CA1046492A

CA1046492A - Process for preparing highly stereoregular polyolefins and catalyst used therefor

Info

Publication number: CA1046492A
Application number: CA219,139A
Authority: CA
Inventors: Akinori Toyota; Norio Kashiwa; Syuji Minami
Original assignee: Mitsui Petrochemical Industries Ltd
Current assignee: Mitsui Petrochemical Industries Ltd
Priority date: 1974-08-10
Filing date: 1975-01-31
Publication date: 1979-01-16
Also published as: ATA77275A; FI59107C; NO148292B; FI752175A; FI59107B; NO148292C; DK361475A; JPS5236913B2; BR7505050A; SU1168095A3; JPS5120297A; NO752784L; AT338512B; SE7508961L; PL106505B1; DK152760B; DK152760C; SE430787B; PH13975A

Abstract

ABSTRACT

A process for preparing highly stereoregular poly-olefins in the presence of a catalyst which comprises (A) a titanium-containing solid catalyst component composed of an organic complex derived from (i) a magnesium halide (ii) an organo polysiloxane of the formula Q(Q2SiO)n SiQ3, (Q2SiO)n and/or x(Q2siO)nSiQ2X, (iii) an organic carboxylic acid ester, and (iv) a titanium compound of the formula Ti(OR)?x4-?
and (B) an organoaluminum catalyst component of the formula R'mAl(OR')3-m .

Description

This invention relates to a process for polymerizing ~-olefins in the presence of a catalyst capable of ~aintaining its superior catalytic activity for prolonged periods of time thereby to afford a highly stereo-regular ~-olefin polymer or copolymer in a high yield which has a higher apparent density and a reduced content of halogen ascribable to the catalyst used; and to said catalyst.
Catalyst systems composed of solid titanium halides and organo-aluminum compounds have previously been used for preparing highly stereo-regular polymers of ~-olefins. Polymerizations using these catalyst systems afford highly stereoregular polyrners; but the yield of the polymer per unit amount of the titanium catalyst component is still low, and an additional step is required to remove the catalyst residue from the resulting polymer.
ReceNtly, some methods, for example, those disclosed in Japanese Laid-Open Patent Publications Nos. 16986/73, 16987/73 and 16988/73 (published March 3, 1973 in the name of Montedison S.p.A.), have been proposed to remove the . .
defects of the prior art techniques. These methods attempt to obtain highly stereoregular poly(~-olefins) by polyrr.erizing ~-olefins such as propylene using a catalyst comprising a solid component which is obtained by copolymer-izing a complex compound formed between a titanium halide and a specific electron donor together with an anhydrous magnesiuTn halide, and the reaction product of a triaIkyl aluminum and a specific electron donor. With these methods, however, the stereoregularity of the resulting polymer is still insufficient, and the yield of the polymer per titanium atom is still unsat-isfactory. In addition, these methods still suffer

- 2 -.~~J ,~

from the defect that the yield of the polymer per chlorine atGm in t~le catalyst is low because the co-pulverlzed produc-t has a low level of titanium content, that the polymeIizatiorl must be performed with a low slurry concentration because of the low apparent density of the resulting polymer, thus rendering the methods economically disadvantageous, and that the polymerization activity of the catalyst is lost within short periods of time.
French ~aid-Open Patent Publication No. 2,113,313 (published ~ay 29, 1972 in the name of Montedison S.p.A.), discloses a process for 10 selectively preparing either an atactic polymer as a main product or a stereoregular polymer as a main product. This Patent Publication states that when a Ti catalyst component obtained by contacting a titanium compound with a mixture of an active-type magnesium halide carrier and an anhydrous compound of an element of Groups I to IV, for example, Si is used in the above process preferably in the form supported on a carrier and subsequently modified with an electron donor, a stereoregular polyrner is obtained as a main product. This Publication3 however, illustrates only SiO2 as the anhydrous compound of Si. Furthermore, this Publication discloses that ethers, thioethers, amines, phosphines, ketones and esters can be utilized ; 20 as the electron donors, but do not exemplify any specific compounds that fall within the esters. The isotacticity of the polymer shown by the boiling n-heptane extraction residue in all of the Examples of the above Patent Publication is at most about 70%, and therefore, the process of this patent is far from satisfactory for preparing highly stereoregular ~L~4~

