CA1194852A - Retreating comminuted olefin polymerization catalyst with a titanium (iv) compound, a haloalkylchlorosilane and an ester - Google Patents

Abstract

Abstract of the Disclosure A comminuted, supported polymerization catalyst for alpha-olefins comprises (A) an organoaluminum compound and (B) a solid titanium-containing com-ponent formed by (1) comminuting a solid reaction product comprising (a) at least one halogen-contain-ing compound of titanium (IV); (b) at least one electron donor; and (c) at least one hydrocarbon-insoluble magnesium-containing compound; and (2) retreating such comminuted product with (a) at least one halogen-containing compound of titanium (IV);
(b) at least one haloalkylchlorosilane; and (c) at least one organic acid ester.

Description

RETREATING COMMINUTÆD OLEFIN POLYMERIZATION CATALYST
WITH A TITANIUM(IV) COMPOUND, A HALOALRYLCHLOROSILANE
AND AN ESTER

Background of ~he Invention Polymerization of alpha-olefins, such as ethylene, propylene and butene~ o normally-solid, substan-tially crystalline polymers using catalyst composi-tions comprising transition metal and organoaluminum compounds is well known. Although many transition metal co~pounds have been disclosed as useful in such polymerizations, including salts of titanium, vanadium and ~irconium, compounds of ti~anium pre-dominate with tetravalent titanium (Ti(IV)) compounds typically proving mos~ useful in ethylene polymeriza-tion and trivalent titanium (Ti(III)) compounds most useful in polymerization of propylene and higher alpha-olefins. Various forms of titanium components have been disclosed in both TilIV3- and Ti(III)-based compositions including a so-called "supported" titan-ium component. Supported titanium catalyst components have been disclosed in which titanium (either Ti(III) or Ti(IV)) is placed onto a metal oxide or metal halide suppo.rtO One view of an advantage of supported titanium catalyst components is that in such compo-nents catalytically active titanium-containing sites are dispersed throughout the supported catalyst composition yielding more efficient use of the titan-ium content and resulting in higher overall catalytic activityl especially if based on titanium content.
Supported titanium cat31yst components have been found most useful in ethylene polymerization such as described in U.S. Patent 3,901,863. Until recently, however, ~upported titanium catalyst components have not been used substantially in com-mercial polymerization of propylene or higher alpha-olefins due to coproduction of high levels of noncrystalline or amorphous polymeric products.
Production of such noncrystalline, amorphous products especially is detrimental in polymerization processes in which such noncrystalline products are not removed by ~olvent extraction.
E~amples of nonsolvent processes are gas-phase and bulk processes. In gas-phase polymerization, solid polymer is formed directly on contact of gaseous monomer with a catalyst; while in a bulk process, polymer is formed in a liguid monomer medium.
In either process solid polymer advantageously is not treated further with a hydrocarbon solvent to remove noncrystalline material. Even in a slurry process in which noncrystalline material can be removed, production of such noncrystalline material usually is minimized because of its lower economic value.
There are many examples of treatment of titanium-containing olefin polymerization catalysts with silicon tetrachloride such as U.S. Patents 3,833,515, 3,992,322, 4,022,958, 4,098,907, 4,149,990, and 4,158,088; German Offen. 2,111,455 (Chem.
Abst. 78:16788j); Japanese Kokai 98,076/77 (Chem.
Abst. 88:38333r); Japanese ~okai 90,389/78 (Chem.
Abst. 89:180621i); 3apanese Kokai 94,908/80 (Chem.
Abst. 93:221319h); and Japanese Kokai 73,707/80 (Chem. Abst. 93:150909n). Other references also describe treatment with chlorosilane (~SiC13) such as Japanese Kokai 10~,98~/78 (Chem~ Abst~ 89:216061f);
Japanese Kokai 119,387/79 (Chem. Abst. 92:42618n);
Japanese Kokai 138,887/79 (Chem. AbstO 92 111526v);
Japanese Kokai 36,203/80 (Chem. Abst. 93:27105v);
Japanese Kokai 147,505/80 (Chem. Abst. 94:122285h);
and Japanese Rokai 147,506/80 (Chem. Abst. 94:122287k).
Alkyl-substituted chlorosllanes, such as methyl trichlorosilane, ethyl trichlorosilane, and methyl dichlorosilane have been used to treat various olefin polymerization catalysts such as U.S. Patents 3,676,418, 3,875,12~, 4;071,672, 4,085,276, and 4,223,117; Japanese Kokai 83~284/75 (Chem.
Abst. 83:179954c); Japanese Kokai 119,388/79 tChem.
Abst. 92:72089); and Japanese Kokai 124,888/79 (Chem~
Abst. 92:7211c).
Specific examples ~f use of alkyl chlorosilanes include U.S~ Patents 4,159,963 and 4,159,965 which describe a titanium polymerization component obtained by reacting an organomagnesium component with a chlorosilane containing an Si~H bond then reacting the pro~uct with a specified titanium compound.
the organosilane has a formula HasiclbR4-(a-~b) wherein a and b are numbers greater than 0 such that a < 2 and a+b < 4 and R is a hydrocarbon radical having 1 to 20 carbon atoms. Examples of chlorosilanes included CH3SiHC12, C2HssiHcl2, n-C3H~siHC12 C6HsSiHC12, and 4-ClC6H4SiHC12.
U.S. Patent 3,B25,524 describes a titanium tri~
chloride composition formed by reacting TiC14 with an organoaluminum chloride with a mixed solYent containing an organosilicon compound such as tetra-hydrocarbyl silanes, organohydrogensilanes and organo-halogensilanes including alkyl trichlorosilanes and alkyl dichlorosilanes.
Supported olefin polymerization catalysts have been disclosed in which crystallinity-promoting components are incorporated. Such components can be electron donor compounds which are associated with titanium containing supported catalyst complexes.
Further, preparations of supported olefin polymeriza-ti~n catalysts have heen disclosed in which the suppor ted catalyst material is comminuted such as by ball-milling in order to increase catalyst activity.
An example of such catalyst material is described in U.S. Patent 4,277~370.

s~

However, it has been found that while comminuting such a catalyst component can increase activity, presumably by exposing more active sitesr ~uch a comminu~ed catalys~ also can yield increased noncrystalline polymer products as evidenced by increased solubles and extractables~
Olefin polymerization catalysts having higher activity and yielding fewer undesirable by-products are always desirable. Many supported titanium-containing catalyst components whlch have beencomminuted such as by ball-milling have been found to be active; however, such a comminuted supported catalyst component which also yields low amounts of noncrystalline polymeric by~prod~cts would be very desirable. A method to produce such a catalyst would be very useful in the olefin polymerization catalyst art.
An i~portant commercial property of olefin poly-mers such as polypropylene is the morphology of powder product. Morphology is a term describing a combination of physical properties of a batch of p~lymer particles including average pore diameterl ~bsence of very small particles (~fines") or large particles, and substantial unifor~ity of particles.
25 One measurement used in evaluating morphology is bulk density. Typicallyl higher bulk density values are desired such as above about 22 pounds per cubic foot or higher. A catalyst which is active, and yields low a~ounts of amorphous products and a high 0 bulk density powder would be very desirable.
Summary of the Invention A co~minuted, supported polymerization ca~alyst for alpha-olefins comprises ~A) an organoaluminum compound and (B) a solid titanium-containing component 35 fs:)rmed by ~1) comminuting a solid reaction product comprising (aj at least on* halsgen-containing com~
pound of titanium~IV); (b) at least one electron donor; and ~c) at l~ast one hydrscarbon-insoluble, ma~nesium-containing compound; and ~2) retre~ting such co~minuted product with ~a) at least one halogen-containing compo~nd of titanium(IV); (b) at least one haloalkylchloro~ ne~ and tc) at least one organic hcid ester.
Brief Description of the lnventlon ~

