CA2065302A1 - Alpha olefin copolmers having a narrow mwd and broad compositional distribution - Google Patents
Alpha olefin copolmers having a narrow mwd and broad compositional distributionInfo
- Publication number
- CA2065302A1 CA2065302A1 CA 2065302 CA2065302A CA2065302A1 CA 2065302 A1 CA2065302 A1 CA 2065302A1 CA 2065302 CA2065302 CA 2065302 CA 2065302 A CA2065302 A CA 2065302A CA 2065302 A1 CA2065302 A1 CA 2065302A1
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- CA
- Canada
- Prior art keywords
- polymer
- weight
- copolymer
- ethylene
- polymerization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
- C08F210/18—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers with non-conjugated dienes, e.g. EPT rubbers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
Abstract
The present invention is directed toward novel copolymers of ethylene and at least one other alpha-olefin mononer which copolymers have an intermolecular compositional distribution (CD), such that at least about 25 % by weight of the polymer differs from the mean ethylene content of the polymer by at least plus or minus 5 wt % ethylene and a relatively narrow molecular weight distribution (MWD) such that the weight average molecular weight (Mw) of the polymer divided by the number average molecular weight (Mn) by the polymer is not greater than about 5Ø The polymers of this invention, which are characterized by exceptional green strength and good processing properties, may be prepared using a catalyst system comprising: a) a vanadium compound with a valence of 3 or more; b) a triorgano aluminum compound; and c) a specific halogenated organic promoter used in catalytic amounts. The catalyst system allows for efficient polymerization of high quality polymer products and at generally higher polymerization temperatures of up to about 140 ·C to yield higher molecular weight polymer products which are essentially free of gel, and which possess excellent green strength and processability.
Description
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i~ IP~A/US 2 2 NOV l991 BACKGROUND OF_?HE INVENTION
1. Field of the Invention This invention is directed toward novel alpha olefin copol~mers having a narrow molecular weight distribution (MWD) and a broad compositional distribution (CD) , and a process for making same.
i~ IP~A/US 2 2 NOV l991 BACKGROUND OF_?HE INVENTION
1. Field of the Invention This invention is directed toward novel alpha olefin copol~mers having a narrow molecular weight distribution (MWD) and a broad compositional distribution (CD) , and a process for making same.
2. Descri~tion of_Related Art Ethylene-propylene copolymers, particularIy elastomer~, are important commercial products. Two basic type~ of elastomeric ethylene-propylene copolymers are commercially available. Ethylene-propylene copolymers (EPM) are saturated compounds requiring vulcanization with free radical generators such as organic peroxides. Ethylene-propylene terpolymers (EPD~) contain a small amount of non-conjugated diolefin, such as dicyclopentadiene, 1,4-hexadiene or ethylidene norbornene, which provides suf~icient unsatura~ion to permit vulcanization with sulfur~ Such polymers that include at least two monomers, i.e. EPM and EPDM, will hereinafter be collectively re~erred to as copolymers.
Thes~ elastomeric copolymers have outstanding resistance to weathering, good heat a~ing properties and the ability to be compounded with large quantities o~ ~illers and pla~ticizers resulting in low cost compounds whiah are particularly useful in automotive .
and industrial mechanical~goods applications. Typical -automotive uses àre tire sidewalls, inner tubes, radiator and heater hose, vacuum tubing, weather stripping and sponge doorseals and Viscosity Index V.I.) improvers for lubricating oil compositions.
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2 - Ip~/US 2 2 NO\1 193' Typical mechanical goods uses are for appliance, industrial and garden hoses, both molded and axtruded sponge parts, gaskets and seals and conveyor belt covers. These copolymers also find use in adhesives, appliance parts as in hoses and gaskets, wires and cable and plastics blending.
As can be seen from th~ above, based on their respective properties, elastomeric EPM and EPDM
copolymers find many and varied uses. It is known that the properties of such copol~mers which make them useful in a particular application are, in turn, determined by their composition and structure. For example, the ultimate properties o~ an EPM or EPDM
copolymer are determined by such factors as composition, compositional distribution, sequenc~
distribution, molecular weight, and molecular weight distribution (MWD).
The efficiency of peroxide curing depends on composition. As the ethylene level increases, it can be shown that the "chemical" cross-links per peroxide molecule increase. Ethylene content also influences the rheological and processing properties, because crystallinity can be introduced. The crystallinity present at very high ethylene contents may hinder proces~ibility and may make the cured product too "hard" at temperatures ~elow the crystalline melting point to be useful as a rubber.
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The properties of EPM and EPDM copolymers are a func~ion o~ the catalyst system and polymerization process used to produce them. Elastomeric olefin :
Copolymers may be produced at relatively low polymerization temperatures and pressures by means of . the so called Ziegler catalysts which comprise a , transition metal compound used in combination with a ; metal alkyl. Mor~ specifically, catalyst systems based `J~T,TUT~ S'l~.
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on a combina~ion of a vanadium compound, an aluminum alkyl or aluminum alkyl halide and, in some cases, a halogen-containing organic compound which serves as a polymerization promoter are known in the art.
For example, UtS. Patent 4/540~753 relates to ethylene copolymers with narrow molecular weight distribution (MWD) and a narrow intermolecular composition distribution (Inter-CD) . The catalyst system used in this refer~nc comprises a hydrocarbon-soluble vanadium compound having the formula:
VClX(O~)3-x and ~n organo-aluminum compound. In the polymerization process, the catalyst components are premixed in the premixing device and aged for 1-50 seconds. The inlet temperature of the reaction mixture is about -50 to 150 C.
As pointed out in the above mentioned U.S.
Patent 4,540,753, Inter-CD defines the compositional variation, in terms of ethylene content, among polymer chains. It is expressed as the mi~imum deviation (analogous to a standard deviation3 in terms of wei~ht percent ethylene from the averase ethylene composition for a given aopolymer sample needed to include a given weight percent of the total copolymer sample which is obtained by excluding equal weight fractions from both ends o~ ~he distribution. The deviation need not be symmetrical, When expressed as a single number for example 15% Inter-C~, it shall mean the larger of the positive or negative deviations. For example, for a Gaussian compositional distribution, 95.5% of the polym~r is within 20 wt.% ethylene o~ the mean if the standard deviation is 10%. The Inter-~D for 95O5 wt.%
of the polymer is 20 wt.% ethylene for such a sample.
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G.B. Patent 902,385 teaches a process of preparing a copolymer of ethylene and higher 1-olefin -that is essentially homogeneous as to its compfsition using a catalyst system based on VYn and ALR3 where Y
is alkoxide or acetyacetonate group, and n is 2 or 3, and R i5 a hydrocarbon radical. A mixture of carbon tetrachloride and an inert organic liquid solvent or carbon tetrachlorida alone is used as the solvent for the copolymerization reaction. Temperature is within the range of from OC to 125C, more preferably from 250C to 80~C. A molar ratio of Al/V is from 3 to 8.
U.S. Patent 3,000,866 teaches ethylene copolymers with about 20% ethylene units by weight and at least 25% alpha-olefin units by weight and about 0.5% to 10% of dicyclopentadiene units by weight. The catalyst system used in this disclosure is made by mixing vanadium tetrachloride or vanadium oxytrichIoride with (R)3Al or (R)2AlX. The polymerization is conducted by contacting ethylene and dicyclopentadiene in a solution of tetrachloro ethylene with the said catalyst system at temperatures between about 20C to lOO-C.
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GB Patent 1,005,282 relates to a catalyst syste~ such as vanadium or chromium acylacetonate, vanadyl diacylacetonate, and vanadyl alkyl orthovanadate and a halogen-free metal organic compound .:
such as aluminum trialkyl or aluminum alkenyl for the preparation o~ linear head-to-tail high molecular weight homopolymers of alpha-ole~in having the general formula R-CH=CH2 The polymerization is carried out in the presence of a halogenated hydrocarbon compound such as chloroform, methylene chloride or a mixture thereof.
The polymerization iB carried out at temperatures of from -80~C to +125~C.
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~ - 5 - IPEAIUS 22NOVl99l U.S. Patent 3,301,834 relates ~o a process for the polymerization of ethyl~n~ and for the copolymerization of ethylene with other ethylenically unsaturated hydrocarbons. The catalyst system comprising vanadium compounds (VOC13 or VC14) and organoaluminum compounds is ~ormed in the presence of a halogenated compound such as benzotrichloride. The ratio of halogenated compound to vanadium compound is preferably from 10l to 100:1. The molar ratio of V/Al generally is 1:3 to 1:30, but higher ratios up to 1:3000 are disclosed to be operable. The polymerization temperature range is from room temperature to about 150C.
U.S. Patent 3,349,064 also relates the same catalyst cystem as that defined in U.S. Patent 3,301,834 except that the halogenated promoter is a group of unsaturated carboxylic compounds containing at least 4 halogen atoms, at least 2 of which are attached to doubly bonded carbon atoms and at least 1 of which is attached to a singly bonded carbon atom alpha to the double bond (e.g., 2, 2, 3, 4, 5, 5-hexachlorocyclopentene) . The use o~ VC14, TEA and hexachlorocylocpentadiene is described in example 6 The molar ratio o~ promoter to vanadium compound is preferably from 10:1 to 100:1. The molar ratio of V/Al 3 to 1:30; 1:60 is disclosed to be operable.
U.S. Patent 3,4i~9,729 rela~es to a method of making EPDM polymar by using the catalyst system compri~ing R3~1 organo-aluminum compounds and vanadium compounds having ~ormula VOYnr toge~her with halogen-containing compounds such as hydrogen chloride, elemental chlorine, benzyl chloride, or t-butyl chloride. The temperature for the polymerization is -100 to 200'F. The molar ratio of organoaluminum compound to vanadium compound is in the range o~ 3/1 to 20/1~ The a~ount of active halogen-containing compound , .
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based on vanadium compound is 1 to 30 mols per mol of vanadium compound.
BE Patent 592,247 teaches a process for preparing copolymer of ethylene with alpha-olefins whose molecular weight depends on the amount of halogenated alXanes used. Triisobu~yl aluminum ([(CH3)2CH2]3Al), vanadium tetrachloride (VC14) and carbon tetrachloride (CC14) may be used as a catalyst system.
GB Patent 1,059,865 relates to the polymerization of ethylene, or ethylen~ togeth~r with one or more ole~in monomers. TE~, CC14, CHC13, an~
vanadium di-isopropyl salicylate are used as the catalys~ system.
The breadth of the intermolecular compositional distribution (CD) and molecular weight distribution (MWD) of polymers such as prepared by the above referenced disclosures are largely a function of the particular catalyst system employed to prepare the polymer. Such catalyst systems generally yield polymers with either narrow CD and narrow NWD or broad CD and broad NWD. Until the present invention, ethylene copolymers (EPN or EPDM) having a broad CD and at the same time a narrow ~WD are not believed to have been disclosed in the art. Such elastomers are especially useful in that they posse~s novel combinations of propertie~ 9uch as excellent green streng~h and processa~ility which lead~ to superior performance in a number of applications.
SUM~ARY OF q; HE INVENTION
The present invention is directed toward novel elastomeric copolymers of ethylene and at least . .
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~_ ~ 7 ~ IP~A/US 2 2 NOV 1991 ., one other alpha-olefin monomer which copolymers have an intermolecular compositional distribution (CD), as hereinafter defined, such that at least about 25% by weight of the polymer differs from the mean ethylene content of the polymer by at least plus or minus 5 wt %
e~hylene, and have a relatively narrow molecular weight distribution (MWD) such that the weight average molecular weight (Mw) of the polymer divided by the number average molecular weight ~Mn) of the polymer is not greater than about 5Ø
The copolymers of this invention which are characterized by exceptional green strength and good processing properties, may be prepared using a catalyst system comprising:
a) a vanadium compound with a valence of 3 or more;
b) a triorgano aluminum compound: and c) a specific halogenated organic promoter used in catalytic amounts.
The catalyst system allows for efficient polymerization of high quality polymer products and at generally higher polymerization temperatures of up to about 140C to yield higher molecular weight polymer products which ar~ essentially free of gel, and which .
possess excellent green strength and processability.
BRI~F DESCRIPTION OF THE DRAWING
Figure 1 is a graph showing pol~mer compositional dis~ribution based on mean polymer content of polymerized ethylene. : .
