CA1193397A - Process for preparing polyolefins - Google Patents

Abstract

ABSTRACT

Provided is a process for preparing a polyolefin by poly-merizing at least one olefin in the presence of a catalyst, said catalyst comprising a solid catalyst component and an organometallic compound, said solid catalyst component comprising a substance obtained by the reaction of at least the following four components:
(1) a compound represented by the general formula R1m(OR2) MgX2-m-n, (2) a compound represented by the general formula Me(OR3)pXz-p, (3) a compound represented by the general formula

Description

~g PROOESS FOR PE~EPARING POLYOLl~.FINS

Background of the Invention The presen~ invention relates to a process or preparing polyolefins using a novel polymerlzation catalyst.
Heretofore in this technical field9 a catalyst compris~ng a ~la~nesium hallde a.d a transition metal compound ~uch as a titanium compound supported thereon has been known from Japanese Patent Publicatio~l No.1.2105/1964, and a catalyst prepared by the co-pulver:Lzation of a magnesium halide and titanium tetrachloride has been known from Belgian Patent No.742,112.
But in the production of polyoleflns it is desirable that the catalyst activity be as high as posslble, and when viewed from this standpoint, the process disclosed in Japanese Patent Publication No.12105/1964 afford~ a still low polymerization acti.vity, and ln the proces~ diaclosed in Belgian Patent No.742,112, the polymerization activlty is falrly high, but a further improveme~t is desired.
In 5erman Patent No.2,137,872, the amount of a magnesium hallde used 15 substantlally decreased by its pulverization together 20 with titanium tetrachloride and alumina, but a remarkable increase in activity per solid, which can be regarded as a guideline for productivity, is not recognized~ and a catalyst of higher activity is deslred.
In the productlon of polyolefins, moreover, 1t is desirable from the aspects of productivlty and slurry handling that the bulk density of the resulting polymer be as hlgh as possible.
From this standpoint, in the process disclosed in Japanese Patent Publication No.12105/1964~ the bulk denslty of the resultant polymer is low and the polymerization activlty ls not ~n a satlsfactory state, and in the process disclosed in Belgian Paten~ No.742,1127 the bulk density of the resultant polymer i3 low although the polymeri~at~on actlvity is hlgh, and thus further ~mprovemen~ are deslred.

Summary of the Invention It 18 the ob~ect of the presen~ invention to provlde a novel polymerization cataly~t capable of remedying the above-mentioned drawbacks, exhiblting a high polymeri7ation actlvity9 affording a polymer of high bulk density ln hlgh yield and permitting an extremely easy execution of a continuous polymerization, as well as a process for homopolymerlæing or copolymerizing oleflns using such polymerization catalyst.
The present invention resides in a process for preparing olefin~ by homopolymerizing or copolymeri~ing olefins in the presence of a catalyst comprising a solid catalyst component and an organo-metallic compound, which solid catalyst component compriscs asubstance obtained by the reactlon o~ at least the following four component~:
(1) a compound represented by the general formula R ~(~R )nMgX2 ~2) a compound represented by the general formula Me(OR ~ X

(3) a compound represented by the general formula R6 _~- Si - O ~ R7 and ~4) a halo~en-containing titanium compound ~n whlch formulae R , R , R3 ~nd R7 are each a hydrocarbon radlcal havin~ l to 24 carbon atoms, R4, R5 and R~ are each a hydrocarbon radlcal havlng 1 to 24 carbon atoms, a~koxy, hydrogen or halogen, X i~ halogen, Me is an element of Group~ I through VIII in the 3~

Perlodic Table, provided that silicon and titanium are excluded~
z ~8 the valenc~ o Me9 and m, nl p and q are as follo~s:
O ~ m c 2, 0 ~ n C 2, 0 ~ m~n c 2, 0 c p ~ z, 1 ~ q c 30 The catalyst of the present inventlon exhibits an e~tremely high polymerization activity, and consequently the partial pressure of monomer is kept law during poly~erization. Furthermore9 t~e bulk density of the resultant polymer is so high that the productivity can be improved. Besides, the amount of cat`alyst rP~n~g in the resultant polymer at the end of polymerization 0 iS 80 small that the polyolefin manufacturlng process can dispense with the catalyst removing step, thus permitting simpllfication of the polymer treating process, ~Id as a whole polyolefins can be prepared extremely economically.
~ In the process of the present invention, the amount of polymer produced per unit polymerization reactor i9 larg~ because of a high bulk density oE the polymer.
1~e present invention has a further advantage such that from the ~tandpoint of particle slze of the resultant polymer, the proportlon of coar~e particles and fine particles below 50 is small despite of a hlgh bulk density, and that consequently not only it becomes easy to perform a continuou~ polymerization reaction but also lt becomes easy to handle polymer particles, for e~ample, ~n centrifugal separation in the polymer treating process and ln powder transportat~on.
~ a still further advantage of the present invention, polyoleflns prepared by using the cataly3t of the present lnvention have a h1~h bulk density as prevlo~sly noted, and those having a desired melt index are obtainable wi~h a l~wer hydrogen concentration than in the conventional processes, thus permitting the total pressure to be set at a relatively small value during polymerization, and consequently a gre~t improvement is attainable in point of economy and productlvity.
Additionallq~ in the polymeri~ation of ole~ins using the catalyst of the present invention 7 the olefln absorbing rate S does not decrease Sd much with the lapse of time, and therefore the polymerization can be conducted for a long ti~e in a smaller amount of the catalyst.
Furthermore9 polymers obtained by using the catalyst of the present invention have an extremely narrow molecular weight distributlon and their hex~ne extraction is small, thus reflecting a minlmi~ed by-production of low grade polymers. Therefore, for example, in the fllm grade, lt is possible to obtain products of good quality superior in ant~-blocking and other properties.
~ The present invent:Lon provides a novel cat`alyst system having many such rharacteristic features and capable of remedying the above-mentloned drawbacks of the prlor art. It is quite surprising that those ~eature~ should be attainable easily by using the catalyst of the present inven~:ion.