It has been found that an improved comminuted supported titanium-containing catalyst component can be ob~ained by retrea~ing such comminuted compo-nent with at least one halogen-containing compound of titanium~IV), at least one haloalkylchlorosilane and at least one organic acid ester.
The supported titanium containing olefin poly~
merization catalyst componen~ of this invention is formed by (l) comminuting the solid reaction product comprising (a) at least one halogen-containing com-pound of titanium(IV); (b) at least one organic electron donor; and (c) at least one hydrocarbon-insoluble, magnesium-containing compound; (2) react-ing such comminute~ product with (a) at least one halogen-containing compound of titanium(IV); and (b) at least one organic acid ester.
The hydrocarbon-insoluble, magnesium containing compound can be a magnesium halide; a reaction product of a magnesium halide, such as MgC12 and MgBr2, with an organic compound, such as an alcohol or an organic acid ester or with an organometallic com-pound of metals of Groups I-III. Preferably, however, the hydrocarbon-insoluble, magnesium-containing compound is based on at least one magnesium alcoholate which preferably has been pretreated with at least one modifier such 35 mineral acid and anhydrides of sulfur, organometallic chalcogenide derivative of hydrogen sulfide, and organic acids and esters thereof. Most preferably such magnesium-containing compound is the pretreatment product of at least one magnesium alcoholate, at least one Group II or IIIA metal alkyl and at least one modifier selected from the group consisting of mineral acids and anhydrides of sulfur, organometallic chalcogenide derivatives of hydrogen sulfide, organic acids and organic acid estersO
Titanium(IV) compounds useful in preparation of the stereospecific supported catalyst components of this invention are titanium halides and haloalcohol~
ates having 1 to about 20 carbon atoms per alcoholate group such as methoxy, ethoxy, butoxy, hexoxy, phenoxy, decoxy, naphthoxy, dodecoxy and eicosoxy. Mixtures of titanium compounds can be employed if desired.
Preferred titanium compounds are the halides and haloalcoholates having 1 to about 8 carbon atoms per alcoholate group. Examples of such compounds include TiCl~, TiBr~, Ti~OCH3)C13, Ti(OC2Hs)C13, Ti(OC4Hg)C13, Ti(OC6Hs)C13, Ti(~C6H13)Br3 Ti(OCgH17JC13, Ti(ocH3)2Br2~ Ti(~c2H5)2cl2l Ti (C6H13) 2C12~ Ti (OC8H17) 2Br2, Ti (OCH3)3Br, Ti(OC2H5)3Cl~ Ti(OC4Hg)3Cl, Ti(OC6H13)3Br~ and Ti(OCgH17)3Cl. Titanium tetrahalides and particu-larly titanium tetrachloride (TiC14) are most pre-ferred from the standpoint of attaining maximum activity and stereospecificity.
Organic electron donors useful in preparation of the stereospecific supported catalyst components o this invention are organic compounds containing one or more atoms of oxygen, nitrogen, sulfur, and phosphorus. Such compounds include organic acids, organic acid esters, alcohols, ethers, aldehydes, ketones, amines, amine oxides, amides, thiols, various phosphorus acid esters and amides, and the like. Mixtures of organic electron donors can be used if desired.
Specific examples of useful oxygen-containing electron donor compounds include organic acids and esters. These compounds also can be used in pre-treating the magnesium-containing component as described below. Organic acids useful according to this invention are acids containing from 1 to about 20 carbon atoms and 1 to abou~ 4 carboxyl groups.
Such acids include aliphatic acids of 1 to about 20 carbon atoms; halogen-, hydroxyl-, oxo-, alkyl-, alkoxy-, aryl-, and aryloxy-substituted aliphatic acids of 1 to about 20 carbon atoms; aromatic acids of 7 to about 14 carbon atoms; and halogen-, hydroxyl-, alkyl-, alkoxy-, aryl-, and aryloxy-substituted aromatic acids of 7 ~o about 20 carbon atoms. Monocarboxylic acids are preferred over the polycarboxylic acids.
Specific examples of useful aliphatic acids include saturated acids such as ormic acid, acetic acidr oxalic acid, malonic acid, butyric acid, pivalic acid, valeric acid, glutaric acid, caproic acid, cyclohexanecarboxylic acid, suberic acid, lauric acid~ stearic acid, and arachidic acid; and unsaturated acids such as acrylic acid, crotonic acid, isocrotonic acid, vinylacetic acid, allylacetic acid, maleic acid, hydrosorbic acid, ~orbic acid, undecenoic acid, oleic acid, and stearolic acid.
Specific examples of useful substituted aliphatic acids include chloroacetic acid, phenylacetic acid, chloromalonic acid, benzylmandellic acid, bromobutyxic acid, ketobutyric acid, 2-hydroxyhexanoic acid, linoleic acid tetrabromide, 3-chloro-2-butenoic acid, benzallactic acid, mucochloric acid, mucobromic acid, piperic acid, and ketocaproic acid.
Specific examples of useful aromatic acids and substituted aromatic acids include benzoic acid, phthalic acid, ~rimellitîc acid, pyromellitic acid, naphthoic acids, chlorobenzoic acids, chloronaphthoic acids, hydroxynaphthoic acids, toluic acids, xylilic acids, isodurylic acids, butylbenzoic acids, dihexyl-benzoic acids, anisic acid, veratric acid, asaronic acid, ethoxybenzoic acids, piperonylic acids, vanillic acid, cresotic acid, and everninic acid.
Organic acid esters useful according to this invention include alkyl and haloalkyl esters of acids such as are described above wherein the alkyl group or groups contain 1 to about 12 carbon atoms, and aryl and haloaryl esters of such acids wherein the aryl gro~p or groups contain 6 to about 10 carbon atoms. Specific examples of useful organic acid esters include the methyl, chloromethyl, ethyl, chloroethyl, bromoethyl, butyl, hexyl, cyclohexyl, octyl, chlorododecyl, phenyl, chlorophenyl, and naphthyl esters of acids such as re named above.
Preferred organic acids and esters are benzoic acid, halobenzoic acids and the alkyl esters thereof wherein the alkyl group contains 1 to about 6 carbon atoms such as methyl benzoate, methyl bromobenzoates, ethyl benzoate, ethyl chlorobenzoates, butyl benzoate, isobutyl benzoate, hexyl benzoate, and cyclohexyl benzoate, as these give good results in terms of activity and stereospecificity and are convenient to use.
Specific examples of other useful oxygen~
containiny electron donors include aliphatic alcohols such as methanols, ethanols, propanols, butanols, pentanols, hexanols, and so forth; aliphatic diols and ~riols such as ethylene glycol, propanediols, glycerol, butanediols, butanetriols, pentanediols, pentanetriols, hexanediols~ hexanetriols, and so forth; aromatic alcohols such as phenol, di-, tri-, and tet~a-hydroxybenzenes~ naphthols, and dihydroxy-naphthalenes; aralkyl alcohols such as benæyl alcohol, phenylethanols, phenylpropanols, phenylbutanols, phenylpentanols, ph~nylhexanols, and the like; alkaryl alcohols such as cresolsl xylenols, ethylphenol~, propylphenols, butylphenols, pentylphenols, 5~

hexylphenols, and the like; dialkyl ethers such as dimethyl, diethyl, methylethyl, dipropyl, dibutyl, dipentyl, dihexyl ethers, and so forth; alkylvinyl and alkylallyl ethers such as methyl-, ethyl-, propyl , butyl-, pentyl-, and hexylvinyl, and hexylallyl ethers; alkaryl ethers such as anisole, phenetole, propylphenyl ether, butylphenyl ether, pentylphenyl ether, hexylphenyl ether and the like;
arylvinyl and arylallyl ethers such as phenylvinyl ether and phenylallyl ether; diaryl ethers such as diphenyl ether; and cyclic ethers such as dioxane and trioxane.
Specific examples of other suitable oxygen~
containing organic electron donors include aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, bu~yraldehyde, valeraldehyde, caproaldehyde, and the like; benzylaldehyde, tolualdehyde, and alpha-tolualdehyde; and ketones such as acetone, diethyl ketone, methyl ethyl ketone, dipropyl ketone, dibutyl ketone, dipentyl ketone, dihexyl ketone, and the like; cyclobutanone, cyclopentanone, and cyclohexa-none, and the like; acetophenone, propionphenone, butyrophenone, valerophenone, caprophenone, and the like; and diphenyl ketone.
Specific examples of useful nitrogen-containing organic electron donors include tertiary amines wherein at least one of the groups bonded to nitrogen contains at least two carbon atoms such as dimethyl-ethylamine, methyldiethylamine, N,N'-tetramethylethyl-enediamine, triethylamine, tri~n-butylamine, dimethyl-n-hexylamine, tetraethylputrescine, diphenylmethyl-amine, triphenylamine, tritolylamine, diphenylbenzyl-amine, triphenylethylamine, triethylphenylamine, bis~die~hylamino)benzenes, and the like, saturated heterocyclic amines and derivatives thereof such as pyrrolidine, piperidine, 2-methylpyrrolidine, 2-methylpiperidine, 2,5-dimethylpyrrolidine, 2,6-dimethylpiperidine, 2/4~6 trime~hylpiperidine,

2,2,6,6-tetramethylpiperidine, and the like;
unsaturated heterocyclic amines and derivatives thereof such as pyridine and pyrimidine, picolines, lutidinesr collidines, ethylpyridines, diethylpyri-dines, triethylpyridines, ben~ylpyridines, methyl~
pyrimidines, ethylpyri~idines, benzylpyrimidines, and the like.
Examples of useful sulfur-containing organic electron donors include thiols such as methanethiols, ethanethiols, ethanedithiols, propanethiols, butane-thiols, butanedithiols, hexanethiols, and the like;
thioethers such as ethylthioethane, e~hylthio-n-butane, and the like; and other thio analogues of the above-described oxygen-containing organic elec~ron donors.
Specific examples of useful phosphorus-containing organic electron donors include phosphorus analogues of the above-described nitrogen-containing organic electron donors such as triethylphosphine, ethyldi-butylphosphine, triphenylphosphine, and the like.
Examples of useful organic electron donors con-taining two or more of oxygen, nitrogen, sulfur, and phosphorus include amides such as acetamide, bu~yramide, oaproamide, benzamide, and the like;
aminoalcohols such as ethanolamine, hydroxyanilines, aminocresols, and the like; amine oxides such as lutidine-N-oxldes and collidine-N-oxides; aminoethers such as bis(2-ethoxyethyl)amine; thioacids such as thioacetic acid, thiobutyric acid, thiovaleric acid, thiobenzoic acid, and the like; organosulfonic acids such as methanesulfonic acid, ethanesulfonic acid, phenylsulEonic acid, and the like; various phosphorus acid derivatives such as trimethyl phosphite, tri-n-propyl phosphite, triphenyl phosphite, trlethyl trithiophosphite, hexamethylphosphoric triamide, and the like; and phosphine oxides such as triethyl-phosphine oxide, triphenylphosphine oxide, and the like.
From the standpoint of catalyst performance and preparative ease, the organic electron donors which are preferred acording to this invention are C1-C6 alkyl esters of aromatic monocarboxylic acids and halogen-, hydroxyl-, oxo- alkyl-, alkoxy-, aryl-, and aryloxy-substituted aromatic monocarboxylic acids. Among these, the alkyl esters of benzoic and ahlobenzoic acids wherein the alkyl group contains 1 to about 6 carbon atoms, such as methyl benzoate, methy bromobenzoate, ethyl benzoate, ethyl chlor-benzoate, ethyl bromobenzoate, butyl benzoate, iso-butyl benzoate, ehxyl benzoate, and cyclohexyl benzoate, are particularly preferred. Best results are attained through the use of ethyol benzoate.
Other suitable esters include ethyl anisate and methyl-p-toluate.
In preparation of the sterospecific supported catalyst components of this invention, the magnesium-containing product, titanium(IV) component, and organic electron donor component are contacted in amounts such that the atomic ratio of titanium to metal in the magnesium-containing component employed in pretreatment is at least about 0.5:1. Preferably, this ratio ranges from about 0.5:1 to about 20:1.
Greater amounts of titanium can be employed without adversely affecting catalyst component performance, but there typically is no need to exceed a titanium to magnesium ratio fo about 20:1 as only a portion of the titanium is affixed to the pretreatment product during the prepartive reaction. More preferably, the titanium to magnesium ration ranges from about 2:1 to about 15:1 to ensure that the catalyst compo-nents contain sufficient titanium to exhibit good activities without being wasteful of the titanium compound employed in preparation. The electron 8~

