WO2000006614A1

WO2000006614A1 - Unbridged monocyclopentadienyl metal complex catalyst having improved tolerance of modified methylaluminoxane

Info

Publication number: WO2000006614A1
Application number: PCT/US1999/017119
Authority: WO
Inventors: Eric Paul Wasserman; Elizabeth Clair Fox; Xinlai Bai
Original assignee: Union Carbide Chemicals & Plastics Technology Corporation
Priority date: 1998-07-29
Filing date: 1999-07-28
Publication date: 2000-02-10
Also published as: BR9912456A; EP1102795A1; CA2338767A1; AU5239099A; KR20010071048A; JP2002521533A; PL345752A1; CN1419570A

Abstract

There is provided a catalyst containing a transition metal precursor having the formula (C5R15)TiY3, (wherein each y is independently selected from the group consisting of a C1-C20 alkoxide, a C1-C20 amide, a C1-C20 carboxylate and a C1-C20 carbomate) an alcohol or carboxylic acid, an aluminoxane, and optionally a substituted bulky phenol and/or a support or spray drying material. There is also provided a polymerization process employing the catalyst composition, a polymer produced using the catalyst, and a cable produced therefrom.

Description

UNBRIDGED MONOCYCLOPENTADIENYL METAL COMPLEX CATALYST HAVING IMPROVED TOLERANCE OF MODIFIED

METHYLALUMINOXANE

Field of the Invention

The invention relates to a catalyst composition for olefin polymerization and a process for polymerizing polyolefins, especially copolymers of ethylene-alpha olefins, ethylene-alpha olefin-dienes, and polypropylene using a metallocene catalyst. More particularly, the invention concerns the polymerization of polyolefins having less than 50% crystallinity using a metallocene catalyst containing a transition metal and an aluminoxane.

Background of the Invention

There has been a growing interest in the use of metallocenes for poly olefin production. Many metallocenes for poly olefin production are difficult and time-consuming to prepare, require large amounts of alumoxane, and exhibit poor reactivity toward higher olefins, especially for making ethylene-alpha olefin copolymers and ethylene- alpha olefin-diene terpolymers. Moreover, the ethylene-alpha olefin copolymers and ethylene-alpha olefin-diene terpolymers prepared using these metallocenes often have undesirably low molecular weights (i.e., Mw less that 50,000).

The so-called "constrained geometry" catalysts such as those disclosed in EP 0 420 436 and EP 0 416 815 can provide a high comonomer response and a high molecular weight copolymer, but are difficult to prepare and purify, and, therefore, are expensive. Another drawback of the bridged amido-cyclopentadienyl titanium catalyst system is that in order to form an active oxide-supported catalyst, it is necessary to use fairly high levels of alumoxane (see, e.g., WO96/16092) or to employ mixtures of aluminum alkyl and an activator based on derivatives of tris(pentafluorophenyl)borane (see, e.g., WO95/07942), itself an expensive reagent, thus raising the cost of running the catalyst. In the constrained geometry catalyst art, such as in EP 0 416 815 A2 (page 2, lines 5-9 and 43-51), it is pointed out that the angle formed by the cyclopentadienyl centroid, transition metal, and amide nitrogen is critical to catalyst performance. Indeed, comparison of the published result using a bridged amido- cyclopentadienyl titanium systems with similar unbridged systems has generally shown the unbridged analogs to be relatively inactive. One such system, described in U.S. Patent No. 5,625,016, shows very low activity, while having some of the desirable copolymerization behavior.

In Idemitsu Kosan JPO 8/231622, it is reported that the active catalyst may be formed starting from (C5Me5)Ti(OMe)3 and that the polymer formed has a relatively wide or broad compositional distribution. The present invention does not utilize this precursor.

Typically, polyolefins such as EPRs and EPDMs are produced commercially using vanadium catalysts. In contrast to other polyolefins produced using vanadium catalysts, those produced by the catalysts of the present invention have high molecular weight and narrower composition distribution (i.e., lower crystallinity at an equivalent alpha olefin content.

There is an on-going need to provide a catalyst employing a metallocene which is easy to prepare, does not require large amounts of aluminoxane and which readily copolymerizes to produce ethylene- alpha olefin copolymers, ethylene-alpha olefin-diene terpolymers, and polypropylene, as well as producing polyethylene. SUMMARY OF THE INVENTION

In contrast to the constrained geometry catalysts, the catalyst of the invention is unconstrained or unbridged and relatively easily and inexpensively prepared using commercially available starting materials. Further, the level of aluminoxane utilized can be lowered. That is, in the present invention, the precursor can be dried onto a support or dried with a spray drying material with Al:Ti ratios below 100:1 to form highly active catalysts with similar polymerization behavior to their unsupported analogs of the invention and polymerization behavior similar to constrained catalysts. Further, the catalyst of the present invention described herein has improved reactivity with methylaluminoxane (MMAO) which contains higher alkyl groups. This enables replacement of some or all of the toluene employed in the polymerization environment with light aliphatic hydrocarbons, since MMAO, unlike aluminoxane (MAO), is soluble in non-aromatic solvents. Use of aliphatic hydrocarbons such as isopentane is often preferred to toluene because of the greater ease of purging it from the polymer after it leaves the reactor and also because of the adverse health concerns associated with aromatic solvents in general.

Accordingly, the present invention provides a catalyst comprising:

(A) a transition metal compound having the formula: (C5Rl-5)TiY3, wherein each Rl substituent is independently selected from the group consisting of hydrogen, a C^-C alkyl, an aryl, and a heteroatom-substituted aryl or alkyl, with the proviso that no more than three Rl substituents are hydrogen; and wherein two or more R^ substituents may be linked together forming a ring; and each Y is independently selected from the group consisting of a C1-C20 alkoxide,

a C1-C20 amide, a C1-C20 carboxylate, and a C1-C20 carbamate;

(B) a compound having the formula: R²OH or R³COOH

wherein each R² or R is a C^-Cs alkyl; and

(C) an aluminoxane.

Optionally, the catalyst can additionally contain (D) a bulky phenol compound having the formula: (CgR^OH, wherein each R4 group is independently selected from the group consisting of hydrogen, halide, a C^-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl, wherein two or more R^ groups may be linked together forming a ring, and in which at least one R^ is represented by a C3-C12 linear or branched alkyl located at either or both the 2 and 6 position (i.e., the ortho positions relative to the OH group being in position 1) of the bulky phenol compound.

There is also provided a polymerization process employing the catalyst composition and a polymer produced using the catalyst. A cable composition is also provided.

Detailed Description of the Invention

Catalyst. The catalyst contains a transition metal (titanium) precursor (Component A), an alcohol or carboxylic acid (Component B), an aluminoxane (Component C), and optionally a substituted bulky phenol (Component D),. The catalyst of the invention can be unsupported (that is, in liquid form), supported, spray dried, or used as a prepolymer. Support and/or spray drying material is described as optional Component E.