Descrlption of the Preferred Embodiments A~ compounds of the formula Rlm(OR2)nMg~ m n used ln the presen~ in~ention, there essentially may be any co~pounds of the same formula provided Rl and R2 are each a hydrocarbon radical having 1 to 24 carbon atoms, but particularly preferred are those wherein Rl and R2 are each an alkyl group. Examples of such compounds include dlethylmagnesi~m, diisopropylmagnesium, di-n-butylmagnesium, di-sec-butylmagnesium, methylmagnesium chloride, ethylmagnesium chloride, ethylmagnesium bromide, ethylmagneslum iodlde, n-propyl~agnesium chloride, n-butylmagnesium chloride9 n-butylmagnesium bromlde, sec-buty~magnesl~mm chloride, phenylmagnesium 3~3~

chloride, decylmagneslum chloride, metho-xymagnesium chlorlde, etho~ymagneslum ~hlorlde~ isopropoxymagnesium chloride, n-butoxymagnesium chlorlde, n-octoxymagnesium chloride, methylmagneslum methox~de, ethylmagnesium methoxide9 n-butylmagnesium ethoxide, sec-butylmagnesium ethoxide, and decylmagnesium ethoxide. Complex with a trlalkylaluminum is also employable, e.g. a c~mp~ex of di-n-butylmagnesium and triethylaluminum~
As compounds of the general formula Me~OR3~ X~ used in the present invention, mention may be made of various compounds such as NaOR, Mg(oR3)2, Mg(oR3)X, CaCOR3?2, Zn~OR3~2, ZnCOR3)X, Cd(OR )2~ Al~OR )3, Al(OR )2X, B(OR )3, B(OR )2X, GaCOR )3, GetoR ) SntoR )4~ P(oR3)3, Cr(OR3)2, Mn(OR3)2, FeCO~ )2~ Fe~OR3)3, Co(OR ~2~
and Ni(oR3)2, in whlch formulae R3 may essentially be any hydrocarhon radical having 1 to 24 carbon atom~, but alkyl and aryl groups are particularly preEerred. Preferred examples of such compounds include Na0C2H5, Na0C4Hg~ Mg(OC~3)2~ g( 2 5 2 3 5 2 Ca(OC2H5)2, Zn(0C2Hs)2, ~n(OC2H5)51~ Al(0~13)3, Al(OC2H5)3, Al(OC2H5)Cl~
Al~OC3~l7)3l Al(OC4~19)3, Al(OC5l~s)3, B(OC2H5)3, BCC2H5)2Cl~ P(OC2H5) P(0C6H5)3, and Fe(0C4Hg~. Especially preferred :Ln the present invention are compolmds represented by the general formulae Mg(oR3) X2 s Al~OR )pX3 p and B(OR )pX3 p, wherein alkyl of Cl to C4 and phenyl are especially preferred as R .

I~ compounds cf the general formula R -~- Si - O ~ R

R
used in the present invention, R4, R and R6 each may essentially be any of hydrocarbon radicals having 1 to 24 carbon atoms, alkoxy, hydrogen and halogen, but alkyl, aryl, alkoxy and halogen are preferred, and R may essentially be any of hydrocarbon radlcals havlng 1 to 24 carbon atoms, but alkyl and aryl groups are preferred.

