CA1121328A - Impregnated polymerization catalyst, process for preparing and use for ethylene copolymerization - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A catalyst formed from selected organo aluminum compounds and a precursor composition of the formula MgmTi1(OR)nXp[ED]q wherein ED is a selected electron donor compound m is ? 0.5 to ? 56 n is 0, 1 or 2 p is ? 2 to ? 116 q is ? 2 to ? 85 R is a C1 to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a C1 to C14 aliphatic or aromatic hydrocarbon radical, and X is selected from the group consisting of Cl, Br, I or mixtures thereof, which catalyst is in particulate form and impregnated is a porous inert carrier material.
A process for preparing such catalyst.
A process for using said catalyst to readily prepare ethylene copolymers having a density of about ?0.91 to ? 0.94 and a melt flow ratio of ? 22 to ?32 in a low pressure gas phgse process at a productivity of ? 50,000 pounds of polymer per pound of Ti.
Novel polymers and molded article are prepared.

Description

~ Z ~ 3~ 8 12131-1 BACKGROUND OF THE INVENTION
Field of the Invention The invention relates to the catalytic copolymerization of ethylene with high activity ~g and Ti containing complex catalysts in a gas phase process to produce ethylene copolymers having a density of ~ O.91 to ~ 0.94 and a melt flow ratio of > 22 to < 32.

Description of the Prior Art Until recently, low density (~ 0.940) polyethylene has been produced commercially~ for the most part, by the high pressure (~7 15,000 psi) homopolymeriza-tion of ethylene in the gas phase in stirred and elongated tubular reactors in the absence of solvents using free radical initiators. On a world wide basis, the amount of low density polyethylene produced in this fashion, annually, amounts to more than thirteen (13) billion pounds.
As recently disclosed in U.S. Patent 4,011,382 and in Belgian Patent 839,380 it has been found that low density polyethylene can be produced commercially at pressures of c1000 psi in a gas phase reaction in the absence of solvents by employing selected chromium and titanium (and, op~ionally, fluorine) containing catalysts under specific operating con~itions in a fluid bed process.
The products produced by the processes of U.S.
4,011,382 and Belgian 839,380, however, have a relatively broad molecular weight distribution (Mw/Mn) of ~ 6 to C 20. As such, although readily useful for a large number of applications in the areas of wire and cable

2.

~.Z13~8 insulation and moLded pipe they are not broadly useful in the areas of injection molding applications. They are also not broadly used in the area of film applications because of the poor optical and mechanical properties of films made from such resins.
To be commercially useful in a gas phase process, such as the fluid bed process of U.S. Patents

3,709,853; 4,003,712 and 4,011,382and Canadian Patent 991,798 and Belgian Patent 339,380, the catal~Jst employed must be a high activity catalyst, that is, it must have a level of productivity of z 50,000, and preferably 100,000, pounds of polymer per pound of primar~J metal in the catalyst. This is so because such gas phase pro-cesses usually do not employ any catalyst residue removing procedures. Thus, the catalyst residue in the polymer must be so small that it can be left in the polymer without causing any undue problems in the hands of the resin fab-ricator and/or ultimate consumer. Where a high activity catalyst is successfully used in such fluid bed processes the heavy metal content of t'ne resin is of the order of 20 parts per million (ppm~ of primary metal at a pro- -ductivity level of ~ 5~,000 and of the order of ~ 10 ppm at a productivity level of ~ lC0,00~ and of the order of 3 ppm at a productivity level of ~ 300,000. Low catal-yst residue contents are also important where the catal-y~t is made with chlorine containing materials such as the titanium, magnesium and/or aluminum chlorides used in some so-called Ziegler or Ziegler-Natta catalysts.
High residual chlorine values in a molding resin will cause pitting and corrosion on the metal surfaces of the molding devices. Cl residues of ~he order of ~-200 ppm are not commercially useful.

~.Z ~ 3 ~ 8 U S. Patent 3,989,881 discloses the use of a hi8h activity catalyst for the manufacture, under slurry polymerization conditions, of ethylene polymers having a relatively narrow molecular weight distribution (~Iw/Mn) of about 2.7 to 3.1. Attempts were made to use catalysts similar to those described in U.S. 3,989,881 for the purpose of making polyethylene of narrow molecular weight distribution by polymerizing ethylene alone or with propylene in the gas phase in a fluid bed process using apparatus and conditions similar to those employed in U,S. 4,011,382 and Belgian Patent 839,380. These attempts were not successful. In order to avoid the use of the solvents in the slurried catalyst systems of U.S.3,989,881 the Ti/~g containing components were dried. However, the dried material, a viscous, gummy, pyrophoric composition, could not be readily fed to the reactor because it was not in a free flowing form. Even when blended with silica, to improve its free flowing properties and then added to the reactor, the results were commercially unacceptable.
The productivity of the catalyst was poor, or the catalyst was pyrophoric and difficult to handle, or the polymer product had a low bulk density i.e.j of the order of ~ 6 pounds/cubic foot.
Polymers of such low bulk density are not commercially desirable because they are flufy. If the polymer is to be stored or sold in granular form, significantly larger amoun~s of storage and shipping space is required for handling these materials. E~en if the granular polymer is to be pelletized prior to shipping, the processing of a given quantity of the low bulk density material through the pelletizing equipment requires ~ Z ~ ~ 2 8 significantly longer processing times than would the same quantity of high bulk density materials, when using the same extrusion equipment.
U.S. Patent 4,124,532 discloses the polymerization of ethylene and propylene with high activity catalysts. These catalysts comprise complexes which may contain magnesium and titanium. These complexes are prepared by reacting the halide MX2 (where M may be Mg) wlth a compound M'Y
(where M' may be Ti and Y is halogen or an organic radical) in an electron donor compound. These complexes are then isolated by either crystallization, by evaporation of the solvent or by precipitation.
Polymerization is carried out with these catalytic complexes and an alkyl aluminum compound.
However, U.S. Patent 4,124,532 does not disclose any special techniques or methods of preparing the catalyst in order to achieve the desirable results described in the present invention. The use of the catalysts described in U.S. Patent 4,124,532~ without ~20 these special methods, would not lead to a commercial fluid bed process to produce polyethylenes at commercial rates. In addition the examples in the gas phase do not describe a practical process of copolymerization to produce the special low density copolymers with attractive polymer morphology described in the present inventionO