Component A (A) a transition metal compound having the formula:

wherein each Rl substituent is independently selected from the group consisting of hydrogen, a C^-Cg alkyl, an aryl, and a heteroatom-substituted aryl or alkyl, with the proviso that no more than three R-*- substituents are hydrogen; and wherein two or more Rl substituents may be linked together forming a ring; and each

Y is independently selected from the group consisting of a C1-C20

alkoxide, a C1-C20 amide, a C1-C20 carboxylate, and a C1-C20 carbamate. Illustrative compounds can include: cyclopentadienyltitanium tribenzoate; cyclopentadienyltitanium tris(diethycarbamate); cyclopentadienyltitanium tris(di-tert- butylamide); cyclopentadienyltitanium triphenoxide; pentamethylcyclopentadienyltitanium tribenzoate; pentamethylcyclopentadienyltitanium tri-pivalate; pentamethylcyclopentadienyltitanium triacetate; pentamethylcyclopentadienyltitanium tris(diethycarbamate); pentamethylcyclopentadienyltitanium tris(di-tert-butylamide); pentamethylcyclopentadienyltitanium triphenoxide; 1,3- bis(trimethylsilyl)cyclopentadienyltitanium tribenzoate; tetramethylcyclopentadienyltitanium tribenzoate; fluorenyltitanium trichloride; 4,5,6,7-tetrahydroindenyltitanium tribenzoate; 4,5,6,7- tetrahydroindenyltitanium tripivalate; 1,2,3,4,5,6,7,8-octahydro- fluorenyltitanium tribenzoate; 1,2,3,4,5,6,7,8-octahydro- fluorenyltitanium tris(diethylcarbamate); 1,2,3,4-tetrahydrofluorenyl- titanium tribenzoate; 1,2,3,4-tetrahydrofluorenyl-titanium tris(di-tert butylamide); 1,2,3-trimethylcyclopentadienyltitanium tributyrate; 1,2,4-trimethylcyclopentadienyltitanium tribenzoate; 1,2,4- trimethylcyclopentadienyltitanium triacetate; l-τz-butyl-3- methylcyclopentadienyltitanium tribenzoate; l-rc-butyl-3- methylcyclopentadienyltitanium tripivalate; methylindenyltitanium tripropionate; 2-methylindenyltitanium tribenzoate; 2- methylindenyltitanium tris(di-n--butylcarbamate); 2- methylindenyltitanium triphenoxide; and 4,5,6,7-tetrahydro-2- methylindenyltitanium tribenzoate. In the pre-cursor, a heteroatom is an atom other than carbon (e.g, oxygen, nitrogen, sulfur and so forth) in the ring of the heterocyclic moiety.

Component B is an alcohol having the formula: R²OH or

R³COOH, wherein each R² or R³ is a Ci-Cg alkyl. Illustrative R²OH compounds in which R² is alkyl can include, for example, methanol, ethanol, propanol, butanol (including n- and t- butanol), pentanol, hexanol, heptanol, octanol. Preferably, R² is a methyl group.

Illustrative of R COOH compounds are acetic acid, propionic acid, benzoic acid, and pivalic acid. Preferred among these are benzoic and pivalic acid.

Component C is a cocatalyst capable of activating the catalyst precursor is employed as Component D. Preferably, the activating cocatalyst is a linear or cyclic oligomeric poly(hydrocarbylaluminum oxide) which contain repeating units of the general formula -(Al(R*)O)-, where R* is hydrogen, an alkyl radical containing from 1 to about 12 carbon atoms, or an aryl radical such as a substituted or unsubstituted phenyl or naphthyl group. More preferably, the activating cocatalyst is an aluminoxane such as methylaluminoxane (MAO) or modified methylaluminoxane (MMAO).

Aluminoxanes are well known in the art and comprise oligomeric linear alkyl aluminoxanes represented by the formula:

and oligomeric cyclic alkyl aluminoxanes of the formula:

wherein s is 1-40, preferably 10-20; p_ is 3-40, preferably 3-20; and R*** is an alkyl group containing 1 to 12 carbon atoms, preferably methyl.

Aluminoxanes may be prepared in a variety of ways. Generally, a mixture of linear and cyclic aluminoxanes is obtained in the preparation of aluminoxanes from, for example, trimethylaluminum and water. For example, an aluminum alkyl may be treated with water in the form of a moist solvent. Alternatively, an aluminum alkyl, such as trimethylaluminum, may be contacted with a hydrated salt, such as hydrated ferrous sulfate. The latter method comprises treating a dilute solution of trimethylaluminum in, for example, toluene with a suspension of ferrous sulfate heptahydrate. It is also possible to form methylaluminoxanes by the reaction of a tetraalkyl- dialuminoxane containing C2 or higher alkyl groups with an amount of trimethylaluminum that is less than a stoichiometric excess. The synthesis of methylaluminoxanes may also be achieved by the reaction of a trialkyl aluminum compound or a tetraalkyldialuminoxane containing C2 or higher alkyl groups with water to form a polyalkyl aluminoxane, which is then reacted with trimethylaluminum. Further, modified methylaluminoxanes, which contain both methyl groups and higher alkyl groups, i.e., isobutyl groups, may be synthesized by the reaction of a polyalkyl aluminoxane containing C2 or higher alkyl groups with trimethylaluminum and then with water as disclosed in, for example, U.S. Patent No. 5,041,584.

The mole ratio of aluminum atoms contained in the poly(hydrocarbylaluminum oxide) to total metal atoms contained in the catalyst precursor is generally in the range of from about 2:1 to about 100,000:1, preferably in the range of from about 10:1 to about 10,000:1, and most preferably in the range of from about 50:1 to about 2,000:1.

Preferably, Component C is an alumoxane of the formula

(AlR⁵O)m(AlR⁶O)n in which R⁵ is a methyl group, R⁶ is a Ci-C alkyl, m ranges from 3 to 50; and n ranges from 1 to 20. Most preferably, R" is a methyl group.

Component D is optional and is a bulky phenol compound having the formula: (CgR^5)OH, wherein each R^ group is independently selected from the group consisting of hydrogen, halide, a C^-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl, wherein two or more R^ groups may be linked together forming a ring, and in which at least one R^** is represented by a C3-C12 linear or branched alkyl located at either or both the 2 and 6 position (i.e., the ortho positions relative to the OH group being in position 1) of the bulky phenol compound;. In the formula, preferably none of the R¹* groups is a methoxy group. Preferably, suitable R^ groups can include, for example, t-butyl, isopropyl, n-hexyl and mixtures thereof. Component E. Preferably, the catalyst of the invention is unsupported. However, optionally, one or more of the above-described catalyst components may be impregnated in or deposited on a support, or alternatively spray dried with a support material. These support or spray drying materials are typically solid materials which are inert with respect to the other catalyst components and/or reactants employed in the polymerization process. Suitable support or spray drying materials can include silica, carbon black, polyethylene, polycarbonate, porous crosslinked polystyrene, porous crosslinked polypropylene, alumina, thoria, titania, zirconia, magnesium halide (e.g., magnesium dichloride), and mixtures thereof. Preferred among these support materials are silica, alumina, carbon black, and mixtures thereof. These are composed of porous particulate supports that usually have been calcined at a temperature sufficient to remove substantially all physically bound water.

The molar ratio of Component B to Component A ranges from about 2:1 to 200:1; preferably about 2:1 to 50:1; and, most preferably, is about 2:1 to 20:1. The molar ratio of Component D to Component A ranges from about 5:1 to 1000:1; preferably about 10:1 to 300:1; and, most preferably is about 30:1 to 200:1. The molar ratio of Component C to Component A ranges from about 10:1 to 10,000:1, preferably about 30:1 to 2,000:1, and most preferably, is about 50:1 to 1000:1, with the provisos that (1) the ratio of Component B to Component C does not exceed 0.7:1, and is preferably between 0.001:1 to 0.050:1; and (2) the ratio of Component D to Component C does not exceed 1:1, and is preferably below 0.7:1. When Component E is employed as a support or spray drying material, it is employed in an amount ranging from about 7 to 200 g/mmol, preferably 12 to 100 g/mmol, and most preferably 20 to 70 g/mmol (grams of Component E per millimole Component A). Process for Making the Catalyst. The individual catalyst components (Components A, B, C, and optionally D and E) can be combined in any order prior to polymerization. Alternatively, the individual catalyst components can be fed to the polymerization reactor such that the catalyst is formed in-situ.