donor component is employed in an amount ranging from about 0.001 to about 1.0 mole per gram atom of titanium, and preferably fro~ about 0. ons to about 0.6 mole per gram atom. Best results are achieved when this ratio ranges from about 0.01 to about 0.3 mole per gram atom of titanium.
The sequence in which the components are con-tacted is not critical. Suitably, magnesium-containing product, titanium(IV) component, and electron donor component are contacted concurrently or two of the components are contacted followed by addition of the remaining component. From the standpoint of catalyst performance and preparative ease, the preferred preparative sequence is to combine the magnesium-containing product and titanium~IV) component and then add the organic electron donor component to the result.
According tc the invention, the magnesium-containing product, titanium(IV), and electron donor components preferably are contacted in the presence of an inert hydrocarbon or halogenated hydrocarbon diluent, although other suitable techniques can be employed. Suitable diluents are materials which are substantially inert to the components employed and are liquid at the temperatures employed or can be maintained in the liquid state through the use of elevated pressure. As in the case of the diluents employed in pretreatment of magnesium alcoholates, it is desirable to purify any diluent to be employed to remove water, oxygen, carbon oxides, and other extraneous catalyst poisons. Examples of suitable diluents include materials such as are identified above as suitable pretreatment diluent~, with nonane, 1,1,2-trichloroethane and carbon tetrachloride being preferred.
Reaction between the magnesium-containing product, titanium component, and organic electron donor is carried out at temperatures ranging from about 50 to about 170Co Best results are obtained at about 130 to abou~ 160C~ Generally the reaction is carried out over a period of several minutes to ~everal hours, with about 1/2 to about 10 hours giving good results at economical rates. Most preferably, the reaction time ranges from about 1 to about 5 hours. When the components employed in preparation of the invented catalyst component~ are contacted according to the preferred preparative sequence, best results are attained when the magnesium-containing product and titanium(IV~
component are combined at about ambient temperature followed by addition of electron donor, at about ambient temperature and with agitation, over about 1/~ to about 1 1/2 hours and then heating at about 130 to about 160~C. for about 1/2 to about 3 hours with continued agitation.
In additionl the reaction mlxture of the magnesium-containing product~ titanium component and electron donor can contain an organochlorosilane in a concentration up to about 80 mole % based upon tit~nium.
The magnesium-containing product used in this invention preferably is obtained by contacting pretreatment components comprising (a) at least one magnesium alcoholate of the formula Mg(ORl)n(OR2)2_n wherein Rl and R2 are identical or different hydro-carbyl radicals of 1 to about 20 carbon atoms and n ranges from 0 to 2; and (b) at least one Group II
or IIIA metal alkyl containing 1 to about 20 carbon atoms per alkyl radical. Preferably, to maximize the activity of the catalysts, the pretreatment components further comprise (c) at least one modifier selected from the group consisting of mineral acids and anhydrides of sulfur, organo-metallic chalcogenide derivatives of hydrogen sulfide, organic acids and esters thereof.
Specific examples of magnesium alcoholates which are useful in forming a pretreated magnesium-contain-ing component aecording to this invention include Mg(OCR3)~, Mg(OC2Hs)~. Mg~oc4H9)2l M9~OC6H5) Mg (OC6H13) 2, Mg (OCgHlg)2, M9~Cl0H7)2- Mg~C12H9) M~(C12~25)2- M9~OC16H33)2, Mg(OC20~4~
Mg (OCEI3) (OC2H5) ~ Mg (OCEI3) ~0C6H13) ~ Mg (~)C2H5) (OC~H17) r Mg(~C6~13)(C20~1), Mg(OC3H7)(OCl~H7), and M9(C16H33)(C18H37). Mixtures of magnesium alcohol-ates also can be employed if desired. Additionally, although not preferred, mixtures of magnesium alcohol-ates ~ith minor amounts of other suitable metalsalts such as alcoholates of lanthanum and the lanthanide metals, magnesium halides, hydroxyhalides, carboxylates, and so forth can be used.
From the standpoint of cost and availability, magnesium alcoholates which are preferred for use according to this invention are those of the formula Mg(ORl)2 wherein Rl is as defined above. In terms of catalytic activity and stereospecificity, best results are achieved through the use of magnesium alcoholates of the formula Mg(ORl]~ wherein Rl is an alkyl radical of 1 to about 6 carbon atoms, an aryl radical of 6 to about 12 carbon atoms or an alkaryl or aralkyl radical of 6 to about 12 carbon atoms. Best results are attained through the use of magnesium ethoxide.
Useful Group II and IIIA metal alkyls are com-pounds of the formula MR3m wherein M is a Group II
or IIIA metal, each R3 is independently an alkyl radical of 1 to about 20 carbon atoms, and m corre-sponds to ~he valence of M. Examples of usefulmetals, M, include magnesium, calcium, zinc, cadmium, aluminum, and gallium. Examples of suitable alkyl 5~

radicals, R3, include methyl, ethyl, butyl, hexyl, decyl, tetradecyl, and eicosyl.
From the standpoint of catalyst component perfor-mance, preferred Group II and IIIA metal alkyls are those of magnesium, zinc, and aluminum wherein the alkyl radicals contain 1 to about 12 carbon atoms.
Specific examples of such compounds include Mg~OE13)2, ~g~C2H5)2~ Mg(~2H5)(C4Hg), ~9(C4H9)2l Mg(C6H13)2 M9(C12~25)2~ Zn(CH3)2, Zn(C2~5)2, Zn(C4H9)2, Zn(c4Hg)(c8Hl7)~ Zn(c6Hl3)2l Zn(C12H25)2l Al(CH3)3 Al(C2Hs)3, Al(C3H7)3/ Al(C4Hg)3, Al(C6H13)3~ and Al(C12H2s)3- More preferably 3 magnesium, zinc, or aluminum alkyl containing 1 to about 6 carbon atoms per alkyl radical is used. Best results are achieved through the use of trialkylaluminums containing 1 to about 6 carbon atoms per alkyl radical, and particularly triethylaluminum.
Modifiers useful in pretreatment of a magnesium-containing component are mineral acids and anhydrides of sulfur, organometallic chalcogenide derivatives of hydrogen sulfide, organic acids, organic acid esters, and mixtures thereof.
Specific examples of useful mineral acids and anhydrides of sulfur include sulfur dioxide, sulfur trioxide, sulfuric acid, fuming sulfuric acid, and halosulfonic acids such as chlorosulfonic and fluoro-sulfonic acids. Hydrogen sulfide, which behaves as a weak acid in a~ueous solution, also is considered a mineral acid of sulfur for purposes hereof. Also ~ontemplated are the organometallic chalcogenide derivatives of hydrogen sulfide in which each hydrogen is replaced by an organosilicon, organogermanium, or organo~i~ group wherein the organic radicals are selected from the group consisting of phenyl, alkyl-substituted phenyl, phenyl-substituted alkyl, and alkyl radicals, such alkyl radicals containing 1 to about 6 carbon atoms. Specific examples of useful