Exa~ples of such compounds include monomethylt~imethoxysllane, monomethyltriethoxyRilane, monomethyltri--n-butoxysllane, monomet~yltri-sec-butoxysilane, monomethyltriisopropoxysilaIIe~
monomethyltrlpentoxysllane, monomethyltrloctoxysilane, 5 monomethyltristearoxysllalle, monometllyltriphenoxysilane, dimethyl-dimethoxysilane, dimethyldiethoxysilane, dimethyldii~opropoxysilane 9 dimethyldiphenoxysilane, trimethylmonomethoxysllane, trimethyl-monoethoxysilane, trimethylmonoisopropoxysilaner trimeth~lmono~
phenoxysilane, monomethyldimethoxymonochlorosilane, 10 monomethyldiethoxymonochlorosilane, monomethylmonoethoxydichloros~lane, monomethyldiethoxymonochlorosilane, monomethyldiethoxymonobromosllane, monoethyldiphenoxymonochlorosilane, dimethylmonoethoxymonochlorosilane9 monoethyltrimethoxysilane, monoethyltriethoxysilane, monoethyltri-, isopropoxy~sllane, monoethyltriphenoxycilane, diethyldimetho~y~ilane, dlethyldiethoxysilane, diethyldiphenoxysilane, triethylmonomethox;y-silane, triethylmonoethoxysilane, trlethyl~lonophenoxysilane, monoethyldimethnxymonochlorosi.lane9 monoethyldiethoxymonochlorosilane, monoethyldiphenoxymonochlorosllane, monoisopropyltrlmethoxysilane, mono-n-butyltrimethoxysilane, mono-n-butyltrlethoxysllane, mono-sec-butyltriethoxysilane, monophenyltriethoxysilane, diphenyldi-ethoxy3ilane~ diphenylmonoethoxymonochlorosilane, monomethoxytri-chlorosilane, monoethoxytrichlorosilane, monoisopropoxytrichlorosilane, mono-n-butoxytrichlorosilane, monopentoxytrichlorosilane, monooctoxytrichlorosllane, monostearoxytrichlorosilane, monophenoxytrlchlorosilane, mono-p-methylphenoxytrlchlorosilane, dlmethoxydichlorosilane, dlethoxydlchloroqilane~ diisopropoxydi-chlorosilane, di-n-butoxydichlorosilane, dioctoxydichlorosilane, trimethoxymonochlorosilane; triethoxymonochlorosllane~
trii~opropoxymonochlorosilane~ tri-n-butoxymonochlorosilane, tri-sec-butoxymonochlorosilané~ tetraethoxysilan~, tetrsisopropoxysilané, and chain-like or cyclic polysiloxanes havlng a repeatlng unlt represented by the formula -~- Si - O t --- obta~ned by condensation of the a~ove compounds.
As halogen-containing titanium compounds used in the present invention, there may be mentioned halides and alkoxyhalidPs of titanium. A~ tltanium compounds are preferred tetravàlent and trivalent titanium compounds. Preferred e-xamples of tetravalent tltanium compounds are those represe~ted by the general formula Ti(OR)rX4 wherein R i8 an alkyl, aryl or aralkyl group havlng ; 10 1 ~o 24 carbon ato~s, X is a halogen atom and r i9 0 ~ r C 4, such a6 tltanium tetrachloride~ titanium tetrabromide, titanium tetraiodide, monomethoxytrichlorotitanium, dilDethoxydi~hlorotitanium, trimethoxymonochlorotitanium, monoethoxytrichlorotitanium, dietho~ydichlorotitanium, triethoxymonochlorotitaniu~, monoiso-propoxytrichlorotitani~m7 diisopropoxydichlorotitanium, tril~o-propoxymonochlorotitanium; monobutoxytrichlorotitani~m, di~utoxydichlorotltanium, monopentoxytrichlorotitanium, monophenoxy-trichlorotitanium, diphenoxydichlorotitanium, and triphenoxymono-chlorotitanium. As trivalent titanium compounds there may be mentioned titanium trihalides obtained by reducing tltanium tetrahalldes such a~ tltanium tetrachloride and tltanium tetrabromide with hydrogen, aluminum, titanium or an organometallic compound of a Group I-III metal ln the Periodic Table, as well as trivalent titanium compounds obtained by reducing tetravalent alkoxytitanlum halide~ of the general formula Ti(OR) X~_ with an organometallic compound of a Group I III metal in the ~erlodlc Table in whlch formula R l~ an alkyl~ aryl or aralkyl group having 1 to 24 carbon atom~9 X iB a halogen atom and ~ i~ O ~ ~ C 4. Tetravalent titanium compound~ are mo~t preferred ln the present inventicn In the pre~ent lnvention, the method for obtaining the solid cataly~ componen~ by reacting tl) a compound o the general formula R m~OR )nX2_m_n~ C2~ a compound of the general for~ula Me(OR )pX p, C3~ a compound of the general formula R -~- Si - O ~ R and (4) a halogen-containing titanlum compo~md, i9 not specially limited. The component~ ~l)-C4) may be ~eacted under heating at a temperature in the range of 20 to 400C, preferably 50 to 300~C9 for a period of time usually in the range of 5 m~nutes to 20 hours, in the presence or absence of an inert solvent, or may be reacted by a co-pulverization treatment, or by suitably co~bining these methods. The order of reaction of the components C1~-(4 , i8 not specially limited9 either. The four components may be reacted at a time, or three of them may be reacted followed by reaction of the remaining one component, or t~o of them may b~
reacted followed by reactlon of on~ of the rP~n~ng two componenta and then reaction of the r~ n~ng one component.
Inert solvents which may be u~ed in the above reaction are not specially limited. ~sually, there may be used hydroca~bon compounds and/or derivatives thereoE not inactivating Ziegler type cataly~ts. E~amples of ~uch solvents include various ~atura~ed allphatic hydrocarbons, aromat~c hydrocarbons and allcycllc hydrocarbons such a~ propane, butane, pentane, hexane, heptane~ octane, benzene, toluenej xylene and cyclohexane, as well a8 alcohols, ethers and e~ters such as ethanol, diethyl ether~ tetrahydrofuran, ethyl acetate and ethyl be~zoa~e.
The appara~us to be u~ed for the co-pulverization is not spec~ally limlted, but u~ually there ia employed a ball mill, a vibration mill, a rod mill~ or an impact mill. Condition~