Preferably, the active catalyst is prepared as follows. In Step 1, Components A and B are mixed in an inert hydrocarbon solvent suitable for dissolving Components A through C, and optionally also D, under an inert atmosphere (e.g., nitrogen) for at least 15 minutes or longer (e.g., up to 3 days). The components are combined such that Component A is mixed with at least three molar equivalents of Component B. Typical inert solvents can include, for example, toluene, xylene, chlorobenzene, etc. Preferred among these solvents is toluene.

In Step 2, Component C (or Component C and Component D, when employed) is mixed in one of the above-described inert hydrocarbon solvents, preferably the same solvent employed in Step 1, under an inert atomosphere (e.g., nitrogen and/or argon) for at least 15 minutes or longer (e.g., for up to 3 days). The ratio of aluminum (in the aluminoxane, Component C) to phenol of the bulky phenol compound (Component D) ranges from 1.4:1 to 1000:1; preferably 3:1 to 100:1; most preferably 3:1 to 10:1.

Optionally, the support or spray drying material (Component E) can be added to any of the above-described solutions, mixtures, and/or slurries. When Component E is employed the mixing should take place for about 30 minutes or more and the ratio of aluminum to support material is in the range of about 0.5 to 10 mmo /g., preferably, 2 to 5 mmol./g.

In Step 3, the mixture of Components A and B is combined with the mixture of Components C (or Components C and D, when D is employed) (and optional E) in such proportion that the molar ratio of aluminum to transition metal is about 5 to 5000, preferably 30 to 1000, and the molar ratio of Component B to aluminum is less than 0.5. The mixture is stirred for at least about 5 minutes. The mixture can be used as a liquid for direct injection into the polymerization reactor, or, if Component E is present, may be dried in vacuo to a free-flowing powder or spray-dried in an inert atmosphere. If Component E is not present, the catalyst is then fed to the reactor in liquid form. If Component E is present and the catalyst is in solid form, it may be introduced into the reactor by a variety of methods known to those skilled in the art such as by inert gas conveyance or by injection of a mineral oil slurry of the catalyst.

While not wishing to be bound by any theory, it is believed that the function of the two protic reagents (Components B and C) is to prevent the degradation of the cationic titanium (IV) active site. It is known that the aluminum trialkyl (A1R3) compounds will rapidly reduce the oxidation state of titanium from +4 to +3. However, it is usually advantageous to have A1R3 or aluminoxanes present during polymerization to serve as scavengers of catalyst poisons which adhere to reactor surfaces or are introduced by reaction media such as monomers, inert gases, and (if appropriate) solvents. Therefore, the catalyst of the invention represents a solution to the titanium reduction problem which allows the presence of alkylaluminum species. It has been postulated that the first step in the activation of titanium by cocatalyst is alkylation, that is, the exchange of two or more titanium substituents with alkyl groups on aluminum atom(s). Then the reason the catalysts based on titanium carboxylates are more active than their trihalide analogs under certain polymerization conditions (notable for EPDM polymerization) is that the aluminum carboxylates which are immediately formed from the alkylation reaction of the tricarboxylates serve as bulky groups. It is believed that these bulky groups prevent a close interaction of the aluminum species with the alkylated titanium species, thus hindering the reduction and complexation reactions.

Polymerization Process and Conditions. The above-described catalyst composition can be used for the polymerization of monomers (e.g., olefins, diolefins, and/or vinyl aromatic compounds) in a suspension, solution, slurry, or gas phase process using known equipment and reaction conditions, and it is not limited to any specific type of reaction. However, the preferred polymerization process is a gas phase process employing a fluidized bed. The gas fluidized bed reactor can be assisted by mechanical stirring or agitation means. Gas phase processes employable in the present invention can include so-called "conventional" gas phase processes, "condensed-mode," and, most recent, "liquid-mode" processes.

In many processes, it is desirable to include a scavenger in the reactor to remove adventitious poisons such as water or oxygen before they can lower catalyst activity. In such cases, it is recommended that trialkylaluminum species (e.g., TIBA) not be used, but rather that methylalumoxane be employed for such purposes.

Conventional fluidized processes are disclosed, for example, in U.S. Patent Nos. 3,922,322; 4,035,560; 4,994,534, and 5,317,036.

Condensed mode polymerizations, including induced condensed mode, are taught, for example, in U.S. Patent Nos. 4,543,399; 4,588,790; 4,994,534; 5,317,036; 5,352,749; and 5,462,999. For polymerizations producing alpha olefin homopolymers and copolymers condensing mode operation is preferred.

Liquid mode or liquid monomer polymerization mode is described in U.S. Patent No. 4,453,471; U.S. Serial No. 510,375; and WO 96/04322 (PCT/US95/09826) and WO 96/04323 (PCT/US95/09827). In liquid mode or liquid monomer polymerizations the temperature in the polymerization zone of the reaction vessel is maintained below the dew point of at least one of the monomers employed. Fluidization is achieved by a high rate of fluid recycle to and through the bed, typically in the order of about 50 times the rate of feed of make-up fluid. The fluidized bed has the general appearance of a dense mass of individually moving particles as created by the percolation of gas through the bed.

For polymerizations such as ethylene-propylene copolymer (e.g., EPMs), ethylene-propylene-diene terpolymer (e.g., EPDMs), and diolefin (e.g., butadiene, isoprene) polymerizations, it is preferable to use liquid mode and to employ an inert particulate material, a so- called fluidization aid. Inert particulate materials are described, for example, in U.S. Patent No. 4,994,534 and include carbon black, silica, clay, talc, and mixtures thereof. Of these, carbon black, silica, and mixtures of them are preferred. When employed as fluidization aids, these inert particulate materials are used in amounts ranging from about 0.3 to about 80% by weight, preferably about 5 to 50% based on the weight of the polymer produced. The use of inert particulate materials as fluidization aids in polymer polymerization produces a polymer having a core-shell configuration such as that disclosed in U.S. Patent No. 5,304,588. The catalyst of the invention in combination with one or more of these fluidization aids produces a resin particle comprising an outer shell having a mixture of a polymer and an inert particulate material, wherein the inert particulate material is present in the outer shell in an amount higher than 75% by weight based on the weight of the outer shell; and an inner core having a mixture of inert particulate material and polymer, wherein the polymer is present in the inner core in an amount higher than 90% by weight based on the weight of the inner core. In the case of sticky polymers, these resin particles are produced by a fluidized bed polymerization process at or above the softening point of the sticky polymer.

The polymerizations can be carried out in a single reactor or multiple reactors, typically two or more connected in series, can also be employed. The essential parts of the reactor are the vessel, the bed, the gas distribution plate, inlet and outlet piping, at least one compressor, at least one cycle gas cooler, and a product discharge system. In the vessel, above the bed, there is a velocity reduction zone, and in the bed a reaction zone.

Generally, all of the above modes of polymerizing are carried out in a gas phase fluidized bed containing a "seed bed" of polymer which is the same or different from the polymer being produced. Preferably, the bed is made up of the same granular resin that is to be produced in the reactor.

The bed is fluidized using a fluidizing gas comprising the monomer or monomers being polymerized, initial feed, make-up feed, cycle (recycle) gas, inert carrier gas (e.g., nitrogen, argon, or inert hydrocarbon such as methane, ethane, propane, isopentane) and, if desired, modifiers (e.g., hydrogen). Thus, during the course of a polymerization, the bed comprises formed polymer particles, growing polymer particles, catalyst particles, and optional flow aids (fluidization aids) fluidized by polymerizing and modifying gaseous components introduced at a flow rate or velocity sufficient to cause the particles to separate and act as a fluid.