U,S. Patents 3,922,322 and 4,035,560 disclose the use of several Ti and Mg containing catalysts for the manu-facture of granular ethylene polymers in a gas phase fluid bed process under a pressure of< 1000 psi. The use of these catalysts in these processes, however, has significant disadvantages, The catalyst of U.S. 3,922,322 provides polymers having a very high catalyst residue content i.e., about 100 ppm of Ti and greater than about 300 ppm Cl, according to the working example of this patent. Further, as disclosed in the worklng example of U.S. 3,922,322, the catalyst is used in the form of a prepolymer, and very high volumes of the catalyst composition must be fed to the reactor. The preparation and use of this catalyst ~hus requires the use of relatively large size equipment for the manufacture, storage and transporting of the catalyst.
The catalysts of U.S. 4,035,560 also apparently provide polymers having high catalyst residues, and the catalyst compositions are apparently pyrophoric because of the types and amounts of reducing agents employed in such catalysts.
Canadian patent application Ser. No.324,724 filed March 30, 1979 in the names of F.J. Karol et al and entitled Preparation of Ethylene Copolymers In Fluid Bed Reactor discloses that ethylene copolymers, having a density of 0.91 to 0.96, a melt flow ratio of ~ 22 ~o < 32 and a relatively low residual catalyst content can be produced 5a ~ 3 ~ 8 in granular form, at relatively high productivities if the monomer(s) are polymeri7ed in a gas phase process with a specific high activity ~Ig-Ti containing complex catalyst which is blended with an inert carrier material.
The granular polymers thus produced have excellent physical properties which allow them to be used in a broad range of molding applîcations. However these polymers have several disadvantages. First, because o the presence of the support material in the cat~lyst which is not removed from the polymer prior to the molding thereof, the polymer containing certain o~ these support materials is not too useful for clear film applications. These support particles may impart poor film rating ~alues to clear films made from such polymers.
Second, the polymers, particularly at the lower polymer densities, also have a relatively low bulk density. The handling of these polymers therefore requires the use of larger volumes of shipping and storing equipment than is required for the pelleted products which the molding industry is more accustomed to handling. As a result larger capital investments are needed for the equipment needed to handle and store these low bulk density granular materials.
Further, the feeding of the low bulk density granular materials to molding and extrusion equipment re~uires longer feed times than is required for the same weight o~
pelleted material because of the larger volumes of the granular material that are involved. Third, the polymer particles formed during the fluid bed polymerization process are irregular in shape and are somewhat difficult to fluidize. The final product also contains a relatively high level of fines,i.e., particles having a particle ~ .2 ~ 3.~ 8 size of ~ 150 microns.

Summary of the Invention It has now been unexpectedly found that ethylene copolymers having a wide density range of 0.91 tc 0.94 and a melt flow ratio of ~ 22 to ~ 32 and which have a relatively low residual catalyst content and a relatively high bulk density and which provide films of good clarity can be produced at relatively high productivities for commercial purposes by a gas phase process if the ethylene is copolymerized with one or more C3 to C8 alpha olefins in the presence of a high activity magnesium-titanium complex catalyst prepared, as described below, under specific activation conditions with an organo aluminum compound and impregnated in a porous inert carrier material.
An object of the present invention is to provide a process for producing, with relatively high productivi-ties and in a low pressure gas phase process, ethylene copolymers which have a density of about ~.91 to 0.94, a melt flow ratio of about 22 to 32, a relatively low residual catalyst content and a bulk density of about 19 to 31, and good film rating values in film form.
Another object of the present invention is to provide granular ethylene copolymers which have a particle shape which is round and more conducive to being fluidized in a fluid bed process and wherein the final polymer product contains a relatively low level of fines.
A further object of the present invention is to provide a process in which ethylene copolymers which a-e ~ 3'~ 8 useful for a variety of end-use applications may be readily prepared.
A still further object of the present invention i9 to provide a variety o~ novel ethylene copolymers and molded articles made therefrom.

Brief Description Of The Drawings The drawing shows a gas phase fluid bed reactor system in ~hich the catalyst system of the present inven-tion may be employed.

DescriPtion Of The Preferred Embodiment It has now been found that the desired ethylene copolymers having a low melt flow ratio, a wide range of density values and relatively high bulk density values and good film properties can be readily produced with relatively high productivities in a low pressure gas phase fluid bed reaction process if the monomer charge is polymerized under a specific set of operating conditions, as detailed beLow, and in the presence of a specific high activity catalyst which is impregnated on an inert porous carrier material, as is also detailed below.

The Ethylene Copolymers The copolymers which may be prepared in the process of the present invention are copolymers of a major ~.Z ~ 3~ 8 mol percent ~ 90%) of ethylene, and a minor mol percent (~ 10%) of one (copolymer) or more (ter-, tetra-polymers) C3 toCg alphaolefins which should not contain anybranching onany of their carbon atoms which is closer than the fourth carbon atom. These alpha olefins include propylene, butene-l, pentene-l, hexene-l, 4-methyl pentene-l, heptene-l and octene-l~ The preferred alpha olefins are propylene, butene-l, hexene-l, 4-methyl pentene-l and oct~ne-lO
.The copolymers have a melt flow ratio of~ 22 to - 32, and preferably of~ 25 to ~ 30. The melt flow ratio value is another means of indicating the molecular wéight distribution of a polymer. The melt flow ratio (MFR) range of~ 22 to ~ 32 thus corresponds to a Mw/Mn value range of about 2.7 to 4.1 and the MFR range of~ 25 to C 30 corresponds to a Mw/Mn r~ange of about 2.8 to 3.6.
The copolymers have a density of about S 0.91 to 0.94 and preferably ~ 0.917 to C 0.935. The density o the copolymer, at a given melt index level for the copolymer~ is primarily regulated by the amount of the C3 to C8 comonomer which is copolymerized with the ethylene. In the absence of the comonomer, the ethylene would homopolymerize with the catalyst of the present invention to provide homopolymers having a density of about ~ 0.96. Thus, the addition of progressively larger amounts of the comonomers to the copolymers results in a progressive lowering of the density of the copolymer~
The amount of each of the various C3 to C8 comonomers needed to achieve the same result will vary from monomer ~.z~3;28 .
to monomer, under the same reaction conditions.
Thus, to achieve the same results, in the copolymers, in terms of a given density, at a given melt index level, larger molar amounts of the different comonomers would be needed in the order of C3~C4~C5~C6>C7~C8.
The melt index of a copolymer is a reflection of its molecular weight. Polymers having a relatively high molecular weight, have a relatively low melt index. Ultra-high molecular weight ethylene polymers have a high load (HIMI) melt index of about 0.0 and very high molecular weight ethylene polymers have a high load melt index (HLMI) of about 0.0 to about 1Ø Such high molecular weight polymers are difficult, if not impossible, to mold in conventional injection molding equipment. The polymers mada in the process of the present invention, on the other hand, can be readily molded, in such equipment. They have a standard or normal load melt index of ~0.0 to about 100, and preferably of about 0.5 ~o 80~ and a high load melt index ~HLMI) of about 11 to about 2000. The melt index of the polymers which are made in the process of the present in~ention is a function of a combina~ion of the polymerization temperature of the reaction, the density of the copolymer and the hydrogen/monomer ratio in the reaction system. Thusg the melt indeg i9 raised by increasing the polymeri~ation temperature and/or by decreasing the density of the polymer and/or by increasing the hydrogen/monomer ratio. In addition to hydrogen, other chain transfer agents such as dialkyl zinc compounds may also be used to further increase the melt index of the copolymers.

10 .