DET~ILED DESCRI~TION OF THE INVENTION
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~ - 8 ~ lP ~/Us 22NOVl991 The term intermolecular compositional distribution (CD) as used herein defines the compositional variation among polymer chains in terms of ethylene content as compared with the mean ethylene conten~ of the copolymer as a whole. The CD is expres~ed by first determining the mean ethylene content of the copolymer sample by a suitable test such as described in ASTM D-3900. Next, the copolymer sample is dissolved in solvent such as hexane and a number o~ ~ractions o~ differing composition are precipitated by ~ihe addition of incremental amounts o~
a liquid such as isopropanol in which the copolymer is insoluble. Generally, from about 4-6 fractions are precipitated in this way and the weight and ethylene content of each fraction are determined after removing the solvent. From the weight of each fraction and its ethylene content, a plot is prepared of weight percent composition vs. cumulative weight percent of polymer which is shown in Figure 1, and a smooth curve is drawn through the points. The ethylene composition corresponding to 50% by weight o~ the polymer is locat~d as shown by th~ construction in the figure, and horizontal lines A-B and C-D are drawn at 1 5 weight percent ekhylene from the mean composition. Vertical lines through points B and D are drawn to locate points Bo and Do respectively at the horizontal base axis, and i~ the cumulative percent of polymer represented by Bo ~inus Do is 75% or less, then the polymer falls within the scope o~ this invention. For example, with the data shown in Flgure l, the mean composition o~ the copolymer a~ a whole is 50 weight percent ethylene, Do is about 41 cumulative %, Bo is about 56 c~mulative %, and Bo minus ~O is therefore about 15%. Thus, with respect to a copolymer as represented in Figure 1, about 85% og the copolymer has an ethylene content which is greater by plu5 or minus 5% than the mean ethylene content of 50~ of the copolymer as a whole.
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This exemplifies a broad compositional distribution within the scope of this invention.
Molecular weight distribution (MWD~ is a measure of the range of molecular weights within a given copolymer sample. It is characterized as a ratio of weight average to number average molecular weight, i.e. Mw/Mn. MWD can be measured by gel permeation chromotography (GPC), for instance, using a waters 150 gel permeation chromatograph equipped with a Chromatix KM-6 on-line light scattering photometer. The system is used at 135C with 1,2~4 trichlorobenzene as mobile phase. Showdex (Showa-Denko America, Inc.) polystyrene gel columns ~02, 803 804 and 805 are used. This technique is discussed in "Liquid Chromatography of Polymers and Related ~aterials III", J. Cazes editor, Marcel Dekker, 1981, p. 207, which is incorporated herein by reference. No corrections for column spreading are employed; however, dat~ on generally accepted standards, e.g., National Bureau of Standards Polyethene 1484 and anionically produced hydrogenated polyisoprene~ (an alternating ethylene-propylene copolymer) demonstrate that such corrections on Mw/Mn or Nz/Mw are less than .05 unit. Mw/Mh is calculated from an elution time-molecular weight relationship wherea-~ M~/Mw is evaluated~using the light scattering photometer. ~ The numerical analyses can be performed using the commercially available computer so~tware GPC2, MOLWT2 available from LDC/Milton Roy-Riviera Beach, Florida. The low molecular weight cut off for the calculation is 1500-2000. ~
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The elastomeric polymer o~ this invention comprises ethylene-containing elastomerlc polymers that have been copolymerized with one or more higher alpha ole~ins and optionally a diene monomer. As applied to polymers of thi~ invention, the terms 'lelastomeric" or "elastomer" are defined to mean that when they are ~ .: . :.
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- 10 - 3PEAlUS 22NOV199t crosslinked, they are capable of recovering from large deformations quickly and forcibly. Free from diluents, the crosslinked polymers retract within one minute to less than 1.5 times their original lengths after being stretched at 18C-29C to twice their lengths and held for one minute before release.
.
Typically elastomers are "sub~tantially amorphous", and when that term is used to defin~ the ethylene containing elastomaric polymers o this invention, it is to be taken to mean having a degree of crystallinity less than 25~, pre~erably less than about 15%, and more preferably less than about 10% as measured by means known in the art. The three major known methods o~ determining crystallinity are based on specific volume, x-ray diffraction, and infrared sp~ctroscopy. Another well-established method, based on measurement of heat content as a function of temperature through the fusion range, is differential scanning calorimetry. It is known that these independent techniques lead to good experimental agreement.
Additionally, it i5 known in the art that the tendency of a particular combination o~ catalyst system and monomers to produce blocky, random, or alterna~-ing monom~r sequence distribution in the polymer can be characterized by the product of the reactivity ratios defined ~or the given monomers under the specific reaction conditions encountered. If this product is egual to 1.0~ th~ sequence distribution will be per~ectly random; the more the product is less than 1.0, the moxe the monomers will approach alternating sequence; and, the more the product is greater than 1.0, th~ more the monomers will tend to have a blocky sqquence distribution. Generally speaXing, the segments of a polymer which crystallize are linear segments which have a number of identical (both by , p ' .
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chemical make-up and stereo-specific orientation) units in a row. A combination of such segments are said to yield blocky polymer. If there is little or no such sequential order within the segments makinq up a polymer chain, that chain will be very unlikely to conform itself into the correct shape to ~it into the spatial ordPr of a crystal and will accordingly exhibit a low degree of crystallinity. The ethylene-containing elastomeric polymers of this invention, accordingly, have a reactivity ratio product less than 2.0, preferably l~ss than about 1.5, and more preferably less than about 1.25, and are substantially amorphous.
As alraady noted, copoly~er~ in accordance with the present invention are compri~ed o~ ethylene and at least one other copolymerizable alpha-olefin~
Such alpha-olefins include tho~e containing 3 to 18 carbon atoms, e.g., propylene, butene-1, pentene-l, hexene 1, etc. Alpha-ole~ins of 3 to 6 carbons are preferred due to economic considerations, and they are generally pre~ent in the copolymer within the range o~
about 10 to so percent by weight, more pxeferably from about 15 to about 70 percent by weight most preferably 20 to about 70 percent by wei~ht. The most preferred copolymers in accordance with the present invention are those comprised of ethylene and propylene or ethylene, propylene and a diene.
As i~ well known to those skilled in the art, copolymers of ethylene and higher alpha-ole~ins such as propylene often include othQr copolym~rizable monomers.
Typical of these other monomers may be non-con~ugated dienes such as the following non-limiting examples:
.
a straight chain acyclic dienes such as 1,4-hexadiene; 1,6-octadiene;
b branched chain acyclic dienes such as 5-me~hyl-l, 4-hexadiene; 3,7-dimethyl~
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`- ` IPEA/US 2 2 NOV 1991 6-octadiene; 3j7-dimethyl -1,7-octadiene and the mixed isomers of dihydro-myrcene and dihydroocinene:
c single ring alicyclic dienes such as:
1,4-cyclohexadiene: 1,5-cyclooctadiene;
and 1,5-cyclododecadiene;
d multi ring alicyclic fused and bridyed ring dienes such as: tetrahydroindene;
methyltetrahydroindene;
dicyclopentadiene; bicyclo-(2,2,1)-hepta2,5-diene: alkenyl, ~lkylidene, cycloalkenyl and cycloalkylidene norbornenes such as S-methylene-2-norbornene (MNB), 5-ethylidene-2-norbornene (ENB~, 5-propyl-2-norbornene, 5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl) -2- norborne~e: 5-cyclohexylidene 2-norbornene.
Of the non~conjugated dienes typically used I to prepare these copolymers, dienes containing at least I one of the double bonds in a strained ring are preferred. The~most preferred diene is 5-ethylidene 2-norbornene (ENB). The amount of diene (wt. basis) in I the copolymer may be ~rom about 0% to 20~ with 0% to i 15% being~preferred~ The most preferred range is 0% to 10%. Where the diene is present, it is generally present at a min~mum level of about 1 weight percent.
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As already noted, the most preferred copolymer in accordance with the present invention is ethylenepropylene or ethylene-propylene-diene. In e~ther event, the ~average ~ethylene content o~ the copolymer may be~as low as~abou~ 10% on a weight basis.
The preferred minimum is about ~5%. A more preferred minim~m is about 30%.~ The maximum ethylene con~ent may be about 90% on a weight basis. The preferrad maximum is about 85%, with the most preferred being about 80%.
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~ 13 ~ IP~/US 22NOVl991 A further unexpected characteristic of the copolymer of this invention is the broad compositional distribution of the optionally included non-conjugated diene. As is known in the art, copoly~er having typically narrow MWD will also be expected to have a narrow compositional distribution of non-conjugated diene. The copolymer of this invention containing non~
conjugated diene will thus exhibit a compositional distribution such that the diene content of at least about plus or minus 20% of the polymer differs from the mean value of incorporated non-conjugated diene by at least plus or minus 0.5 weight percent diene. A
typical curve representing this compositional distribution appears in the upper portion o~ Figure 1.
The molecular weight of copol~mer made in accordance with the prçsent invention can vary over a wide range. The preferred minimum is about lO,OoO
The most preferred minimum is about 20,000. The maximum weight average molecular weight may be as high as about 12,000,000~ The preferred maximum is about 1,000,000, with the most prefarred maximum being about 750,000.
Copolymers prepared in accordance with the present invention exhibit a broad CD with at least about 25% of the polymer differing from the mean ethylene content by ~ 5% e~hylene, and a relatively narrow molecular weight distribution within the range of from about 2 to 5, evaluated as described above.
Copolymers having the most.superior green strength and processing properties are those having a CD breadth ranging from about 40% to about 80% of the polymer differing from the mean ethylene content by + 5% and (MW/Mn) of ~rom greater than about 2.0 up to about 4.5.
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~ 14 ~ IPEA/uS 2 2 NOV1991 As indicated above, the novel copolymers o~
this invention are produced using a catalyst system comprising:
a) a hydrocarbon soluble, non-supported vanadium compound with a valence of three or more;
b) a triorgano aluminum compound: and c) a specific halogenated organic promoter used in catalytic amounts.
The vanadium component of the catalyst system may have the genera~ formulas ':
O
VXaYb or VXcYdr wherein X is halogen, preferably chlorine, and Y is an organic substituent selected from the group consisting of an alcoholate, carboxylate, ketonate or diketonate having up to 10 carbon atoms, a and b may range from O
to 3 with the proviso that the sum of a and b is 2 or 3, and c and d may range from O to 4 with the proviso that the sum of c and d is 3 or 4. Preferred vanadium compounds for the purposes of this invention include:
~OC13, 14, v- E O-C-R~3, and VO~OR)3/ ¦1 Vocl2(oR)i Cl V-CO C-R]2 wherein R is a hydrocarbon radical preferably having ~rom about l to 10 carbon atoms. R preferably represents ~an ~ aliphatic, alicycllc or aromatic hydrocarbon :radical ~such as ethyl (Et) , phenyl, isopropyl, butyl (Bu) , propyl, n-butyl, i-butyl, t~
butyl, hexyl, cyc}ohexyl, octyl, naphthyl and so forth.
Non limiting and illustrative examples of preferred iT~ SI~E~
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vanadium compounds are vanadyl tetrahalides and trihalides, ~lkoxy halides and alkoxides, such as VC14, VOC13, vocl2 (OEt), vOC12 (OBu), VO (OBu)3 and vo(oc2Hs)3 The most pref~rred vanadium compounds are the chlorinated compound~ such as VOC13, VC14 and vocl2(R) The triorgano aluminum component of the catalyst system has the ~ormula AlR3 wherein R is a hydrocarbon radical having one & to ten carbon atoms as defined above with respect to the vanadium compounds.
Examples of suitable R groups include methyl, ethyl, i-butyl, hexyl and phenyl. Preferred compounds are trialkyl aluminum compounds, including triethyl, tri isobutyl and tri n-hexyl aluminum. It is important for the purposes o~ this invention that the aluminum compound is free o~ halogen, i.e., that aluminum alkyl halides not be used. Catalytic activity is markedly reduced using these latter compounds.
The selection of the proper halogenated polymerization promoter is a key feature of the present invention. A certaln range of halogen substituent reactivity toward the catalyst is required to give the proper balance of ca~alyst activity and properties of the ~opolymer product. If the reactivity is too low, catalyst e~ficiency ls reduced, while if it is too high, undesirable side reac~ions occur which are deleterious to catalyst performance. Cooper (T.A
Cooper, Journ. ~n. C~m. Soc., 95, 4158 (1973), the di~alosure o~ which is incorpora~ed herein by reference, has de~ined in Table 1 an organic halide activity index based an the ability of the halide to oxidize VC12 (py)4 to V(III) under standard conditions.
For example, CCl~ is assigned a reactivity of l in tetrahydrofuran at 200-C.,`ànd other listed halogenated organic compounds have reactivitie5 of from about 0.02 to greater than 200 relative to CC14.
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~ 16 IPEA/US 2 2 NOV 1991 It has been found that organic halides as defined in the above referenced article with a Cooper Index ranging from about 0.01 up to about 30 are suitable promoters for the purposes o~ this invention.
Most preferred promoters meeting this criteria are selected ~rom the group consisting of carbon tetrachloride, hexachloroethylene, benzyl bromide, benzyl chloride and 2,3-or 1,3-dichloropropylene.