In general, the polymerization conditions in the gas phase reactor are such that the temperature can range from sub-atomos- pheric to super- atmospheric, but is typically from about 0 to 120°C, preferably about 40 to 100°C, and most preferably about 40 to 80°C. Partial pressure will vary depending upon the particular monomer or monomers employed and the temperature of the polymerization, and it can range from about 1 to 300 psi (6.89 to 2,0067 kiloPascals), preferably 1 to 100 psi (6.89 to 689 kiloPascals). Condensation temperatures of the monomers such as butadiene, isoprene, styrene are well known. In general, it is preferred to operate at a partial pressure slightly above to slightly below (that is, for example, + 10°C for low boiling monomers) the dew point of the monomer.

Polymers Produced. Olefin polymers that may be produced according to the invention include, but are not limited to, ethylene homopolymers, homopolymers of linear or branched higher alpha-olefins containing 3 to about 20 carbon atoms, and interpolymers of ethylene and such higher alpha-olefins, with densities ranging from about 0.84 to about 0.96. Homopolymers and copolymers of propylene can also be produced by the inventive catalyst and process. Suitable higher alpha-olefins include, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4- methyl-1-pentene, 1-octene, and 3,5,5-trimethyl-l-hexene. Preferably, the olefin polymers according to the invention can also be based on or contain conjugated or non-conjugated dienes, such as linear, branched, or cyclic hydrocarbon dienes having from about 4 to about 20, preferably 4 to 12, carbon atoms. Preferred dienes include 1,4-pentadiene, 1,5-hexadiene, 5-vinyl-2- norbornene, 1,7-octadiene, 7-methyl-l,6-octadiene, vinyl cyclohexene, dicyclopentadiene, butadiene, isobutylene, isoprene, ethylidene norbornene and the like. Aromatic compounds having vinyl unsaturation such as styrene and substituted styrenes, and polar vinyl monomers such as acrylonitrile, maleic acid esters, vinyl acetate, acrylate esters, methacrylate esters, vinyl trialkyl silanes and the like may be polymerized according to the invention as well. Specific olefin polymers that may be made according to the invention include, for example, polyethylene, polypropylene, ethylene/propylene rubbers (EPR's), ethylene/pro- pylene/diene terpolymers (EPDM's), polybutadiene, polyisoprene, and the like.

The present invention provides a cost-effective catalyst and method for making compositionally homogeneous, high-molecular weight ethylene-alpha olefin copolymers with very high levels of alpha olefin. One advantage is that the catalyst has a very high comonomer response, so the ratio of alpha olefin to ethylene present in the reaction medium can be very low, which increases the partial pressure of ethylene possible in the reactor. This improves catalyst activity. It also lessens the level of residual comonomer which must be purged or otherwise recovered from the polymer after it exits the reactor. The catalyst is also suitable for incorporation of non-conjugated dienes to form completely amorphous rubbery or elastomeric compositions. The catalyst's very high comonomer response also makes it a good candidate for the incorporation of long-chain branching into the polymer architecture through the insertion of vinyl-ended polymer chains formed via β-hydride elimination. The ethylene copolymers produced by the present invention have polydespersity values (PDI) ranging from 2 to 4.6, preferably 2.6 to 4.2.

Polymers produced using the catalyst and/or process of the invention have utility in wire and cable applications, as well as in other articles such as molded and extruded articles such as hose, belting, roofing materials, tire components (tread, sidewall, inner-liner, carcass, belt). Polyolefins produced using the catalyst and/or process of the invention can be cross-linked, vulcanized or cured using techniques known to those skilled in the art.

In particular, there is provided by the invention a cable comprising one or more electrical conductors, each, or a core of electrical conductors, surrounded by an insulating composition comprising a polymer produced in a gas phase polymerization process using the catalyst of the invention. Preferably, the polymer is polyethylene; a copolymer of ethylene, one or more alpha-olfins having 3 to 12 carbon atoms, and, optionally, a diene(s).

Conventional additives, which can be introduced into the cable and/or polymer formulation, are exemplified by antioxidants, coupling agents, ultraviolet absorbers or stabilizers, antistatic agents, pigments, dyes, nucleating agents, reinforcing fillers or polymer additives, slip agents, plasticizers, processing aids, lubricants, viscosity control agents, tackifiers, anti-blocking agents, surfactants, extenders oils, metal deactivators, voltage stabilizers, flame retardant fillers and additives, crosslinking agents, boosters, and catalysts, and smoke suppressants. Fillers and additives can be added in amounts ranging from less than about 0.1 to more than about 200 parts by weight for each 100 parts by weight of the base resin, for example, polyethylene.

Examples of antioxidants are: hindered phenols such as tetrakis[methylene(3,5-di-tert- butyl-4-hydroxyhydrocinnamate)]- methane, bis[(beta-(3,5 di-tert-butyl-4-hydroxybenzyl)-methylcarb- oxyethyl)] sulphide, 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thio- bis(2-tert-butyl-5-methylphenol), 2,2'-thiobis(4-methyl-6-tert-butyl- phenol), and thiodiethylene bis(3,5 ditert-butyl-4-hydroxy)hydro- cinnamate; phosphites and phosphonites such as tris(2,4-di-tert-butyl- phenyl) phosphite and di-tert-butylphenyl-phosphonite; thio compounds such as dilaurylthiodipropionate, dimyristylthiodipropionate, and distearylthiodipropionate; various siloxanes; and various amines such as polymerized 2,2,4-trimethyl-l,2-dihyroquinoline. Antioxidants can be used in amounts of about 0.1 to about 5 parts by weight per 100 parts by weight of polyethylene. The resin can be crosslinked by adding a crosslinking agent to the composition or by making the resin hydrolyzable, which is accomplished by adding hydrolyzable groups such as -Si(OR)3 wherein R is a hydrocarbyl radical to the resin structure through copolymerization or grafting.

Suitable crosslinking agents are organic peroxides such as di- cumyl peroxide; 2,5-dimethyl- 2,5-di(t-butylperoxy) hexane; t-butyl cumyl peroxide; and 2,5-dimethyl-2,5-di(t-butylperoxy)hexane-3. Dicumyl peroxide is preferred.

Hydrolyzable groups can be added, for example, by copoly- merizing ethylene with an ethylenically unsaturated compound having one or more -Si(OR)3 groups such as vinyltrimethoxy- silane, vinyltri- ethoxysilane, and gamma-methacryloxypropyltrimethoxysilane or grafting these silane compounds to the resin in the presence of the aforementioned organic peroxides. The hydrolyzable resins are then crosslinked by moisture in the presence of a silanol condensation catalyst such as dibutyltin dilaurate, dioctyltin maleate, dibutyltin diacetate, stannous acetate, lead naphthenate, and zinc caprylate. Dibutyltin dilaurate is preferred.

Examples of hydrolyzable copolymers and hydrolyzable grafted copolymers are ethylene/ vinyltrimethoxy silane copolymer, ethy- lene/gamma- methacryloxypropyltrimethoxy silane copolymer, vinyltrimethoxy silane grafted ethylene/ethyl acrylate copolymer, vinyltrimethoxy silane grafted linear low density ethylene/1-butene copolymer, and vinyltrimethoxy silane grafted low density polyethylene.

The cable and/or polymer formulation can contain a polyethylene glycol (PEG) as taught in EP 0 735 545.