~.Z~ 3'~

The copolymers of the present invention have an unsaturated group content of ~ 1, and usually > 0.1 to ~0.3, C-C/1000 carbon atoms.
The copolymers of the present invention have a n-hexane extractables content (at 50C.) of less than about 3, and preferably of less than about 2, weight percent.
The copolymers of the present invention have a residual catalyst content, in terms of parts per million of titanium metal, of the order of >0 to ~ 20 parts per million, (ppm) at a productivity level of >50,000, and of the order of > 0 to ~ 10 ppm at a productivity level of ~ 100,000 and of the order of > 0 to ~ 3 parts per million at a productivity level oE ~ 300,000. In terms of Cl, Br or I residues, the copolymers of the present invention have a Cl, Br or I residue content which depends upon the Cl, Br or I content of the precursor.
From the TL to Cl, Br or I ratio in the inLtial precursor, it is possible to calculate Cl, Br, or I residues from knowledge of the productivity level based on titanium residue only. For many of the copolymers of the present invention made only wi~h Cl containing components of the catalyst system (Cl/Ti - 7), one can calculate a Cl residue content of ~ 0 toc 140 ppm at a productivity of > 50,000, a Cl content of ~0 to ~ 70 ppm at a ~.Z ~ 3~ ~

productivity of ~ 100,000, and a Cl content of ~ 0 to ~ 20 ppm at a productivity of ~ 300,000. The copolymers are readily produced in the process of the present invention at productivities of up to about 500,000.
The copolymers of the present invention are granular materials which have an average particle size of the order of about 0.005 to about 0.07 inches, and preferably of about 0.02 to about 0.04 inches, in diameter. The particle size is important for the purposes of readily fluidizing the polymer particles in the fluid bed reactor, as described below. The copolymers of the present invention have a bulk density of about 19 to 31 pounds per cubic foot.
In addition to being useful for making film therefrom the copolymers of the present invention are useful in other molding applications.
For film making purposes the preerred copolymers of the present invention are thosa having a density of about > 00912 to ~ 0.940, and preferably of about ~ 0.916 to ~ 0.928; a moLecular weight distribution (M~/Mn) of > 2.7 to ~- 3.6, and preferably of about ~ 2.8 to 3.1; and a standard melt index of ?0.5 to ~ 5.0 and preferably of about ~ 0.7 to _ 4Ø
The films have a thickness of ~ 0 to 10 mils and preferably ~.2~ 3 of >O to ~ 5 mils and more preferably of ~O to 1 mil.
For the injection molding of flexible articles such as.houseware materials, the preferred copolymers of the present invention are those having a density of ~0.920 to .~ 0.940 and preferably of about ~ 0.925 to ~ 0.930; a molecular weight distribution Mw/Mn of >.2.7 to ~ 3.6, and preferably of about > 2.8 to '- 3.1;
and a standard melt index of ~ 2 to ~ 100 and preferably of abou~ 2 8 to ~ 80.
High Activity Catalyst The compounds used to form the high activity catalyst used in the present invention comprise at least one titanium compound, at least one magnesium compound, : at least one ele~tron donor compound, at least one activator compound and at least one porous inert carrier : material, as defined below.
The titanium compound has the structure Ti (oR)axb wherein R is a Cl to C14 aliphatic or aromatic hydrocarbon radical, or COR' where R' is a Cl to C14 aliphatic or aromatic hydrocarbon radical, ~ 2 ~ 3 ~ ~

X is selected from the group consisting of Cl, Br, I or mixtures thereof, a is 05 1 or 2, b is 1 to 4 inclusive and a ~ b = 3 or 4.
The titanium compounds can be used individually or in combinations thereof, and would include TiC13, TlC14, Ti(OCH3)C13~ Ti(OC6H5)C13, Ti(OCOCH3)C13 and T ( 6 5) 3 The magnesium compound has the structure MgX2 wherein X is selected from the group consisting of Cl, Br, I or mixtures thereof. Such magnesium compounds can be used individually or in combinations thereof and would include MgCl~, MgBr2 and MgI2.
Anhydrous MgC12 is the particularly preferred magnesium compound.
About 0.5 to 56, and preferably about 1 to lQ, mols of the magnesiwm compound are used per mol of the titanium compound in preparing the catalysts employed in the present invention.
The titanium compound and the magnesium compound should be used in a form which will facilitate their dissolution in the electron donor compound, as 14.

~.Z ~ 3 described herein below.
The electron donor compound is an organic compound which is liquid at 25C and in which the titanium compound and the magnesium compound are soluble. The electron donor compounds are known, as such, or as Lewis bases.
The electron donor compounds would include such compounds as alkyl esters of aliphatic and aromatic carboxylic acids, aliphat-c e~hers, cyclic ethers and aliphatic ketones. Among these electron donor compounds the preferable ones are alkyl esters of Cl to C4 saturated aliphatic carboxylic acids; alkyl esters of C7 to C8 aromatic carboxylic acids; C2 to C8, and preferably C3 to C4, aliphatic ethers; C3 to C4 cyclic ethers, and preferably C4 cyclic mono- or di-ether; C3 to C6, and pref~rably C3 to C4, aliphatic ketones. The most preferred of these electron donor compounds would include methyl formate, e~hyl aceta~e9 butyl acetate, ethyl ether, hexyl ether, tetrahydrofuran, dioxane, acetone and methyl i.sobutyl ketone.
The electron donor compounds can be used individually or in combinations thereof.
About 2 to 85, and preferably about 3 ~o 10 mols of the electron donor compound are used per mol of Ti.

~ Z~ 3Z 8 The activator compound has the structure Al(R")C XdHe wherein X' is Cl or OR"', R" and R"' are the same or different and are Cl to C14 saturated hydrocarbon radicals, d is O to l.S, e is 1 or O and c ~ d + e - 3.
Such activator compounds can be used individually or in combinations thereof and would include Al(C2H5)3, Al(C2H5)2Cl, Al(i-c4Hg)3~ A12(C2H5)3C13~ Al(i-C4Hg)2H~
Al(C6H13)3~ AL(C8H17)3~ Al~C2~s)2H and Al(c2H5)2(oc2H5).
About 10 to 400, and preferably about 10 to 100, mols of the activator compound are used per mol of the titanium compound in activating the catalysts employed in the present invention.
The carrier materials are solid, particula~e porous materials which are inert to the other components of the catalyst composition, and to the other active components of the reaction system. These carrier materials would include inorganic materials such as oxides o silicon and/or aluminum. The carrier materials are used in the form of dry powders having an average particle size of about 10 to 250, and preferably o about 50 to 150 microns. These materials are also 16.

~ z ~ 3 z ~ 12131-1 -?o~ous and have a surface area of > 3, and preferably of ~ 50, square meters per gram. Catalyst activity or productivity is apparently also improved with silica having pore sizes of > 80 Angstrom units and preferably of ~ 100 Angstrom units. The carrier material should be dry, that is, free of absorbed water. Drying of the carrier material is carried out by heating it at a temperature of ~ 600C. ~lternatively, the carrier material dried at a temperature of ~ 200C may be treated with about l to 8 weight percent of one or more of the aluminum alkyl compounds described above. This modifi-cation of the support by the aluminum alkyl compounds provides the catalyst composition with increased activi-ty and also improves polymer partirle morphology of the resulting ethylene polymers.

Catalyst Preparation Formation of Pre ursor T~e catalyst used in the present invention is prepared by first preparing a precursor composi~ion from the titanium compound, the magnesium compound, and the electrbn donor compound, as described below, and then impregnating the carrier material with the precursor composition and ~hen treating the impregna~ed precursor composition with the activator compound in one or more steps as described below.

17.

l~.Z~3'~8 The precursor composition is formed by dissolving the titanium compound and the magnesium compound in the electron donor compound at a temperature of about 20C up to the boiling point o~ the electron donor compound.
The titanium compound can be added to the electron donor 17-A.