It is important that ~he vanadium component of the catalyst system is both not hydrocarbon insoluble and not supported on an inert or hydrocarbon insoluble support. Vanadium Catalyst systems that are hydrocarbon insoluble or deposited on inert supports are not typically useful for the preparation of elastomeric copolymers of ethylene according to the procedures o~ this invention.
The polymerization in accordance with this invention may be carried out either in ~olution or in suspension, but solution polymerization is preferred to avoid problems of reactor fouling. The process may be carried out as a batch process or a continuous process, although continuous flow stirred tank reactors are pre~erred, and at normal atmospheric pressure or under elevated or reduced pressures. The polymeri2ation may also be carried out u~ing a series o~ two or more conkinuou~ flow atirred tank reactors or equivalents thereof. Normally, pressures of 1-10 atmospher2s are pre~erred. The polymerization may be aarried out at temperatures in the range of about 60 to about 140~C, as well as the more common temperatures within the range o~ about 10 to 60 Q C. When the polymerization i5 conducted at the higher range o~ about 55C to 140 there is additional process advantage in that the energy requirements ~or both recovering the polymer from solution and cooling the reactor during CU8ST~TUTE S~EET
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poly~erization are reduced. Preferred polymerization temperatures for the purposes of this invention lie in the range of from about 40 to 120C, more pre~erably from about 55 to 100~C. Solvents used in the process include one or a mixture of hydrocarbons such as pentane, hexane, benzene, toluene, xylene, cyclo hexane and the like. Diluents useful for a suspension process are propane, butane or a mixture of the liquefied monomers use~ul in accordance with this invention.
PrePerably, but not necessarily, the solvent will al~o be a solvent for the vanadium catalyst compound. The po~lymerization reaction should be conducted in the absence of oxygen, carbon dioxide, water and other materials which have a deleterious effect on the catalyst activity.
The catalyst and halogenated promoter may be combined prior to contact with the monomers, or dilute solutions of these components may be introduced separately into the reactor. It is pre~erred ~or the purposes o~ this invention that the vanadium catalyst and alkyl aluminum are introduced separately into the reactor and allowed to react to form the active catalyst in the presence of the monomers, since catalyst activity may suffer if the catalyst components are prem~xed. Also, it is preferable not to premix the promoter and alkyl aluminum since undesirable side xeactions might occur.
. .
Polymer molecular weight may be controlled by the introduction of known chain trans~er agents such as hydrogen gas or diethyl zinc. In general, the quantity o~ chain trans~er agent in~roduced into the reactor ranges ~rom about 0.1 to about 100 moles per mole of vanadium catalyst. In some cases it may also be desirable to add known chain branching suppressors, including Lewis Bases such as NH3, pyridl~e and Si(oEt)4 to the reactor along with the catalyst ~'..
.;~,r-i3~^~
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~ ~<- 18 ~lp ~/~S 22NOV1991 components. The preferred molar ratio of such suppressors ranges from about 1:2 to 10:1 with respect to the quantity of the vanadium catalyst employed.
The average residence time o~ the reactants in the reactor generally ranges from about 5 minutes to about 2 hours or more.
Following polymeri2ation, the polymer product can be conventionally recovered from the effluent by coagulation with a nonsolvent such as isopropyl alcohol or ~-butyl alcohol, acetone, or the polymer can be recovered by stripping the solvent with heat or steam.
An antioxidant can be incorporated in the polymer during the recovery procedure, such as phenyl-beta-naphthylamine, di-tert-butylhydroquinone, triphenyl phosphite, heptylated diphenylamine, 2,2'-methylene-bis(4-methyl-6-tert-butyl)phenol, and 2,2,4-trimethyl-5-phenyl-1,2-dihydroquinoline.
The amount of the vanadium catalyst employed in the present invention is relatively low as compared ~I with prior art processes not employing a promoter. In qeneral, the amount of vanadium catalyst ranges from about 0.02 to about 0.5 millimoles per liter of solvent solution, with~ levels of from about 0.05 to about 0.5 millimoles being most preferred.
- For best catalytic per~ormance, tha molar amounts of vanadium catalyst and aluminum compound added to the reaction medium should provide a molar ratio of aluminum to vana~ium ~Al/V) o~ at least about 10 and not greater than about 250. Pre~erred such ratio~ rang~ from about 15 to 50. The amount of b ,halogenated~organic~promoter used with respect to the vanadium oompound may generally range in the promoter/V
molar ratio of ~etween about 5 to about 250. It is ; desirable that the promo~er/V ratio be not '. :
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9 IPEA/US 22NOVl991 substantially higher than the Al/V ratio, and preferred ratios range from about 5 to about 50.
This invention is further illustrated by the following examples. In Examples 1-14, polymerizations were conducted in a 1 liter volume continuous flow, stirred tank reactor. Feeds to the reactor were purified to remove water and other polar impurities that could act as catalyst poisons. Ethylene and propylene were metered through calibrated rotameters into a stream o~ hexane solvent which was pumped at a known rate with a metering pump. This mixture then entered a heat exchanger which lowered the temperature to about -20 to -10C to prechill the feed prior to reaction and to dissolve the monomers in the hexane.
The cold stream leaving the heat exchanger then entered the reactor. Catalyst, cocatalyst, promoter, and diene monomer were prepared as dilute solutions in hexane and each was pumped separately into the reactor via metering pumps. H2 was also added to the reactor to control polymer molecular weight, and in some cases NH3 was added to suppress any tendency for long chain branchlng. Temperature in the reactor was controlled by circulating water through a jacket. Iso-propyl alcohol was added to the polymer solution exiting the reactor to terminate poly~erization, and the solution was added to boilinq water to remove solvent and monomers. The wet polymer was then dried on a hot rubber mill to yield the final product. Polymerization rate was measured by determining the weight of polymer produced in a fixed perlod of time.
Polymer ethylene content was determined by ASTM D3900. ~Ethylidene norbornene content was measured by infrared based on the haight of the 1690 cm~1 band.
Mooney viscosity~ was determined by AS~M D1646. The compositional distribution (CD) and molecular weight , ,' .
: , .
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.
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~ - 20 - IPEA/U~; 2 2 Nav 199~ -distribution (MWD) of the polymer were determined as described above.
Specifically, the CD was determined by cutting a,sample of the finished copolymer into small pieces and adding the pieces to hexane to give a concentration of about lg/lOOcc. This mixture was then stirred gently at 22~C for 48 hours, or until equilibrium is reached. The mixture i5 then poured through a fine me~h stainless steel screen to recover any insolubLe polymer, which is dried, weighed and analyzed for composition. Isopropanol is then slowly added to the solution until precipitated polymer first appears. This polymer is recovered on a screen, dried, weighed and also analyzed for composition. Additional isopropanol is adde~ incrementally to the remaining solution to precipitate four to six fractions in total, all of which are recovered as described previously. The final isopropanol~hexane solution is then evaporated to dryness to yield a final polymer fraction. From the weight o~ each fraction and its ethylene and termonomer (i~ any~ composition, a plot is prepared of weight percent composition vs cumulative weight percent polymer as described above and as illustrated in Figure 1. ' Exam~le 1 A polymerization was c~nducted by the process de~crlbed ahove with a VC14- triethyl aluminu~ (TEA) catalyst system with CC14 as a promoter at a temperature of 75 C. NH3 was also added to the reactor at a NH3/V molar ratio of 1:1. Hexane feed rate was 2500 g/hr. All other polymerization conditions are given in rrable 1. The po~ymerization went smoothly giving high monomer conversion and high catalyst activity.
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Polymer fract}onation by the process described above gave the cumulative compositian curve shown in Figure 1. Polymer species were pr~sent that ranged from at least 65.5 wt~ ethylene to at least 35.5 : wt% ethylene. From this figure it can be determined that about 44% the polymer had an ethylene content 5%
hi~her than the mean of 5Q%, while about 41% of the ; polymer had an ethylene content 5% less than the mean.
Thus, the CD of this polymer is 85%. Mw/Mn for this polymer was 3Ø
Example 2 This example illustrates the use of the VOCl3/TEA
catalyst system with CC14 promoter at a polymerization temperature of 75C. NH3 was added to the reactor at NH3/V molar ratio of 1:1. Hexane flow rate was 2500 g/hr. As shown in Table l., catalyst activity was high and monomer conversions were good. About 65% of the polymer has an ethylene content +5% greater than th~
I . mean value. Mw/Mn for this pol~mer was 3.8.
¦ Example 3 I
Polymeriza~ion was attempted with a VOCl3/
diethylaluminum chloride ~DEAC) catalyst system at 75~C
accord~ng to the conditions in Table 1 with a hexane ~eed of 2500 g/hr. Very poor polymerization resulted giving large amount~ o~ insoluble polymer and low polymerizatlon rate~. The DEAC feed was replaced by an equal molar feed of TE~. Polymerization rates began to improv and the insoluble polymer disappeared. After allowing th~ reactor to reach steady stat~, high polymerization rat~ and good monomer conversion was measured as shown in Table 1.
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Exam~le 4 This run illustrates the use of benzyl chloride as a promoter with the VC14/TEA catalyst system. Benzyl chloride has a cooper reactivity index of .0S. An NH3jV molar ratio of 1:1 was used and the hexane flow rate was 2500 g/hr. The composition distributlon of the polymer was such that 64 wt% of the polymer has an ethylene content + 5~ greater than the mean value. Mw/Mn for the polymer is 3.1.
Example 5 (A.B.C.D~
This example illustrates the use of various promoters with the VOC13/TEA catalyst system at 75C
polymerization temperature. The hexane feed rate was 2500 g/hr and the other polymerization conditions are as shown in Table 1. The promoters used are indicated below:
Cooper Example Promoter Reactivitv Index 5A Benzyl bromide .1 5B 2,3 Dicholoropropylene .02 5C 1,3 Dichloropropylene .02 5D Hexachloroethylene 5 A~ shown by the results in Table l all of these promoters gave good catalyst activity and monomer conversion.
.
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~ 23 _ 3P ~/~S 22NOV~91 Comparative ExamPle 6 An attempt was made to conduct a -pol~merization with the VOC13-TEA catalyst system and benzoyl chloride as the ' '"
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PEA/US
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amounts of in~oluble polymer were produced and steady state operating data could not be obtained.
Comparative Example 7 ~A, B, C) In this example, trichlorotoluene was used as a promoter with the VOCl3-TEA catalyst system.
TrichlorotoIuene has a Coopex Index of 40.
Polymerization conditions and result~ are shown in Table 1. Hexane feed .rate was 2500 g/hr, In the copol~meri%ation runs, 7A and 7~, catalyst activity was very high. GPC analysis of the copolymer produced in run 7B indicated a broad, bimodal MWD, with a low MW
mode shifted to a Mn of 251 and a high MW mode with an Mn of 31,000. Mw/Mn ~or polymer 7B was 80.
Introduction of ENB into the polymerization in run 7C, which is at conditions otherwise similar to 7A, caused catalyst activity and monomer conversion to drop substantially re}ative. to 7A. GPC analysis of this polymer showed a single.broad peak and Mw/Mn was 8Ø
The compositional distribution for the polymer mode in Example 7C is broad with 37% of the polymer greater than.~ 5~ ethylene of the mean~
:
; ExamQle 8 fA.B.C,D~ ~
.
A series o~ terpolymerization runs were carried out with the VOCl3-triisobutyl aluminum (TIBA~ .
catalyst system at di~erent CCl4/V and Al/V ratios. A ..
NH3/V ratio o~ 1.0 wa~ usQd and the hexane ~eed rate was 2500 g/hr. As shown by the result in Table 2, catalyst` activity wa~ good over the entire range of conditions tested. ~ -: ~ . ...
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~26 - ~PEA/U~ 2 2 NOV 1991 ~ Example 9 Vanadium tris~hexanoate was prepared by reacting VC13 with kexanoic acid. A terpolymerization was carried out with this catalyst and TEA cocatalyst with CC14 as the promoter. Polymerization results are shown in Table 2. H~xane feed rate was 3030 g/hr and a NH3/V ratio of 0.65 was used. The compositional distribution was broad with 77% of the pol~mer greater than +5 wt% ethylene from the mean. Mw/Mn was 4.3.
Exam~le 10 (A.B.C) This run was made with varying levels of CC14 promoter and the VC14-TEA catalyst system. The hexane flow rate was 2~00 g/hr and the NH3/V ratio was 1.}. In examples lOA through lOC in Table 2, the CC14/V ratio was reduced from 20/1 to 1.67/1. ~s shown by the results in the Table, polymerization rates are reduced consid~rably when insufficient CC14 is present and Mw/Mn goes up as CC14/V is reduced. The compositional distributions for polymers lOB and lOC are broad. For polymer lOB, 90% of the polymer has a composition greater than +5 wt% ethylene from the mean, while for polymer lOC, 87% o~ the polymer differs from the mean by great2r than +5 wt~ ethylene.