The cable of the invention can be prepared in various types of extruders, e.g., single or twin screw types. Compounding can be effected in the extruder or prior to extrusion in a conventional mixer such as Brabender_™ mixer or Banbury™ mixer. A description of a conventional extruder can be found in U.S. Patent No. 4,857,600. A typical extruder has a hopper at its upstream end and a die at its downstream end. The hopper feeds into a barrel, which contains a screw. At the downstream end, between the end of the screw and the die, is a screen pack and a breaker plate. The screw portion of the extruder is considered to be divided up into three sections, the feed section, the compression section, and the metering section, and two zones, the back heat zone and the front heat zone, the sections and zones running from upstream to downstream. In the alternative, there can be multiple heating zones (more than two) along the axis running from upstream to downstream. If it has more than one barrel, the barrels are connected in series. The length to diameter ratio of each barrel is in the range of about 15:1 to about 30:1. In wire coating, where the material is crosslinked after extrusion, the die of the crosshead feeds directly into a heating zone, and this zone can be maintained at a temperature in the range of about 130 C to about 260°C, and preferably in the range of about 170°C to about 220°C.

All references cited herein are incorporated by reference.

Whereas the scope of the invention is set forth in the appended claims, the following specific examples illustrate certain aspects of the present invention. The examples are set forth for illustration only and are not to be construed as limitations on the invention, except as set forth in the claims. All parts and percentages are by weight unless otherwise specified.

Examples Glossary and abbreviations: DSC: differential scanning calorimetry DTBP: 2 ,6-di-t-butylphenol ENB: 5-ethylidene-2-norbornene

FI: flow index, ASTM standard 121, in dg/ in

ICP: inductively coupled plasma method for elemental analysis

Irganox Irganox® 1076, a product of Ciba-Geigy

Kemamine Kemamine® AS-990, a product of Witco Corp.

MAO: methylalumoxane (Ethyl/Albemarle, solution in toluene, 1.8 or 3.6 moles Al L)

MMAO modified methylalumoxane (Akzo Nobel)

PDI: polydispersity index, or Mw/Mn

PRT: peak recrystallization temperature, or the exothermic peak of the cooling trace in a DSC experiment

SEC: size-exclusion chromatography method for molecular weight estimation

TIBA triisobutylaluminum, 0.87 mol/L in hexanes

Materials

Pentamethylcyclopentadienyltitanium trichloride and indenyl titanium trichloride were obtained from Strem Chemicals Inc., and used without further purification.

Examples 1 - 5.

These examples demonstrate the use of the catalyst of this invention to copolymerize ethylene and 1-hexene. In these examples, the toluene was dried first by holding over anhydrous MgSO4 for at least 7 days, followed by filtration through paper, sparging with nitrogen, storage over sodium/potassium alloy for at least 24 hours, and filtration through dried alumina. Thus dried, it was stored in a drybox under nitrogen.

Example 1.

Preparation of (C₅Me5)Ti(O₂CPh)3.

All manipulations were conducted under nitrogen atmosphere. A Schlenk flask was charged with stirbar, 25 mL dry toluene, and 2.01 g (C5Me5)TiCl3 (6.94 mmol). In a second flask were placed 3.37 g benzoic acid (27.6 mmol) and stirbar, and the solution of (C5Me5)TiCl3 was transferred thereto via cannula. To the resulting orange mixture were added 2.9 mL (20.7 mmol) triethylamine, and the solution was allowed to stir at ambient temperature for 3 hours and then was filtered. The solid was washed with toluene, leaving it colorless. The filtrate was reduced in υacuo to approx. 10 mL, and then was held at - 21°C for ca. 5 hours. The mixture was then filtered and washed with cold toluene, and briefly dried by nitrogen flowing through the filter cake, leaving 0.747 g orange-yellow solid. The ^H nmr spectrum revealed the presence of residual solvent and benzoic acid. The latter was estimated to be 0.83 molar equivalents per titanium atom. After subtracting out the contributions from benzoic acid, the major nmr peaks for the titanium complex are as follows (δ, solvent CD2CI2): (^H nmr) 7.97 (2H, d, J = 7.1 Hz), 7.52 (1H, m), 7.40 (2H, t, J = 7.5 Hz), 2.12 (15H, s); (¹³C {iH} nmr) 133.1, 129.2, 128.6, 11.8.

A toluene solution of (C5Me5)Ti(O2CPh)3 containing 0.83 eq. benzoic acid (0.025 g in 5 mL, 7.7 mmol Ti L) was prepared under nitrogen. A mixture was prepared composed of 1 mL above solution and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039 mmol MeOH, MeOH/Ti = 5.1) which was stirred for 40 min at room temperature. A 1.3 L stainless-steel reactor (Fluitron®), dried by flowing nitrogen while it was held at 100°C for at least 1 hour (h.), was cooled, then charged with 650 mL hexane, 40 mL 1-hexene, 0.69 mL MAO (1.8 mol/L in toluene, 1.24 mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182 mol L, 0.25 mmol, Al DTBP = 5.0). The reactor had a removable two-baffle insert and a variable speed propeller- shaped impeller, which was run at 800 rpm. The reactor was heated to 40°C and vented to release most of the nitrogen, then resealed. The reactor was heated to 70°C and pressurized with ethylene (100-120 psig, ca. 0.7-0.8 MPa). A sample of the (C5Me5)Ti(O2CPh)₃/MeOH mixture (0.33 mL, 1.92 x 10^~6 mol Ti) was injected into the reactor and the temperature allowed to rise to 85°C. The temperature was held between 80 and 85°C for the remainder of the test, during which time ethylene flowed to make up monomer lost to polymerization. At a time 30 min after the injection of the titanium complex, the reaction was quenched with methanol and the reactor vented. The polymer in hexane was recovered as a sticky mass which was broken up and dried in vacuo overnight at 40°C, yielding 45.6 g rubbery polymer, for a catalyst activity of 48 kg(PE)/mmol(Ti)^«h*100psiC2⁼. The polymer had MI = 0.09 and FI = 2.2. DSC of the copolymer showed melting points at 35.2, 65.9, and 115.9°C, with the last peak being about 3% as tall as the dominant peak (65.9°C) and a total crystallinity of 17.3%; the peak recrystallization temperature was found to be 52.9°C. SEC revealed M_w = 2.25 x 10⁵ and M_w/M_n = 2.88. By nmr, the copolymer contained 25.0 wt % 1-hexene.

Example 2.

A second crop of (C5Me5)Ti(O2CPh)3/benzoic acid was obtained by reducing in vacuo the mother liquor from which the precursor used in Example 1 was filtered, cooling and filtering as in Example 1, which yielded a bright yellow powder. The second crop, however, still contained benzoic acid (1.4 eq. per Ti).