1~.2 ~ 3 ~ ~ 12131-1 compound before or after the addi~ion of the magnesium compound, or concurrent therewith. The dissolution of the titanium compound and the magnesium compound can be acilitated by stirring, and in some instances by refluxing these two compounds in the electron donor compound After the titanium compound and the magnesium compound are dissolved, the precursor composition may be isolated by crystallization or by precipitation with a C5 to C8 aliphatic or aromatic hydrocarbon such as hexane, isopentane or benzene.
The crystallized or precipitated precursor composition may be isolated, in the form of fine, free flowing particles having an average particle size of about 10 to 100 microns and a bulk density of about 18 to 33 pounds per cubic foot.
When thus made as disclosed above the precusor composition has the formula M~mTil(OR)~Xp[ED~q wherein ED is the electron donor compound, m is > 0.5 to ~ 56g and preerably ~ 1.5 to ' 5, n is 0, 1 or 2 p is > 2 to ~ 116, and preferably ~ 6 to ~ 14, q is ~ 2 to ~ 85, and preferably .> 4 to ~ 11 9 R is a Cl to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a Cl to C14 aliphatlc or 1~ .

1~131-1 ~ .Z~ 3Z ~
aromatic hydrocarbon radical and, X is selected ~rom the group consisting of Cl, Br, I or mixtures thereof.
The subscript for the element titanium (Ti) is the arabic numeral one.

Catalyst Preparation: Imp~nation of Precursor in Support The precursor composition is then impregnated, in a weight ratio of about 0.033 to 1, and preferably about 0~1 to 0.33, parts of the precursor composition into one part by weight of the carrier material.
The impregnation of the dried (activated) support with the precursor composition may be accomplished by dissolving the precursor composition in the electron donor compound, and by then admixing the support with the dissolved precursor composition so as to allow the precursor composition to impregnate the support. The solvent is then removed by drying at temperatures of ~ 70C.
The support may also be impregnated with the precursor composition by adding the support to a solution of the chemical raw materials used to form the precursor composition in the elec~ron donor compound, without isolating the precursor composition from such solution~
The excess electron donor compound is then removed by drying or washing and drying at temperatures of C 70C.

19.

~ 2 8 12131-1 Activation of Precursor Composition In order to be used in the process of the present invention the precursor composition must be fully or compLetely activated, that is, it must be treated with sufficient activator compound to transform the Ti atoms in the precursor composition to an active state.
It has been found that, in order to prepare a useful catalyst it is necessary to conduct the activation in such a way that, at leas~ the final activation stag~
must be conducted in the absence of solvent so as to avoid the need for drying the fully active catalyst to remove solvent therefrom. Two procedures have been developed to accomplish this result.
In one procedure, the precursor composition is completely activated9 outside the reactor, in the absence o solvent, by dry blending the impreg~ated precursor composition with the activator compound. In this dry blendingprocedure the activator compound is used while im-pregnated in a carrier material. In this procedure the fully activated precursor composition is prepared without having to heat the composition above50 C prior to feeding it to thepolymerization reactor.
` In the second, and pr~ferred of such catalyst activation procedures, the precursor composition is partially activated outside thepolymerization reactor with enough activator compound so as to provide a partially activated precursor composition which has an activator compound/Ti molar ratio of about~ 0 to ~ 10:1 and preferably of about

4 to 8:1. This partial activation reactio~ is pre~erably 20.

~ 12131 -1 carried out in a hydrocarbon solvent slurry followed by drying of the resulting mixture, to remove the solvent, at temperatures between 20 to 80, and preferably of 50 to 70C. The resulting product is a free-flowing solid particulate material which can be readily fed to the polymerization reactor. The partially activated and impregnated precursor composition is fed to the polymeri-zation reactor where the activation is completed with additional activator compound which can be the same or a different compound.
The additional activator compound and the partially activated impregnated precursor composition are preferably fed to the reactor through separate feed linesO The addi-tional activator compound may be sprayed into the reactor in the form of a solution thereof in a hydrocarbon solvent such as isopentane, hexane, or mineral oil. This solution usually contains about 2 to 30 weight percent of the acti-vator compound. The additional activator compound is added to the reactor in such amounts as to provide, in the r~actor, with the amounts of activator compound and titanium compound fed with the partially activated and impregnated precursor composition, a total Al/Ti molar ratio of ~ 10 to 400 and preferably of about 15 to 60. The additional amounts of activator compound added to the reactor, react with, and complete the activation of, ~he titanium compound in the reactor.

21.

~ Z~328 l2l3l l In a continuous gas phase process, such as the fluid bed process disclosed below, discrete portions of the partiaLly or completeLy activated precursor composition impregnated on the support are continuously fed to the reactor, with discrete portions of any additional activator compound needed to complet`e the activation of the partially activa~ed precursor composition, during the continuing 21a ~ 3 Z ~ 31 -1 polymerization process in order to replace active catalyst sites that are expended during the course of the reaction.

The Polymerization Reaction ~ he polymerization reaction is conduc~ed by contacting a stream of the monomers, in a gas phase process, such as in the fluid bed process described below, and substan~ially in the absence of catalyst poisons such as moisture, oxygen, carbon monoxide, carbon dioxide alld acetylene with a catalytically effective amount of the comple~ely activated precursor composition (the catalyst) impregnated on a support at a temperature and at a pressure sufficient to initiate the polymerization reaction.
In order to achieve the desired density ranges in the copolymers it is necessary to copolymerize enough of the ~ C comonomers with ethylene to achieve a level of 1 to 10 mol percent of the C3 to ~8 comonomer in the copol~mer. The amount of comonomer needed to achieve this result will depend on ~he particular comonomer(s) employed.
Th~re is provided below a listing of the amounts, in mols, of various comonomers that must be copolymerized wi~h ethylene in order to provide polymers having the desired density range at any given melt index. The listing also indicates the relative molar concentration, of such comonomer to ethylene, which must be present in the gas s~ream of monomers which is fed to the reactor.

~131-l .Z ~ 3 ~

Gas Stream mol % needed Comonomer/Ethylene Comonomer in copolymer molar ratio propylene 3.0 to 10 0.2 to 0.9 butene-l 2.5 to 7.0 0.2 to 0.7 pentene-l 2.0 to 6.0 0.15 to 0.45 hexene-l 1.0 to 5.0 0.12 to 0.4 octene-l 0.8 to 4.5 0.10 to 0.35 A fluidized bed reaction system which can be used in the practice of the process of the present invention is illustrated in Figure 1~ With reference thereto the reactor 10 consists of a reaction zone 12 and a velocity reduction zone 14.

~.Z ~ 3'Z8 The reaction zone 12 comprises a bed of growing polymer particles, formed polymer particles and a minor amount of catalyst particles fluidized by the continuous flow of polymerizable and modifying gaseous components in - the form of make-up feed and recycle gas through the reaction zone. To maintain a viable fluidized bed, the mass gas flow rate through the bed must be above the minimum flow required for fluidization, and preferably from about 1.5 to about 10 times Gmf and more preferably from about 3 to about 6 times G fO G f is used in the accepted form as the abbreviation for the minimum mass gas flow required to achieve fluidization, C. Y. Wen and Y. H. Yu, "Mechanies of Fluidiæation," Chemical Engineering Progress Symposium Series, Vol. 62, p. 100-111 (1966).
It is essential that the bed always contains particles to prevent the formation of localized "hot spots"
and to entrap and distribute the particula_e catalyst throughout the reac~ion ~one. On start up) the reaction zone is usually charged with a base of particulate polymer particles before gas flow is initiated. Such particles may be identical i~ nature to the polymer to be formed or different thererom. When different, they are withdrawn with the desired formed polymer particles a~
the irst product. Eventually, a fluidized bed of the 24.