. .":
~21~ , .'..
This run was made to demonstrate ¦polymerization with the VC14/trinormal hexyl aluminum catalyst sy~tem and CC14 promoter. Hexane ~eed rate was 3030 ~/hr. As shown by the results in Table 2, high cataly~t activity was obtained. The polymer had an Mw/~n value o~ 4.5 and the CD was broad with 79% of . ..
.
S~STIIUT~ SHEEl IPEAIU~:
f. - 27 - 22NOV1991 the polymer differing from the mean ethylene content by greater than 5 wt~ ethylene.
Example 12_ ~A.B.C.D~
.
This run was made to investigate the effect of NH3 on the polymerization with the VCl 4/TEA
catalyst system and CC14 as a promoter. Hexane ~eed rate was 2500 g/hr. In runs A through D, increasing amounts of NH3 were added to the reactor. After each change in NH3 feed, the reactor was allowed to reach steady state and a sample was tak2n to determine polymerization rate and polymex properties. As shown by the results in Table 2, NH3 has no effect on polymer composition or Mooney viscosity until a level of 13.6 :~:
mole/mole V was reached in run D at which point a decrease in catalyst activity occurred. Mw/Mn stayed constant at about 3.4 for this series of runs. 70% of the polymer differed from the mean ethylene content by .. .
at least +5 wt% ethylene in Run C, and 66% of the polymer differed from the mean ethylene content by at least i5 wt% ethylene in Run D. The lack of effect of NH3, a long chain branching suppressor, on Mooney viscosity or MW/Mn indioates that the catalyst system o~ this invention produces polymers with a low ranching lev~l. .
: , .
' ' Example 13 Vanadium chloride bis hexanoate was prepared by the reaction of VC13 with 2 moles of hexanoic acid.
A~polymerizat~ion was~carried out with this catalyst and ~EA coca~alyst with ~C14 as the promoter. As shown by the result~ in Table 2, catalyst activity was good.
The polymer had~an Mw/Mn of 4.0 and 72% of the polymer IJ' S I iT~JTE SHEE~
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`'`3 - 29 IP~ 22NOV1991 J
Example 14 (A,B.C) This run was made to investigate the effect of reaction temperature on ethylene-propylene copolymerization with the VOC13/TEA catalyst system and CC14 as promoter. Hexane feed rate was 2500g/hr.
Other reaction conditions are shown in Table 3. As indicated by the results in this Table, catalyst activity remains almost constant at polymerization temperatures from 65 to 97C.
; Example 15 fA,B,C) This run was made to investigate the effect of reaction temperature on ENB terpolymerization with VOC13/TEA catalyst and CC14 promoter. ~exane fPed rate was 2500 gjhr and other conditions are shown in Table ; 3. The results in Table 3 indicate that catalyst performance was una~fected by temperature over the i range o~ 55 to 75~C.
~ll Exam~ 16 (A.B~
. .
The polymerization procedure described in Example 15 was used except that the polymerization was carried out in two 7.6 liter volume stirred tank reactor~ connected in series. Cataly~t, solvent and mono~ers were fed to the first reactor, and the pr~duct stream entered the second raac~or to whlch additional monomers dissolved in hexane solvent were added~
Poly~erization~conditions are given in Table 3. The catalyst system was VC14jTEA with CCL4 as promoter.
Hexane ~eed to the two reaotors was 29.9 and 4.45 kg/hr respectively. Runs A and B are es~entially similar except that additional ethylene was fed to the second reactor in Example 16B.
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31 Lp~A/us 2 2 NOV l99~ -The results of the polymerization are also shown in Table 3. In this Table, the conversions, catalyst efficiency~ polymerization rate, and polymer composition shown for reactor 2 are the cumulative results for operating both reactors in series. As indicated by the data, series reactor operation gives increased catalyst efficiency and ethylene and propylene conversion.
Reasonable variations or modifications of this invention can be made or followed, in view of the foregoing, without d~parting from the spirit or scope thereof.
~I'.,S, ) ~ U','c SHE
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-: .
.
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Thes~ elastomeric copolymers have outstanding resistance to weathering, good heat a~ing properties and the ability to be compounded with large quantities o~ ~illers and pla~ticizers resulting in low cost compounds whiah are particularly useful in automotive .
and industrial mechanical~goods applications. Typical -automotive uses àre tire sidewalls, inner tubes, radiator and heater hose, vacuum tubing, weather stripping and sponge doorseals and Viscosity Index V.I.) improvers for lubricating oil compositions.
~SU~STI~UIE ~HEE~
IPEAIUS
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2 - Ip~/US 2 2 NO\1 193' Typical mechanical goods uses are for appliance, industrial and garden hoses, both molded and axtruded sponge parts, gaskets and seals and conveyor belt covers. These copolymers also find use in adhesives, appliance parts as in hoses and gaskets, wires and cable and plastics blending.
As can be seen from th~ above, based on their respective properties, elastomeric EPM and EPDM
copolymers find many and varied uses. It is known that the properties of such copol~mers which make them useful in a particular application are, in turn, determined by their composition and structure. For example, the ultimate properties o~ an EPM or EPDM
copolymer are determined by such factors as composition, compositional distribution, sequenc~
distribution, molecular weight, and molecular weight distribution (MWD).
The efficiency of peroxide curing depends on composition. As the ethylene level increases, it can be shown that the "chemical" cross-links per peroxide molecule increase. Ethylene content also influences the rheological and processing properties, because crystallinity can be introduced. The crystallinity present at very high ethylene contents may hinder proces~ibility and may make the cured product too "hard" at temperatures ~elow the crystalline melting point to be useful as a rubber.
: . .
The properties of EPM and EPDM copolymers are a func~ion o~ the catalyst system and polymerization process used to produce them. Elastomeric olefin :
Copolymers may be produced at relatively low polymerization temperatures and pressures by means of . the so called Ziegler catalysts which comprise a , transition metal compound used in combination with a ; metal alkyl. Mor~ specifically, catalyst systems based `J~T,TUT~ S'l~.
~? ~ ~P~A/US
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; ; - 3 ~ IP ~/~S 22NOVl991 .
on a combina~ion of a vanadium compound, an aluminum alkyl or aluminum alkyl halide and, in some cases, a halogen-containing organic compound which serves as a polymerization promoter are known in the art.
For example, UtS. Patent 4/540~753 relates to ethylene copolymers with narrow molecular weight distribution (MWD) and a narrow intermolecular composition distribution (Inter-CD) . The catalyst system used in this refer~nc comprises a hydrocarbon-soluble vanadium compound having the formula:
VClX(O~)3-x and ~n organo-aluminum compound. In the polymerization process, the catalyst components are premixed in the premixing device and aged for 1-50 seconds. The inlet temperature of the reaction mixture is about -50 to 150 C.
As pointed out in the above mentioned U.S.
Patent 4,540,753, Inter-CD defines the compositional variation, in terms of ethylene content, among polymer chains. It is expressed as the mi~imum deviation (analogous to a standard deviation3 in terms of wei~ht percent ethylene from the averase ethylene composition for a given aopolymer sample needed to include a given weight percent of the total copolymer sample which is obtained by excluding equal weight fractions from both ends o~ ~he distribution. The deviation need not be symmetrical, When expressed as a single number for example 15% Inter-C~, it shall mean the larger of the positive or negative deviations. For example, for a Gaussian compositional distribution, 95.5% of the polym~r is within 20 wt.% ethylene o~ the mean if the standard deviation is 10%. The Inter-~D for 95O5 wt.%
of the polymer is 20 wt.% ethylene for such a sample.
SU8STI~UTE SHE~
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G.B. Patent 902,385 teaches a process of preparing a copolymer of ethylene and higher 1-olefin -that is essentially homogeneous as to its compfsition using a catalyst system based on VYn and ALR3 where Y
is alkoxide or acetyacetonate group, and n is 2 or 3, and R i5 a hydrocarbon radical. A mixture of carbon tetrachloride and an inert organic liquid solvent or carbon tetrachlorida alone is used as the solvent for the copolymerization reaction. Temperature is within the range of from OC to 125C, more preferably from 250C to 80~C. A molar ratio of Al/V is from 3 to 8.
U.S. Patent 3,000,866 teaches ethylene copolymers with about 20% ethylene units by weight and at least 25% alpha-olefin units by weight and about 0.5% to 10% of dicyclopentadiene units by weight. The catalyst system used in this disclosure is made by mixing vanadium tetrachloride or vanadium oxytrichIoride with (R)3Al or (R)2AlX. The polymerization is conducted by contacting ethylene and dicyclopentadiene in a solution of tetrachloro ethylene with the said catalyst system at temperatures between about 20C to lOO-C.
: ' :
GB Patent 1,005,282 relates to a catalyst syste~ such as vanadium or chromium acylacetonate, vanadyl diacylacetonate, and vanadyl alkyl orthovanadate and a halogen-free metal organic compound .:
such as aluminum trialkyl or aluminum alkenyl for the preparation o~ linear head-to-tail high molecular weight homopolymers of alpha-ole~in having the general formula R-CH=CH2 The polymerization is carried out in the presence of a halogenated hydrocarbon compound such as chloroform, methylene chloride or a mixture thereof.
The polymerization iB carried out at temperatures of from -80~C to +125~C.
. . .
STITl~T~ SH~E~
~pF~ s .
.
` - . ~ - ~ . ^ - ~ . .
:~
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~c ~ /v s G ~ ~
~ - 5 - IPEAIUS 22NOVl99l U.S. Patent 3,301,834 relates ~o a process for the polymerization of ethyl~n~ and for the copolymerization of ethylene with other ethylenically unsaturated hydrocarbons. The catalyst system comprising vanadium compounds (VOC13 or VC14) and organoaluminum compounds is ~ormed in the presence of a halogenated compound such as benzotrichloride. The ratio of halogenated compound to vanadium compound is preferably from 10l to 100:1. The molar ratio of V/Al generally is 1:3 to 1:30, but higher ratios up to 1:3000 are disclosed to be operable. The polymerization temperature range is from room temperature to about 150C.
U.S. Patent 3,349,064 also relates the same catalyst cystem as that defined in U.S. Patent 3,301,834 except that the halogenated promoter is a group of unsaturated carboxylic compounds containing at least 4 halogen atoms, at least 2 of which are attached to doubly bonded carbon atoms and at least 1 of which is attached to a singly bonded carbon atom alpha to the double bond (e.g., 2, 2, 3, 4, 5, 5-hexachlorocyclopentene) . The use o~ VC14, TEA and hexachlorocylocpentadiene is described in example 6 The molar ratio o~ promoter to vanadium compound is preferably from 10:1 to 100:1. The molar ratio of V/Al 3 to 1:30; 1:60 is disclosed to be operable.
U.S. Patent 3,4i~9,729 rela~es to a method of making EPDM polymar by using the catalyst system compri~ing R3~1 organo-aluminum compounds and vanadium compounds having ~ormula VOYnr toge~her with halogen-containing compounds such as hydrogen chloride, elemental chlorine, benzyl chloride, or t-butyl chloride. The temperature for the polymerization is -100 to 200'F. The molar ratio of organoaluminum compound to vanadium compound is in the range o~ 3/1 to 20/1~ The a~ount of active halogen-containing compound , .
i' SU8ST!TUTE SHEEf !P~A /IJS
. . ' . . , -.
` ' ~G l ~V' ~ q c /G~
f~ - 6 - IPEA/US 22NOVl99~ ~
based on vanadium compound is 1 to 30 mols per mol of vanadium compound.
BE Patent 592,247 teaches a process for preparing copolymer of ethylene with alpha-olefins whose molecular weight depends on the amount of halogenated alXanes used. Triisobu~yl aluminum ([(CH3)2CH2]3Al), vanadium tetrachloride (VC14) and carbon tetrachloride (CC14) may be used as a catalyst system.
GB Patent 1,059,865 relates to the polymerization of ethylene, or ethylen~ togeth~r with one or more ole~in monomers. TE~, CC14, CHC13, an~
vanadium di-isopropyl salicylate are used as the catalys~ system.
The breadth of the intermolecular compositional distribution (CD) and molecular weight distribution (MWD) of polymers such as prepared by the above referenced disclosures are largely a function of the particular catalyst system employed to prepare the polymer. Such catalyst systems generally yield polymers with either narrow CD and narrow NWD or broad CD and broad NWD. Until the present invention, ethylene copolymers (EPN or EPDM) having a broad CD and at the same time a narrow ~WD are not believed to have been disclosed in the art. Such elastomers are especially useful in that they posse~s novel combinations of propertie~ 9uch as excellent green streng~h and processa~ility which lead~ to superior performance in a number of applications.