A toluene solution of (C5Me5)Ti(O2CPh)3 containing 1.4 eq. benzoic acid (0.025 g in 5 mL, 7.0 mmol Ti/L) was prepared under nitrogen. A mixture was prepared composed of 1 mL above solution and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039 mmol MeOH, MeOH/Ti = 5.6) which was stirred for 90 min at room temperature. The autoclave reactor, dried by flowing nitrogen while it was held at 100°C for at least 1 h, was cooled, then charged with 650 mL hexane, 40 mL 1-hexene, 0.69 mL MAO (1.8 mol/L in toluene, 1.24 mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182 mol/L, 0.25 mmol, Al/DTBP = 5.0). The reactor was heated to 40°C and vented to release most of the nitrogen, then resealed. The reactor was heated to 70°C and pressurized with ethylene (100-120 psig, ca. 0.7- 0.8 MPa). A sample of the (C5Me5)Ti(O2CPh)3/MeOH mixture (0.33 mL, 1.75 x 10"6 mol Ti) was injected into the reactor and temperature allowed to rise to 85°C. The temperature was held between 80 and 85°C for the remainder of the test, during which time ethylene flowed to make up monomer lost to polymerization. At a time 30 min after the injection of the titanium complex, the reaction was quenched with methanol and the reactor vented. The polymer in hexane was recovered as a sticky mass which was broken up and dried in vacuo overnight at 40°C, yielding 46.3 g rubbery polymer, for a catalyst activity of 53 kg(PE)/mmol(Ti)^«h^«100psiC2⁼. The polymer had MI = 0.10 and FI = 2.7. DSC of the copolymer showed melting points at 35.8, 70.1, and 115.9°C, with the last peak being less than 10% as tall as the dominant peak (70.1°C) and a total crystallinity of 15.1%; the peak recrystallization temperature was found to be 41.6°C. SEC revealed M_w = 2.12 x 10⁵ and M_w/M_n = 2.75. By nmr, the copolymer contained 25.7 wt % 1-hexene. Example 3.

A toluene solution of (C5Me5)Ti(O2CPh)3 containing 1.4 eq. benzoic acid (0.025 g in 5 mL, 7.0 mmol Ti/L) was prepared under nitrogen. A mixture was prepared composed of 1 mL above solution and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039 mmol MeOH, MeOH/Ti = 5.6) which was stirred for 60 min at room temperature. The autoclave reactor, dried by flowing nitrogen while it was held at 100°C for at least 1 h, was cooled, then charged with 650 mL hexane, 40 mL 1-hexene, 0.72 mL MMAO (1.74 mol/L in heptane, 1.25 mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182 mol/L, 0.25 mmol, Al/DTBP = 5.0). The reactor was heated to 40°C and vented to release most of the nitrogen, then resealed. The reactor was heated to 70°C and pressurized with ethylene (100-120 psig, ca. 0.7-0.8 MPa). A sample of the (C5Me5)Ti(O2CPh)₃/MeOH mixture (0.33 mL, 1.75 x 10^~6 mol Ti) was injected into the reactor and the temperature allowed to rise to 80°C, where it was held for the remainder of the test, during which time ethylene flowed to make up monomer lost to polymerization. At a time 30 min after the injection of the titanium complex, the reaction was quenched with methanol and the reactor vented. The polymer in hexane was recovered as a viscous solution and dried in vacuo overnight at 40°C, yielding 19.2 g rubbery polymer, for a catalyst activity of 22 kg(PE)/mmol(Ti)^»h^»100psiC2=. The polymer had MI = 0.05 and FI = 1.24. DSC of the copolymer showed melting points at 34.6, 67.5, and 116.7°C, with the last peak being about 3% as tall as the dominant peak (67.5°C) and a total crystallinity of 14.8%; the peak recrystallization temperature was found to be 45.5°C. SEC revealed M_w = 2.63 x 10⁵ and M_w/M_n = 2.94. By nmr, the copolymer contained 25.4 wt % 1-hexene. Example 4.

Preparation of (C5Me₅)Ti(O2CCMe3)₃.

All manipulations were conducted under nitrogen atmosphere. A Schlenk flask was charged with stirbar, 25 mL dry toluene, and 2.0 g (C5Me5)TiCl3 (6.9 mmol). In a second flask were placed 2.11 g pivalic acid (20.7 mmol) and stirbar, and the solution of (C5Me5)TiCl3 was transferred thereto via cannula. To the resulting orange mixture were added 2.9 mL (20.7 mmol) triethylamine, and the solution was allowed to stir at ambient temperature for 3 hours and then was filtered. The solid was washed with toluene, leaving it colorless. The filtrate was reduced to an orange oil in vacuo which then crystallized, from which 2.86 g was obtained (85%). The nmr peaks for the titanium complex are as follows (δ, solvent CD₂Cl2): (¹H nmr) 1.94 (15H, s), 1.09 (27H, s); (13C {lH} nmr) 194.4, 130.3, 38.7, 26.5, 11.2.

A toluene solution of (C5Me5)Ti(O2CCMe3)3 (0.025 g in 5 mL, 10.3 mmol Ti/L) was prepared under nitrogen. A mixture was prepared composed of 1 mL above solution and 0.32 mL of a solution of methanol in toluene (0.123 mol/L, 0.039 mmol MeOH, MeOH/Ti = 3.8) which was stirred for 35 min at room temperature. The stainless-steel reactor, dried by flowing nitrogen while it was held at 100°C for at least 1 hour (h.), was cooled, then charged with 650 mL hexane, 40 mL 1-hexene, 0.69 mL MAO (1.8 mol/L in toluene, 1.24 mmol Al), and 1.4 mL of a solution of DTBP in toluene (0.182 mol/L, 0.25 mmol, Al/DTBP = 5.0). The reactor had a removable two-baffle insert and a variable speed propeller-shaped impeller, which was run at 800 rpm. The reactor was heated to 40°C and vented to release most of the nitrogen, then resealed. The reactor was heated to 75°C and pressurized with ethylene (100 psig, 0.7 MPa). A sample of the (C5Me₅)Ti(O₂CCMe3)3/MeOH mixture (0.33 mL, 2.5 x 10"6 mol Ti) was injected into the reactor and the temperature allowed to rise to 80°C, where it stayed for the remainder of the test, during which time ethylene flowed to make up monomer lost to polymerization. At a time 30 min after the injection of the titanium complex, the reaction was quenched with methanol and the reactor vented. The polymer in hexane was recovered as a sticky mass which was broken up and dried in vacuo overnight at 40°C, yielding 52.8 g rubbery polymer, for a catalyst activity of 42 kg(PE)/mmol(Ti)^»h^» 100psiC2⁼. The polymer had MI = 0.17 and FI = 4.4.

Example 5.

The polymerization described in Example 2 was repeated, except that in place of the DTBP, a 50 molar equivalents of benzoic acid (0.63 mL of a 0.2 mol/L solution in toluene) were mixed with the MAO prior to polymerization. After workup, 1.9 g polymer were obtained. DSC of the copolymer showed melting points at 34.6 and 65.9°C, and a total crystallinity of 15.1%; the peak recrystallization temperature was found to be 44.2°C. SEC revealed M_w = 3.27 x 10⁵ and M_w/M_n = 3.57. By nmr, the copolymer contained 24.1 wt % 1-hexene.

Examples 6 - 11.

These examples demonstrate the use of the catalyst of this invention to copolymerize ethylene, propylene, and ENB. In all these examples, the toluene was used as obtained (Aldrich Chemical Co., anhydrous, packaged under nitrogen).

Example 6.