~i ~;3~1~

desired polymer particles supplants the start-up bed.
The partially or completely activated precursor compound (the cacalyst) used in the flui~ized bed is preferably stored for service in a reservoir 32 under a blanket of a gas which is inert to the stored material, such as nitrogen or argon~
Fluidization is achieved by a high rate of gas recycle to and through the bed, typically in the order of about 50 times the rate of feed of make-up gas. The fluidized bed has the general appearance of a dense mass of viable particles in possible free-vortex flow as created by the percolation of gas through the bed. The pressure drop through the bed is equal to or slightly greater than the mass of the bed divided by the cross-sectional area. It is thus dependent on the geometry of the reactor.
Make-up gas is fed to the bed at a rate equal to the rate at which particulate polymer product is withdrawn. The composition of the make-up gas is determined by a gas analyæer 16 positioned above the bed. The gas analyzer determines the composition of the gas being recycled and the composition of ~he make-up gas is adjusted accordingly to maintain an essentially steady state gaseous composition within the reaction zone.

~.Z~ 3~ 8 12131-1 To insure complete fluidization, the recycle gas and, where desired, part o the make~up gas are returned to the reactor at point 18 below the bed.
There exists a gas distribution plate 20 above the point of return to aid fluidizing the bed.
The portion of the gas stream which does not react in the bed constitutes the recycle gas which is removed from the polymerization zone, preferably by passing it into a velocity reduction zone 14 above the bed where entrained particles are given an opportunity to drop back into the bed. Particle return may be aided by a cyclone 22 which may be part of the velocity reduction zone or exterior thereto. Where desired, the recycle gas may then be passed through a filter 24 designed to remove small particles at high gas flow rates to prevent dust from contacting heat transfer surfaces and compressor blades.
The recycle gas is then compressed in a compressor 25 and then passed through a heat exchanger 26 wherein it is stripped of heat of reaction before it is returned to the bed. By constantly removing heat of reaction, no noticeable temperature gradient appears to exist within the upper portion of the bed. A temperature gradient will exist in the bottom of the bed in a layer of about 6 to 12 inches, between the temperature of the 26.

inlet gas and the temperature of the remainder of the bed.
Thus, it has been observed that the bed acts to almost immediately adjust the temperature of the recycle gas above this bottom layer of the bed zone to make it conform to the temperature of the remainder of the bed thereby maintaining itself at an essentially constant temperature under steady conditions. The recycle is then returned to the reactor at its base 18 and to ~he fluidized bed through distribution plate 20. The compressor 25 can also be placed upstream of the heat exchanger 26, The distribution plate 20 plays an important role in the operation of the reactor. The fluidized bed contains growing and formed particulate polymer particles as well as catalyst particles. As the polymer particles are hot and possibly active, they must be prevented from settling, for if a quiescent mass is allowed to exist, any active catalyst contained therPin may continue to react and cause fusion. Diffusing recycle gas through the bed at a rate sufficient to maintain fluidization at the base of the bed is, therefore, important. The distribution plate 20 serves this purpose and may be a screen, slotted plate, perforated plate, a plate of the bubble cap type and the like. The elements of the plate may all be stationary, or the plate may be of the mobile type ~.2 ~ 3'~ ~ 12131-1 disclosed in U.S. 3,298,792. Whatever its design, it must dif~use the recycle gas through the particles at the base of the bed to keep ~hem in a fluidized condition, and also serve to support a quiescent bed o~ resin particles when the reactor is not in operation. The mobile elements of the plate may be used to dislodge any polymer particles entrapped in or on the plate.
Hydrogen may be used as a chain trans~er agent in the polymerization reaction of the present invention.
The ratio o hydrogen/ethylene employed will vary between about 0 to about 2.0 moles of hydrogen per mole of the monomer in the gas stream.
Any gas inert to the catalyst and reactants can also be present in the gas stream. The activator compound is preferably added to the gas recycle system at the hottest portion thereof. Addition into the recycle line, therefore, downstream rom the heat exchanger is preferred, as from dispenser 27 thru line 27A.
Compounds of the structure Zn(Ra)(Rb), wherein Ra and Rb are the same or dif~erent Cl to C14 aliphatic or aromatic hydrocarbon radicals, may be usad in conjunction with hydrogen, with the catalysts of the present invention as molecular weight control or chain transfer agents, that is, to increase the melt inde~
values of the copolymers that are produced. About 0 to 50, 28.

~.2 ~ 3~ ~

and preferably about 20 to 30, moles of the Zn compound (as Zn) would be used in the gas stream in the reactor per mol of titanium compound (as Ti) in the reactor.
The zinc compound would be introduced into the reactor preferably in the form of a dilute solution (2 to 10 weight percent) in a hydrocarbon solvent or absorbed on a solid diluent material, such as silica, in amounts of about 10 to 50 weight percent. These compositions tend to be pyrophoric. The zinc compound may be added into the recycle gas stream from a feeder adjacent to feeder 27.
It is essential to operate the fluid bed reactor at a temperature below the sintering temperature of the polymer particles. To insure that sintering will not occur, operating temperatures below the sintering temperature are desired. For the produc~ion of ethylene copolymers in the process of th~ present invention an operating temperature of about 30 to 105C. is preferred and a temperature of about 75 to 95C. is most preferred.
Temperatures of about 75 to 90C. are used to prepare products having a density of about 0.91 to 0.92, and temperatures of about 80 to 100C. are used to prepare products having a density of about ~ 0.92 to 0.94.

29.

12,131-1 The fluid bed reactor is operated at pressures of up to about 1000 pSi9 and is preferably operated at a pressure of from about 150 to 350 psi, with operation at the higher pressures in such ranges favoring heat transfer since an increase in pressure increases the unit volume heat capacity of the gas.
The partially or completely activated precursor composition is injected into the bed at a rate equal to its consumption at a point 30 which is above the distribu-tion plate 20. Injecting the catalyst at a point above the distribution plate is an important fea~ure of this invention.
Since the catalysts used in the practice of the invention are highly active, injection of the fully activated catalyst into the area below the distribution plate may cause polymerization to begin there and eventually cause plugging of the distribution plate. Injection into the viable bed, instead, aids in distributing the catalyst throughout the bed and tends to preclude the formation of localized spots of high catalyst conce~tration which may result in the formation of "hot spots".
A gas which is inert to the catalyst such as nitrogen or argon is used to carry the partially or completely reduced precursor composi~ion, and any 30.

.2 ~ 3~2~3 1~,131 -1 additional activator compound or non-gaseous chain transfer agent that is needed, into the bed.
The production rate of the bed is con-trolled by the rate of catalyst injection. The produc.ivicy of the bed may be increased by simply increasing the rate of catalyst injection and decreased by reducing the rate of catalyst iniection.
Since any change in the rate of catalyst injection will change the rate of generation of the heat of reaction, the temperature of the recycle gas is adjusted upwards or downwards to accomodate the change in rate of heat generation. This insures the maintenance of an essentially constant temperature in the bed.
Complete instrumentation of both the fluidized bed and the recycle gas cooling system, is, of course, necessary to detect any temperature change in the bed so as to enable the operator to make a suitable adjustment in the temperature of the recycle gas.
Under a given set of operating conditions, the fluidized bed is maintained at essentially a constant height by withdrawing a portion of the bed as product at a rate equal to the rate of forma~ion of the particulate polymer product. Since the rate o heat generation is directly rela~ed to prod~ct formation, a measurement of the temperature rise of the gas across the reactor (the difference between inlet gas temperature 31.