polymersO On the other hand, the electron donor used in this patent ~or production of isotactic polymers is onl~ ,N', N",N"'-tetra~eth,vl eth~ler,e diamineO More-over, only an~ydrous lith,ium chloride and SiO2 are specifi-cally used in -this patent as the anhydrous cornpound of an element of Groups I to IV.
'~e nave made investigations with a view to removing the defec-ts of the conventional techMiques, and consequently found that a titaniu~--containing catalyst component composed of an organic complex derived from (i) a magnesium halide, (ii) an organo-polysiloxane, (iii) an organic carboxylic acid ester and (iv) a specific ~i compound, w~len-combined wi-th an organoaluminum compound, becomes a superior catalyst for preparation of highly stereoregular polyolefinsO Our investigations also led to the discovery that by using this catalyst, highly stereoregular ~-olefin polymers or copolymers can be pre-pared in high yields while maintaining the superior catalytic activity over a long period of time, and that the halogen ~O content of the resulting polymer or copolymer ascribable to -the ca-talyst can be reduced and the resulting polymers or copolymers have a high apparen-t density.
Accordingly, an objec-t of -this inven-tion is to provide a process for preparing highly stereoregular pol~olefins having -the above-mentioned improved effects~
- ~nother object of this invention is to provide a ca-talyst for use in the process of this inven-tionO

, - 4 -~any other objects and advantages of this invention will become more apparent from the followi.ng descript:ion.
! The polymerization or copolymerization of ~-olefins having at least 3 carbon atoms, as referred to in this application, includes homo-polyrr,erization of ~ olefins having at lea,t 3 carbon atoms, copolymerizations of at least two of ~-olefins having at least 3 carbon atoms with each other, - and copolymerization of ~-olefins having at least 3 carbon atoms with ethylene and/or diolefins in an amount of preferably up to 30 mol ~.
Examples of the ~-olefins are propylene, l-butene, 4-methyl-1-pentene, and 3-methyl-1-butene, and examples of the diolefins include con-jugated diolefins such as butadiene and non-conjugated dienes such as di-cyclopentadiene, ethylidenenorbornene and 1,5-hexadiene.
The catalyst used in this invention is composed of the following titanium-containing solid catalyst component (A) and organoaluminum catalyst component (B).
Component (A) consists of an organic complex prepared from (i) a magnesium halide, (ii) an organo-polysiloxane, (iii) an organic carboxylic acid ester, and (iv) a titanium compound of the formula Ti(OR)QX4 Q
wherein R is an alkyl group, for example, a Cl-C4 alhyl group, X is a halogen atom such as Cl, Br and I and Q is an integer of 0 to 4.

.. ~

z Examples of co~pon~n-t (i) are mag~e$ium chloride, magnèsium bromlde and magnesium iodide 9 the magnesium chloride (MgC12) being especially preferred.
Examples of component (ii) are organic polysiloxanes of the formula Q(Q25iO)nSiQ3 wherein Q groups are identical or different, ; and each represent a hydrogen atom 9 an alkyl group, for example 9 an alkyl group containing 1 to 4 carbon atoms 9 a cycloalkyl group9 for example9 a cycloalkyl group containing to 8 carbon atoms9 or an aryl group9 for example 9 an aryl group contaim~ng 6 -to 8 carbon atoms with the proviso that all Q
groups are not hydrogen atoms at the sa~e . time9 n is an integer of 1 to 10009 organic polysiloxanes of the formula .~ (Q25iO)n wherein Q and n are the same as defined above 9 .~ 20 and organic polysiloxanes of the formula `, X ( Q2sio~)nsiG2x . wherein Q, and n are the same as defined above and X is a halogen atom.
Examples of the organic carboxylic acid es-ters (iii) include esters formed between Cl-C89 preferably Cl-C4, saturated or unsaturated aliphatic carboxylic - acids which may optionally be su.bstituted by a halogen atom and alcohols selected from the group consisting of . Cl-C8, preferably Cl-C49 saturated or unsaturated aliphatic primary alcohols, C3-C8, preferably C5-C6, saturated or . unsaturated alicyclic alcohols and Cl-C4 saturated or un-saturated aliphatic primary alcohols substituted by C6-C10, preferably C6-C89 aromatic groups or halogen atoms; esters formed between C7-C12, preferablY C7 C10, a carboxylic acids and alcohols selected from the group c3nai~sting o~ Cl-C8~ preferablyoC~C~, $atu~ated or un-saturated aliphatic primary alcohols9 C3~C89 preferably C5-C6 9 saturated or unsaturated alicyclic alcohols and Cl-C4 saturated or unsaturated alipha-tic primary alcohols substituted by CC-Cl09 preferably C6-C8 aromatic groups or halogen atoms; and alicyclic carboxylic acid esters such as methyl cyclopentanecarboxyla~te, methyl hexahydro~
benzoate, ethyl hexahydrobenzoate 9 methyl hexahydrotoluate, and ethyl hexahydrotoluate.
In the present invention, a part or -the whole of the organic carboxylic acid ester (iii) can be used in the form of ester-trea-ted produc-ts or adducts of the compounds (i), (ii) and (iv) by bringing i-t in advance . into contact w:ith these compounds (i), (ii) and (iv).
Desirably 9 the magnesium halide (i) as a con-. stitutent or the titanium-containing solid catalyst com-ponent (A) is as anhydrous as possible 9 but the inclusion of moisture is permissible to an extent such tha~t ~the moisture does not subst~ntially affect the performance of the catalyst. The halide may be one obtained by de-hydrating a commercially available grade at 100 to 400C.
under reduced pressure prior to use. For convenience of use, the ma~nesium halide is preferably used in the form of a powder having an average par-ticle diameter of 1 to 50 microns~ But when i-t is to be pulverized by a mechanical contacting treatmen-t during catalys-t preparation, powders of larger particle sizes can also be used. The average particle diameter of 1 to 50 microns mean that at least 80% by weight of the -total particles have a par-ticle diameter of 1 to 50 microns.
Specific examples of linear polysiloxanes of the formula Q(Q2SiO)nSi~3 as the Si component (ii) are hexamethyldisiloxane9 decamethyl-tetrasiloxane9 tetra-cosamethylundecasiloxane, 3-hydroheptamethyltrisiloxane 3

