought into contact with the *solid to be preactivated, in a molar ratio between the total initial quantity of compound employed and the quantity of TiC13 contained in the solid of between 0.05 and 0.5 mole/mole.

The solid according to any one of claims 1 to 9, wherein said solid has been preactivated by bringing the preactivator into contact with a solid precursor corresponding to the formula: TiCI 3 (AlR"C1 2 ).Cy in which R" is an alkyl radical containing from 2 to 6 carbon atoms, C is a complexing agent chosen from amongst aliphatic ethers, the aliphatic radicals of which contain from 2 to 8 carbon atoms, x is any number less than 0.20 and y is any number greater than 0.009.

11, The solid according to claim 10, wherein the solid a9 -31- i- precursor is in the form of spherical particles of diameter between 5 and 100 microns, which consist of an agglomerate of microparticles which are also spherical and which have a diameter of between 0.05 and 1 micron and the porosity of which is such that the specific surface area 2 of the solid precursor is between 100 and 250 m /g and that the total internal porosity is between 0.15 and 0.35 cm3/g.

12. A process for the preparation of a complexed titanium trichloride-based catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, preactivated by chemically binding an organoaluminium activator onto a complexed titanium trichloride-based solid precursor, wherein the said preactivator comprises the reaction product prepared by bringing into contact a compound chosen from amongst organoaluminium compounds with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is sterically hindered, the reaction products resulting from complexed titanium trichloride-based catalytic solid which can be used for the stereospecific polymerization of alpha-olefins, which has been preactivated by chemical binding with an organoaluminium i preactivator, wherein the said preactivator comprises the reaction product prepared by bringing into contact a compound chosen from amongst organoaluminium compounds with a compound chosen from amongst hydroxyaromatic compounds, the hydroxyl group of which is sterically hindered; wherein said preactivator does not include the reaction products resulting from the contact of an aluminium alkyl of formula A-AI-B where A and B are each an alkyl radical of not more than 8 carbon atoms and Z is a chorine atom or an alkyl radical of not more than 8 carbon atoms with a sterically hindered phenolic compound having a tendency to crystallize -32- k/II r out of solution with heptane at low temperature in a mole ratio of the aluminium alkyl to the phenolic compound of 1:1 to 1:3.

13. The process according to claim 12, wherein the compound is chosen from amongst compounds of formula: Al R X 3 -n in which: R represents hydrocarbon radicals, which may be identical or different, containing from 1 to 18 carbon atoms, X is a halogen, and n is a number such that 0 n .3.

14. The process according to claim 12, wherein the compound is chosen from amongst mono- or polycyclic hydroxyarylenes containing a secondary or tertiary alkyl radical in the two ortho positions relative to the hydroxyl group.

The process according to claim 12, wherein the compound is chosen from amongst di-tert-alkylated monocyclic monophenols and that compound and compound are brought into contact with each other in a molar ratio of between 50 and 0.1 moles of compound per mole of compound

16. The process according to claim 12, wherein the compound is chosen from amongst 3-(3',5'-di-tert. butyl-4-hydroxyphenyl) propionic acid esters and that compound and compound are brought into contact with each other in a molar ratio of between 50 and 2 moles of compound per mole of compound

17. The process according to claim 12, wherein the preactivator is brought into contact with the solid precursor in a molar ratio between the total initial "u quantity of compound employed and the quantity of TiC1 3 contained in the precursor of between 10 2 and 1 mole/mole.

18. The process according to claim 12, wherein the solid precursor and the preactivator are maintained in contact with each other at a temperature between 20 and 40 0 C for a period between 15 and 90 minutes. I. -z

19. The process according to any one of claims 12 to 18, wherein the preactivated catalytic solid is separated from the preactivation medium and washed with an inert hydrocarbon diluent before being used in the polymerization.

A process for the polymerization of alpha-olefins in the presence of a catalytic system containing an organometallic compound of metals of groups Ia, IIa, IIb and IIIb of the Periodic Table and complexed titanium trichloride-based catalytic solid which has been preactivated by chemically binding with an organoaluminium preactivator, wherein the said polymerization is carried out in the presence of a complexed titanium S, trichloride-based catalytic solid according to any one of claims 1 to 11. S,

21. A process for the polymerization of alpha-olefins in the presence of a catalytic system containing an organometallic compound of metals of groups la, IIa, lIb *and IIIb of the Periodic Table and complexed titanium 20 trichlorido-based catalytic solid which has been preactivated by chemically binding with an organoaluminium preactivator, wherein the said polymerization is carried out in the presence of a complexed titanium Strichloride-based catalytic solid prepared according to the process of any one of claims 12 to 19.

22. The process according to claim 20 or claim 21, applied to the stereospecific polymerization of propylene.

23. The process according to claim 20 or claim 21, applied to the stereospecific polymerization of propylene in suspension in an inert hydrocarbon diluent.

24. The process according to claim 20 or claim 21, applied to the stereospecific polymerization of propylene in the monomer in the liquid state.

The process according to claim 20 or claim 21, applied to the stereospecific polymerization of propylene in the gaseous phase.

26. The solid according to claim i, substantially as herein described with reference to the accompanying 9 -34- r I Examples.

27. The process according to claim 12, substantially as herein described with reference to the accompanying Examples.

28. The polymerization process according to claim substantially as herein described with reference to the accompanying Examples. DATED: 6 JULY, 1990 PHILLIPS ORMONDE FITZPATRICK Attorneys For: SOLVAY CIE V) t V4-. 3Ii 1595Z kL L 1 1