~ 12131-1 and exit gas temperature) is determinative of the rate of particulate polymer formation at a constant gas velocity.
The particulate polymer product is preferably continuously withdrawn at a point 34 at or close to the distribution plate 20 and in suspension with a portion of the gas stream which is vented before the particles settle to preclude further polymerization and sintering when the particles reach their ultimate collection zone. The suspending gas may also be used, as mentioned above, to drive the product of one reactor to another reactor.
The particulate polymer product is conveniently and preferably withdrawn through the sequential operation of a pair of timed valves 36 and 38 defining a segregation zone 40. While valve 38 is closed, valve 36 is opened to emit a plug of gas and product to the zone 40 between it and valve 36 which is then closed. Valve 38 is then opened to deliver the product to an external recovery zone. Valve 38 is then closed to await the next product recovery operation.
Finally, the fluidized bed reactor is equipped with an adequate venting system to ~llow venting the bed during start up and shut down. The reactor does not require the use of stirring means and/or wall scraping means.
The highly active supported catalyst system of this invention appears to yield a 1uid bed product having an average particle size between about 0.01 to about 0.07 inches and preferably about 0.02 to about 0.04 inches wherein catalyst residue is unusually low. The polymer particles are relatively easy to fluidize in a fluid bed process.
The polymer product contains a relatively low level of fines (~ 150 microns) i.e., 4% by weight.
32.

-_131-l 2~28 The Eeed stream of gaseous monomer, with or witllout inert gaseous diluents, is fed into the reacto-~
at a space time yield of about 2 to 10 pounds/ ~our/cubic foot OL bed volume.
The term ~irgin resin or polymer as used herein means polymer, in granular form, as it is recovered from the polymerization reactor.
The following Examples are designed to illustrate the process of the present invention and are not intended as a limitation upon the scope thereof.
The properties of the polymers produced in the Examples were determined by the following test methods:
Density A plaque is made and conditioned for one hour at 100C to approach equilibrium crystallinity.
Measurement for density is then nade in a density gradient column.
Melt Index (MI) ASTM D-2338 - Condition E-Measured at l~OaC. - reported as grams per 10 minutes.
20 Flow Rate (HLMI) AS~I D-1238 - Condition F -Measured at 10 ~imes the -weight used in the melt index test above.
Melt Flow Ratio (MFR) = Flow Rate - Melt Index productivity a sample of the resin product is ashed, and the weight % of ash is determined; since the ash is essentially composed of the catalyst, the productivity is thus t'ne l~.Z~3'~3 pounds of polymer produced ?er pound of total catalyst cons~med.
The amount of Ti, Mg and Cl in the ash are determined by elementals analysis.
Bulk Density The resin is poured via 3/8"
diameter funnel into a lO0 mil graduated cylinder to lO0 mil line without shaking the cylinder, and weighed by difference.
Molecular W~ight Gel Penneation Chromatography Distribution ~w/Mn) Styrogel Packing: (Pore Size Sequence is 107, 105, 104, 103, 60 A ) Solvent is Perchloro-ethylene at 117C. Detection:
Infra red at 3.45.~.
Film Rating: A sample of film is viewed with the naked eye to note the size and distribution of gels or other foreign particles in comparision to standard film samples.
The appearance of the film as thus compared to the standard sa~nles is then given a rating on a scale of -lO0 (very poor) to -~ 100 (excellent).

3~.

3Z8 l~l3l l n-hexane extractables (FDA test used for polyethvlene film intended for food contact applications). A 200 square inch sample of 1.5 mil gauge film is cut into strips measuring 1" x 6" and weighed to the nearest 0.1 mg.
The strips are placed in a vessel and extracted with 300 ml of n-hexane at 50 + 1C.
for 2 hours. The extract is then decanted into tared culture dishes. After drying the extract in a vacuum desiccator the culture disE
is weighed to the nearest 0.1 mg. The extractables, normalized with respect to the original sample weight, is then reported as the weigbt fraction of n-hexane extractables.

Unsaturation Infrared SpectrophotomRter (Perkin Elmer Model 21). Pressings made from the resin which are 25 mils iD thickness are used as test sFecimens. A-bsorbance is measured at 10.35~ for transvinylidene unsaturation, 11.0~ for terminal vinyl unsaturation.

35.

~.2 ~ 3 ~ ~

and 11.25~ far pendant viny-lidene unsaturation. The ab-sorbance per mil of thickness of the pressing is directly proportional to the product of unsaturation concentration and absorbtivity. Absorbtivities are taken rom the literature values of R. J. de Kock, et al, J. Polymer Science9 Part B, 2, 339 (1964).

la. Preparation of Impregnated Precursor In a 12 1 flask equipped with a mechanical stirrer are placed 41.8g (0.439 mol) anhydrous MgC12 and 2.5 1 tetrahydrofuran (THF). To this mi~ture, 27.7g (o.184 mol) TiC14 is added dropwise over 1/2 hour. It may be necesse-sary to heat the mixture to 60C. for about 1/2 hour in order to completely dissolve the material~

The precursor composition can be isolated from solution by crystallization or precipitation. It may be analyz~d at this point or Mg and Ti content since some o the Mg and/or Ti compound may have been lost during th~

isolation of the precursor composition. The empirical formulas used herein in reporting the precursor compositions 36.

3 ~ 8 are derived by assuming that the Mg and the Ti still exist in the form of the compounds in which they were first added to the electron donor compound. The amount of electron donor is determined by chromatography.
500g of porous silica dehydrated to 800 C and optionally treated with 4 to 8 wt. % triethyl aluminum is added to the above solution and stirred for 1/4 hour.
The mixture is dried with a N2 purge at 60C. for about 3-5 hours to provide a dry free flowing powder having the particle size of the silica. The absorbed precursor composition has the formula TiMg3Oocllo (THF)6.7 Ib. Preparation of Impregnated Precursor from Preformed Precursor Composition In a 12 liter flask equipped with a mechani~al stirrer, 146g of precursor composition is dissolved in 2.5 liters dry THF. The solution may be heated to 60C
in order to facilitate dissolution. 500g of porous silica is added and the mixture is stirred for 1/4 hour. The mixture is dried with a N2 purge at ~60Co for about 3-5 hours to provide a dry free flowing powder having the particle size o~ the silica.

~ z~8 12131-1 II. Activation Procedure The desired weights of impregnated precursor composition and activator compound are added to a mi~ing tank with sufficient amounts o anhydrous aliphatic hydrocarbon diluent such as isopentane to provide a -slurry system.
The activator compound and precursor compound are used in such amounts as to provide a partially activated precursor composition which has an Al/Ti ratio of >0 to ~10:1 and preferabLy of 4 to 8:1.

The contents of the slurry system are then thoroughly mixed at room temperature and at atmospheric pressure for about 1/4 to l/2 hour. The resulting slurry is then dried under a purge of dry inert gas such as nitrogen or argon~ at atmospheric pressure and at a temperature of 65 + lO~C. to remove ~he hydro-carbon diluent. Th.s process usually requires about 3 ~o 5 hours. The resulting catalyst is in the form of a partially activated precursor composition which is impregnated within the pores of the silica. The material is a free flowing particulate material having the size and shape of the silica. It i5 not pyrophoric unless the aluminum alkyl content exceeds a loading of 10 weight percent. It is stored under a dry inert gas such as nitrogen or argon prior to future use, It is now ready for use and injec~e~ into, and fully activated within, the polymerïza~ion reactor.

38.