3~-dihydrooctamethyltetrasiloxane9 3,5 9 7-trihydronona-methylpenta ~ 9 te-tramethyl-l 9 3-diphenyldisi].oxane 9 pentamethyl-1,3 9 5-triphen-yltrisiloxane9 heptaphenyldisiloxane, . and octaphenyltrisiloxane Specific examples of cyclopolysiloxanes of the formula (Q2SiO)n asthe Si component (ii) include 2,496-trimethylcyclo-trisiloxane, 2,4,6,~-tetracnethylcyclote~tra-siloxane9 hexarnethylcyclotrisiloxane9 octamethylcyclo-tetrasiloxane, decamethylcyclopentasiloxane, dodecame-~hyl-cyclohexasiloxane, triphenyl-19395-trimethylcyclotrisiloxane, hexaphenylcyclo-trisiloxane9 and octaphenylcyclotetrasiloxane.
Specific examples of linear a9~-dihalo poly-siloxanes of the formula X(Q2SiO)nSiQ2X as the Si compo nent include 193-dichlorotetramethyldisiloxane9 1,5-'?

~6~2 :
dichlorohexamethyltrisiloxarle, and 1,7-dichlorooctame-thyl tetrasiloxane.
Of these organic polysiloxanes, the linear alkylpolysiloxanes are preferredO Methylpolysiloxane and - 5 ethylpolysiloxane having a viscosity of no-t more than 200 centipoises at 25 C. are especially preferred.
Specific examples of -the organic carboxylic acid ester as component (iii) of the titanium-contai~i~ng solid catalyst component (A) are primary alkyl esters of mono~alent saturated fatty acids such as methyl formate, ethyl acetate 9 n-amyl acetate, 2-ethylhexyl acetate, n-butyl formate, ethyl butyrate, or ethyl valerate, pen~yl acetate; allyl acetate; primary alkyl esters of halo-alipha-tic carboxylic acids such as ethyl chloroacetate 9 n-propyl dichloroacetate and ethyl chlorobutyrate9 primary alkyl esters of unsaturated fatty acids such as methyl acrylate 9 methyl methacryla-te OI` i-butyl crotonate; primary alkyl esters of benzoic acid such as;~ethyl benzoate9 :- et.~yl benzoate, n-propyl benzoate, n- and i-butyl benzoates, n- and i-amyl benzoates 9 n-hexyl benzoate, n-octyl benzoate and 2-ethylhexyl benzoate; primary alkyl esters of toluic acid such as methyl tolua-te, ethyl tolua-te9 n-propyl toluate, n~ and i-butyl toluates, n- and i-amyl toluates or 2-ethyl-hexyl toluate; primary alkyl ~s-ters of ethylbenzoic acid such as methyl ethylbenzoate, ethyl ethylbenzoate, n-propyl . ethylbenzoate9 and n- and i-butyl ethylbenzoates 9 primary alkyl esters of xylylenecarboxylic acid such as ~e-thyl 3,4-xylylene-l-carboxylate9 ethyl 3,5-xylylene-1 carboxylate, and n-propyl 2~4-xylylene-l carboxylate9 primary alkyl g _ esters of anisic acid such as metnyl anlsate 9 e-thyl anisa-te 9 n-propyl anisate9 and n- and irbutyl anisates9 and primary alkyl esters of naphthoic acid such as methyl naphthoate9 ethyl naph-thoate9 n-propyl naphthoate9 and n- and i-butyl naphthoates.
Of these primary alkyl esters of arornatic carbo-xylic acids,primary Cl-C4 alkyl esters are preferred.
Methyl benzoa-te and ethyl benzoates are especially preferred, As already mentioned9 a par~t or -the whole of the organic carboxylic acid ester (i:ii) can be used in -the form of ester-treated products or adduc-ts of the compounds (i)9 (ii) and (iv) by bringing it in advance into contact with these compounds (i)9 (ii) and (iv).
Specific examples of the titanium compound of formula Ti(OR)~,,Y4 ~componen-t (iv)) include titanium tetrahalides such as titanium tetrachloride9 titanium -te-trabromide or titanium tetraiodide9 alkoxy titanium trihalides such as methoxy -titanium -trichloride, ethoxy ti-: 20 -tanium trichloride9 n-butoxy titanium trichloride, e~thoxy titanium tribromide or i-bu-toxy ti-tanium tribromide;
dialkoxy titanium dihalides such as dime-thoxy -ti~tar.ium dichloride9 dicthoxy titanium dichlorideS di-n-butoxy titanium dichloride or diethoxy ti-tanium dibromide;
trialkoxy ti-tanium monohalides such as -trimethoxy -ti-tanium cllloride 9 tri.ethoxy titanium chloride9 tri-n-bu-toxY
titanium chloride and -trie-thoxy ti-tanium bromidt9 and .,. tetraalkoxy titaniums such as te-tramethoxy ti.tanium9 tetrae-thoxy titanium and tetra-n-butoxy -titanium. Of ~4~
these, the titanium te-trahalides, especially ti-tanium tetrachloride, are preferr~d.