3~

organometallic chalcogenide pretreatment modifiers include bis(triphenyltin)sulfide, bis(tritolyltin)sul-fide, bis(triethylphenyltin)sulfide, bis(trihexyl-phenyltin)sulfide, bis(triphenylmethyltin)sulfide, bis(triphenylethyltin)sulfide~ bis(triphenyl-hexyltin)sulfide, bis(trimethyltin)sulfide, bis(triethyltin)sulfide, bis(tributyltin)sulfide, bis~trihexyltin)sulfide, and similar silicon- and germanium-containing compounds.
~mong the mineral acid~ and anhydrides of sulfur and organometallic chalcogenide derivatives, sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, and hydrogen sulfide are preferred because they lead to the best overall improvements in activities and stereospecificities.
Organic acids useful in pretreatment of a magnesium-containing component according to this invention are acids containing from 1 to about 20 carbon atoms and 1 to about 4 carboxyl groups.
Such acids include aliphatic acids of 1 to about 20 carbon atoms; halogen-, hydroxyl-, oxo-, alkyl-, alkoxy-, aryl-, and aryloxy-substituted aliphatic acids of 1 to about 20 carbon atoms; aromatic acids of 7 to about 14 carbon atoms; and halogen-, hydroxyl-, alkyl-, alkoxy-, aryl-, and aryloxy-substituted aromatic acids of 7 to about 20 carbon atoms. Monocarboxylic acids are preferred over the polycarboxylic acids.
Specific examples of useful aliphatic acids include saturated acids such as formic acid, acetic acid, oxalic ac.id, malonic acid, butyric acid, pivalic acid, valeric acid, glutaric acid, caproic acid, cyclohexanecarboxylic acid, suberic acid, lauric acid, stearic acid, and arachidic acid; ~nd unsaturated acids such as acrylic acid, crotonic acid, isocrotonic acid, vinylacetic acid, allylacetic acid, maleic acld, hydrosorbic acidl sorbic acid, undecenoic acid, oleic acid, and stearolic acid.
Specific examples of useful substituted aliphatic acids include chloroacetic acid, phenylacetic acid, chloromalonic acid, benzylmandellic acid, bromobutyric acid, ketobutyric acid, 2whydroxyhexanoic acid, linoleic acid tetrabromide, 3-chloro-2-butenoic acid, benzallactic acid, mucochloric acid~ mucobromic acid, piperic acid, and ketocaproic acid.
Specific examples of useful aromatic acids and substituted aromatic acids include benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, naphthoic acids, chlorobenzoic acids, chloronaphthoic acids, hydroxynaphthoic acids, toluic acids, xylilic acids, isodurylic acids, butylbenzoic acids, dihexyl-benzoic acids, anisic acid, veratric acid, asaronic acid, ethoxybenzoic acids, piperonylic acids, vanillic acid, cresotic acid, and everninic acid.
~0 Qrganic acid esters useful as pretreatment compo~
nents according to this invention include alkyl and haloalkyl esters of acids such as are described above wherein the alkyl group or groups contain 1 to about 12 carbon atoms, and aryl and haloaryl esters of such acids wherein the aryl group or groups contain 6 to about 10 carbon atoms. Specific examples of useful organic acid esters include the methyl, chloromethyl, ethyl, chloroethyl, bromoethyl, butyl, hexyl t cyclohexyl, octyl~ ohlorododecyl, phenyl r chlorophenyl, and naphthyl esters o~ acids such as are named aboYe.
Preferred organic acids and ester~ are benzoic acid, halobenzoic acids and the alkyl esters thereof wherein the alkyl group contains 1 to about 6 carbon atoms such as methyl benzoate, methyl bromobenzoates, ethyl benzoate, ethyl chlorobenzoates, butyl benzoate, isobutyl benzoate, hexyl benzoate, and cyclohexyl ~:19 ~352 ~18-benzoate, as these give good results in terms of activity and stereospecificity and are convenient to u~e.
Mixtures of pretreatment modifiers which are preferred according to this invention are combina-tions of at least one of the above-described mineral acids or anhydrides of sulfur or organometallic chalcogenide derivatives with at least one of the above-described organic acids or organic acid esters.
More preferred combinations are those containing at least one of the preferred sulfur containing modifiers identified above (i.e.~ sulfuric acid, fuming sulfuric acid, chlorosulfsnic acid, and hydrogen sulfide) and at least one of the preferred organic acids and esters identified above (i~e., benzoic acid, halo-benzoic acids, and ~he Cl ~o about C6 alkyl esters thereof). Best results are obtained through the use of a combination of chlorosulfonic acid and methyl benzoate.
The pretreated magnesium-containing component is obtained by contacting components comprising at least one magnesium alcoholate and at least one Group II or IIIA metal alkyl. Preferably, at least one of the abvve-degcribed pretreatment modifiers also is employed in preparation of the pretreatment product. The components are employed in amounts such that the atomic ratio of metal in the Group II
or IIIA metal alkyl component to metal in the m3g-nesium aleoholate component ranges from about 0.001:1 to about 1:1. Preferably, this ratio ranges rom about 0.005:1 to about 0.5-1 as these amounts provide for good improvements in catalyst performance without hindering removal of unreacted Group II or IIIA metal alkyl from the reaction product which ultimately forms. In the preferred embodiment of this invention, wherein at least one pretrea~ment modifier is employed in preparation of the pretreated 3~

magnesiu~-containing product, the modifier is employed in an amount which is effective to improve catalyst component performance but not so great as to hinder pretreatment due to ormation of excessive amounts of solids on reaction with the Group II or IIIA
metal alkyl pretreatment component. Preferably, this amount ranges from about 0 a001 to about 2 moles of pretreatment modifier per mole of Group II or IIIA metal alkyl componentO Best results are attained when the molar ratio of pretreatment modifier to metal alkyl component ranges from about 0.005sl to about 1:1, and particularly from about 0.01:1 to about 0.5:1. According to a particularly preferred embodiment of the invention wherein the modifier component employed is a mixture of at least one mineral acid or anhydride of sulfur or organo-metallic chalcogenide derivative and at least one organic acid or ester, it is preferred to employ from about 3.5 to about 20 moles of the organic acid or ester per mole of sulfur-containing modifier.
More preferably, this ratio ranges from about 1 1 to about 15:1~
As indicated above the pretreatment product employed according to this invention is free of unreacted Group II or IIIA metal. alkyl and is pre-pared by contacting the pretreatment componentsO
Although not required, it is preferred to contact the components in the presence of an inert diluent to aid in conductance of heat evolved on reaction of the magnesium alcoholate and metal alkyl compo~
nents away from the reaction product and further, because in the absence of a diluent the magnesium alcoholate and metal alkyl components typically react to form a sticky mass which can be difficult to handle in subsequent preparative manipulations.
Although it is preferred to contact the pretreatment components in the presence of an inert diluent, other techniques such as pulverization of magnesium alcoholate in the presence of metal alkyl and, optionally, modifier component or a fluidized bed treatment of solid magnesium alcoholate with Group II or IIIR metal alkyl, and optionally, one or more modifiers al50 can be employed~ Most preferably, Group II or IIIA metal alkyl dissolved in an inert diluent is added to a suspension of magnesium alcohol-ate in a diluent. Modifier components, when used, can be employed in any convenient form.
Diluents suitable or u~e in pretreatment include hydrocarbons and halogenated derivatives thereof that are substantially inert to the pretreatment components employed and, preferably, are liquid at pretreatment temperatures. I~ also is contemplated to conduct the pretreatment at elevated pressure so that lower-boiling diluents can be used even at hiyher temperatures. ~xamples of useful diluents include alkanes such as hexane, cyclohexane, ethyl-cyclohexane, heptane, octane, nonane, decane,undecane, and so forth; aromatics such as xylenes and ethylbenzene, and halogenated and hydrogenated aromatics such as chlorobenzene, o-dichlorobenzene, tetrahydronaphthalene, and decahydronaphthalene.
Preferred diluents are the alkanes and especially hexane.
The 6equence in which the pretreatment components are contacted is not critical. When pretreatment is carried out without the use of pretreatment modifier, the magnesium alcoholate and Group II or IIIA metal alkyl components are simply combined.
When one or more modifier oomponents are employed, magnesium alcoholate component, Group II or IIIA
metal alkyl component/ and modifier component can be contacted concurrently or two of the components can be brought together and then the third component added to the result. Best results are attained ~hen the modifier component is added to a solution of Group II or IIIA metal alkyl component in a diluent and then the resulting solution i added to the magnesium alcoholate component.
Pretreat~ent according to this invention is carried out at temperatures ranging from about -30 to about 130C. Preferably, the pretreatment temperature ranges from about 0 to about 60C., with about 10 to about 30~C. being more preferred from the standpoint of convenience. The time of pretreatment generally ranges from several minutes to several hours, with about 1 to about 10 hours being preferred~ When pretreatment is conducted in the presence of an inert diluent~ it i~ desirable to agitate the components during pretreatment to ensure thorough contacting of the components.
Following contacting of pretreatment components as described above, unreacted Group II or IIIA metal alkyl component is removed from the reaction product of the pretreatment components to avoid reduction of the titanium component employed ;n subsequent preparative stepsO When pretreatment is conducted in ~he presence of an inert diluent, the reaction product preferably is separated from the diluent, for example, ~y filtration or decantation, and unreacted Group II or III~ metal alkyl is removed therefrom by ~ashing with hexane or another alkane.
The above-described pretreatment is conducted in the substantial absence of water, oxygen, carbon oxides, and other extraneous materials capable of adversely affecting the performance o~ the invented catalyst components. Such materials are conveniently excluded by carrying out the pretreatment in the presence of an inert gas uch as nitrogen or argon, or by other suitable means. Optionally, all or part of the pretreatment may be conducted in the presence of one or more alpha-olefins which, when -22~
introduced into the preparative system in ~aseous orm~ can serve to exclude catalyst poisons. The presence of one or more alpha-olefins during pre-treatment also can result in improved stereo-specificity. Useful alpha-olefins include ethylene, propylene, butene-l, pentene-l, 4-methylpentene-1, hexene-l, and mixtures thereof. Of course, any alpha-olefin employed during pretreatment should be of relatively high purity, for example, polymeriza-tion grade or higher. Other precautions which aid in excluding extraneous poisons include purification of any diluent to be employed, such as by percolation through molecular sieves and/or silica gel prior to use, and drying and/or heating of magnesium alcohol-ate pretreatment components.
As a result of the pretreatment in accoxdance with this invention, there is obtained a hydrocarbon-insoluble, magnesium-containing pretreatment prQduct which can be reacted with at least one halogen-containing titanium~IV) compound and at least one organic electron donor to form a stereospecific supported catalyst component especially useful in the stereospecific polymerization of alpha-olefins of 3 or more carbon atoms.
Due to the sensitivity of catalyst components to catalyst poisons such as water, oxygen, and carbon oxides, the catalyst components are prepared in the substantial absence of such materials.
Catalyst poisons can be excluded by carrying out the preparation under an atmosphere of an inert gas such as nitrogen or argon, or an atmosphere of alpha-olefin as described hereinabove. As noted above, purification of any diluent to be employed also aids in removing poisons from the preparative system.
3S As a result of the above-described preparation there is obtained a solid reaction product suitable for use as a catalyst component. Prior to such use~ it is desirable to remove incompletely-reacted starting materials from the solid reaction product.
This is conveniently accomplished by washing the solid, after separation from any preparative diluent, with a suitable solvent, such as a liquid hydrocarbon or chlorocarbon, preferably within a short time after completion of the preparative reaction because prolonged contact between the catalyst component and unreacted starting materials may adversely affect catalyst component performance.
Although not required, the solid reaction product prepared as described herein may be contacted with at least one liquid Lewis acid prior to polymeriza-tion. Such Lewis acids useful according to this invention are materials which are liquid at treatment temperatures and have a Lewis acidity hi~h enough to remove impurities such as unreacted starting materials and poorly affixed compounds from the surface of the above-described solid reaction product.
Preferred Lewis acids include halides of Group III-V
metals which are in the liquid state at temperatures up to about 170~C. Specific examples of such materials include BC13, AlBr3, TiC14, TiBr4, SiC14, GeCl~, SnC14, PC13, SbCls, and haloalkylchlorosilanes such as C12HC-SiC13. Preferable Lewis acids are TiC14, SiC14 and C12HC-SiC13. Mixtures of Lewis acids can be employed if desired.
Although not required, the above-described solid reacticn product may be washed with an inert liquid hydrocarbon or halogenated hydrocarbon before contact with a Lewis acid. Suitable inert liquids include those identified hereinabove as pretreatment and preparative diluents. I~ such a wash is conduc~ed it is preferr~d to substantially remove the inert liquid prior to contacting the washed solid ~ith Lewis acid.