S

33~

such as pulverization temperature and pulverlæation tlme can be determined easil~ by those skilled ln the art according to the pulverizatlon method adopted. Generally, the pulverization temperature ranges from 0 to 200C, preferably 20 to 100C, and the pulverization time fro~ 0.5 to 50 hours, prefera~ly l to 30 hours. Of course;
the co-pulverizing cperation should be performed in an lnert gas atmosphere, and the moisture should be kept to a m~n~m~
Partlcularly preferred in the present invention is`
the method wherein the components ~ 4~ are reacted in solution, or the method wherein the components ~1)-C3) are reacted ln solution and the reaction product is co-pulverized and reacted with the component ~4).
As to the ratio of the components Cl) and C2) to be ' used, both too small and too large amounts of the compound of the general formula MeCOR ~ Xz_ptend to lower the polymerization activity. l~e range of 1/0.001 to 1/20, preEerably 1/0.01 to ltl and most preferably l/O.OS to 1/0.5, in terms o Mg/Me mole ratio, ls desirable for preparing a high activity catalyst.
The ratio of the componellts ~1) and (3) to be used ls such that the amount of component (3) i3 in the range of 0.i to 300 g., preferably 0.5 to 200 g., per 100 g. of component (1).
The amount of the halogen containing titanium compound i8. most preferably adjusted so that the amount of titanium contained ln the solid catalyst component is in the range of 0.5 to 20%
by weight. The range of 1 to 10% by weight is especially desirable for obtaining a well-balanced activity per titanium and that per solid.
In the preparation of the solid catalyst component, it is also preferable to use as component (5) a member or members selected from the group consisting of organic halides, halogenating agents, phosphoric esters, electron donor~ and polycyclic aromatic compounds, in addition to the components (l)-C4). ~le react-lon me~hod in the case of u6ing the component ~5~ is not specially limited. Preferably employed is the method whereln the components (1)-(5~ are reacted ~n 901ution~ or the method wherein the components (1), ~2) 3 (3~ and ~5) are reacted in solution and the reac~ion product ~e co-pulveri~ed with the component C4~.
In the ca~e of using the component C5~, its àmount range3 from 0.01 to 5 ~ole3~ preferabiy 0.~5 to 2 moles, per mole of the component Cl~.
Organic hallde~ which may be used as component ~5) are saturated or unsaturated aliphatic hydrocarbons and aromatlc hydrocarbons which are partially substituted by halogen. The , halogen may be any of fluor~ne, chlorine, bromine and iodi~e.
Examples of such organic halides include methylene chloride, chloroform9 carbon tetrachloride, b~omochloromethane, dichlorodifluoromethane, l-bromo-2-chloroethane, chloroethane, 1,2-dibromo-l,l-dichloroethane, l,l-dlchloroethane, 1,2-dlchloroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, hexachloroethane, pentachloroethane, 1,1,1,2-tetrachloroethane, 1,192,2-tetrachloroethane7 l,l,l-trichloroethane, 1,1,2-trichloroethane, l-chloropropane, 2-chloropropane, 1,2-dichloropropane, 1,3-dichloropropane~ 2,2-dichlo~opropane, 1,1,1,2,2,3,3-heptachloropropane, 191,2,2~3,3-hexachloropropane, octachloropropane~
1~1,2-trichloropropane, ~-chlorobutane, 2-chlorobutane, 1 chloro-2-methylpropane~ 2-chloro-2-methylpropane, 1,2-dichlorobutane, 1,3-d~chlorobutane, 194-dichlorobutane, 2,2-dic~lorobutane, 1 chloropentane, l-chlorohe~ane, l-chloroheptane, l-chlorooctane, l-~hlorononane~ l-chlorodecane, Ylnyl chloride, l,l-dichloroethylene9 1,2-dichloroethylene, tetrachloroethylene, 3-chloro-1-propene, 1~