I~hen a magnesium halid.e (i) treated with the organic carboxylic acid ester (iii~ is used in -the f`orm-ation of the titanium-containing solid catalyst component (A) used in this invention, it is preferred to use a mechanical pulverizing means for contacting both with each otne.r According to this pulverizing contact, the organic acid ester in a wide r~nge of proportions acts effectively on the magnesium halide. A sufficierlt treating effect can be obtained even if -the proportion of the former is small as compared with the latter (in a molar ratio of ... about 1/1 to 1/20).
When the Si component (ii) treated with the organic carboxylic acid ester (iii) is used~ the treatment is effected, for example, by a method comprising adding the organic carboxylic acid ester at room temperature to a silicon compound itself or its solution in a suitable inert solvent such as pentane 9 hexane, heptane or kerosene 9 or or a method comprising preparing a solution of the organic carboxylic acid ester in the above inert solvent 5 and -then adding the silicon compound to -the solution. Of course, the treatment can be completed within short periods of : time a-t an elevated temperature9 but if desired, the ; 25 trea-tment can also be carried out under cooling.
~1hen the titanium compound (iv) is used in -the .. form of an adduct of` it with the organic carboxylic acid ester (iii), the adduct can be prepared by adding the organic carboxylic acid ester (iii) in an equimol&r or larger amount (calcula-ted based on the ester) to the tita-nium compound ltself (if it is l:Lquid) or a solu-tion of it in the above inert solvent (if it is solid) 9 and separating the resulting precipitate by filtration. Even when -the titanium compound is liquid9 it can be used in the adduct-forming reflction in the form of its solution in the above inert solvent. The washing of the resultin~ precipitate (the removal of the unreacted ti-tanium compound and organic carboxylic acid ester) can also be carried out using the above solventO
The ratio of the anhydrous magnesium halide (i)/
: the Si component (ii)/the organic carboxylic acid ester (iii)/
the titanium compound (iv) as the starting materials for the catalyst componen-t (A) is not particularly restricted, but i.s usually 1/1000-0,01/10-0.005/100 0.0019 preferably 1/10-0.01/1-0.01/30-0.01.
Preferably 9 the titanium-containing solid catalys-t component (A) is prepared by bringing the components (i), (ii) 9 (iii) and (iv) into contact with each other under the pulverizing conditions. A nurrlber of modes are possible in regard to the order of addi-tion of these componen-ts, the method of addition and the method of contacting, and some examples are shown below, (1) The anhydrous magnesium halide (i), the organic polysiloxane (ii) 9 the organic carboxyli.c acid ester (iii) and the titanium compound (iv) are con-tac-ted with each other intimately by a mechanical pulverizing means (to be referred to as pulverizing contact) 9 and -the resulting titanium-can-taining solid component is treated preferably ~ 29 with -the coMpound (iv) or its solution in an inert solvent~
(2) Th~ magn~s um halide (i) 9 the organic poly silox2ne (ii) 9 and the organic carboxylic acid es-ter are pulverizingly contactecl. The resulting solid component is treated by suspending in -the titanium compound (iv) or its solution in an jnert solven-t. Or the solid component and the titanium compound (iv) are pulverizingly contacted in the substantially dry s-tate 9 and then treated by suspending preferably in the -ti-tanium compound (iv) or its solution in an inert solven-t.
(3) The ar~lydrous magnesium halide (i) and the organic carboxylic acid ester (iii) are pulverizingly contacled and then further contacted pulverizingly with the organic polysiloxane (ii) to form a solid component. Or the magnesiurn halide (i) and the Si component (ii) are first pulverizlngly contacted and then wi-th the organic carboxylic acid ester (iiiJ;to form a solid component.
~ither of such solid components is suspended in the titanium compound (iv) or its solu-tion in an inert solvent to treat it. Or ^the solid component is pulverizingly con-tacted wi-th the -titanium component (iv) substantially in the dry sta-te 9 and then suspended preferably in ~the titanium compound (iv) or i-ts solution in an iner-t solven-t to treat ito