~.Z~3~1~

When additional activator compound is fed to the polymerization reactor for the purpose of compLeting the activation of the precursor composition, it is fed into the reactor as a dilute solution in a hydrocarbon solvent such as isopentane. These dilute solutions contain about 5 to 30% by volume of the activator compound.
The activator compound is added to the polymerization reactor so as to maintain the Al/Ti ratio in the reactor at a level of about ~ 10 to 400:1 and preferably of 15 to 60:1.
ExamPles 1 to 6 Ethylene was copolymeriz_d with butene-l in each of this series of 6 examples.
In Examples 1 to 3 the catalyst used was formed as described above. The silica impregnated catalyst svstem of Examples L and 2 contained 14.5 weight % of precursor com-position, and the silica impregna~ed catalyst system of Example 3 contained 20~0 weight % of precursor composit.on.
The silica support used for the catalyst of Example 2 was treated with triethyl aluminum, before it was used ~o make the supported catalyst system.
The catalysts used in Examples 4 to 6 were prepared by methods outside the scope of the catalysts of.the present invention for comparative purposes. The ca~alyst of Example 4 was prepared by physically blending 7.5 weight % of the unimpregna~ed precursor composition of preparation Ia with 92.5 weight %

39.

~.Z ~ 3 ~ 8 12131-1 of polyethylene powder. The polyethylene powder is high pressure, low density, ( C0.94) ethylene homopolymer which has an average particle size o~ about 50 to 150 microns.
The catalyst of Examples 5 and 6 was prepared by physically blending 20 weight % of the unimpregnated precursor compo-sition of preparation Ia with 80 weigh~ % of silica having a surface area of 300m2/gram and an average particle size of 70~ . In each of Examples 1 to 6 the precursor compo-sition was partially activated with triethyl aluminum so as to provide the silica/precursor composition with an Al/Ti mol ratio of 5 T 1. The completion of the activation of the precursor composition in the polymerization reactor was accomplished with a 5% by weight solution of ~riethyl aluminum in isopentane so as to provide the completely activa~ed catalyst in the reactor with an Al/Ti mol ratio of 25 to 30.
Each of the reactions was conducted for 1 hour, after equilibrium was reached, at 85 C and under a pressure of 300 psig, a gas velocity of abou~ 3 to 6 times Gmf and a space time yield of about 4.4 to 6 3 in a fluid bed reactor system. The reaction system was as described in the drawing above. It has a lower section 10 feet high and 13 1/2 inches in (inner) diameter, and an upper section which was 16 feet high and 23 1/2 inches in (inner) diameter.
Table I below lists the butene-l/ethylene molar ratio and H2/ethylene molar ratio and the space time yield (lbs/hr/ft3 of bed space) used in each example, as well as 40.

.Z ~ 3~ 8 the various properties of the polymers made in such examples, and various properties of film samples made from some of such polymers.
As compared to granular copolymers made in copending Canadian application Ser. No 324,724 filed on March 30, 1979 in the names of F J, Karol et al and entitled "Preparation of Ethylene Copolymers in Fluid Bed Reactor" the copolymers of the present invention, in virgin powder form, and at a given density and melt index, have a smaller average particle size, a narrower particle size distribution, are easier to fluidize, have higher bulk densities and are easier to convey pneumatically. In film form, the copolymers made by the process of the present invention have significantly better film propertias than the copolymers made in said copending application.

41, j 3l -T~BL~ I

Example 2 1 3 4 ~ 6 Operatin~ Conditions C4/C2 mol ratio 0.448 00472 0.402 0.462 0,4230.401 H2/C2 mol ratio 0.193 0.215 0.535 0.204 0.2070.394 Space time y~eld 5.4 6.3 5.2 4.4 5.3 (lbs/hr/~t bed space) Polvmer Properties Melt index 1.8 2.2 17.8 2.3 1.3 15.7 Melt flow ratio 25.3 25.1 23.7 25.5 25,325.0 Density 0.9238 0.9208 0.9278 0.924 0.923 0O928 Ti, ppm 5-6 5-6 7-9 2-3 2-3 fO ash 0.042 0.049 0.059 ~ 0.0340.034 Film Pro~erties Gloss (%) 159 141 - _ _ _ Haze (%) 9.7 13.6 Hexane extractables (%) 0.17 0.41 Film rating +30 +25 - +40 -60 Granular Properties Bulk density 20.9 1993 24.9 14.5 16.016.72 Umf (ft/ sec) 0.47 0.65 0.28 1.3 0.72 Umx (ft/sec) 0.85 1~2 0.7 2.1 1.1 Screen A~alysis (wei~ht 7/.) .

screen size - 8 mesh 1.4 108 0.0 7,7 17.4 1.3 12 " 4.4 8.7 0.4 ~805 14.4 2.5 20 " 27.7 38.713.4 42.9 28.4 11.4 40 " 40.2 37.147.9 15.9 19.0 41.9 60 " 16.7 lloO2S.3 4.0 9.1 25.4 100 " 7.0 2~2 9.4 0.6 8.1 14.7 pan 206 0.6 3.6 0.2 3.4 2.8 Avera~e ~article size, inch 090324 0.0375 0.022 C.0586 0.0~42 0.023 42.

~ 3 z ~ 12l3 Examples 7 to 10 Ethylene was copolymerized with butene-l in each o these series of examples.
In these examples the silica impregnated catalyst precursor was formed as described above. The silica impregnated catalyst system contained 20.0 weight % of precursor composition. The silica support used for the catalysts of these examples was treated with triethyl alumi-num, before it was used to make the support-ed catalyst system. In each of these examples the precursor composition was partially ac~ivated wi~h the aluminum com-pound shown in Table II~ according to the procedure as described above, so as to provide the impre~nated precursor with an Al/Ti mol ratio as shown in Table II.
The compLetion of the activation of the precursor composi~
tion ~ the polymerization reactor was accomplished with a 5% by weight solution of triethyl aluminum in isopentane so as to provide the completely activated catalyst in ~he reactor with an Al/Ti mol ratio of 25 to 30.
Each of the polymerization reactions was conducted as described in Examples 1 to 6.
Table II below lists the activator compound and Al/Ti mole ratio in preparing the precursor composition.
The butene-l/ethylene molar ratio and H?/ethylene molar ratio and the space time yield (lbs/hr/ft of bed space) used in each example~ as well as the various properties of the polymers made in such examples.

~ 3.

~ 3 ~ ~ 12131-1 TABLE II
Example 2 7 8 9 10 Precursor ~ctivation Activator compound TEAL TIBALTIBAL TNHEXAL TNOCTAL
AL/Ti mol ratio 4.5 6.7 4.5 6.6 7.5.
Operating Conditions C4/C2 mol ratio 0.448 0.375 0.369 0.375 0.368 H2/C2 mol ratio 0.193 0.266 0.247 0.266 0.249 Space time yi~ld 5.4 5.8 5.0 5.3 7.8 (lbs/hr/ ft bed space) olymer Properties Melt index 1.8 2.8 1.1 2.9 2.2 Melt flow ratio 25.3 29.9 25.5 28.4 26.4 Density 0.9238 0.920 0.928 0.921 0.923 Ti, ppm . 5-6 3-5 2-4 3-5 2-4 % ash 0.042 0.037 0.030 0.036 0~023 Granular Properties Bulk density 20.9 25.6 19.7 26.2 21.2 Average particle Size, in. 0.0324 0.0488 0.0493 0.0463 0.0538 _ _ TEAL is triethyl aluminum TIBAL is tri-isobutyl al~minum TNHEXAL is tri-n-hexyl aluminum TNOCTAL is tri-n~octyl aluminum 44.