SUM~ARY OF q; HE INVENTION
The present invention is directed toward novel elastomeric copolymers of ethylene and at least . .
S~8STIIUTE SH~
JS
.
. .
', , . . ~ ' , .. . . . . . .
. .
... . . . . .. ` .. .. . . .
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~_ ~ 7 ~ IP~A/US 2 2 NOV 1991 ., one other alpha-olefin monomer which copolymers have an intermolecular compositional distribution (CD), as hereinafter defined, such that at least about 25% by weight of the polymer differs from the mean ethylene content of the polymer by at least plus or minus 5 wt %
e~hylene, and have a relatively narrow molecular weight distribution (MWD) such that the weight average molecular weight (Mw) of the polymer divided by the number average molecular weight ~Mn) of the polymer is not greater than about 5Ø
The copolymers of this invention which are characterized by exceptional green strength and good processing properties, may be prepared using a catalyst system comprising:
a) a vanadium compound with a valence of 3 or more;
b) a triorgano aluminum compound: and c) a specific halogenated organic promoter used in catalytic amounts.
The catalyst system allows for efficient polymerization of high quality polymer products and at generally higher polymerization temperatures of up to about 140C to yield higher molecular weight polymer products which ar~ essentially free of gel, and which .
possess excellent green strength and processability.
BRI~F DESCRIPTION OF THE DRAWING
Figure 1 is a graph showing pol~mer compositional dis~ribution based on mean polymer content of polymerized ethylene. : .
DET~ILED DESCRI~TION OF THE INVENTION
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~ - 8 ~ lP ~/Us 22NOVl991 The term intermolecular compositional distribution (CD) as used herein defines the compositional variation among polymer chains in terms of ethylene content as compared with the mean ethylene conten~ of the copolymer as a whole. The CD is expres~ed by first determining the mean ethylene content of the copolymer sample by a suitable test such as described in ASTM D-3900. Next, the copolymer sample is dissolved in solvent such as hexane and a number o~ ~ractions o~ differing composition are precipitated by ~ihe addition of incremental amounts o~
a liquid such as isopropanol in which the copolymer is insoluble. Generally, from about 4-6 fractions are precipitated in this way and the weight and ethylene content of each fraction are determined after removing the solvent. From the weight of each fraction and its ethylene content, a plot is prepared of weight percent composition vs. cumulative weight percent of polymer which is shown in Figure 1, and a smooth curve is drawn through the points. The ethylene composition corresponding to 50% by weight o~ the polymer is locat~d as shown by th~ construction in the figure, and horizontal lines A-B and C-D are drawn at 1 5 weight percent ekhylene from the mean composition. Vertical lines through points B and D are drawn to locate points Bo and Do respectively at the horizontal base axis, and i~ the cumulative percent of polymer represented by Bo ~inus Do is 75% or less, then the polymer falls within the scope o~ this invention. For example, with the data shown in Flgure l, the mean composition o~ the copolymer a~ a whole is 50 weight percent ethylene, Do is about 41 cumulative %, Bo is about 56 c~mulative %, and Bo minus ~O is therefore about 15%. Thus, with respect to a copolymer as represented in Figure 1, about 85% og the copolymer has an ethylene content which is greater by plu5 or minus 5% than the mean ethylene content of 50~ of the copolymer as a whole.
SU~S~l~lltE SH~
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This exemplifies a broad compositional distribution within the scope of this invention.
Molecular weight distribution (MWD~ is a measure of the range of molecular weights within a given copolymer sample. It is characterized as a ratio of weight average to number average molecular weight, i.e. Mw/Mn. MWD can be measured by gel permeation chromotography (GPC), for instance, using a waters 150 gel permeation chromatograph equipped with a Chromatix KM-6 on-line light scattering photometer. The system is used at 135C with 1,2~4 trichlorobenzene as mobile phase. Showdex (Showa-Denko America, Inc.) polystyrene gel columns ~02, 803 804 and 805 are used. This technique is discussed in "Liquid Chromatography of Polymers and Related ~aterials III", J. Cazes editor, Marcel Dekker, 1981, p. 207, which is incorporated herein by reference. No corrections for column spreading are employed; however, dat~ on generally accepted standards, e.g., National Bureau of Standards Polyethene 1484 and anionically produced hydrogenated polyisoprene~ (an alternating ethylene-propylene copolymer) demonstrate that such corrections on Mw/Mn or Nz/Mw are less than .05 unit. Mw/Mh is calculated from an elution time-molecular weight relationship wherea-~ M~/Mw is evaluated~using the light scattering photometer. ~ The numerical analyses can be performed using the commercially available computer so~tware GPC2, MOLWT2 available from LDC/Milton Roy-Riviera Beach, Florida. The low molecular weight cut off for the calculation is 1500-2000. ~
.:
The elastomeric polymer o~ this invention comprises ethylene-containing elastomerlc polymers that have been copolymerized with one or more higher alpha ole~ins and optionally a diene monomer. As applied to polymers of thi~ invention, the terms 'lelastomeric" or "elastomer" are defined to mean that when they are ~ .: . :.
o)'v~TlTuTE S13EET
IP~A/US
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- . , . ... ... . ~ . .. .. ~ .. - . . ... .... ..
C1 c/~
- 10 - 3PEAlUS 22NOV199t crosslinked, they are capable of recovering from large deformations quickly and forcibly. Free from diluents, the crosslinked polymers retract within one minute to less than 1.5 times their original lengths after being stretched at 18C-29C to twice their lengths and held for one minute before release.
.
Typically elastomers are "sub~tantially amorphous", and when that term is used to defin~ the ethylene containing elastomaric polymers o this invention, it is to be taken to mean having a degree of crystallinity less than 25~, pre~erably less than about 15%, and more preferably less than about 10% as measured by means known in the art. The three major known methods o~ determining crystallinity are based on specific volume, x-ray diffraction, and infrared sp~ctroscopy. Another well-established method, based on measurement of heat content as a function of temperature through the fusion range, is differential scanning calorimetry. It is known that these independent techniques lead to good experimental agreement.
Additionally, it i5 known in the art that the tendency of a particular combination o~ catalyst system and monomers to produce blocky, random, or alterna~-ing monom~r sequence distribution in the polymer can be characterized by the product of the reactivity ratios defined ~or the given monomers under the specific reaction conditions encountered. If this product is egual to 1.0~ th~ sequence distribution will be per~ectly random; the more the product is less than 1.0, the moxe the monomers will approach alternating sequence; and, the more the product is greater than 1.0, th~ more the monomers will tend to have a blocky sqquence distribution. Generally speaXing, the segments of a polymer which crystallize are linear segments which have a number of identical (both by , p ' .
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chemical make-up and stereo-specific orientation) units in a row. A combination of such segments are said to yield blocky polymer. If there is little or no such sequential order within the segments makinq up a polymer chain, that chain will be very unlikely to conform itself into the correct shape to ~it into the spatial ordPr of a crystal and will accordingly exhibit a low degree of crystallinity. The ethylene-containing elastomeric polymers of this invention, accordingly, have a reactivity ratio product less than 2.0, preferably l~ss than about 1.5, and more preferably less than about 1.25, and are substantially amorphous.
As alraady noted, copoly~er~ in accordance with the present invention are compri~ed o~ ethylene and at least one other copolymerizable alpha-olefin~
Such alpha-olefins include tho~e containing 3 to 18 carbon atoms, e.g., propylene, butene-1, pentene-l, hexene 1, etc. Alpha-ole~ins of 3 to 6 carbons are preferred due to economic considerations, and they are generally pre~ent in the copolymer within the range o~
about 10 to so percent by weight, more pxeferably from about 15 to about 70 percent by weight most preferably 20 to about 70 percent by wei~ht. The most preferred copolymers in accordance with the present invention are those comprised of ethylene and propylene or ethylene, propylene and a diene.
As i~ well known to those skilled in the art, copolymers of ethylene and higher alpha-ole~ins such as propylene often include othQr copolym~rizable monomers.
Typical of these other monomers may be non-con~ugated dienes such as the following non-limiting examples:
.
a straight chain acyclic dienes such as 1,4-hexadiene; 1,6-octadiene;
b branched chain acyclic dienes such as 5-me~hyl-l, 4-hexadiene; 3,7-dimethyl~
':
SUBST~TUTE SHEET
IPEA/US
~ ~. ; ' . . ... ,.. ~ . .. , ..... ; .
c ~ q~ s f ` ~
`- ` IPEA/US 2 2 NOV 1991 6-octadiene; 3j7-dimethyl -1,7-octadiene and the mixed isomers of dihydro-myrcene and dihydroocinene:
c single ring alicyclic dienes such as:
1,4-cyclohexadiene: 1,5-cyclooctadiene;
and 1,5-cyclododecadiene;
d multi ring alicyclic fused and bridyed ring dienes such as: tetrahydroindene;
methyltetrahydroindene;
dicyclopentadiene; bicyclo-(2,2,1)-hepta2,5-diene: alkenyl, ~lkylidene, cycloalkenyl and cycloalkylidene norbornenes such as S-methylene-2-norbornene (MNB), 5-ethylidene-2-norbornene (ENB~, 5-propyl-2-norbornene, 5-isopropylidene-2-norbornene, 5-(4-cyclopentenyl) -2- norborne~e: 5-cyclohexylidene 2-norbornene.
Of the non~conjugated dienes typically used I to prepare these copolymers, dienes containing at least I one of the double bonds in a strained ring are preferred. The~most preferred diene is 5-ethylidene 2-norbornene (ENB). The amount of diene (wt. basis) in I the copolymer may be ~rom about 0% to 20~ with 0% to i 15% being~preferred~ The most preferred range is 0% to 10%. Where the diene is present, it is generally present at a min~mum level of about 1 weight percent.
. . . . ..
As already noted, the most preferred copolymer in accordance with the present invention is ethylenepropylene or ethylene-propylene-diene. In e~ther event, the ~average ~ethylene content o~ the copolymer may be~as low as~abou~ 10% on a weight basis.
The preferred minimum is about ~5%. A more preferred minim~m is about 30%.~ The maximum ethylene con~ent may be about 90% on a weight basis. The preferrad maximum is about 85%, with the most preferred being about 80%.
TUT~ S~IEF~
IPEA/US
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~ 13 ~ IP~/US 22NOVl991 A further unexpected characteristic of the copolymer of this invention is the broad compositional distribution of the optionally included non-conjugated diene. As is known in the art, copoly~er having typically narrow MWD will also be expected to have a narrow compositional distribution of non-conjugated diene. The copolymer of this invention containing non~
conjugated diene will thus exhibit a compositional distribution such that the diene content of at least about plus or minus 20% of the polymer differs from the mean value of incorporated non-conjugated diene by at least plus or minus 0.5 weight percent diene. A
typical curve representing this compositional distribution appears in the upper portion o~ Figure 1.
The molecular weight of copol~mer made in accordance with the prçsent invention can vary over a wide range. The preferred minimum is about lO,OoO
The most preferred minimum is about 20,000. The maximum weight average molecular weight may be as high as about 12,000,000~ The preferred maximum is about 1,000,000, with the most prefarred maximum being about 750,000.
Copolymers prepared in accordance with the present invention exhibit a broad CD with at least about 25% of the polymer differing from the mean ethylene content by ~ 5% e~hylene, and a relatively narrow molecular weight distribution within the range of from about 2 to 5, evaluated as described above.
Copolymers having the most.superior green strength and processing properties are those having a CD breadth ranging from about 40% to about 80% of the polymer differing from the mean ethylene content by + 5% and (MW/Mn) of ~rom greater than about 2.0 up to about 4.5.
.
. .
SU~STl~UTE SHEEl~
IPEA/US
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.
. ' , ' ~
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~ 14 ~ IPEA/uS 2 2 NOV1991 As indicated above, the novel copolymers o~
this invention are produced using a catalyst system comprising:
a) a hydrocarbon soluble, non-supported vanadium compound with a valence of three or more;
b) a triorgano aluminum compound: and c) a specific halogenated organic promoter used in catalytic amounts.
The vanadium component of the catalyst system may have the genera~ formulas ':
O
VXaYb or VXcYdr wherein X is halogen, preferably chlorine, and Y is an organic substituent selected from the group consisting of an alcoholate, carboxylate, ketonate or diketonate having up to 10 carbon atoms, a and b may range from O
to 3 with the proviso that the sum of a and b is 2 or 3, and c and d may range from O to 4 with the proviso that the sum of c and d is 3 or 4. Preferred vanadium compounds for the purposes of this invention include:
~OC13, 14, v- E O-C-R~3, and VO~OR)3/ ¦1 Vocl2(oR)i Cl V-CO C-R]2 wherein R is a hydrocarbon radical preferably having ~rom about l to 10 carbon atoms. R preferably represents ~an ~ aliphatic, alicycllc or aromatic hydrocarbon :radical ~such as ethyl (Et) , phenyl, isopropyl, butyl (Bu) , propyl, n-butyl, i-butyl, t~
butyl, hexyl, cyc}ohexyl, octyl, naphthyl and so forth.