~33~

1,3-dichloroprope~e, chloroprenej oleyl chlorlde, chlorobenzene9 chloronaphthalenej benzyl chloride, benzylldene chloride, chloroethylbenzene, styrene dichlorlde, and ~-chlorocumeneO
Examples of halogenating agents which may be used as component ~5? include non-metal halides such as sulfur chloride, PC13, PC15 and SiC14, and non-metal oxyhalides such as POC13, Cl:)C12, NOC12, SOC12 and S02C12.
Examples of electron donors ~7hich may be use~ as component ~5) include alcohols, ethera, ketones, aldehydes, organic aclds, org~nlc acld esters~ acld halides, acid amides, amines and nitriles.
As alcohols, there may be used, for example, alcohols havlin~ 1 to 18 carbon atoms such as ~ethyl alcohol, ethyl alcohol, ~ n-propyl alcohol, lsopropyl alcohol, allyl alcohol, n-butyl alcohol, isob~tyl alcohol, sec~butyl alcohol, t-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, cyclohexyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, ~tearyl alcohol, oleyl alcohol, benzyl alcohol, naphthyl alcohol, phenol, and cresol.
As ethersl there may be used, Eor example, ethers having

2 to 20 carbon atoms auch as dimethyl ether, diethyl ether, dibutyl ether, isoamyl ether~ an-lsole9 phenetole, diphenyl ether, phenylallyl ether3 and benzofuran.
AB ketones3 there may be used, for example, those - having 3 to 18 carbon atoms such as acetonea methyl ethyl ketone, methyl lsobutyl ketone, methyl phenyl ketone, ethyl phenyl ketone~
and diphenyl ketone.
As aldehyde$, there may be used, for example, those having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, and naphthaldehyde.
As organ~c acids~ there may be used, for exan!ple~ tho~e having 1 to 2ll carbon atoms such as formic, acetic, propionic, butyric, valer~c, pivalic? caproic, caprylic, stearic, oxalic, ma]onic, succlnic, adiplc, methacrylic, benzoic, toluic, anlslc, oleic, l~noleic and linolenic acids.
As organlc acid esters, there may be used, for example, those having 2 to 30 carbon atoms such as methyl formate, methyl acetate, ethyl acetate, propyl acetate, octyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, methyl methacrylate, methyl benzoate, ethyl benzoate, propyl benzoate, octyl benzoate, phenyl benzoate, 10 benzyl ben~oate, butyl p-ethoxybenzoate, methyl ~ toluylate, ethyl p-toluylate, ethyl p-ethylbenzoate, methyl salicylate, phenyl salicylate, methyl naphthoate, ethyl naphthoate, and ethyl anisate.
As acid halldes, there may be used, Eor exarnple, those 15 havin~ 2 to 15 carbon atoms such as acetyl chloride, ben70yl chloride, toluoyl chloride; and anisoyl chloride.
As acid amides, there may be used, for examyle, acetamide, benzamide and toluamide.
As amines; there may be used, for example, methylamine, ethylamine, diethylamine~ tributylamine, piperidine, tribenzylamine, aniline, pyridincl plcoline, and tetramethylenedlamine.
As nitriles, there may be used, for e~ample, acetonitrlle, ~enzonitrile and tolunitrile.
Phosphoric esters which may be used as component C5) OR
are those represented by the generaI formula P - OR whereln R, o OR
which may be alike or different, is a hydrocarbon radical having 1 to 24 carbon atom~. Examples of such compounds include triethyl phosphate, tri-n-butyl pho~phate9 triphenyl phosphate, tribenzyl ~33~

phosphate, trioctyl phosphate9 tricresyl phos2hate, tritolyl phospha~e, trlxylyl phosphatej ~nd diphenyl~ylenyl phosphate.
E~amples of polycrcl~c aromatic compoundx which mc~y be used as component (5) lnclude naphthaleney phenanthrene, triphenylene, S chrysene, 3,4-benzophenanthrene, 1,2-benzochrysene, picene, anthracene, tetraphene, 1,2,3,4-dibenzanthracene, pentaphene, 394-benzopentaphene, tetracene, 1,2-ben~otetracene, hexaphene, heptaphene, diphenyl, fluorene, biphenylene, perylene, coronene, bisantene, ovàlene, pyrene, perinaphthene, and halo~en- and alkyl-substituted derivative~
i 10 thereof.
The solid catalyst component thus obtained may be ; supyorted on oxides of Group II-IV metals in the Periodic Table, and this mode oE use i~ al~o adoptable preferably. In this case, not only oxides of Group II-IV metals in the Periodic Table each 1 15 alone, but also double oxides of the~e metals, as well as mixt~res thereoE, are employable. Exatnples of such metal oxlde~ :Lnclude MgO CaO ZnO, ~aO, SiO2, SnO2, A1203, MgO ~1203, 2 2 3 MgO-SiO2, MgO-CaO-A1203, and A1203 CaO, with S102, A1203, SiO2-Al~03 and MgO-A1203 belng particularly preferred.
The method for supporting the solld catcalyst component on the oxide of a Group II-IV metal in the Periodlc Table is not specially limited. As a preferable e~ample~ there may be adopted method wherein the components ~1~, C2)l (3) and also the component (5~ ~ required, are reac~ed using an ether compound as a solvent ~n the presence of the metal oxlde, then the liquid phase portion ls removed by washing, dry up or other suitable means and thereater the component (4) is added and reacted together wi~h a hydrocarbon such as he~ane to obtain a supported solid catalys~ component.
As organometalllc compound used in the pre~ent inventlon, there may be mentloned organometallic compounds of Group I-IV metals _ 13 33~