In a glovebox under nitrogen, a small oven dried glass vial was charged with magnetic stirbar and 0.025 g (C5Me5)Ti(O2CPh)3 containing 0.83 eq. benzoic acid. This vial was sealed and brought out of the glovebox. Toluene (5 mL) was added to the vial to form a solution with a concentration of 7.7 mmol/L. In another oven dried glass vial sealed under nitrogen, 0.05 mL methanol (MeOH) was mixed with 10ml toluene resulting in a 0.123 mol/L concentration MeOH/toluene solution. In a third small oven dried glass vial, 2.06 g of DTBP and 20mL toluene were added under nitrogen to form a DTBP/toluene solution with concentration of 0.5 mol/L. A small oven dried glass vial with a stir bar was sealed under nitrogen. To this vial, 0.5 mL of (C5Me5)Ti(O2CPh)3/toluene solution (0.00385 mmol Ti) and 0.16 mL of MeOH/toluene solution were mixed at room temperature for 60 minutes (MeOH/Ti = 5.1). A 100 mL glass oven dried bottle with a stir bar was sealed with a septum and purged with nitrogen. To this bottle the following components were added under nitrogen: 50 mL of hexane; 1.43 mL MMAO (1.74 mol(Al)/L in heptane); 1.0 mL of DTBP/toluene solution; 0.66 mL of (C5Me5)Ti(O2CPh)3/MeOH mixture made above and 2 mL of ENB. In this bottle the final active catalyst was formed with ratios of DTBP/Ti = 130, MeOH/Ti = 5.1, MMAO/Ti = 650. The 1 L stainless-steel Fluitron reactor was baked for one hour at 100°C with nitrogen constantly flowing through it. It was then cooled to 40°C and charged with 500 mL hexane. The activated catalyst mixture made above was transferred to the reactor by nitrogen overpressure. The reactor was sealed and the temperature was brought to 60°C. Ethylene (C2⁼) and propylene (C3⁼) gases (C3⁼/C2⁼ fill ratio = 1:1) were charged to the reactor until the reactor pressure reached 90 psi (0.62 MPa). The ratio of the gases was then adjusted to C3⁼/C2⁼ = 0.33. The polymerization was carried out for 1 hour after the introduction of the monomer gases. Two charges of ENB (0.5 mL) were injected to the reactor under pressure at polymerization times of 10 min and 30 min. Therefore 3 mL total ENB was charged to the reactor. Polymerization was terminated by injecting 2 mL of ethanol killing solution (0.5 g BHT, 1.0 g Kemamine, 0.5 g Irganox in 125 mL of ethanol). The monomer gas flows were shut off and the reactor was vented and cooled to room temperature. The polymer was scooped out, blended in methanol and dried in a vacuum oven at 40°C overnight. The collected polymer weighed 12.0 g, for catalyst activity of 3.1 kg(EPDM)/mmol Ti/hr. The polymer had FI = 0.52 and a P.R.T of 10.8°C. This demonstrates that MMAO can be used as cocatalyst with (C5Me5)Ti(O2CPh)3 in EPDM polymerization

Example 7.

A similar experiment as Example 6 was carried out except that 2.86 mL of MMAO (1.74 mol/L) solution (MMAO/Ti = 1290) was used. After polymerization only 1.1 g of EPDM polymer was collected which shows much lower catalyst activity. This demonstrates that MMAO/ (C5Me5)Ti(O2CPh)3 ratio is important to EPDM polymerization activity.

Example 8.

A similar experiment as Example 6 was carried out except that 0.86 ml of MMAO (1.74 mol/L) solution (MMAO/Ti = 390) was used. After polymerization, 18.2 g of EPDM polymer was collected for better catalyst activity of 4.7 kg(EPDM)/mmolTi/h. The nmr analysis of the EPDM sample shows that it contains 31.8 wt% propylene and 3.4 wt% ENB, and a PRT of 1.1°C. This further demonstrates that MMAO/(C5Me₅)Ti(O₂CPh)3 ratio is important to EPDM polymerization activity.

Example 9.

In a glovebox under nitrogen, a small oven dried glass vial was charged with magnetic stirbar and 0.025 g (C5Me5)Ti(O2CPh)3 containing 0.83 eq. benzoic acid. This vial was sealed and brought out of the glovebox. Toluene (5 mL) was added to the vial to form a solution with a concentration of 7.7 mmol L. In another oven dried glass vial sealed under nitrogen, 0.05 mL methanol was mixed with 10 mL toluene resulting in a 0.123 mol/L concentration MeOH/toluene solution. In a third small oven dried glass vial, 2.06 g of 2,6-di-t- butylphenol (DTBP) and 20 mL toluene were added under nitrogen to form a DTBP/toluene solution with concentration of 0.5 mol/L.

A small oven dried glass vial with a stir bar was sealed under nitrogen. To this vial, 0.5 mL of (C5Me5)Ti(O2CPh)3/toluene solution (0.00385 mmol Ti) and 0.16 mL of MeOH/toluene solution were mixed at room temperature for 60 minutes (MeOH/Ti = 5.1).

A 100 mL glass oven dried bottle with a stir bar was sealed with a septum and purged with nitrogen. To this bottle the following components were added under nitrogen: 50ml of hexane; 0.30 mL MAO (3.36 mol/L in toluene); 1.0 mL of DTBP/toluene solution; 0.66 mL of (C5Me5)Ti(O2CPh)3/MeOH mixture made above and 2 mL of ENB. In this bottle the final active catalyst was formed with ratios of DTBP/Ti = 130, MeOH/Ti = 5.1, MAO/Ti = 260.

The IL stainless-steel Fluitron reactor was baked for one hour at 100°C with nitrogen constantly flowing through it. It was then cooled to 40°C and charged with 500 mL hexane. The activated catalyst mixture made above was transferred to the reactor by nitrogen over pressure. The reactor was sealed and the temperature was brought to 60°C. Ethylene (C2⁼) and propylene (C3⁼) gases (C2⁼/C3^~ fill ratio = 1:1) were charged to the reactor until the reactor pressure reached 90 psi (0.62 MPa). The ratio of the gases was then adjusted to C2⁼7C3⁼ = 0.33. The polymerization was carried out for 1 hour after the introduction of the monomer gases. ENB (0.5 mL) was injected to the reactor under pressure at polymerization time of 10 min and 30 min. Therefore 3 mL total ENB was charged to the reactor.

Polymerization was terminated by injecting 2 mL of ethanol killing solution (0.5 g BHT, 1.0 g Kemamine, 0.5 g Irganox in 125 mL of ethanol). The C2⁼ and C3⁼ gases were shut down and the reactor was vented and cooled to room temperature. The polymer was scooped out, blended in methanol and dried in a vacuum oven at 40°C overnight. The collected polymer weighed 59.7 g, for catalyst activity of 15.5 kg(EPDM)/mmol Ti/hr. The polymer had FI = 1.32 and a P.R.T of -26.2°C.

Example 10.

In a glove box under nitrogen, a small oven-dried glass vial was charged with magnetic stir bar and 0.024 g (C5Me5)Ti(O2CCMe3)3. This vial was sealed and brought out of the glove box. Toluene (5 mL) was added to the vial to form a solution with a concentration of 0.01 mol/L. In another oven-dried glass vial sealed under nitrogen, 0.05 L methanol was mixed with 10 mL toluene resulting in a 0.123 mol/L concentration MeOH/toluene solution. In a third small oven dried glass vial, 2.06 g of 2,6-di-t-butylphenol (DTBP) and 20 mL toluene were added under nitrogen to form a DTBP/toluene solution with concentration of 0.5 mol/L.

A small oven dried glass vial with a stir bar was sealed under nitrogen. To this vial, 0.5 mL of (C5Me5)Ti(O2CCMe3)3/toluene solution (0.005 mmol Ti) and 0.16 mL of MeOH/toluene solution were mixed at room temperature for 60 minutes (MeOH/Ti = 4).

A 100 mL glass oven-dried bottle with a stir bar was sealed with a septum and purged with nitrogen. To this bottle the following components were added under nitrogen: 50 mL of hexane; 0.30 L MAO (3.36 mol/L in toluene); 1.0 mL of DTBP/toluene solution; 0.66 mL of (C5Me5)Ti(O2CCMe3)3/MeOH mixture made above and 2 mL of ENB. In this bottle the final active catalyst was formed with ratios of DTBP/Ti = 100, MeOH/Ti = 4, MAO/Ti = 200.