Non limiting and illustrative examples of preferred iT~ SI~E~
IPtA/lJS
Pc I /~" ~~ q c/C ~~ c ~ ~
15 - IPEA/US 22NOV1991 ~
vanadium compounds are vanadyl tetrahalides and trihalides, ~lkoxy halides and alkoxides, such as VC14, VOC13, vocl2 (OEt), vOC12 (OBu), VO (OBu)3 and vo(oc2Hs)3 The most pref~rred vanadium compounds are the chlorinated compound~ such as VOC13, VC14 and vocl2(R) The triorgano aluminum component of the catalyst system has the ~ormula AlR3 wherein R is a hydrocarbon radical having one & to ten carbon atoms as defined above with respect to the vanadium compounds.
Examples of suitable R groups include methyl, ethyl, i-butyl, hexyl and phenyl. Preferred compounds are trialkyl aluminum compounds, including triethyl, tri isobutyl and tri n-hexyl aluminum. It is important for the purposes o~ this invention that the aluminum compound is free o~ halogen, i.e., that aluminum alkyl halides not be used. Catalytic activity is markedly reduced using these latter compounds.
The selection of the proper halogenated polymerization promoter is a key feature of the present invention. A certaln range of halogen substituent reactivity toward the catalyst is required to give the proper balance of ca~alyst activity and properties of the ~opolymer product. If the reactivity is too low, catalyst e~ficiency ls reduced, while if it is too high, undesirable side reac~ions occur which are deleterious to catalyst performance. Cooper (T.A
Cooper, Journ. ~n. C~m. Soc., 95, 4158 (1973), the di~alosure o~ which is incorpora~ed herein by reference, has de~ined in Table 1 an organic halide activity index based an the ability of the halide to oxidize VC12 (py)4 to V(III) under standard conditions.
For example, CCl~ is assigned a reactivity of l in tetrahydrofuran at 200-C.,`ànd other listed halogenated organic compounds have reactivitie5 of from about 0.02 to greater than 200 relative to CC14.
:
~ SU~S~I~UTE 5HEEI
lp~/us .... . . . . . ... 1 . `~ . ; ... ` ~ - `
~c // ~ q c/~ c ~ ~
~ 16 IPEA/US 2 2 NOV 1991 It has been found that organic halides as defined in the above referenced article with a Cooper Index ranging from about 0.01 up to about 30 are suitable promoters for the purposes o~ this invention.
Most preferred promoters meeting this criteria are selected ~rom the group consisting of carbon tetrachloride, hexachloroethylene, benzyl bromide, benzyl chloride and 2,3-or 1,3-dichloropropylene.
It is important that ~he vanadium component of the catalyst system is both not hydrocarbon insoluble and not supported on an inert or hydrocarbon insoluble support. Vanadium Catalyst systems that are hydrocarbon insoluble or deposited on inert supports are not typically useful for the preparation of elastomeric copolymers of ethylene according to the procedures o~ this invention.
The polymerization in accordance with this invention may be carried out either in ~olution or in suspension, but solution polymerization is preferred to avoid problems of reactor fouling. The process may be carried out as a batch process or a continuous process, although continuous flow stirred tank reactors are pre~erred, and at normal atmospheric pressure or under elevated or reduced pressures. The polymeri2ation may also be carried out u~ing a series o~ two or more conkinuou~ flow atirred tank reactors or equivalents thereof. Normally, pressures of 1-10 atmospher2s are pre~erred. The polymerization may be aarried out at temperatures in the range of about 60 to about 140~C, as well as the more common temperatures within the range o~ about 10 to 60 Q C. When the polymerization i5 conducted at the higher range o~ about 55C to 140 there is additional process advantage in that the energy requirements ~or both recovering the polymer from solution and cooling the reactor during CU8ST~TUTE S~EET
IPEAtUS
.
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~ c ~ q c/~ ~~ c~ ~
~ J ~ h ~ J V !J~ ~
poly~erization are reduced. Preferred polymerization temperatures for the purposes of this invention lie in the range of from about 40 to 120C, more pre~erably from about 55 to 100~C. Solvents used in the process include one or a mixture of hydrocarbons such as pentane, hexane, benzene, toluene, xylene, cyclo hexane and the like. Diluents useful for a suspension process are propane, butane or a mixture of the liquefied monomers use~ul in accordance with this invention.
PrePerably, but not necessarily, the solvent will al~o be a solvent for the vanadium catalyst compound. The po~lymerization reaction should be conducted in the absence of oxygen, carbon dioxide, water and other materials which have a deleterious effect on the catalyst activity.
The catalyst and halogenated promoter may be combined prior to contact with the monomers, or dilute solutions of these components may be introduced separately into the reactor. It is pre~erred ~or the purposes o~ this invention that the vanadium catalyst and alkyl aluminum are introduced separately into the reactor and allowed to react to form the active catalyst in the presence of the monomers, since catalyst activity may suffer if the catalyst components are prem~xed. Also, it is preferable not to premix the promoter and alkyl aluminum since undesirable side xeactions might occur.
. .
Polymer molecular weight may be controlled by the introduction of known chain trans~er agents such as hydrogen gas or diethyl zinc. In general, the quantity o~ chain trans~er agent in~roduced into the reactor ranges ~rom about 0.1 to about 100 moles per mole of vanadium catalyst. In some cases it may also be desirable to add known chain branching suppressors, including Lewis Bases such as NH3, pyridl~e and Si(oEt)4 to the reactor along with the catalyst ~'..
.;~,r-i3~^~
. :
.. . .. . . . . .. .. .. . .. . . .
; . ., : ~ . . .- .. . . :
.,, : . . : :-. . ~ ., . . .. . :,. ~ .. . ,, . , . , -, . ., . ... ,,, ,, .. ,. .... . .. , . . . : .
~c ~ -q c~ c ~ S
~ ~<- 18 ~lp ~/~S 22NOV1991 components. The preferred molar ratio of such suppressors ranges from about 1:2 to 10:1 with respect to the quantity of the vanadium catalyst employed.
The average residence time o~ the reactants in the reactor generally ranges from about 5 minutes to about 2 hours or more.
Following polymeri2ation, the polymer product can be conventionally recovered from the effluent by coagulation with a nonsolvent such as isopropyl alcohol or ~-butyl alcohol, acetone, or the polymer can be recovered by stripping the solvent with heat or steam.
An antioxidant can be incorporated in the polymer during the recovery procedure, such as phenyl-beta-naphthylamine, di-tert-butylhydroquinone, triphenyl phosphite, heptylated diphenylamine, 2,2'-methylene-bis(4-methyl-6-tert-butyl)phenol, and 2,2,4-trimethyl-5-phenyl-1,2-dihydroquinoline.
The amount of the vanadium catalyst employed in the present invention is relatively low as compared ~I with prior art processes not employing a promoter. In qeneral, the amount of vanadium catalyst ranges from about 0.02 to about 0.5 millimoles per liter of solvent solution, with~ levels of from about 0.05 to about 0.5 millimoles being most preferred.
- For best catalytic per~ormance, tha molar amounts of vanadium catalyst and aluminum compound added to the reaction medium should provide a molar ratio of aluminum to vana~ium ~Al/V) o~ at least about 10 and not greater than about 250. Pre~erred such ratio~ rang~ from about 15 to 50. The amount of b ,halogenated~organic~promoter used with respect to the vanadium oompound may generally range in the promoter/V
molar ratio of ~etween about 5 to about 250. It is ; desirable that the promo~er/V ratio be not '. :
: SU8STI~UTE SHEEI
lPEA/U~
. .. .. . . .~ .. . .. .. , , , . ~ , . . . . .. . . .. .. ... .
.: . -:` ., :.-. , .... . - . : .: : . ~ . . . .... . ..
,, . ,, ~ . . .. .. . . ...
.. . . - .. . . . . . : . . . . : ... .
9 IPEA/US 22NOVl991 substantially higher than the Al/V ratio, and preferred ratios range from about 5 to about 50.
This invention is further illustrated by the following examples. In Examples 1-14, polymerizations were conducted in a 1 liter volume continuous flow, stirred tank reactor. Feeds to the reactor were purified to remove water and other polar impurities that could act as catalyst poisons. Ethylene and propylene were metered through calibrated rotameters into a stream o~ hexane solvent which was pumped at a known rate with a metering pump. This mixture then entered a heat exchanger which lowered the temperature to about -20 to -10C to prechill the feed prior to reaction and to dissolve the monomers in the hexane.
The cold stream leaving the heat exchanger then entered the reactor. Catalyst, cocatalyst, promoter, and diene monomer were prepared as dilute solutions in hexane and each was pumped separately into the reactor via metering pumps. H2 was also added to the reactor to control polymer molecular weight, and in some cases NH3 was added to suppress any tendency for long chain branchlng. Temperature in the reactor was controlled by circulating water through a jacket. Iso-propyl alcohol was added to the polymer solution exiting the reactor to terminate poly~erization, and the solution was added to boilinq water to remove solvent and monomers. The wet polymer was then dried on a hot rubber mill to yield the final product. Polymerization rate was measured by determining the weight of polymer produced in a fixed perlod of time.
Polymer ethylene content was determined by ASTM D3900. ~Ethylidene norbornene content was measured by infrared based on the haight of the 1690 cm~1 band.
Mooney viscosity~ was determined by AS~M D1646. The compositional distribution (CD) and molecular weight , ,' .
: , .
ST'IllT SllE~
IPEA/US
.
l ' )-q ~ s G ;~ ~
~ - 20 - IPEA/U~; 2 2 Nav 199~ -distribution (MWD) of the polymer were determined as described above.
Specifically, the CD was determined by cutting a,sample of the finished copolymer into small pieces and adding the pieces to hexane to give a concentration of about lg/lOOcc. This mixture was then stirred gently at 22~C for 48 hours, or until equilibrium is reached. The mixture i5 then poured through a fine me~h stainless steel screen to recover any insolubLe polymer, which is dried, weighed and analyzed for composition. Isopropanol is then slowly added to the solution until precipitated polymer first appears. This polymer is recovered on a screen, dried, weighed and also analyzed for composition. Additional isopropanol is adde~ incrementally to the remaining solution to precipitate four to six fractions in total, all of which are recovered as described previously. The final isopropanol~hexane solution is then evaporated to dryness to yield a final polymer fraction. From the weight o~ each fraction and its ethylene and termonomer (i~ any~ composition, a plot is prepared of weight percent composition vs cumulative weight percent polymer as described above and as illustrated in Figure 1. ' Exam~le 1 A polymerization was c~nducted by the process de~crlbed ahove with a VC14- triethyl aluminu~ (TEA) catalyst system with CC14 as a promoter at a temperature of 75 C. NH3 was also added to the reactor at a NH3/V molar ratio of 1:1. Hexane feed rate was 2500 g/hr. All other polymerization conditions are given in rrable 1. The po~ymerization went smoothly giving high monomer conversion and high catalyst activity.
:
SUBSTITUTE SHEE~
IPEA/US , "
:. .
.
. . . :
. .. - .. .. . ` .. . ` . . . . .. ..... . . . . . . . . . . . . . .
C ~ Gjo ~
Polymer fract}onation by the process described above gave the cumulative compositian curve shown in Figure 1. Polymer species were pr~sent that ranged from at least 65.5 wt~ ethylene to at least 35.5 : wt% ethylene. From this figure it can be determined that about 44% the polymer had an ethylene content 5%
hi~her than the mean of 5Q%, while about 41% of the ; polymer had an ethylene content 5% less than the mean.
Thus, the CD of this polymer is 85%. Mw/Mn for this polymer was 3Ø
Example 2 This example illustrates the use of the VOCl3/TEA
catalyst system with CC14 promoter at a polymerization temperature of 75C. NH3 was added to the reactor at NH3/V molar ratio of 1:1. Hexane flow rate was 2500 g/hr. As shown in Table l., catalyst activity was high and monomer conversions were good. About 65% of the polymer has an ethylene content +5% greater than th~
I . mean value. Mw/Mn for this pol~mer was 3.8.
¦ Example 3 I
Polymeriza~ion was attempted with a VOCl3/
diethylaluminum chloride ~DEAC) catalyst system at 75~C
accord~ng to the conditions in Table 1 with a hexane ~eed of 2500 g/hr. Very poor polymerization resulted giving large amount~ o~ insoluble polymer and low polymerizatlon rate~. The DEAC feed was replaced by an equal molar feed of TE~. Polymerization rates began to improv and the insoluble polymer disappeared. After allowing th~ reactor to reach steady stat~, high polymerization rat~ and good monomer conversion was measured as shown in Table 1.