The liquid Lewis acid employed according to the invention preferably is used neat although it also is contemplated to employ liquid Lewis acid diluted with up to about 40 vol.~ of an inert solvent therefor. Suitable solvents include those materials useful as diluents in preparation of pretreatment product and supported catalyst component as described hereinabove. Of course, any such solvent should be purified prior to use. The amount of Lewis acid used~ whether neat or diluted, is not critical.
Prom a practical standpoint~ however, the amount should be great enough to provide a high degree of contact between the solid and liquid~ but not so great as to waste the Lewis acid or require exces-sively large vessels for the contacting. Most preferably, from about 3 to about 10 milliliters of Lewis acid are used for each gram of solid to be treated.
Temperature in the liquid Lewis acid-contacting step is at least high enough to avoid solidification of the Lewis acid employed, but not so high as to adversely affect ultimate catalyst component perfor-mance. Preferred temperatures range from about 0 to about 170C. ~hen TiC14 i5 used as the Lewis acid, temperatures of about 20~ to about 135C. are preferred as the same result in desirable improve-ments in catalytic performance while avoiding waste of TiC14 through vaporization thereof and exposure of catalyst comp~nents to conditions more severe than necessary.
The time of contact with liquid Lewis acid is not critical and generally ranges from several minutes to several hours. It is desirable to agitate the solid and Lew;s acid during at least a substantial portion of this time to ensure a high degree o~ contact. Preferred contact times range from 1 to about 30 minutes as the same yield the desired improvements without occupying preparation equipment for undesirably lengthy periods of time.
As in preparation of the solid reaction product, the Lewis acid-contacting step according to this inven~ion is conducted in the substantial absence of oxygen, water, carbon oxides and extraneous catalyst poisons. Such materials are excluded by any convenient manner as described hereinabove.
Following contacting with Lewis acid, solids are allowed to settle and supernatant is removed therefrom such as by filtration or decantation.
One or more additional Lewis acid-contacting steps can be carried out with the same or different Lewis acid. In addition, a series of alternating Le~is acid and inert liquid hydrocarbon or halogenated hydrocarbon washes can be conducted if desired.
Prior to use in the polymerization of alpha-olefins, the catalyst components used in this inven-tion are mechanically activated by comminution.
Mechanical activation improves the polymerization performance of the invented catalyst components, ~hether or not treated with Lewis acid, in terms of both activity and susceptibility to modification by crystallinity-promoting modifiers; however, comminu-tion typically forms a catalyst component whichyields increased noncrystalline products. The preferred technique for mechanically activating the invented catalyst components i~ dry ball-milling, that is, ball-milling in substantial absence of inert diluent. However, good results also can be obtained by ball-milling in the presence of a minor amount of an inert diluent ~uch as hexane or another alkane, as well as by other techniquesO The above-described catalyst components can be comminuted in the presence of one or more organic electron Zonors of the general type employed in preparation of the catalyst components. Techniques of comminution by ball-milling generally are known in the art.
Typically, titanium-containing catalyst component and hard, nonreactive balls, such as steel or burundum balls, are placed in a closed container which is agitated usually by rolling, shaking or rocking.
Such combination is continued for a few hours up to several days, typically about 12 to about 36 hours, until the catalyst compoentn is ground to a desired particle size typically about 5 to about 50 microns.
Since mechanical action of comminution can cause a temperature increase in the comminuting mixture, care should be taken to keep the temperature below the decomposition temperature of the catalyst component. Typically, the comminuting mixture should be kept at below about 50°C.
Optimum comminution techniques for a specific catalyst component can be determined by routine experimentation.
Optimum polymerization performance is attained by treating with Lewis acid and then mechanically activating. Treatment of mechanically activated catalyst component with Lewis acid alone is not preferred as it may result in agglomeration of the component and inferior polymerization performance.
According to this invention comminuted titanium-containing catalyst component is retreated by contact with a halide-containing titanium(IV) compound and an organochlorosilane and an ester.
Titanium(IV) compounds useful in retreatment are titanium halides and haloalcoholates having 1 to about 20 carbon atoms per alcoholate group such as methoxy, ethoxy, butoxy, hexoxy, phenoxy, decoxy, naphthoxy, dodecoxy and eicosoxy. Mixtures of titanium compounds can be employed if desired.
The titanium(IV) compounds used in this invention can be used in mixtures with corresponding silicon, germanium and tin compounds.

Preferred titanium compounds are the halides and haloalcoholates having 1 to about 8 carbon atoms per alcoholate group. Examples of such compounds include TiC14, Ti~r4, Ti(OCH3)C13, Ti(OC2Hs)C13, Ti(OC4~g)C13, Ti (OC6H5)C13~ Ti ~C6H13)Br3 Ti(OC~H17)Cl3, Ti(Qc~3)~Br2~ ~i(oc2H5)2cl2~
Ti(~C6H13)2C12, Ti(ocgHl7)2Br2~ Ti(OCH3)3Br, Ti(OC2Eis)3Cl, TilOC4Hg)3Cl, Ti(OC6H13)3Br, and ~i(OCgH17)3Cl. Titanium tetrahalides and particu-larly titanium tetrachloride (TiC14) are preferred from the standpoint of attaining maximum activity and stereospecificity. The most preferred titanium(IV) halide for retreatment is titanium tetrachloride~
Haloalkylchlorosilanes useful in this invention include compounds with the formula X
R--Si--Cl xl wherein R is a haloalkyl radical containing one to about ten carbon atoms or a halosilyl radical or haloalkylsilyl radical containing one to about eight carbon atoms, and X and xl are halogen, hydrogen, or alkyl or haloalkyl radicals containing one to about ten carbon atoms. Typically, R is a chloroalkyl radical containing one to about eight carbon atoms and one to about twelve chlorine atoms, and X is chlorine or a chloroalkyl radical containing one to four carbon atoms, and xl is a hydrogen or chlorine.
Preferable haloalkylchlorosilanes useful in this invention are dichlorosilanes and trichlorosilanes.
Also preferable are haloalkylchlorosilane~ containing a chloroalkyl group containin~ one to about four carbon atoms and one to ten chlorine atoms. Pre-ferable haloalkylchlorosilanes include dichloromethyl trichlorosilane, trichloromethyl trichlorQsilane, dichloromethyl dichlorosilane, trichloromethyl dichlorosilane, chloromethyl trichlorosilane and hexachlorodisilane. Trichloromethyl trichlorosilane and dichloromethyl trichlorosilane are most preferred.
Organic acid esters useful in retreatment are alkyl and haloalkyl esters of organic acids wherein the a~kyl group or groups contain one to about twelve carbon atoms, and aryl and haloaryl esters of such acids wherein the aryl group or groups contain six to about ten carbon atoms. Specific examples o useful organic acid esters include the methyl, chloro-methyl, ethyl, chloroethyl r bromoethyl, butyl, hexyl,cyclohexyl, octyl, chlorododecyl, phenyl, chlorophenyl, and naph~hyl esters of organic acids. Organic acids from which such esters can be formed are acids con-taining from 1 to about 20 carbon atoms and 1 to about 4 carboxyl groups. Such acids include alipha-tic acids of 1 to about 20 carbon atoms; halogen-, hydroxyl-, oxo-, alkyl-, alkoxy-, aryl-, and aryloxy-substituted aliphatic acids of 1 to about 20 carbon atoms; aromatic acids of 7 to about 14 carbon atoms;
and halogen-, hydroxyl-, alkyl-, alkoxy-, aryl , and aryloxy-substituted aromatic acids of 7 to about 20 carbon atoms. Monocarboxylic acids are preferred over the polycarboxylic acids.
Examples of aliphatic acids include saturated acids such as formic acid, acetic acid, oxalic acid, malonic acid, butyric acid, pivalic acid, valeric acid, glutaric acid, caproic acid, cyclohexane-carboxylic acid, suberic acid, lauric acid, stearic acid, and arachidic acid; and unsaturated acids such as acrylic acid, crotonic acid, isocrotonic acid, vinylacetic acid, allylacetic acid, maleic acid, hydrosorbic acid, sorbic acid J undecenoic acid, oleic acid, and stearolic acid.
Examples of substituted aliphatic acids include chloroacetic acid, phenylacetic acid, chloromalonic acid, benzylmandellic acid~ bromobu~yric acid, ketobutyric acid, 2-hydroxyhexanoic acid, linoleic acid tetrabromide, 3-chloro~2-butenoic acid, benzallac-tic acid, mucochloric acid, mucobromic acid, piperic acid, and ketocaproic acid.
E~amples of aromatic acids and substituted aromatic acids include ben~oic acid, phthalic acid, trimellitic acid, pyromellitic acid, naphthoic acids chlorobenzoic acids, chloronaphthoic acids, hydroxy-naphthoic acids, toluic acids, xylilic acids, iso-durylic acids, butylbenzoic acids, dihexylbenzoic acids, anisic acid, veratric acid, asaronic acid, ethoxybenzoic acids, piperonylic acids, vanîllic acid, cresotic acid, and everninic acid.
Preferred esters are esters of benzoic acid and halobenzoic acids wherein the alkyl group contains 1 to about 6 carbon atoms such as methyl benzoate, methyl bromobenzoates, ethyl benzoate, ethyl chloro-benzoates, butyl benzoate, isobutyl benzoate, hexyl benzoate, and cyclohexyl ben~oate, as these give good results in terms of activity and stereospecific-ity and are convenient to use. Most preferable retreatment esters include ethyl benzoate, ethyl anisate and methyl-p-toluate.
In retreatment of a comminuted supported titanium-containing catalyst component according to this invention, a retreatment amount of titanium(IV) compound is contacted with the comminuted product.
Typically, the atomic ratio of re~reat~ent titanium(IV) to titanium contained in the comminuted catalyst component is about 50:1 to about 500:1 and preferably is about 200:1 to about 250:1.
In retreatment, an haloalkylchlorosilane and an organic acid ester also are contacted with comminuted catalyst component. Typically; the ratio of moles of ester to gram-atom of ~itanium contained in such component is about 0.5-1 to about 10 1 and preferably is about 2:1 to about 4:1; and the ratio of moles of haloalkylchlorosilane to gram-atom of titanium 5~