(4) The anhydrous magnesium halide (i)9 the organic polysiloxane (ii) and an adduct of the -titanium compound (iv) and the organic carboxylic acid ester (iii) are pulverizingly contac-ted 9 and the resulting titaniu~l-con-taining solid component is suspended preferably in the 9~
titanium compound (iv) or its solution in an inert solvent to trea-t it.

(5) The anhydrous magnesium halide (i) and the organic polysiloxane (ii) are pulverizingly contacted, and then further pulverizingly contacted with an adduct of the titanium compound (iv) and the organic carboxylic acid ester (iii). The resulting titaniu~-containing solid component is suspended preferably in the titanium compound (iv) or its solution in an inert solvent to treat it.

(6) In the procedures of (1) and (3) aboveg the titanium compound (iv) is used in the form of an adduct of it with the organic carboxylic acid ester (iii).

(7) The anhydrous magnesium halide (i), the - 15 organic polysiloxane (ii) 9 the titanium compound (iv) 9 and an adduct of the titanlum compound (iv) and the organic 7 carboxylic acid ester (iii) are pul-verizingly contacted, and the resulting titaniurn-containing solid component is suspended preferably in the titanium compound (iv) or its solution in an inert solvent to treat i-t.

(8) In the procedure in paragraph (7) above, the organic carboxylic acid ester (iii) itself is also added to the pulverizing contact system.
The pulverizingly contact means in the prepara-tion of the titanium-containing solid titaniurn componen-t (A) in the present invention Lay9 for example9 include means using a rotary ball mill 9 a vibratory ball mill, or an impact mill. As a result of contact by such a pulveri-zing contact ~eans 9 the organic carboxyllc acid ester . .

' :

(iii)9 the organic polysiloxane (ii) and -the ti~tanium compound (iv) immediately act on the ac~tive surface resul-ting from the pulverization of the magnesium halide (i) to form an organic complex whose chemical structure has not been elucidated yet. This can be confirmed by the fact ~that the diffraction patterrl of the magnesium nalide powder changes.
The trea-ting condi-tions employed for pulverizingly cont,acting two or more of the starting ma-terials for -the catalyst component (A) using various mills can be selected as followso Taking up the use of a ro-tary ball mill flS an example 9 100 balls each with a diame-ter of 15 mm made of' stainless steel (SUS 32) w*re accomodated in a ball cylin-drical receptacle made of stainless steel (SUS 32) and having an inner capacity of 800 ml. and an inside diameter of 100 mmc ~lhen 20 to 40 g of the materials are placed in it 9 the pulveriza-tion treatmenl, is carried out usually for at least 48 hours 9 preferably at least 72 hours at a speed of 125 rpm. The temperature for the pulverization treatmen-t is usually a point in the vicini~ty of room tem-perature, ~lhen -there is a marked exovherm, the system is preferably cooled~ and the pulverizing con-tact is performed a-t a temperature lower than room -temperature.
The treat~ent of the solid component obtained by pulverizing contac-t of the star-ting materials o~ the solid component (A) with the titanium compound (iv) can be suitably carried out by stirring the mixture usually a~t 40~C. to the boiling point of -the treating mixture ~or ~L~4~
at least l hour. Alttrnatively9 this can be accomplished by pulverizing contact un~er the above pulveriza1;ion con-ditions for ei; least lO0 hours usLng the ball mill.
~en titanium compourlds are used vn two differ~nt occasions in the above treatment proc~dure9 they may be the same as 9 or different from9 each other so long as they are chosen from compounds of the above general formula.
The titanium-contalning solid catalyst cornponent (A) results after separating the organic complex solid prepared in the above manner from -the suspension. Pre-ferablyg i-t is fully washed with hexane or other inert liquid media so tha-t the free -titanium compound (iv) is no longer detected in -the wash liquidO
The catalyst component (B) to be combined with the catalys-t componen-t (A) ir -the present invention is an organoaluminum compound of the general formula R'mAl(OR')3 m wherein R' is an alkyl group9 preferably a Cl-C4 s-traight-chain or branched-chain alkyl group9 the two or more R' groups being identical or different9 and m is a number in the range of l.5 = m - 3, Examples of the organoaluminum compound are as follows;
~ hen m is 3, the compound is a -crialkyl aluminurnO Specific examples are -trimethyl aluminum3 triethyl aluminum3 tri-n- and -i-propyl aluminums9 tri-n-and -i-butyl ,~luminum9 and trihexyl aluminum. The triethyl aluminum and tributyl aluminum are preferred.
They may also be used in combination of two or more.