The IL stainless-steel Fluitron reactor was baked for one hour at 100°C with nitrogen constantly flowing through it. It was then cooled to 40°C and charged with 500 mL hexane. The activated catalyst mixture made above was transferred to the reactor by nitrogen over pressure. The reactor was sealed and the temperature was brought to 60°C. Ethylene (C2⁼) and propylene (C3⁼) gases (C2⁼/C3= fill ratio = 1:1) were charged to the reactor until the reactor pressure reached 90 psi (0.62 MPa). The ratio of the gases was then adjusted to C2⁼/C3⁼ = 0.33. The polymerization was carried out for 1 hour after the introduction of the monomer gases. ENB (0.5 mL) was injected to the reactor under pressure at polymerization time of 10 min and 30 min. Therefore 3 mL total ENB was charged to the reactor.

Polymerization was terminated by injecting 2 mL of ethanol killing solution (0.5 g BHT, l.Og Kemamine, 0.5 g Irganox in 125 mL of ethanol). The C2⁼ and C3⁼ gases were shut down and the reactor was vented and cooled to room temperature. The polymer was scooped out, blended in methanol and dried in a vacuum oven at 40°C overnight. The collected polymer weighed 34.1 g, for catalyst activity of 6.82 kg(EPDM)/mmol Ti/hr. The polymer contained 51.2 wt % propylene and 4.5 wt % ENB. The polymer had FI = 1.6 and no PRT

Example 11.

An experiment similar to Example 10 was conducted except that 0.57 mL MMAO (1.74 mol(Al)/L in heptane) was used in place of MAO. The final active catalyst was formed with ratios of DTBP/Ti = 100, MeOH/Ti = 4, MMAO/Ti = 200. The collected polymer weighed 26.2 g, for catalyst activity of 5.24 kg(EPDM)/mmol Ti/hr. The polymer did not flow because of high molecular weight.

Comparative Example 1.

A similar experiment as Example 6 was carried out except that (C5Me5)TiCl3 precursor instead of (C5Me5)Ti(O2CPh)3 was used. After polymerization only 0.8 g of polymer was collected. This experiment shows that (C5Me5)TiCl3 is not active with MMAO cocatalyst for EPDM polymerization at a high aluminum: titanium ratio.

Comparative Example 2.

A similar experiment as Comparative Example 1 was carried out except that the aluminum:titanium molar ratio was only 200:1. After polymerization 44.5 g of polymer was collected for a catalyst activity of 8.90 kg(EPDM)/mmol Ti/hr. The polymer had FI = 0.44 and a PRT of -34.8°C.

Claims

What is claimed is:

1. A catalyst comprising:

(A) a transition metal compound having the formula: (C5Rl5)TiY3, wherein each Rl substituent is independently selected from the group consisting of hydrogen, a C -Cg alkyl, an aryl, and a heteroatom-substituted aryl or alkyl, with the proviso that no more than three Rl substituents are hydrogen; and wherein two or more Rl substituents may be linked together forming a ring; and each Y is independently selected from the group consisting of a C1-C20 alkoxide,

a C1-C20 amide, a C1-C20 carboxylate, and a C1-C20 carbamate;

(B) a compound having the formula: R²OH or R³COOH,

wherein each R² or R is a C^-Cg alkyl; and

(C) an aluminoxane.

2. The catalyst of Claim 1 wherein each Y is independently selected from the group consisting of a C1-C20 carboxylate and a Cl-

C20 carbamate.

3. The catalyst of Claim 1 which further comprises: (D) a bulky phenol compound having the formula: (C╬▓R^OH, wherein each R^ group is independently selected from the group consisting of hydrogen, halide, a C^-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl, wherein two or more R^ groups may be linked together forming a ring, and in which at least one R^ is represented by a C3-C12 linear or branched alkyl located at either or both the 2 and 6 position of the bulky phenol compound.

4. The catalyst of Claim 1 wherein a support or spray drying material is employed.

5. The catalyst of Claim 3 wherein the molar ratio of Component B to Component A ranges from about 2:1 to 200:1; the molar ratio of Component C to Component A ranges from about 5:1 to 1,000:1; the molar ratio of Component D to Component A ranges from about 10:1 to 10,000:1 with the proviso that the ratio of Component B to Component D does not exceed 1:1.

6. The catalyst of Claim 5 which further comprises as Component E a support or spray drying material in an amount ranging from about 7 to 200 g/mmol.

7. The catalyst of Claim 3 wherein each Rl substituent is a methyl group; R²OH is methanol; Y is selected from the group consisting of acetate, benzoate, pivalate, and mixtures thereof; R¹* is tert -butyl or isopropyl; and the aluminoxane is modified methylaluminoxane.

8. A process for the polymerization of at least one olefin which comprises contacting said olefin under polymerization conditions with a catalyst comprising:

(A) a transition metal compound having the formula: (C5Rl5)TiY3, wherein each Rl substituent is independently selected from the group consisting of hydrogen, a C^-Cg alkyl, an aryl, and a heteroatom-substituted aryl or alkyl, with the proviso that no more than three R substituents are hydrogen; and wherein two or more Rl substituents may be linked together forming a ring; and each Y is independently selected from the group consisting of a C1-C20 alkoxide,

a C1-C20 amide, a C1-C20 carboxylate, and a C1-C20 carbamate;

(B) a compound having the formula: R OH or R³COOH,

wherein each R² or R is a C^-Cg alkyl; and

(C) an aluminoxane.

9. The process of Claim 8 wherein each Y is independently selected from the group consisting of a C1-C20 carboxylate and a Cl-

C20 carbamate.

10. The process of Claim 8 wherein each Rl substituent is a methyl group; R²OH is methanol; Y is selected from the group consisting of acetate, benzoate, pivalate, and mixtures thereof; R^ is tert -butyl or isopropyl; and the aluminoxane is modified methylaluminoxane

11. The process of Claim 8 wherein the catalyst further comprises:

(D) a bulky phenol compound having the formula: (CgR^OH, wherein each R^ group is independently selected from the group consisting of hydrogen, halide, a C^-Cg alkyl, an aryl, a heteroatom substituted alkyl or aryl, wherein two or more R^ groups may be linked together forming a ring, and in which at least one R^ is represented by a C3-C12 linear or branched alkyl located at either or both the 2 and 6 position of the bulky phenol compound.

12. The process of Claim 8 wherein the catalyst additionally employs a support or spray drying material.

13. The process of Claim 8 wherein an inert particulate material is employed as a fluidization aid.

14. The process of Claim 8 wherein the polymer produced is selected from the group consisting of polyethylene, polypropylene, an ethylene-alpha olefin copolymer, an ethylene-alpha olefin-diene terpolymer, a propylene copolymer, and a polydiene.

15. A polymer produced using the catalyst of Claim 1.

16. A polymer produced using the catalyst of Claim 3.

17. A cable comprising one or more electrical conductors, each, or a core of electrical conductors, surrounded by an insulating composition comprising a polymer produced in a gas phase polymerization process using the catalyst of Claim 1.

18. A cable comprising one or more electrical conductors, each, or a core of electrical conductors, surrounded by an insulating composition comprising a polymer produced in a gas phase polymerization process using the catalyst of Claim 3.

19. The cable of Claim 17 wherein the polymer is selected from the group consisting of polyethylene; a copolymer of ethylene and one or more alpha-olfins having 3 to 12 carbon atoms; and a copolymer of ethylene, one or more alpha-olefins having 3 to 12 carbon atoms, and at least one diene.