contained in such component is about 4:1 to about 500:1 and preferably is about 200:1 to about 300:1.
The haloalkylchlorosilane and organic acid ester can be diluted in a liquid hydrocarbon before retreat-ment. Although the titanium(IV) compound and halo-alkylchlorosilane and organic acid ester ~an be combined ~efore retreatment, the usual procedure is to contact the comminu~ed component irst with the haloalkylchlorosilane then with the titanium(IV~
compound in a diluent.
Although the chemical structure o the catalyst components described herein is not presently known, the components preferably contain from about 1 to about 6 wt.% titanium, from about 10 to about 25 ~t.~ magnesium, less than about 1 wt.% Group IIIA
metal and from about 45 to about 65 wt.~ halogen.
From the standpoint of attaining maximum efficiency of titanium, catalyst components which are more preferred according to this invention contain from about 1.5 to about 3 wt.~ titanium, from about 15 to about 20 wt.% magnesium, less than about 0 5 wt.% Group IIIA metal, and from about 50 to about 60 wt.% chlorine.
The catalysts of this invention comprise a stereo-specific supported component as described above, and at least one organoaluminum activator. Preferably, the invented catalysts further comprise one or more crystallinity promoters capable of further improving catalyst stereospecificity. Suitable organoaluminum activators include trihydrocarbylaluminum compounds and dihydrocarbylaluminum hydrides having 1 to about 20 carbon atoms per hydrocarbyl radical. SpeciEic examples of useful organoaluminum compounds include Al~CH3~3, P~15C2Hs)3, Altc3~7)3t A~(C4Hg)3 Al (C5~11) 3, Al (C6H13) 3, Al (cgHl7) 3, Al (C12H25) Al (CH3) 2H, Al (C2Hs) 2H, Al ~C3H7) 21~, ~1 (C4Hg) 2H~
Al ~C5~11) 2H, Al (C~H13) ~H, Al (CgH17) 2H, and i2 AllC12H2s)2H. Mixtures also can be employed if desired. Preferred organoaluminum compounds are the trialkylaluminums containing 2 to about 6 carbon atoms per alkyl radical as these lead to best results in terms of activity and stereospecificity. Most preferably, the organoaluminum compound is triethyl-aluminum, triisobutylaluminum or a mixture thereof.
The organoaluminum compound is employed in at least an amount which is effective to prOmGte the polymeri-7ation activity of the supported component. Prefer-ably the ratio of moles of organoaluminum component to gram-atom of titanium in the supported component is at least about 3:1. More preferably, this ratio ranges from about 5:1 to about 300:1, although sub-stantially greater amounts of organoaluminum componentalso can be employed and often give highly desirable results.
Usef~l crystallinity promoters are materials capable of further improving the stereospecificity of the invented catalysts and incl~de a wide variety of materials and combina$ions of materials. Examples of useful materials include a variety of organic electron donors, such as those employed in prepara-tion of the invented; stereospecific supported catalyst components, and various inorganic mineral acids, anhydrides, and derivatives, including those emplcyed in pretreatment as described hereinabove.
The particular materials or combination to be employed can be readily determined by persons of skill in the art and the examples appearing hereinafter illustrate the use of various crystallinity promoters.
Preferred materials are those capable of improving stereospecificity without leading to substantial decreases in activity. Examples of preferred crystal-linity promoters include methyl-p-toluate, methyl anisate, ethyl benzoate, ethyl-p-anisate, ethyl pivalate, 2,2,6~6-tetramethylpiperidine, 2-ben2yl-pyridine, 2-acetylpyridine, and combinations thereof.
Comminuted catalyst may be prepolymerized with an alpha-olefin before use as a polymerization S catalyst component. In prepolymerization, commin~ted catalyst and an organoaluminum compound co~catalyst such as triethylaluminum a~e contacted with an alpha-olefin such as propylene under polymerization con-ditions, preferably in the presence of a modifier such as methyl-p-toluate and in an inert hydrocarbon such as hexane. Typically, the polymer/catalyst weight ratio of the resulting prepolymerized component is about 0.1:1 to about 20:1. Prepolymerization forms a coat of polymer around catalyst particles which in many instances improves particle morphology, activity, and stereospecificity.
The above-described catalysts are useful in polymerization of alpha-olefins such as ethylene and propylene, and are most useful in stereospecific polymerization of alpha-olefins containing 3 or more carbon atoms such as propylene, butene-l, pentene-1, 4-methylpentene-1, and hexene-l, as well as mixtures thereof and mixtures thereof with ethylene. The invented catalysts are particularly effective in the stereospecific polymerization of propylene or mixtures thereof with up to about 20 mole % ethylene or a higher alpha-olefin. Propylene homopolymeriza-tion is most preferred. According to the invention, highly crystalline polyalpha~olefins are prepared by contacting at least one alpha-olefin with th2 above-described catalyst compositions under poly-merizing conditions. Such conditions include poly-merization temperature and time~ ~onomer pressure, avoidance of con~amination Qf catalyst, shoice of polymerization medium in slurry processes, the use of additives to control polymer molecular weights, and other conditions well known to persons of skill ~33-in the art. Slurry, bulk~ and vapor phase polymeri-zation processes are oontemplated herein.
The amount of catalyst to be employed varies depending on choice of polymerization technique, 5 reactor size, monomer to be polymerized, and other factors known to persons of skill in the art, and can be determined on the basis of the example~
appearing hereinafter.
Irrespective of tne polymerization process employed, polymerization should be carried out at temperatures sufficiently high to ensure reasonable polymerization rates and avoid unduly long reactor residence times, but not so high as to result in the production of unreasonably high levels of stereo-random products due to excessively rapid polymeriza-tion rates. Generally, temperatures range from about 0 to about 120~C. with about 20 ~o about 95Co being preferred from the standpoint of attaining good catalyst performance and high production rates.
More preferably, polymerization according to this invention îs carried out at temperatures ranging from about 50 to about 80C.
Alpha-olefin polymerization according to this invention is carried out at monomer pressures of about atm~spheric or above. Generally, monomer pressures range from about 20 to about 600 psi, although in vapor phase polymerizations, monomer pressures should not exceed the vapor pressure at the polymerization temperature of the alpha~olefin to be polymerized.
The polymeriæation time is not critical and will generally range from about l/2 to several hours in batch processes. Polymerization times ranging from about l to about 4 hours are typical in auto-clave-type reactionsO In slurry processes, the polymerization time can be regulated as desiredO
Polymerization times ranging from about 1~2 to 5i2 several hours are generally suficient in continuous slurry processes.
Diluents suita~le for use in slurry polymeriza-tion processes include alkanes and cycloalkanes such ~s pentane, hexane, heptane, n-octane, isooctane, cyclohexane, and methylcyclohexane; alkylaromatics such as toluene, xylene, ethylbenzene, isopropyl-benzene, ethyl toluene, n-propyl--benzene, diethyl-benzenes, and mono- and dialkylnaphthalenes; halogena-ted and hydrogenated aromatics such as chlorobenæene,chloronaphthalene, ortho-dichlorobenzene, tetrahydro-naphthalene, decahydronaphthalene; high molecular weight liquid paraffins or mixture~ thereoÇ, and oth~r well known diluents. It often is desirable to purify the polymerization medium prior to use such as by distillation, percolation through molecular sieves, contacting with a co~pound such as an alkyl-aluminu~ compound capable of removing trace impurities, or by other suita~le means. Examples of gas-phase polymerization processes in which the catalyst of this ;n~ention is useful are described in UOS~ Patents 3,957,448; 3,965,083; 3,971,768; 3,972,611; 4,129,701;