in the Perlodic Table which are known as a component of Ziegler type catalysts, with organoalumlnum compounds and organozinc compounds being particularly preferred. E~amples of such compou~ds include organoaluminum compounds of the general formulae R3Al, R2AlX, RAlX2~ R2~10R, RAl~OR?X and R3Al~X3 whereln R, which may be allke or,different~ is an alkyl, aryl or aralkyl group having 1 to 24 carbon atoms and X is a halogen atom, and organozinc compounds o~ the general formula R2 & wherein R, which may be alike or different, is an alkyl group having 1 to 24 carbon atoms, such as triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, diisopropylaluminum chloride, ethylaluminum sesquichlorlde, d:Lethylzlnc, and mixtures ~ thereof. Together with these organometalllc compounds there may be used organocarboxylic acid ester~ such as ethyl benæoate, ethyl o- or p-toluylate and ethyl p-anisate. The amount of the organometallic compound to be u3ed ls not specially limited. Usually, it may range from 0.1 to 1,000 moles per mole of the titanium compound.

The olefin polymerization using the catalys~ of the present invention may be carried out in the form of slurry polymerization, solution polymeriæation or vapor phase polymerizatlon, wl~h vapor phase polymerizatlon bein8 partlcularly suitable. The polymerl~ation r~act~on is performed in the same way as in the conventional olefin polymerl~ation reactlon using a Ziegler type catalyst; that is, the reactlon ls conducted in a substantlally oxygen- and water-free condition and in the presence OT absence of an inert hydrocarbon.
Olefin polymerizing condltions involve temperatures in the range of 20 to 12GC, preferably 50 to 100C , and pressures ranging 30 from atmospheric pressure to 70 kg/cm2, preferably 2 to 60 kgjcm .

_ 14 ~33~
/

Ad~ustment of the molecular ~eight can be made to some extent by changin~ polymeriza~ion condltions ~uc~ as the polymerization temperature and the catalyst mole ratio, but the addition of hydrogen into the polymerization system is more effective for thls purpo~e.
Of course~ uslng the catalyst of the present lnvent~on, there can be performedg without any trouble, ~wo or more multi-~tage polymerization reactions involvlng different polymerizatlon conditions 8UC~ as different hydrogen concentrations and different polymerization temperatures.
The process of the present lnvention is applicable ts the polymerlzation of all olefins that can be polymer~zed wl~h a Ziegler type catalyst~ wlth ~-olæfins having 2 to 12 carbon atoms being particularly preferred. For example~ it iB suitable to the hom~polymeri~ation oE ~-olefin~ such as ethylene, propylene, butene-l, hexene-l, 4-methylpentene-l and octene-l, the copolymer-lza-tion of ethylene and propylene, ethylene and butene-l, ethylene and hexena 1, ethylene and 4-methylpen~ene-1, ethylene and octene-l, and propylene and butene-l, and the copolymerization of ethylene and other two or more a-olefi~s.
There also may be conduc~ed copolymerlzation wit~
dienes for the purpose of modification of polyolefins. Example~
of diene compounds which may be used in t~s copolymerization lnclude butadiene, 1,4-hexadiene, ethylidene norbornene and dicyclopentadiene.
Worklng examples of the present invent~on are given below to further illu9 trate the invention 9 but it 18 to be understood that the lnvention is not llmited thereto.

_ 15 ~a33~

Example 1 (a) Preparation of a Solid Catalyst Component Into a three-~ecked 500 ml. fiask equipped with a stirrer were charged 200 ~1. of ~thanol, 20 g. of ethoxymagnesium chloride CMg/Cl mole ratlo - 0.81~ obtained by treating magnesium diethoxide,wi~l HCl, 15 g. of alumilium tri-sec-butoxide and 20 g.
of tetraethoxysllane, and reaction was allowed to take place for

3 hours under reflux of ethanol~ Therea~ter, the ethanol was dried off, then 200 ml of hexane and 5 ml. of titanium tetrachlorlde were added and reacted for 2 hours under reflux of hexane. Thereaf~er, the supernatant liqù~d was removed to obtain a sol~d catalyst component, which was washed with hexane three times. The solid catalyst component proved to contain 25 mg. of tltanium per gram thereof.
, ~b) Polymerization A stainles~ ~teel autoclave was used as a vapor phase polymeri2ation apparatus, and a loop wa~ formed by means of a blower, a 1OW controller and a dry cyclone. The temperature of the autoclave wa~ ad~usted ky passing a warm water through a ~acket.
Into the autoclave ad~usted to 8QGC were fed the solid catalyst component prepared above and triethylaluminum at thè
rates of 50 mg/hr and 5 mmol/hr~ respectlvely9 and ethylene, butene-l and hydrogen gases were introduced while ad~usting tD give a butene-l/ethylene ~ole ratio of 0.27 in the vapor phase within the autoclave and a ~Iydrogen concentration of 15% of the total pressure. Polymerlzatlon was carried out while recycling the intra-system ga~es by the blower to maintain the total pressure at 10 k~/cm G. m e ethylene copolymer thus prepared had a bulk denslty of 0.289 a melt lndex (MI) of 1.2 and a density of 0.9203.
The catalys~ actiYlty wa~ 254,000g.copolymer/g.Ti.