. . , ' ' , ,','.,.
~IJCi~ S~!E~
~PEA~US
.
; -- 22 -'~~' J~ 0~
J
Exam~le 4 This run illustrates the use of benzyl chloride as a promoter with the VC14/TEA catalyst system. Benzyl chloride has a cooper reactivity index of .0S. An NH3jV molar ratio of 1:1 was used and the hexane flow rate was 2500 g/hr. The composition distributlon of the polymer was such that 64 wt% of the polymer has an ethylene content + 5~ greater than the mean value. Mw/Mn for the polymer is 3.1.
Example 5 (A.B.C.D~
This example illustrates the use of various promoters with the VOC13/TEA catalyst system at 75C
polymerization temperature. The hexane feed rate was 2500 g/hr and the other polymerization conditions are as shown in Table 1. The promoters used are indicated below:
Cooper Example Promoter Reactivitv Index 5A Benzyl bromide .1 5B 2,3 Dicholoropropylene .02 5C 1,3 Dichloropropylene .02 5D Hexachloroethylene 5 A~ shown by the results in Table l all of these promoters gave good catalyst activity and monomer conversion.
.
, :~
~: . . . . .. .. : . .. ~ . .. . . . . .. , , ~
p C i/U ~- q C~
~ 23 _ 3P ~/~S 22NOV~91 Comparative ExamPle 6 An attempt was made to conduct a -pol~merization with the VOC13-TEA catalyst system and benzoyl chloride as the ' '"
SU~STlTUTE SHEE~
IPEA~US
/~C ~ q Q/~ G ~ ~
~: ~`i IP~A/US 2 2 NoV~991 __ o ~ T ELE L Irl . ¦~ _ _ o o l -"u ' U- ~ ~ l .- . . .. _ ~ ql ~
. ~v~ c~ o ~ t ~ ~ ,. ~ I~ID . ~ ~
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vOI '~, ~. ~, ~n, o. ~, ~. o. _ r~ ~, ~, 3~ . U~ ~ ~D ~ U~ U~ ~. ff _ .. .~ . _ _ _ _ _ _ _ _ ZJ~ . P n _ __ I _ _ _ r~ , __ ~ '~ ~ ~ ~ ~'I d _ ~'q ~ ~ .~ .
.' . tJ U !i ~ ~ u~ ~ n u- ~ u~ 1 ~
_ _ _ _ _ _ _ _ _ I_ _ rl r~ ~ .~ ~ ~ ~ r~ O ~D .~ . ' ~ ~ r~ ~ ~ ~ ~ ~> ~ o o .: ~ qoww/a~ ~ ~r ~ ~ ~ r~ ~ ~ r~ ~ ~ ~ . , .
_ _ . ... r~ ~D n _ _ 2~--o _ ~ ~ _ ~'IO~O~ ~0~/~ ~ _, ~ ~ o~ ~ _, ~ ~ ~o '.'' _ _ _ _ _ _ _ _ _ _ _ _ _ , ~ OWli~ ff ~ _~ O 1~ ~ 1~ r e) o o R ~ _l ~ ~ ~ ~ ~ ~ . .
_ _ _. _ . _ _ . _ _ _ OS;I~Y~ o o r~ t~ o o o ~ ~ o ~ -.:
;!W~O~I ~lr~i .~ rl ~ ~o rl I ~ . .
~1 _ _ __ _ _ 1~, ._ _ _ ~l. _ __ Ir~ a- ..
.; 0~ Yq'O ~ O _ ~ O O O ~ 01 d ~
~/~O~O~OUd ~ :_ __ _ :1 . ----~ ~ i ~~ ~I ~ O n 1~ o _ r~ ~1 ~IATCIYM' . . . . . _ . _ _ .
. . a/~ 2 ~ 0 n O O O O O
. Q _ _ _ __ _ _ _ _ _ __ _ . ~ a~do~ ~ 3 o ~ 3 ~ u~ o~ m In ~n ~ .. ~ ~ _ _ C ~ _ _ _ ~ _ _ : 31~ Haa In 1 ~ 1~1 ~1 U~ 1~1 111 P In Itl . _ . ._ _ _ _ _ _ _ _ ~_ _ _ _ . . SNIW ~S5 5~1 d ~ ~ ~ ~ ~1 C~
.. ~ .,,. _ _ _ _ ~ _ _ _ ._ _ .~ .
: ~ ~3S ~n r. ~ ~ #~ ~ U~ h~ :~ U- n ~ . .
'~X3 ~ . ~ i e ~ It~ ~ e D U ~ ~ , . ,,: :
.' , ~
.
SU8STITUT~ S~EE~ :
PEA/US
.~ , . ~ -.
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~ 25 - IP~/US 22NOV1991 J
amounts of in~oluble polymer were produced and steady state operating data could not be obtained.
Comparative Example 7 ~A, B, C) In this example, trichlorotoluene was used as a promoter with the VOCl3-TEA catalyst system.
TrichlorotoIuene has a Coopex Index of 40.
Polymerization conditions and result~ are shown in Table 1. Hexane feed .rate was 2500 g/hr, In the copol~meri%ation runs, 7A and 7~, catalyst activity was very high. GPC analysis of the copolymer produced in run 7B indicated a broad, bimodal MWD, with a low MW
mode shifted to a Mn of 251 and a high MW mode with an Mn of 31,000. Mw/Mn ~or polymer 7B was 80.
Introduction of ENB into the polymerization in run 7C, which is at conditions otherwise similar to 7A, caused catalyst activity and monomer conversion to drop substantially re}ative. to 7A. GPC analysis of this polymer showed a single.broad peak and Mw/Mn was 8Ø
The compositional distribution for the polymer mode in Example 7C is broad with 37% of the polymer greater than.~ 5~ ethylene of the mean~
:
; ExamQle 8 fA.B.C,D~ ~
.
A series o~ terpolymerization runs were carried out with the VOCl3-triisobutyl aluminum (TIBA~ .
catalyst system at di~erent CCl4/V and Al/V ratios. A ..
NH3/V ratio o~ 1.0 wa~ usQd and the hexane ~eed rate was 2500 g/hr. As shown by the result in Table 2, catalyst` activity wa~ good over the entire range of conditions tested. ~ -: ~ . ...
':
; ~ . ; ' ' ~ ,? t ~ rr ~
~ ,'F~
: : ~
~C /~ qG/C~ G~ ~
~26 - ~PEA/U~ 2 2 NOV 1991 ~ Example 9 Vanadium tris~hexanoate was prepared by reacting VC13 with kexanoic acid. A terpolymerization was carried out with this catalyst and TEA cocatalyst with CC14 as the promoter. Polymerization results are shown in Table 2. H~xane feed rate was 3030 g/hr and a NH3/V ratio of 0.65 was used. The compositional distribution was broad with 77% of the pol~mer greater than +5 wt% ethylene from the mean. Mw/Mn was 4.3.
Exam~le 10 (A.B.C) This run was made with varying levels of CC14 promoter and the VC14-TEA catalyst system. The hexane flow rate was 2~00 g/hr and the NH3/V ratio was 1.}. In examples lOA through lOC in Table 2, the CC14/V ratio was reduced from 20/1 to 1.67/1. ~s shown by the results in the Table, polymerization rates are reduced consid~rably when insufficient CC14 is present and Mw/Mn goes up as CC14/V is reduced. The compositional distributions for polymers lOB and lOC are broad. For polymer lOB, 90% of the polymer has a composition greater than +5 wt% ethylene from the mean, while for polymer lOC, 87% o~ the polymer differs from the mean by great2r than +5 wt~ ethylene.
. .":
~21~ , .'..
This run was made to demonstrate ¦polymerization with the VC14/trinormal hexyl aluminum catalyst sy~tem and CC14 promoter. Hexane ~eed rate was 3030 ~/hr. As shown by the results in Table 2, high cataly~t activity was obtained. The polymer had an Mw/~n value o~ 4.5 and the CD was broad with 79% of . ..
.
S~STIIUT~ SHEEl IPEAIU~:
f. - 27 - 22NOV1991 the polymer differing from the mean ethylene content by greater than 5 wt~ ethylene.
Example 12_ ~A.B.C.D~
.
This run was made to investigate the effect of NH3 on the polymerization with the VCl 4/TEA
catalyst system and CC14 as a promoter. Hexane ~eed rate was 2500 g/hr. In runs A through D, increasing amounts of NH3 were added to the reactor. After each change in NH3 feed, the reactor was allowed to reach steady state and a sample was tak2n to determine polymerization rate and polymex properties. As shown by the results in Table 2, NH3 has no effect on polymer composition or Mooney viscosity until a level of 13.6 :~:
mole/mole V was reached in run D at which point a decrease in catalyst activity occurred. Mw/Mn stayed constant at about 3.4 for this series of runs. 70% of the polymer differed from the mean ethylene content by .. .
at least +5 wt% ethylene in Run C, and 66% of the polymer differed from the mean ethylene content by at least i5 wt% ethylene in Run D. The lack of effect of NH3, a long chain branching suppressor, on Mooney viscosity or MW/Mn indioates that the catalyst system o~ this invention produces polymers with a low ranching lev~l. .
: , .
' ' Example 13 Vanadium chloride bis hexanoate was prepared by the reaction of VC13 with 2 moles of hexanoic acid.
A~polymerizat~ion was~carried out with this catalyst and ~EA coca~alyst with ~C14 as the promoter. As shown by the result~ in Table 2, catalyst activity was good.
The polymer had~an Mw/Mn of 4.0 and 72% of the polymer IJ' S I iT~JTE SHEE~
IPEA/US
. .... ... .... .. .. . . . . . , ~ . .
~ l/u~ q~/c~
NO\/~' _ 28 --T~BLE 2 ~ ~, ~ ~
- I __ _ _ _ _ _ _ C ~ _ ~ ~ _ ~ _ ll _ l ' _ ~ ~ l ~o ~n ~ fl ~ ~ _ ~. ;) i` ~g ~ ~ ~ ~. ., o~ ~ v ~ ~ ~ ~ r~ q ~- r~ ~ ~1 1 ~
_ r ~ ~ O Q ~ ~ 1~ O ~ 'O ........ !`
Q ~ ~ ~ lo ~ ~ ~n Y ~ ~ ~ In o o- ~n ~
2 ~ ~ 1- ~ ~ r~ o ~ o~ r- o~ I _ _ 7 Y ~ ~ 1 ~ r~ ~ ~ ~ ~ 1~ ~ 1! ~_~ U~
C~ ' _ _ _ __ _ _ _ _ _ _ _ _ _ _ 3~ ~ ~ ~ ~ _ ~ .~ 1~ ~ ~ _ r~ ~ ~ ~
8 ~ ~ ~ ~ ~ ~ ~ ~ ~ n ~ c r o ~ ~ r~ lo ~ o 1~ I ~ ~, o _ o~ _ ,.
__ _ ~ _ . _ _ _ _ _ _ 10~ q ~ O ~ ~ 1~ ~ ~ o~ ~ a ~ O
~1~# ~ ~ t- r 1~ O ¦ O _ o r o O
a~ a ., n ~ ~ ~ _ I ~ ~ _ ~ ~ _ r~
_ _ _ _ _ _ _ _ YrSO~OA.~ ell ~ ~ _ O a ~ ~ O r ~ e~ ~ o OS W wqC~ Il~ ~ ~ O O n ~ O ~ ~ ~ ~ o .. ..
. ___ _ _ _ _ . _ _ _ _ _ 1 r~ n ~ o o o o a ~- .- ,.
. ~Ul; ~YY5t~ n ~ n n o, n n ~ ~ ~ , ~ ~ ~
. YIIJ6 _ _ ~ _ _ _ _ _ . _ ~ ~ ~ " ~. ~ ~ a~ ~ _ ~ ~111 ~ D ~1 e~ ' _ __ _ __ _ _ _ _ _ _ _ .
- ~ a~o~a ~0 c 3 n 0 ~ cl e~ a n ~ n ~o ~
bl ' ~_ _ _ _ _ _ _ _, . _ _ _ _ _ YIV 5 n r n n o n ~ n o n ~ ~ ~ o~
~ISS~ Y ~ ~ ' ~ ~ r~ ~ ~ ~ ~ ~ ~ .~ . ~ ~ ; ' , . . . _ _ _ _ _ ~ _ . _ _ _ _ .