4,101,289; 3,652,527 and 4,003,712.
Irrespective of polymerization technique, poly merization is carried out under condition~ that exclude oxygen, water, and other materials that act as catalyst poisons. Typically, no special precau-tions need be taken to exclude such materials because a positive pressure of monomer gas commonly exists within the reactor~
Also, according to this invention, polymerization can be carried out in the presence of additives to control polymer molecular weights. Hydrogen is typically employed or this purpose in a manner well known to persons of skill in the art.
Upon completion of polymerization, or when it is desired to terminate polymerization or deactivate the catalysts of thi~ invention, the catalyst can be contacted with waterO alcohols, acetone, or other suitable catalyst deactivators in a manner known to persons of skill in the art.
The products produced in accordance with the process of this invention are normally solid, pre-dominantly isotactic polyalpha~olefins. Polymer yields are sufficiently high relative to the amount of catalyst employed so that useful products can be obtained without separation of catalys~ residues.
Further, levels of stereorandom by-products are sufficiently low so that useful products can be obtained without separation thereof. The polymeric products produced in the presence of the invented catalysts can be fabricated into useful articles by extrusionl injection molding, and other co~mon techniques.
The following example illustates but does not limit the described invention.
Example (A) Preparation of Pretreated Magnesium~contain-ing Component Into a one-liter ~lask equipped with magnetic stirrer and maintained under nitrogen in a drybox were added lno milliliters of dry n-hexane and 11.4 grams of anhydrous magnesium ethoxide tobtained from Dynamit Nobel) at ambient temperature. The resulting suspension was stirred and 20 milliliters of a mixture formed by combining 60 milliliters of a 25 wt.% solution of triethylaluminum (TEA) in dry n-hexane, 3.03 milliliter of chlorosulfonic acid and 0.2 milliliter of methyl benzoate were added dropwise to the stirred suspension over a period of about l/4 hour at ambient temperature. Stirring was continued for one hour following completion of the addition of TEA solution and then the solid reaction product was allowed to settle. The super--3~-natant then was decan~ed and the solid ~as washed twice with 125-~illiliter portions of dry n-hexane.
The atomic ratio of aluminum to magnesium employed in preparation of the pretreatment product was ~.15:1.
(B) Preparation of Supported Catalyst Component the pretreatment product prepared in (A), 114 milliliters of titanium tetrachloride and 114 milliliters of dichloromethyl trichlorosilane were mixed at ambient temperature. To the resultin~
mixture there ~as added dropwise 3.0 milliliters of ethyl benzoate over a period of about 1/4 hour at ambient temperature with stirring. After addition of the ethyl benzoate solution was completed, the resulting mixture was heated to 95C., stirred at this temperature for 1-1/2 hours, and then allowed to cool to about 115 to 120C. The supernatant liquid then wa~ decanted and the remaining solid was washed once with a 150-milliliter portion of dry n-hexane. After the final wash, the solid was separated from the liquid by filtration and dried.
(C) Comminution of Supported Catalyst Component A portion of the solid catalyst component pre pared in (Bl and 80 stainless steel balls having a diameter of 10 millimeters were placed in a Roalox, burundum-fortified porcelain mill jar (manufactured by A. Daigger Company) having a capacity of 1/4 quart (about 280 milliliters) and milled in a rotary ball mill (manufactured by Paul 0. Abbe, Inc., motor speed = 1725 rpm) for 24 hours at ambient temperature under an atmosphere of dry nitrogen. The solid was sieved to remove all particles which could not pass th~ough a 200 mesh (U.S. Sieve Series) sieve.
The atomic ratio of titanium employed in ~B) to magnesium employed in (A) was 4.6:1 and the ratio of ethyl benzoate to titanium was 0.03 mole per gram-atom.

(D) Retreatment of Comminuted Catalys~ Component A 9.2 gram portion of ~he solid obtained from (C~ was mixed with 94.4 millili~ers of titanium tetrachloride and 92.4 milliliters of dichloromethyl trichlorosilane. After 2.49 milliliters of ethyl benzoate were added dropwise to this mixture with stirring, the resulting suspension was heated to 95C for 1.5 hours while stirring. After solid product w~s allowed to settle, supernatant liquid was removed by decantation and the residue washed four times with 150-millili~er portions of n-hexane.
The remaining solid was filtered and dried. Elemen tal analysis of the solid showed l.9U wt~ titanium, 17.8 wt~ magnesium and 57.4 wt.% chlorine.
(E) Propylene Polymerization A series of bulk propylene polymerizations were conducted using aliquots of titanium~containing catalyst components prepared above. Triethylalumi-num (TEA), methyl-p-toluate (MpT) and 1:1 complex of MpT and aluminum trichloride (MpT AlC13) and titanium-containing catalyst component were combined in a drybox under nitrogen and flushed into a two-liter Parr reactor in 300 milliliters of prvpyleneO
After an additional 1000 milliliters of propylene and 30 psig of hydrogen were sharged to the reactor, the reactor was closed and polymerization conducted at 71C. for two hours. After the reactor was cooled and vented, the resulting solid polymer was air dried overnight and then ~eighedL Results are shown in Table 1.

5~

Table I

Yield tgram/
gram of titanium Extract- Bulk com- ables Density Molar Ratio 1~ (wt. %?- (lbs/ft3 TEA/Ti/Mpt AlC13 ~1) 284/1/73.6 15,186 3.9 25.7 TEA/T i /ME~ ~ 1 ) 379/1/163.2 7,170 3.1 ~2.4 EA/Ti/Mpt-AlC13/Mpt (2) 291/1/54 n 3/35.514,246 4.1 24.7 317/1/44.9/30.621,7 56 6 ~ 1 25 ~ 4 317/1/49.4/33.018,592 5.1 26.8 (1) 0.021 gram of titanium-containing component used t23 0.015 gram of titanium-containing component used The data show that olefin polymerization catalyst prepared according to the invention is active while maintaining low amounts of amorphous product and high bulk density.

, . .

Claims (44)

What is claimed is:

1. A polymerization catalyst for alpha-olefins comprising (A) an organoaluminum compound and (B) a solid, titanium containing component formed by (1) comminuting a solid reaction product com-prising (a) at least one halogen-containing com-pound of titanium (IV);
(b) at least one electron donor containing at least one atom of oxygen, nitrogen, sulfur, or phosphorus; and (c) at least one hydrocarbon-insoluble, magnesium-containing compound; and (2) retreating such comminuted product with (a) at least one halogen-containing com-pound of titanium (IV);
(b) at least one haloalkylchlorosilane and (c) at least one carboxylic organic acid ester.

2. The catalyst of claim 1 wherein retreatment component (2)(a) is titanium tetrachloride.

3. The catalyst of Claim 1 wherein the halo-alkylchlorosilane (2)(b) has a formula wherein R is a haloalkyl radical containing one to about ten carbon atoms or a halosilyl radical or haloalkylsilyl radical containing one to about eight carbon atoms, and X and X1 are halogen, hydrogen, or alkyl or haloalkyl radicals containing one to about ten carbon atoms.

4. The catalyst of Claim 3 wherein R is a chloroalkyl radical containing one to about eight carbon atoms and one to about twelve chlorine atoms, and X is chlorine or a chloroalkyl radical containing one to four carbon atoms, and X1 is chlorine or hydrogen.

5. The catalyst of claim 1 wherein retreatment component (2)(c) is an alkyl, haloalkyl, aryl or haloaryl ester of an aliphatic or aryl organic acid.

6. The catalyst of claim 2 or 3 wherein the retreatment component (2)(c) is ethyl benzoate, ethyl anisate or methyl-p-toluate.

7. The catalyst of claim 1 wherein the solid titanium component is comminuted by ball-milling.

8. The catalyst of claim 1 wherein the magnesium-containing compound (1)(c) is a pretreatment product of components comprising (i) at least one magnesium alcoholate; and (ii) at least one Group II
or Group IIIA metal alkyl.

9. The catalyst of claim 1 wherein the magnesium-containing component (l)(c) is (i) a magnesium halide or (ii) a reaction product of a magnesium halide with an organometallic compound of Groups I-III metals.

10. The catalyst of claim 1 wherein the molar ratio of electron donor (1)(b) to titanium (IV) compound (1)(a) is about 0.001:1 to about 1:1 and the atomic ratio of titanium in (1)(a) to magnesium in (1)(c) is at least about 0.5:1.

11. The catalyst of claim 1 wherein component (1)(a) comprises titanium tetrachloride.

12. The catalyst of claim 1 wherein component (1)(b) comprises a C1-C6 alkyl ester of an aromatic monocarboxylic acid or of an aromatic monocarboxylic acid substituted with at least one halogen, hydroxyl, oxo, alkyl, alkoxy, aryl or aryloxy substituent.