" .
', ' If desired 9 the trialkyl aluminurlrnay be rtac-ted with the organic carboxy:':c acid ester prior to use. rl'his reaction may be carried out in -the polymerization system before the lnitiation of polymerization9 or it may be carried out separately 9 and then the reaction product is added to the polymerization system. rl'he reaction proceeds sufficiently by contacting the trialkyl aluminum directly with an organic carboxylic acid ester (or using one of them as a solution in an inert solvent). The ratio between the amounts of these materials is such -that the proportion of the trialkyl ~luminum is usually 2 to 100 mols (based on the aluminum atom) per gram equivalen-t of the ester group of the organic carboxylic acid ester. The organic carboxylic acid ester may be selected from the various organic carboxylic aci~ esters as component (iii) in the formation of the catalyst component (A). Usually9 it may be the same kind of acid ester as that used in forming the catalyst component (A)o (2) ~rhen m is at least 1.5 bu-t below 3 (1.5-m <3) 9 the above aluminum compound is a partially alkoxylated alkyl - aluminumO Such an alkyl aluminum is prepared9 for example9 by adding a calculated amount of an alcohol to a trialkyl aluminum or dialkyl alumiIlum hydride. Since -this reaction is vigorous 9 at leas-t one of them is preferably used as a solution in an inert solvent in order -to cause the reac-tion to proceed mildly.
In order -to polymerize or copolymerize ~-olefins having a-t least 3 carbon atoms using -the catalys~t composed of the -titanium~cor.taining solid catalyst component (A) and -the organoaluminurn ca-talys-t cornponent (~) 9 polymeriza--tion conditiorls known -t~, ~e ~mployed in polymeriza-tions or copolyrr.eriz~tions of .~-olefins using Zieglcr-type catalysts can be properlv chosen, Usually9 polymeriza~--tion termperatures of from room ternpera-ture to abou-t 200C.
and pressures from atmospheric pressure to about 50 Kg/cm2 can be used. The polymerizations or copolymerizations can be carried out either in the preserlce or in -the absence of an inert liquid medlurll. Examples of the l,iquid meclium are pentane 9 hexane 9 heptane 9 iso-octane and keroserle. Where the polymeriza-tlon or copolymerlzation is carrled out in the absence of a liquid medium, it rr,ay be performed in the presence of a liquid olefin monomer, or l-t may be carrled ouc ln -the vapor phase 9 for example 9 by uslng a fluldized bed catalyst.
The concentration of -the catalyst to be charged into the polymerization system for polyrnerization can be changed as desired. For example 9 in solid~phase polyme-rizations 9 the tltanium-containlng solld catalyst cornponen-t (A) is used in a concentra-tion of usually 0.0001 to 1.0 m-mol/liter calcula~ted as tit.aniurr a-tom 9 and -the ca-talyst component (B) is used in a concen-tration of usually 1/1 to ; 100/1 9 preferably 1/1 to 30/1, in terms of the alurninum atom/-titanium atom ratio, In vapor-phase polymerizations 9 the ti~tanium-con~taining solid catalyst comp~nen-t (A) can be used in a concentra-tion of 0.001 - 0.5 m-mol (_alcula-ted as titanium atom) 9 and the catalyst component (B) 9 in an amount of 0.01 - 5 m-mol (calculated as aluminurn atom), bo-th per llter of the volume of the reac-tion zone, " 1~

' In order to lower the molecular weight of the resulting polymer (in order to increase the melt index of the polymer), hydrogen may be caused to be present in the polymerization system.
The following Examples and Comparative Examples illustrate the present invention more specifically.
Exam~
Preparation of Catalyst Component (A):-A 800 ml. stainless steel (SUS 32) ball mill with an inside diameter of 100 mm accomodating therein 100 stainless steel (SUS 32) balls each with a diameter of 15 mm was charged with 20 g of anhydrous magnesium chloride, 6.0 ml. of ethyl benzoate and 3.0 ml. of methyl polysilo-xane (having a viscosity of 20 centipoises at 25C.) in an atmosphere of nitrogen, and pulverizingly contacted for 100 hours at a rotating speed of 125 rpm. The resulting solid product was suspended in 150 ml. of titanium tetrachloride, and the suspension was stirred at 80C.
for 2 hours. Then, the solid component was collected by filtration, and washed with purified hexane until free titanium tetrachloride was no longer detected. The result-ing component contained 4.1% by weight of titanium and 58.2% by weight of chlorine as atoms.
Polymerization:-A 2-liter autoclave was charged with 0.05 ml.
(0.375 m-mol) of triethyl aluminum, 43.8 mg (0.0375 m-mol cal-culated as titanium atom) of the titanium-containing solid component (A) obtained above and 750 ml. of kerosene (purified ~ ~h ~0~ 2 kerosene) sufficiently free from oxygen and mois-ture.
The polymeriza-tion system was hea-ted9 and when thP tempera-ture reached 70C.9 propylene was in-troducedO Polymeriza-tion of the propylene was started at a total pressure of 7.0 Kg/cm2. After contimlirlg the polymerization a-t 70C, for 3 hours 9 the in-troduction of propylene was stopped.
The inside of tne autoclave was cooled to room -tempera-ture 9 and the catalyst was decomposed by addition of methanol, The solid component was collected by fil~tration, washed with methanol, and dried to afford 410.3 g of polypropylene as a white powder. The boiling n-heptane extraction residue (II) of the powder was 94.5%9 and its - apparent density was 0.30 g/rnlO
On the ot,her hand 9 concen-tration of the liquid phase afforded 15.1 g of a solvent~soluble polymer.
The average specific polymeriza-tion activity per titanium atom of the ca-talyst used above was 540 g/
Ti-m M hr~atm.