. ~0 ~S ~ ~n d~ n n I~ ~ r n ~ ~ ~ ~ ~n _ ~ __ _ _ I_ _ ~0 ~01 ~ rl ~C ~ ~ Q ~ o :
SUBSTITUTE SHEE~
IPEA!US
.~
- . : . .. . ... . .. . ~ ~ ... .. . .... .
r-~ p C / /~ ) q O /~
`'`3 - 29 IP~ 22NOV1991 J
Example 14 (A,B.C) This run was made to investigate the effect of reaction temperature on ethylene-propylene copolymerization with the VOC13/TEA catalyst system and CC14 as promoter. Hexane feed rate was 2500g/hr.
Other reaction conditions are shown in Table 3. As indicated by the results in this Table, catalyst activity remains almost constant at polymerization temperatures from 65 to 97C.
; Example 15 fA,B,C) This run was made to investigate the effect of reaction temperature on ENB terpolymerization with VOC13/TEA catalyst and CC14 promoter. ~exane fPed rate was 2500 gjhr and other conditions are shown in Table ; 3. The results in Table 3 indicate that catalyst performance was una~fected by temperature over the i range o~ 55 to 75~C.
~ll Exam~ 16 (A.B~
. .
The polymerization procedure described in Example 15 was used except that the polymerization was carried out in two 7.6 liter volume stirred tank reactor~ connected in series. Cataly~t, solvent and mono~ers were fed to the first reactor, and the pr~duct stream entered the second raac~or to whlch additional monomers dissolved in hexane solvent were added~
Poly~erization~conditions are given in Table 3. The catalyst system was VC14jTEA with CCL4 as promoter.
Hexane ~eed to the two reaotors was 29.9 and 4.45 kg/hr respectively. Runs A and B are es~entially similar except that additional ethylene was fed to the second reactor in Example 16B.
.'' ' ' ' ' ' '''.,"S,I~IJ~E SHEFI
~, IpF,Q./I~
.. .. . . . . ... . . . ' - . : .
~ , - , : :.:
~C l/c/S-q/~ Q
IPEA/US 2 2 NOYl991 i o U ~ _ _ rABL ' 3 . _ _ _: . . .
S ~ ~ ~ r~ ~ ~ ~ e~ al eo ~_ _ ,, _ _ _ _ _ o 8 ~ I l l ~ ~ o r ~
~ ~ - .~. _ _ _ __ ~ _ o ~ ~ ~ ~ ~D a~ O O O O ~r ~Ir ~ ~
8~ ~ ~ ~ u~ u~ u~ ~ u~ ~ u~ u~
. . _ _ _ _ , ~ . _ ~ l l ~ ~D ~ ~ ~ ~ ~ D~
Z ! ! l ~ ~_ ~ ~ ~ . .~ r~
O U~l' ~:~ cl:l cn ,~ w ~o ~ ~o ~9 ~o r~
~:~~r ~ ~r 1~ ~ t~ r~ ~lr r~ \1-~ l_ __ _ _ ._ _ 8 !u ~ N O O O O~1 r u~
~ r~ ~ O ~ ~ ~ ~ ~ C~
oww/a~ ~ ~ ~ O 0 ~D ~ I~ ~ ~ r ;LYa ~ ~- ~r ~ ~ ~ ~~r r~ In ., ' .
~ ~ ~ ~ O 0~ O ~r ~O
W~qO-10;~ ~0 :a.l;Y~I _~ _l _ _~ ,~ ~ u~ c In , ~ _ . .............. _ _ _ .. _ XH~'IOWW ~ r~ ~ r' ~` r~
a~ Z~ ., ~ r. ~ ~. ~ O O O O
.- ~ _ _ _ _ OI~lnI o o o o o o o , o ~Y-iO~/~
OI~ 2~IOW ,~ _ _~ r~ ~ o t o l .Ow~a ., ~1~ 'ID~' ~ o o o o o o o _ o l;S~ . ~. ~. . . ~ ~ ~ r`
WnIaNYA . . . . . . . .
,_ _ _ _ __ . _ I
r~ a~ P~ o~ ~, ~N~ o o o r` ~_ r` o. o~
__ ._ _ _ _ _ _ _ ` ~'6 o o o o o o ~ o ~ o N~ ao~la u~ ~ ~ o O O ~ _ O _ UH/ 0 . ~ ~ u~
~tN: I'IX~3 1~ r~ 1~ ,~ ,~ ~ o o o ,, _ ,_ __ ___ _ _~ __ -'_ .~ ., SNIW ~tI~ S:~ . ~-r ~ ~ ~ '1 ,~ ~ ,~
. . .__ , _ . _ . _ aO a~ In ~ ~ ~ U~ In ~D U~ 10 U . ~ .
~ -- ------ ~----- ~-~ e ~ r~ ~ 6~ t~ ~ ~ ~ 3 ~~~ ~ ~
~ , SU~S~I~ul~ SHEE~
IpEAlus ;
~r f c 1/(~ /O ~~C ~
31 Lp~A/us 2 2 NOV l99~ -The results of the polymerization are also shown in Table 3. In this Table, the conversions, catalyst efficiency~ polymerization rate, and polymer composition shown for reactor 2 are the cumulative results for operating both reactors in series. As indicated by the data, series reactor operation gives increased catalyst efficiency and ethylene and propylene conversion.
Reasonable variations or modifications of this invention can be made or followed, in view of the foregoing, without d~parting from the spirit or scope thereof.
~I'.,S, ) ~ U','c SHE
pF,4illS
-: .
.
. . ., ; : , ,
Claims (26)
1. A process for preparing an elastomeric copolymer of ethylene, at least one other alpha-monoolefin having from 3 to 18 carbon atoms, and from zero to 20% by weight of a non-conjugated diene, said copolymer containing from about 30 to about 85 weight percent of ethylene and from about 15 to about 70 weight percent of said other alpha-monoolefin, said copolymer further characterized by a broad intermolecular compositional distribution such that at least about 25% by weight of the copolymer differs from the mean ethylene content of the copolymer by greater than plus or minus 5%, and said copolymer having a molecular weight distribution such that the weight average molecular weight divided by the number average molecular weight as dete=ined by GPC is from about 2 to wherein X is halogen, Y is an organic alcoholate, carboxylate, ketonate or diketonate having up to 10 carbon atoms, a may range from 1 to 3 with the sum of a and b being 2 or 3, c may range from 1 to 4 with the sum of c and d being 3 or 4, b) an aluminum compound having the formula AlR 3 "
wherein R is a hydrocarbon radical having from one to ten carbon atoms, and c) a halogenated organic polymerization promoter having a Cooper reactivity index in the range of from about 0.01 to about 30, the Cooper reactivity index of carbon tetrachloride being 1Ø
wherein R is a hydrocarbon radical having from one to ten carbon atoms, and c) a halogenated organic polymerization promoter having a Cooper reactivity index in the range of from about 0.01 to about 30, the Cooper reactivity index of carbon tetrachloride being 1Ø
2. The process of Claim 1 wherein said copolymer contains from about 40 to about 80% by weight ethylene and from about 20 to about 60% by weight of said other alpha-monoolefin.
3. The process of Claim 1 wherein said other alpha-monoolefin is propylene.
4. The process of Claim 1 where said copolymer contains at least about 1% by weight of said non conjugated diene.
5. The process of Claim 4 wherein said non-conjugated diene is selected from the group consisting of straight chain acyclic dienes, branched chain acyclic dienes, multi ring alicyclic fused and bridged ring dienes, and single ring alicyclic dienes.
6. The process of Claim 5 wherein said copolymer contains from about 1 to about 10% by weight of said non-conjugateddiene.
7. The process of Claim 6 wherein said nonconjugated diene is 5-ethylidene-2-norbornene.
8. The process of Claim 1 wherein at least about 50% by weight of the copolymer differs from the mean ethylene content of copolymer by greater than plus or minus 5%.
9. The process of Claim 1 wherein said halogenated promoter is selected from the group consisting of carbon tetrachloride, hexachloroethylene, benzyl bromide, benzyl chloride and 2,3-or 1,3-dichloropropylene.
10. The process of Claim 1 wherein the vanadium compound is present in the reaction solvent at a level of from about 0.02 to about 0.5 millimoles per liter of solvent.
11. The process of Claim 10 wherein said aluminum trialkyl compound is present at a level such that the aluminum to vanadium molar ratio ranges from about 10 to about 250, and said halogenated promoter is present at a level such that the molar ratio of promoter to vanadium ranges from about 5 to about 250.
12. The process of Claim 10 wherein said polymerization is conducted at a temperature within the range of about 10 to about 140°C.
13. The process of Claim 12 wherein said polymerization is conducted at a temperature within the range of about 40 to about 120°C.
14. The process of Claim 12 wherein said polymerization is conducted at a temperature within the range of about 55 to 100°C.
15. The process of Claim 10 wherein said vanadium compound is selected from the group consisting of VOC13, VC14 and VOC12 (OR) wherein R is a hydrocarbon radical having from 1 to 10 carbon atoms.
16. The process of Claim 15 wherein said aluminum compound is triethyl, triisobutyl or tri n-hexyl aluminum.
17. The process of Claim 10 wherein said polymerization is conducted in the presence of a chain transfer agent.
18. The process of Claim 10 wherein said polymerization is conducted in the presence of a chain branching suppressor.
19. The process of Claim 1 conducted in at least one continuous flow stirred tank reactor.
20. The process of Claim 10 wherein the vanadium compound is present in the reaction solvent at a level greater than 0.05 millimoles per liter of solvent.
21. The process of Claim 9 wherein said halogenated promoter is carbon tetrachloride.
22. The process of Claim 9 wherein said halogenated promoter is benzyl chloride.
23. The process of Claim 9 wherein said halogenated promoter is benzyl bromide.
24. The process of Claim 9 wherein said halogenated promoter is hexachloroethylene.
25. The process of Claim 9 wherein said halogenated promoter is 2, 3- or 1, 3- dicholo-ropropylene.
26. The process of Claim 1 wherein at least about 40% by weight of the copolymer differs from the mean ethylene content of the copolymer by greater than plus or minus 5%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US40395389A | 1989-09-06 | 1989-09-06 | |
| US403,953 | 1989-09-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2065302A1 true CA2065302A1 (en) | 1991-03-07 |
Family
ID=23597548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2065302 Abandoned CA2065302A1 (en) | 1989-09-06 | 1990-09-04 | Alpha olefin copolmers having a narrow mwd and broad compositional distribution |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0490946A1 (en) |
| JP (1) | JPH05500080A (en) |
| AU (1) | AU6337690A (en) |
| CA (1) | CA2065302A1 (en) |
| WO (1) | WO1991003505A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL9400758A (en) * | 1994-05-06 | 1995-12-01 | Dsm Nv | Process for the preparation of a high molecular weight polymer from ethylene, alpha olefin and optionally diene. |
| US6242545B1 (en) | 1997-12-08 | 2001-06-05 | Univation Technologies | Polymerization catalyst systems comprising substituted hafinocenes |
| US8497330B2 (en) | 1997-12-08 | 2013-07-30 | Univation Technologies, Llc | Methods for polymerization using spray dried and slurried catalyst |
| IT1302259B1 (en) * | 1998-09-24 | 2000-09-05 | Enichem Spa | PROCEDURE FOR THE PREPARATION OF COPOLYMERS EP (D) M A RESTRICT DESTRUCTION OF THE MOLECULAR WEIGHTS. |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB902385A (en) * | 1959-10-14 | 1962-08-01 | Hercules Powder Co Ltd | Improvements in or relating to copolymerization process |
| US3349064A (en) * | 1962-09-28 | 1967-10-24 | Hercules Inc | Polymerization and copolymerization of ethylene using halogen-containing promoters |
| GB1059865A (en) * | 1964-07-30 | 1967-02-22 | Shell Int Research | Ethylene polymerisation and copolymerisation |
| US4786697A (en) * | 1983-06-15 | 1988-11-22 | Exxon Research & Engineering Co. | Molecular weight distribution modification in a tubular reactor |
| US4540753A (en) * | 1983-06-15 | 1985-09-10 | Exxon Research & Engineering Co. | Narrow MWD alpha-olefin copolymers |
| JPH0696655B2 (en) * | 1985-08-02 | 1994-11-30 | エクソン・ケミカル・パテンツ・インク | Ethylene propylene elastomer with good processability |
-
1990
- 1990-09-04 EP EP19900913408 patent/EP0490946A1/en not_active Withdrawn
- 1990-09-04 JP JP51256290A patent/JPH05500080A/en active Pending
- 1990-09-04 CA CA 2065302 patent/CA2065302A1/en not_active Abandoned
- 1990-09-04 WO PCT/US1990/005025 patent/WO1991003505A1/en not_active Application Discontinuation
- 1990-09-04 AU AU63376/90A patent/AU6337690A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO1991003505A1 (en) | 1991-03-21 |
| JPH05500080A (en) | 1993-01-14 |
| AU6337690A (en) | 1991-04-08 |
| EP0490946A1 (en) | 1992-06-24 |
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