13. The catalyst of claim 1 wherein the atomic ratio of retreatment titanium (IV) (2)(a) to titanium contained in the comminuted product is about 50:1 to about 500:1, the ratio of moles of organic acid ester to gram-atom of titanium contained in the comminuted product is about 0.5:1 to about 10:1, and the ratio of moles of haloalkylchlorosilane to gram-atom of titanium contained in the comminuted product is about 40:1 to about 500:1.

14. A polymerization catalyst for alpha-olefins comprising (A) an organoaluminum compound and (B) a solid, titanium-containing component formed by (1) comminuting a solid reaction product com-prising (a) at least one halogen-containing com-pound of titanium(IV);
(b) at least one electron donor containing at least one atom of oxygen, nitrogen, sulfur or phosphorus;
(c) at least one hydrocarbon-insoluble, magnesium-containing pretreatment product comprising (i) at least one magnesium alcoholate;
and (ii) at least one Group II
or Group IIIA metal alkyl: and (d) an haloalkylchlorosilane; and (2) retreating such comminuted product with (a) at least one halogen-containing com-pound of titanium (IV);
(b) at least one haloalkylchlorosilane;
and (c) at least one organic acid ester.

15. The catalyst of claim 14 wherein the retreat-ment titanium (IV) compound (2)(a) comprises titanium tetrachloride.

16. The catalyst of claim 14 wherein the haloalkylchlorosilane (1)(d) and (2)(b) is dichloro-methyl trichlorosilane, trichloromethyl trichloro-silane, dichloromethyl dichlorosilane, trichloromethyl dichlorosilane, chloromethyl trichlorosilane, or hexachlorodisilane.

17. The catalyst of claim 15 wherein the haloalkylchlorosilane (1)(d) and (2)(b) is dichloro-methyl trichlorosilane or trichloromethyl trichloro-silane.

18. The catalyst of claim 14 wherein the re-treatment organic acid ester (2)(c) is an alkyl, haloalkyl, aryl or haloaryl ester of an aliphatic or aryl organic acid.

19. The catalyst of claims 15 or 17 wherein the retreatment organic acid ester (2)(c) is ethyl benzoate, ethyl anisate or methyl-p-toluate.

20. The catalyst of claim 14 wherein the solid titanium component is comminuted by ball-milling.

21. The catalyst of claim 14 wherein the titanium (IV) compound (1)(a) is titanium tetra-chloride.

22. The catalyst of claim 14 wherein the electron donor (1)(b) comprises an alkyl ester of benzoic acid or an alkyl- or halo-substituted benzoic acid wherein the alkyl radicals contain one to about six carbon atoms.

230 The catalyst of claim 14 wherein the electron donor (1)(b) comprises methyl benzoate.

24. The catalyst of claim 14 wherein component 1(c)(ii) comprises a compound of the formula MR3m wherein M is aluminum, magnesium, or zinc, each R3 is independently an alkyl radical of 1 to about 20 carbon atoms, and m corresponds to the valence of M.

25. The catalyst of claim 14 wherein component (1)(c)(i) comprises a compound of the formula Mg(OR1)n(OR2)2-n wherein R1 and R2 are identical or different hydrocarbyl radicals of 1 to about 20 carbon atoms and n ranges from 0 to 2.

26. The catalyst of claim 14 wherein magnesium-containing compound (1)(c) further includes at least one pretreatment modifier selected from the group consisting of mineral acids and anhydrides of sulfur, organometallic chalcogenide derivatives of hydrogen sulfide in which each hydrogen is replaced by an organosilicon, organogermanium or organotin group wherein the organic radicals are selected from the group consisting of phenyl, alkyl-substituted phenyl, phenyl-subtituted alkyl and alkyl radicals, said alkyl radicals containing 1 to about 6 carbon atoms, organic acids containing 1 to about 20 carbon atoms and 1 to about 4 carboxyl groups and C1 to about C12 alkyl and haloalkyl and C6 to about C10 aryl and haloaryl esters of said organic acids.

27. The catalyst of claim 26 wherein the pre-treatment modifier comprises methyl benzoate, chlorosulfonic acid or a mixture thereof.

28. The catalyst of claim 26 wherein component (1)(b) comprises an alkyl ester of benzoic acid or a halobenzoic acid, said alkyl radical containing 1 to about 6 carbon atoms.

29. The catalyst of claim 26 wherein component (1)(c)(ii) comprises a compound of the formula MR3m wherein M is aluminum, magnesium, or zinc, each R3 is independently an alkyl radical of 1 to about 20 carbon atoms, and m corresponds to the valence of M.

30. The catalyst of claim 26 wherein component (1)(c)(i) comprises a compound of the formula Mg(OR1)n(OR2)2-n wherein R1 and R2 are identical or different hydrocarbyl radicals of 1 to about 20 carbon atoms and n ranges from 0 to 2.

31. The catalyst of claim 26 wherein the pre-treatment modifier comprises sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, hydrogen sulfide, benzoic acid, a C1 to about C6 alkyl benzoate or halobenzoate, or a mixture thereof.

32. The catalyst of claims 1 wherein the organoaluminum compound (A) comprises a trialkyl-aluminum containing 2 to about 12 carbon atoms per alkyl radical.

33. The catalyst of claim 32 further character-ized in that said catalyst comprises at least one crystallinity promoter.

34. The catalyst of claim 33 wherein the organo-aluminum compound (A) comprises triethylaluminum.

35. A propylene polymerization catalyst com-prising (A) triethylaluminum, triisobutylaluminum or mixture thereof and (B) a solid, titanium-contain-ing component formed by (1) ball-milling the solid reaction product comprising (a) titanium tetrachloride (b) ethylbenozate or benzoyl chloride (c) a hydrocarbon-insoluble, magnesium containing pretreatment product com-prising (i) magnesium ethoxide;
(ii) triethylaluminum;
(iii) chlorosulfonic acid; and (iv) methyl benzoate; and (d) dichloromethyl trichlorosilane or trichloromethyl trichlorosilane; and (2) retreating such ball-milled product with (a) titanium tetrachloride;
(b) dichloromethyl trichlorosilane or trichloromethyl trichlorosilane; and (c) ethyl benzoate, ethyl anisate or methyl-p-toluate.

36. A process for preparing a catalyst component useful in polymerization of alpha-olefins comprising (A) contacting components comprising (1) at least one magnesium alcoholate, and (2) at least one Group II or IIIA metal alkyl in amounts such that the atomic ratio of metal in (2) to metal in (1) ranges from about 0.001:1 to about 1:1;
(B) removing unreacted Group II or IIIA metal component from the product of (A) to form a solid, hydrocarbon-insoluble, magnesium-containing pretreatment product;
(C) contacting said pretreatment product with components comprising at least one titani-um (IV) halide or haloalcoholate and at least one organic electron donor contain-ing at least one of oxygen, nitrogen, sulfur and phosphorus, in amounts such that the atomic ratio of titanium to metal in (A)(1) is at least about 0.5:1 and the ratio of organic electron donor to titanium ranges from about 0.001 to about 1 mole per gram-atom, to form a solid catalyst component;
(D) comminuting the resulting product; and (E) retreating the comminuted product by con-tacting such product with components com-prising at least one titanium (IV) halide or haloalcoholate, at least one haloalkyl-chlorosilane and at least one carboxylic organic acid ester in amounts such that the atomic ratio of retreatment titanium to titanium contained in the comminuted product is about 50:1 to about 500:1, the ratio o moles of organic acid ester to gram-atom of titanium contained in the comminuted product is about 0.5:1 to about 10:1, and the moles of haloalkyl-chlorosilane to gram-atom of titanium con-tained in the comminuted product is about 40:1 to about 500:1.

37. The process of claim 36 wherein the step of comminuting is by ball-milling.

38. The process of claim 37 wherein retreatment titanium compound is titanium tetrachloride.

39. The process of claim 38 wherein retreatment organic acid ester is ethyl benzoate, ethyl anisate or methyl-p-toluate.

40. The process of claim 38 wherein retreatment chlorocarbon is dichloromethyl trichlorosilane or trichloromethyl trichlorosilane.

41. The process of claims 38 wherein components in (A) further include at least one pre-treatment modifier from the group consisting of mineral acids and anhydrides of sulfur; organometallic chalcogenide derivatives of hydrogen sulfide in which each hydrogen is replaced by an organosilicon, organogermanium or organotin group wherein the organic radicals are selected from the group consisting of phenyl, alkyl-substituted phenyl, phenyl-substituted alkyl and alkyl radicals, said alkyl radicals con-taining 1 to about 6 carbon atoms; organic acids containing 1 to about 20 carbon atoms and 1 to about 4 carboxyl groups; and C1 to about C12 alkyl and haloalkyl and C6 to about C10 aryl and haloaryl esters of said organic acids.

42. The process of claims 39 wherein components in (A) further include at least one pre-treatment modifier from the group consisting of mineral acids and anhydrides of sulfur; organometallic chalcogenide derivatives of hydrogen sulfide in which each hydrogen is replaced by an organosilicon, organogermanium or organotin group wherein the organic radicals are selected from the group consisting of phenyl, alkyl-substituted phenyl, phenyl-substituted alkyl and alkyl radicals, said alkyl radicals con-taining 1 to about 6 carbon atoms; organic acids containing 1 to about 20 carbon atoms and 1 to about 4 carboxyl groups; and C1 to about C12 alkyl and haloalkyl and C6 to about C10 aryl and haloaryl esters of said organic acids.

43. The process of claim 41 or 42 wherein (A) is conducted in the presence of at least one alpha-olefin.

44. The process of claim 41 or 42 further character-ized in that said solid catalyst component is con-tacted with at least one liquid Lewis acid having a high enough Lewis acidity to remove impurities from the surface of said solid.