After a continuous ope~ation for 10 hours, the autoclave 1~

~3;~

wa~ opened and its interlor was checked. As a re~ult, the inner wall o the autoclave and the ~tirrer prov~dr to be clean with no polymer adheslon thereto~
l~/MI2.16) represented in terms of the ratio of a melt index M¢10 of the copolymer determined at a load of 10 kgo to a melt index MI2 16 thereof determined at a load of 2.16 kg. both at 190C accordlng to the method defined by AsTM-Dl238-65T was Y.2 and thus the molecular welght distribution of the copolymer was very narro~.
A film was formed from the copolymer and extracted in boiling hexane for 10 hour~; as n result, it~ hexane extraction was 1.3 wt~% and thus very small.

Comparative Example 1 A solid catalyst component was prepared in the same way as ~n Example 1 except that tetraethoxysilane was not added~
It contained 21 mg. of titanium per gram thereof.
A continuous vapor pha~e polymerization of ethylene and butene-l was carrled out tn the same manner as ln Example 1 except that the solid cataly~t component ~ust prepared above was fed at the rate of 50 ~g/hr. The ethylene copolymer thus prepared had a bulk density of 0.25, a density of 0.9213 and a melt index of 1.2. The catalyst activity was 186,000g.copolymer/g.Tl.
The ~.R. value of the copolymer was 8.2. A film waR
formed from the copoly~er and extracted in boiling hexane for 10 hours; as a resul~, its hexane extraction proved to be 4.2 wt.%.

Example 2 (a) Preparation of a Solid Cataly~t Component A solid cat~lyst component was prepared in the same _ 17 qJ~DqldloJ b way as in Example 1 except that 15 gO oE boron triethoxlde was used in place of 15 g. of aluminum trl-sec-butoxide. It contained 27 mg. of titanium per gram thereof.

(b) Polymerizatlon A rontinuous vapor phase polymerization of ethylene and butene-l was carried out in the same way as in Example 1 except that the 301id cataiys~ component prepared above was fed at the rate of 50 mg/hr. The ethylene copolymer thus prepared had a bulk density of 0.27, a density of 0.9195 and a melt index of 1.1.
The catalyst actlvity was 223,0QOg.copolymer/g.Ti and thus very high.
After a continuous operation Eor 10 hours, the autoclave was opened and i~B interior wa~ checked. As a result, the inner wall of the autoclave and the stirrer proved to be clean with no polymer adhesion thereto.
Ihe F.R. value of the copolymer was 7.3. A fllm was ~ormed from the ~opoly~er and extracted ln boiling hexane for 10 hours; a~ a result, lt~ hexane e~tractlon was 1.5 wt.~ and thua very small.

Example 3 ~a~ Preparation of a Solid Catalyst Component A solid cataly~ component was prepared in the same way as ln ~xample 1 except that 20 g. of a pentamer of tetraethoxysilane was used in place of 20 g. of tetraethoxysllane. It contained 21 mg.
of titanium per gram thereof.

~b) ~olymerization A continuous vapor phase polymerization of ethylene and butene-l was carrled out in the same manner as in ~xample 1 except that the solid cataly6t component Just prepared above was ~ed at the rate of 5~ mgihr. The e~hylene copolymer thus prepared had a bulk denslt~ of 0.34, a densi~y of 0.9200 and a melt index of 1Ø The catalyst activity was 332,000g.copolymer/g.Ti and thus ~ery high.
S After a con~inuous operatlon or 10 hours~ the autoclave was opened and its interior was checked. ~s a result, the inner wall of the autoclave and the stirrer proved to be clean with no polymer adhesion thereto.
The T.R. value o~ the copolymer wa~ 7.2. A film was formed from the copolymer and extracted in boillng hexane for lO
.
hours; as a result, it8 hexane extraction was 1 3 wt.~ and thus very small.

Example 4 (a) Preparation of a Solid Catalyst Component Into a three~necked 500 1~ , Elask equipped with a ~tirrer were charged 200 ml. of n-hexane, 20 g. of n~butylmagnesiu~
chlorlde, 15 g. of aluminum triethoxide and 20 g. of trietho~y -,no-chloro~ilane, and reaction wa~ allowed to take place for 3 hour~
under reflux o hexane. Thereafter, the supernatant liquld wa~
remo~ed and the reaction product was dried up to obtaln a white solid su~stance.
Then9 10 g. of the solid substance ~ust prepared above and 1.2 g. of titanlu~ te~rachloride were placed in a ~tainless steel pot having a content volume of 400 ml~ and containing 25 stainless steel balls each 1/2 inch in diameter, and ball-milled for 16 hour~ at room temperature ln a nitrogen atmosphere, to obtain B solld catalyst component which contained 27 mg. of tltanlum per gram thereof.