~ 3.~8 12131 -1 The examples of Table II demonstrate that ~opolymers having high bul~ density, low catalyst residues, and attractive polymer properties can be prepared with the catalysts of the present invention which catalysts are pre-paredwith two different activator compounds.

45.

Claims (21)

WHAT IS CLAIMED IS:

1. A catalyst composition comprising a precursor composition of the formula MgmTi1(OR)nxp[ED]q wherein R is a Cl to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a Cl to C14 aliphatic or aromatic hydrocarbon radical, X is selected from the group consisting of Cl, Br, I or mixtures thereof, ED is an electron donor compound, m is ? 0.5 to ? 56, n is 0, 1 or 2, p is ? 2 to ? 116, and q is ? 2 to ? 85, said precursor composition being impregnated in a porous support and being either unactivated, or partially activated with > 0 to ?10 mols of activator compound per mol of Ti in said precursor composition or completely activated with > 10 to > 400 mols of activator compound per mol of Ti in said precursor composition, said activator compound having the formula Al(R'')cX?He wherein X' is Cl or OR''', R" and R''' are the same or different, and are Cl to C14 saturated hydrocarbon radicals, d is 0 to 1.5, e is 1 or 0 and c + d + e = 3, 46.

said electron donor compound being a liquid organic compound in which said precursor composition is soluble and which is selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones.

2. A catalyst composition as in claim 1 where in said partially activated precursor composition is completely activated in a polymerization reactor with> 10 to ? 400 mols of said activator compound per mol of titanium compound in said precursor composition.

3. A catalyst composition as in claim 1 wherein said partially activated precursor composition is completely activated with >10 to? 400 mols of said activator compound per mole of Ti in said precursor composition, said complete activation being conducted so as to thereby prepare a solid dry catalyst composition prior to the feeding thereof to a polymerization reactor, without having to heat said catalyst composition above 50°C.

4. A catalyst composition as in claim 1 in which the source of the Mg in said catalyst comprises MgCl2.

5. A catalyst composition as in claim 4 in which said electron donor compound comprises at least one ether.

6. A catalyst composition as in claim 5 in which said electron donor compound comprises tetrahydro-furan.

47.

7. A catalyst composition as in claim 5 in which the source of the Ti in said catalyst comprises TiC14.

8. A process for preparing a catalyst composition which comprises A) forming a precursor composition of the formula MgmTi1(OR)nXp[ED]q wherein R is a C1 to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a Cl to C14 aliphatic or aromatic hydrocarbon radical, X is selected from the group consisting of Cl, Br, I or mixtures thereof, ED is an electron donor compound, m is ? 0.5 to ? 56, n is 0, 1 or 2, p is ? 2 to ? 116, and q is ? 2 2 to ? 85 by dissolving at least one magnesium compound and at least one titanium compound in at least one electron donor compound so as to thereby form a solution of said precursor composi-tion in said electron donor compound, and recover-ing said precursor composition from said solution, said magnesium compound having the structure MgX2, said titanium compound having the 48.

structure Ti(OR)aXb wherein a is 0, 1 or 2, b is 1 to 4 inclusive and a + b = 3 or 4, said electron donor compound being a liquid organic compound in which said magnesium compound and said titanium compound are soluble and which is selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones, said magnesium compound, said titanium compound and said electron donor compound being employed in such amounts as to satisfy the values of m, n, p and q, B) impregnating said precursor compo-sition onto a porous support either before or after recovering said precursor composition from the electron donor solution thereof, and C) partially activating said precursor composition with > O to ? 10 mols of activator compound per mol of Ti in said precursor composi-tion, said activator compound having the formula Al(R'')cXdHe wherein X' is Cl or OR''', R" and R''' are the same or different, and are Cl to C14 saturated hydrocarbon radicals, d is 0 to 1.5, e is 1 or 0 and c + d + e = 3, 49.

said activating being conducted after the recovery of said impregnated precursor composi-tion from the electron donor solution thereof.

9. A process as in claim 8 in which said partially activated impregnated precursor composition is completely activated in a polymerization reactor with >10 to ? 400 mols of said activator compound per mol of titanium compound in said precursor composition.

10. A process as in claim 8 in which said partially activated impregnated precursor composition is completely activated with > 10 to ? 400 mols of said activator compound per mol of Ti in said precursor composition, said complete activation being conducted so as to thereby prepare a solid dry catalyst composition, prior to the feeding thereof to a polymerization reactor, without having to heat said catalyst composition above 50°C,

11. A process as in claim 10 in which said magnesium compound comprises MgCl2.

12. A process as in claim 11 in which said electron donor compound comprises at least one ether.

13. A process as in claim 12 in which said electron donor compound comprises tetrahydrofuran,

14. A process as in claim 13 in which said titanium compound comprises TiC14.

15, A catalytic process for producing ethylene copolymer containing >?90 mol percent of ethylene and ?10 mol percent of one or more C3 to C8 alpha olefins with a Ti containing catalyst at a productivity of ? 50,000 pounds of polymer per pound of Ti in a reactor under a pressure of < 1000 psi in the gas phase 50.

said polymer being produced in granular form and having a density of ? 0,91 to ? 0.94 and a melt flow ratio of ? 22 to ? 32 which comprises polymerizing ethylene with at least one C3 to C8 alpha olefin ah a temperature of about 30 to 105°C. by contacting the monomer charge with, in the presence of about 0 to 2.0 mols of hydrogen per mol of ethylene in the gas phase reaction zone, particles of a catalyst composition comprising a precursor composition of the formula MgmTil(0R)nXp[ED]q wherein R is a C1 to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a C1 to C14 aliphatic or aromatic hydrocarbon radical, X is selected from the group consisting of Cl, Br, I or mixtures thereof, ED is an electron donor compound, m is ? 0.5 to ? 56, n is 0, 1 or 2, p is ? 2 to ? 116, and q is ? 2 to ? 85, said precursor composition being impregnated in a porous support and being first partially activated outside of said reactor in a hydrocarbon slurry with > 0 to ? 10 mols of activator compound per mol of Ti in said precursor com-position, and then completely activated in said reactor with > 10 to ?400 mols of activator compound per mol of Ti in said precursor composition in the absence of a solvent so as to avoid the need for drying the fully active catalyst to remove solvent therefrom, 51.

said activator compound having the formula Al(R")cXdHe wherein X' is Cl or OR''', R" and R''' are the same or different, and are Cl to C14 saturated hydrocarbon radicals, d is 0 to 1.5, e is 1 or 0 and c + d + e = 3, said electron donor compound being a liquid organic compound in which said precursor composition is soluble and which is selected from the group consisting of alkyl esters of aliphatic and aromatic carboxylic acids, aliphatic ethers, cyclic ethers and aliphatic ketones.

16. A process as in claim 15 which is conducted in a fluid bed process.

17. A process as in claim 16 which is conducted under a mass gas flow rate of about 1.5 to 10 times Gmf.

18. A process as in claim 17 which is conducted at a productivity of ? 100,000.

19. A process as in claim 18 in which said precursor composition is partially activated with about > 0 to ?10 mols of said activator compound outside of said reactor and is completely activated in said reactor with sufficient activator compound to provide an Al/Ti ratio of about 15 to 60 in said reactor.

20. A process as in claim 15 in which ethylene is copolymerized with propylene.

21. A process as in claim 15 in which ethylene is copolymerized with butene-1.

52.