~ rative Exam~
Preparation of a titanium-con-taining catalyst component~-A ball mill of -the same type as used in Example 1 was charged with 20 g of anhydrous magnesium chloride and 17.8 g of an adduc-t having -the average composition of the formula TiClL~-C6H5COOC2~-l59 and they were con-tacted pulverizingly under -the same conditions as in Example 1 for 100 hours at a speed of 125 rpr.l. The resul-ting solid titanium catalyst component ~corresponding to the component (A) in Example 1) was considerably agglomerated in a ball - 20 ~

mill, and was difficult to obtain in powder form. A part of the solid component was washed with 1 liter of purified hexane to the same extent as in Example l, and dried to form a titanium catalyst component. The titanium catalyst component contained 4.2% by weight of titanium and 6.30% by weight of chlorine calculated as atoms.
Polymerization:-Propylene was polymerized under the same conditions as in Example 1 using ll~ mg of the titanium catalyst component obtained above. There were only obtained 8.8 g of polypropylene as a white powder and 1.7 g of a solvent-soluble polymer.
Examples 2, 3, 4 and 5 : In each runl a titanium catalyst component (A) was prepared in the same way as in Example 1 except that each of the polysiloxanes described in Table l was used.
Propylene was polymerized under the same conditions as in - Example 1 using the resulting titanium catalyst component in the amount indicated in Table 1. The results are also shown in Table l.

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In each run9 a cat~lyst, colnpon~n-t (A) was pre-pared under the same conditions as in Example 1 except that each of tne substituted benzoic acid es-ters showr in Table 2 was used in -the ~mount shown in Table 2.
P.ropylene was polymerized in the same wa~ as in Example 1 using the c?talys-t cornponen-t (A) in the amoun-t shown in Table 2. The results are shown in Table 2.

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2 Lr Ex~ le 9 ,. .~ ._ Prepara1;ion of Catalyst Componerlt (A)-A solid cornponent- was prepared by the ball rnill treatment of anhydrous magnesium chloride 9 e-thyl ben~oa-te and methylhydropolysiloxane in -the same way as in ~?xample l.
The resulting solid cornpontnt was suspended in lO0 ml, of - kerosene containing 50 ml, of ti-tanium -tetrachloride 9 and -thus treated at 100C, for 2 hours with stirring, The solid component was collected by filtration9 and washed with purified hexane unt;il free ti-tanium tetrachloride was no longer detectedO l'he resulting catalyst cornponen-t (A) contained 3.0% ~y weight of titaniur,l and 61,2% by weight of chlorine calculated as a-toms, Polymerization.-15A 2-liter autoclave was charged wi-th 750 ml, of purified kerosene7 0.095 n1l, (0,375 m-mol) of triisobutyl aluminum and 59,5 ml. (0~0375 m-mol calculated as titanium atom) of the catalyst comporent (A). The polymeriza-tion sys+em was hea-ted9 and when -the tempera-ture reached 70C, 9 propylene was in-troducedO The polymerization of propylene was started at a -to-tal pressure of 7.0 Kg/cm2. With stirring 9 the polymeriza-tion was carried out for 5 hours at 70 C. with s-tirring 9 and then -the in-troduc-tion of propylene was stopped. The inside of the au+oclave was cooled to room temperature 9 and the solid componen-t was collected by fil-tration, washed with methanol and dried to afford 390.4 g of polypropylene as a whi-te powder and 12,l ~ of a solvent-soluble polyrner. The powdery polymer had an n-hep-tane extraction residue of 96,4%9 and an apparent density of 0.31 g/ml. The average specific polymerization ac-tivity of -t~le catalyst was 306 g of polypropylene/Ti-rmnol~hr a-tm.