(b~ Polymerizat~on A continuou~ vapor phase polymerizatlon of ethylene and butene-l was ~arried out in the same way as in Example 1 except that the solid catalyst component ~ust prepared above was fed at the rate of 50 mg/hr. The ethylene copolymer thus prepared had a bulk density of 0.31, a density of 0.9205 and a melt ~ndex of 1.1. I~e catalyst activity waa 248,000g.copolymer/g.Ti ~nd thus very hlgh.
After a continuous operation for 10 hours, the autoclave wa~ opened and its interior wa~ checked. A~ a result, the inner wall of the autoclave and the stirrer proved to be clean wlth no polymer adhesion thereto.
The F.R. value of the copolymer was 7.5. A f-llm was formed from the copolymer and extracted in boiling hexane for 10 hours; as a result, its hexane extraction was 1.4 wt.% and thus very small.

~xample 5 A stainless steel 2 liter autoclave equipped w~th an induction stirrer was purged with aitrogen and then charged with 1,000 ml. o~ hexane, then 1 mmol of triethylaluminum and 20 mg.
of the solid powder obtained ~n Example 1 were added and the temperature was rai~ed to 90C with stirringO The system, was pressuriæed to 2 kg/cm G due to the vapor pressure of hexane.
Hydrogen was introduced ~mtll the total pressure was 4.8 kg/cm2-G, then ethylene ~as introduced 80 as to maintaln the total pres~ure at 10 kgJcm2 G~ and polymerlzatlon was allowed to take place for 1 hour. Thereafter, the polymer alurry was transferred into a beaker and he~ane removed under reduced pressure to yield 183 g.

of a wh~te polyethylene having a melt index of 1.3 and a bulk _ 20 ~

3~

denslty of 0.33. The catalyst activity was 709400g.polyethylene/g.
Tl-hr C2HL,~ pressure, 1,760g.polymer/g.solid-hr-C2H,, pressure.
The F.R. value of the polyetl:lylene was 8.2 and ~hus the molecular we~ght dlstribution was very narrow. It~ he~ane extraction wa~ 0.15 wt.% and thus very smal1.

Claims (12)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for preparing a polyolefin by polymerizing at least one olefin in the presence of a catalyst, said catalyst comprising a solid catalyst component and an organometallic compound, said solid catalyst component comprising a substance obtained by the reaction of at least the following four components:
(1) a compound represented by the general formula R1m(OR2)nMgX2-m-n, (2) a compound represented by the general formula Me(OR3)pXz-p, (3) a compound represented by the general formula and (4) a halogen-containing titanium compound in which formulae R1, R2, R3 and R7 are each a hydrocarbon radical having 1 to 24 carbon atoms, R4, R5 and R6 are each a hydrocarbon radical having 1 to 24 carbon atoms, alkoxy, hydrogen or halogen, X is halogen, Me is an element of Groups I-VIII in the Periodic Table provided that silicon and titanium are excluded, z is the valence of Me, and m, n, p and q are as follows: 0 ? m ? 2, 0 ? n < 2, 0 < m+n ? 2, 0 < p ? z, 1 ? q ? 30.

2. The process of claim 1 wherein said components (1) and (2) are used in a ratio ranging from 1/0.001 to 1/20 in terms of Mg/Me mole ratio.

3. The process of claim 1 wherein said components (1) and (3) are used in a ratio such that the amount of said component (3) is in the range of 0.1 to 300 grams per 100 grams of said component (1).

4. The process of claim 1 wherein said component (4) is used in an amount ranging from 0.5 to 20% by weight in terms of titanium contained in said solid catalyst component.

5. The process of claim 1 wherein Me is Na, Mg, Ca, Zn, Al, B, P, or Fe.

6. The process of claim 1 wherein said halogen-containing titanium compound is a titanium halide or a titanium alkoxyhalide.

7. The process of claim 1 wherein said solid catalyst component comprises a substance obtained by reacting said components (1) through (4) with a component (5), said component (5) comprising at least one member selected from the group consisting of organic halides, halogenating agents, phosphoric esters, electron donors and polycyclic aromatic compounds.

8. The process of claim 7 wherein said component (5) is used in an amount of 0.01 to 5 moles per mole of said component (1).

9. The process of claim 1 wherein said solid catalyst component is supported on an oxide of a Group II-IV metal in the Periodic Table.

10. The process of claim 1 wherein said organometallic compound is an organoaluminum compound or an organozinc compound.

11. The process of claim 1 wherein the polymerization reaction is carried out at a temperature ranging from 20 to 120°C
and at a pressure ranging from atmospheric pressure to 70 kg/cm2.

12. The process of claim 1 wherein said olefin is an .alpha.-olefin having 2 to 12 carbon atoms.