Examples_10 -to 14 . 5 In each run9 a catalyst component (A) was pre-pared under the same conditions as in Example 1 except that each of the polysiloxanes shown in Table 3 was used instead of the methyl polysiloxane. Propylene was polymerized in the same way as in Example 1 using the catalyst component (A) in the amount shown in Table 3, The results are shown in Teble 3, ;

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preparing highly stereoregular polyolefins, which comprises polymerizing or copolymerizing .alpha.-olefins having at least 3 carbon atoms in the presence of a catalyst, said catalyst comprising (A) a titanium-containing solid catalyst component composed of an organic complex derived from (i) a magnesium halide (ii) an organo polysiloxane selected from the group consisting of compounds of the formula Q(Q2SiO)nSiQ3 wherein Q's are identical or different, and represent a group selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group and an aryl group, with the proviso that all Q groups are not hydrogen atoms at the same time, and n is an integer of 1 to 1000, compounds of the formula (Q2SiO)n wherein Q and n are the same as defined above, and compounds of the formula X (Q2SiO)nSiQ2X
wherein Q, and n are the same as defined above, and X is a halogen atom, (iii) an organic carboxylic acid ester, and (iv) a titanium compound of the formula Ti(OR)?X4-?

wherein R is an alkyl group, X is the same as defined above, and ? is 0 or an integer of 1 to 4, and (B) an organoaluminum catalyst component of the formula R'mAl(OR')3-m wherein R' groups are identical or different, and represent an alkyl group, and m is a positive number of 1.5 to 3.

2. The process of claim 1 wherein said magnesium halide (i) is selected from the group consisting of magnesium chloride, magnesium bromide and magnesium iodide.

3. The process of claim 1 wherein said silicon component (ii) is a compound selected from compounds of formula Q(Q2SiO)nSiQ3 wherein Q groups are the same or different and each selected from the group consisting of a hydrogen atom, C1-C4 alkyl groups 9 C3-C8 cycloalkyl groups and C6-C8 aryl groups 9 with the proviso that all Q
groups are not hydrogen atoms at the same time, and n is an integer of 1 to 1000; compounds of the formula (Q2SiO)n wherein Q and n are the same as defined above); and com-pounds of the formula X(Q2SiO)nSiQ2X wherein Q and n are the same as defined above 9 and X is a halogen atom.

4. The process of claim 1 wherein said organic carboxylic acid ester (iii) is an organic carboxylic acid ester selected from the group consisting of esters formed between C1-C8 saturated or unsaturated aliphatic carboxylic acids optionally substituted by halogen and alcohols selected from the group consisting of C1-C8 saturated or unsaturated aliphatic primary alcohols, C3-C8 saturated or unsaturated alicyclic alcohols and saturated or unsaturated aliphatic primary alcohols substituted by C6-C8 aromatic groups or halogen atoms; esters formed between C7-C12 aromatic monocarboxylic acids and alcohols selected from the group consisting of C1-C8 saturated or unsaturated aliphatic primary alcohols, C3-C8 saturated or unsaturated alicyclic alcohols and saturated or unsaturated aliphatic primary alcohols substituted by C6-C8 aromatic groups or halogen atoms; and alicyclic carboxylic acid esters selected from the group consisting of methyl cyclopentane-carboxylate, methyl hexahydrobenzoate, ethyl hexahydro-benzoate, methyl hexahydrotoluate and ethyl hexahydrotoluate.

5. The process of claim 1 wherein the amount of said catalyst is such that the proportion of said titanium-containing solid catalyst component (A) is 0.0001 to 1.0 m-mol/liter, calculated as titanium atom, based on the volume of the liquid phase of the polymerization system, and the proportion of said organo-aluminum catalyst component (b) is 1/1 to 100/1 in terms of the aluminum atom/titanium atom ratio.

6. A catalyst for polymerization or copolymerization of .alpha.-olefins having at least 3 carbon atoms, comprising (A) a titanium-containing solid catalyst component composed of an organic complex derived from (i) a magnesium halide, (ii) an organo polysiloxane selected from the group consisting of compounds of the formula Q(Q2SiO)nSiQ3 wherein Q's are identical or different and represent a group selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group and an aryl group, with the proviso that all Q groups are not hydrogen atoms at the same time, and n is an integer of 1 to 1000, compounds of the formula (Q2SiO)n wherein Q and n are the same as defined above, and compounds of the formula X(Q2SiO)nSiQ2X

wherein Q and n are the same as defined above, and X is a halogen atom, (iii) an organic carboxylic acid ester, and (iv) a titanium compound of the formula Ti(OR)?X4-?

wherein R is an alkyl group, X is the same as defined above, and ? is O or an integer of 1 to 4, and (B) an organoaluminum catalyst component of the formula R'mAl(OR')3 m wherein R' groups are identical or different, and represent an alkyl group, and m is a positive number of 1.5 to 3.